Maxillary and Zygomatic Bone Fracture: Clinical Guidelines

List of Abbreviations

BP – blood pressure

TMJ – Temporomandibular joint

Maxilla – upper jaw

MFR – maxillofacial region

TBI – traumatic brain injury

RTA – road traffic accident

ZB – zygomatic bone

MFZ – mid-face zone

UFZ – upper-face zone

NOE – nasoorbitoethmoid fracture

NSAIDs – non-steroidal anti-inflammatory and antirheumatic drugs

OMC – oral mucosa

SCT – spiral computed tomography

CBCT – cone-beam computed tomography

MFT – facial bones

PAP – perioperative antibiotic prophylaxis

SSI – surgical site infection

Terms and Definitions

Subcutaneous emphysema is an accumulation of air or gas bubbles in the subcutaneous adipose tissue.

Bone crepitus is the sensation upon palpation of a "crunch" during movements at the fracture site.

A bone fracture is a pathological condition in which there is a partial or complete disruption of bone continuity.

Subcutaneous crepitus is a characteristic crunching sound caused by the movement of gas bubbles in the tissues.

"Step-off" sign is the detection upon palpation of an area of a displaced bone fragment.

Indirect load sign is the appearance of sharp pain in the fracture area due to the displacement of fragments and irritation of the damaged periosteum when pressure is applied to a knowingly undamaged area of the jaw.

Hypoesthesia is a decrease in sensitivity.

Malevich sign ("Broken Pot") is a sign of a fracture of the zygomatic bone or maxilla; percussion of the teeth produces a dull, rattling sound resembling that of a cracked clay pot being lightly tapped.

Occlusion is the closure of dental arches or individual groups of antagonist teeth.

Central occlusion is the closure of dental arches in which there is a maximum number of interdental contacts.

Diplopia is the double vision of a single object.

Mid-face zone is the zone bounded superiorly by a conventional line passing through the upper orbital margins, and inferiorly by the occlusal line of the teeth. It includes the nasal bones, orbital walls, zygomatic bones and arches, and the maxillae proper.

Upper-face zone is the zone conventionally including the structures of the facial skull located above the line passing through the upper orbital margins. It includes the frontal bone, frontal and ethmoidal sinuses. Injury to it can damage the anterior cranial fossa and the frontal lobes of the brain.

Hypophthalmos is a lower, compared to normal, position of the eyeball in the orbit.

Enophthalmos is a deeper, compared to normal, position of the eyeball in the orbit.

Exophthalmosis a more protruding, compared to normal, position of the eyeball in the orbit.

Open fracture of the zygomatic bone is a type of fracture in which the fracture line communicates with the external environment through a skin wound, a wound (rupture) of the oral mucosa, or a wound of the maxillary sinus mucosa with the development of hemosinus.

Bone reduction in the fracture area is a procedure aimed at aligning bone fragments in the area of its fracture.

Osteosynthesis is the joining of bone fragments after a fracture or osteotomy during reconstructive surgery.

Anisocoria – a condition characterized by unequal pupil sizes, sometimes accompanied by slight pupillary distortion.

Hemosinus is the accumulation of blood in the paranasal sinuses.

Liquorrhea is the leakage of cerebrospinal fluid through a dural defect.

Nasal liquorrhea is liquorrhea into the nasal cavity through a dural defect in the anterior cranial fossa.

Otoliquorrhea is the leakage of cerebrospinal fluid through the external auditory meatus via a dural defect in the middle cranial fossa.

"Handkerchief" sign: a clean handkerchief moistened with cerebrospinal fluid remains soft upon drying, whereas if moistened with nasal discharge, it becomes stiff ("starched").

"Double ring" sign: the leaking blood forms a brown spot in the center on a gauze pad, surrounded by a peripheral yellow halo of cerebrospinal fluid.

"Panda" sign ("spectacle hematoma"): hemorrhage into the eyelid tissues.

Superior orbital fissure syndrome: ophthalmoplegia (paralysis of eye muscles), ptosis (drooping of the upper eyelid), loss of sensitivity of the upper eyelid and forehead skin, and fixed dilated pupil.

Guerin sign: pain along the fracture line upon pressing the index finger on the pterygoid hamuli of the sphenoid bone (from bottom to top).

Frankfurt (or orbitomeatal) horizontal plane is a conventional plane passing through the upper margins of the external acoustic meatus (porion) and the lowest point of the inferior margin of the left orbit (orbitale).

Closed fracture of the zygomatic bone is a type of fracture in which the fracture line does not communicate with the external environment through a skin wound, a wound (rupture) of the oral mucosa, or the mucosa of the maxillary sinus with the development of hemosinus. This type of fracture is most commonly encountered in isolated fractures of the zygomatic arch.

External approach is a type of surgical approach performed by sequential incision of the skin/conjunctival mucosa and deeper soft tissue layers to visualize bone fragments in the fracture zone.

Intraoral approach is a type of surgical approach performed within the oral cavity by sequential incision of the oral mucosa, periosteum, and sometimes deeper soft tissue layers to visualize bone fragments in the fracture zone.

Isolated maxillofacial trauma is a trauma in which there is a single injury within its boundaries.

Multiple maxillofacial trauma is a trauma in which there are injuries to several bone and soft tissue structures within the maxillofacial region.

Multiple head trauma is injury to several organs or systems located in the head region (maxillofacial and masticatory apparatus, visual and/or auditory analyzers and their structures, craniocerebral structures) as a result of exposure to one or more wounding projectiles.

Combined maxillofacial trauma is the simultaneous injury of the maxillofacial region along with other anatomical regions of the body (head, neck, abdomen, pelvis, spine, extremities) by a single damaging factor.

1. Brief information on the disease or condition

The maxilla is a paired bone of the facial skeleton.

Anatomical features of the maxilla

The maxilla has a body and 4 processes:

1. Frontal process

2. Zygomatic process

3. Alveolar process (contains tooth sockets)

4. Palatine process of the maxilla

Maxillary foramina:

• Maxillary sinus ostium – a large opening on the nasal surface of the maxilla leading into the maxillary sinus.

• Infraorbital foramen – located on the anterior surface of the maxilla, serving as the exit point of the infraorbital canal.

• Alveolar foramina – several openings on the infratemporal surface of the maxilla, through which blood vessels pass to the upper large molars.

Maxillary canals:

• Infraorbital canal – a canal that begins as a groove on the orbital surface of the maxilla, passes through it, and opens on the anterior surface, below the infraorbital margin, via the infraorbital foramen; the neurovascular bundle of the same name passes through the canal.

• Nasolacrimal canal – formed by the frontal process of the maxilla, the lacrimal bone, and the inferior nasal concha, connecting the orbital cavity and the nasal cavity. The canal originates in the lower part of the medial wall of the orbit and opens into the inferior nasal meatus. Through this canal, lacrimal fluid drains into the nasal cavity, which is particularly noticeable when crying.

• Incisive canal – an unpaired osseous canal formed by the fusion of the palatine processes of the right and left maxillae; a passageway for blood vessels and nerves.

• Greater palatine canal – formed by the junction of the maxilla and the perpendicular plate of the palatine bone. It connects the pterygopalatine fossa with the oral cavity and opens in the posterior part of the hard palate via the greater palatine foramen. It transmits the greater palatine vessels and nerves.

The maxilla participates in the formation of the walls of:

1. The orbit

2. The nasal cavity

3. The oral cavity

4. The infratemporal fossa

5. The pterygopalatine fossa

Le Fort maxillary fractures are complex fractures of the middle third of the facial skeleton resulting from a directed traumatic force with high kinetic energy.

Maxillary fractures of all three types are typically accompanied by traumatic brain injury (concussion, contusion, etc.) and frequently by a skull base fracture.

Zygomatic bone (lat. Os zygomaticum) – the strongest paired bone of the facial skeleton. It articulates with the frontal and temporal bones (via the frontal and temporal processes), the greater wing of the sphenoid bone, and the maxilla. It participates in the formation of the lateral and inferior walls of the orbit and the infratemporal fossa. Together with the zygomatic process of the temporal bone, it forms the zygomatic arch, which serves as the lateral boundary of the temporal fossa. In addition to its processes, the zygomatic bone presents lateral, temporal, and orbital surfaces. The orbital surface features the zygomaticoorbital foramen, which leads to a canal opening via the zygomaticofacial foramen (on the lateral surface of the bone) and the zygomaticotemporal foramen (on the temporal surface).

Typical sites of zygomatic bone fracture: from the infraorbital suture to the zygomaticoalveolar crest, in the region of the frontozygomatic, sphenozygomatic, and temporozygomatic sutures. Upon injury, the body of the zygomatic bone is typically displaced inferiorly and medially, resulting in a disruption of the integrity of the anterior/lateral orbital wall, rupture of the maxillary sinus mucosa, epistaxis, and compression of the infraorbital nerve.

1.1 Definition of the disease or condition

Maxillary fracture – damage to the maxilla resulting in a disruption of its integrity.

Zygomatic bone fracture – damage to the zygomatic bone resulting in a disruption of its integrity.

1.2 Etiology and pathogenesis of the disease or condition (group of diseases or conditions)

Mechanical (traumatic) fracture of the maxilla (zygomatic bone) – damage to the maxilla with a disruption of its integrity caused by a load exceeding the structural strength of the traumatized bone segment [52].

A fracture of the maxilla (zygomatic bone) may occur either as a result of a direct blow or due to compression of the facial skeleton.

Le Fort I fracture typically occurs as a result of a horizontal force directed slightly inferiorly and applied to the anterior part of the alveolar process of the maxilla.

Le Fort type II and III fractures are localized in the upper half of the middle third of the facial skeleton; their localization, pattern, and combination depend not so much on the point of force application as on the direction of this force vector relative to the Frankfort horizontal plane. A horizontal impact to the upper half of the middle third of the face typically results in Le Fort II fractures. An oblique downward impact causes complete separation of the facial skeleton from the neurocranium (Le Fort III) due to fractures in the frontonasal, lacrimal, and ethmoid bone regions as well as the orbital region.

Maxillary fractures are frequently asymmetrical, can be unilateral, and are often combined with comminuted injuries of the nasoorbitoethmoidal complex and central facial regions.

Displacement of bone fragments in a fracture depends on the direction of the traumatic force vector. Typically, they are displaced medially and inferiorly.

Pathological fracture of the maxilla (zygomatic bone) – complete or partial disruption of bone integrity within an area of pathological bone remodeling (affected by a disease such as osteoporosis, tumor, osteomyelitis, etc.) [52].

Anatomical and physiological features of the pediatric organism that influence the etiopathogenesis, clinical presentation, diagnosis, and management of midface fractures.

Anatomical and topographical features of the maxillofacial region in children (elastic skin, abundant subcutaneous fat layer, well-developed facial blood supply, incomplete bone mineralization, presence of growth zones in maxillofacial bones, presence of teeth and tooth buds at various stages of development) determine the general clinical features of trauma in these areas. The age-related anatomical ratio of the neurocranium to the facial skeleton contributes to a relatively lower incidence of facial bone fractures in children compared to adults. In children under 5–7 years of age, the relatively small size of the facial skeleton and its distal position relative to the neurocranium (which appears to overhang it) contribute to a lower incidence of midface and lower face fractures compared to adolescents. In the toddler and preschool age groups (under 6 years), soft tissue facial trauma is accompanied by extensive and rapidly developing collateral edema, tissue hemorrhage (infiltrative type), and the formation of interstitial hematomas. When these injuries are combined with fractures of the facial bones and teeth—despite the good “protection” provided by the soft tissue cover of the maxillofacial bones—typical pediatric fractures may occur, such as "greenstick" fractures of the mandible, subperiosteal fractures, or complete fractures without fragment displacement [36]. Luxated teeth may penetrate into the soft tissues and become an additional factor of mechanical injury. During the mixed dentition period, determining the "absence" of a tooth in the dental arch and locating it visually or by palpation within the thickness of the soft tissues, particularly the floor of the mouth, can be challenging. Subsequently, such a "foreign body" within the soft tissues may cause purulent-inflammatory processes in the perimaxillary soft tissues of the face. This relatively frequently occurs following trauma to the maxillary alveolar process with impaction of a primary or permanent tooth into the nasolabial sulcus, cheek, floor of the nose, etc., with potential damage to permanent tooth buds.

1.3 Epidemiology of the Disease or Condition

Among patients with facial bone trauma, midface injuries account for up to 40% of cases [2,13,19,36]. The upper boundary of the middle third of the facial skeleton is a conventional line drawn from the frontozygomatic suture on one side to the frontozygomatic suture on the opposite side, passing through the frontonasal and frontomaxillary sutures, while the lower boundary is the occlusal plane of the maxillary dental arch.

The age of patients with combined midface trauma is most frequently between 4 and 16 years, with the vast majority being males [36,39,41,42,46,50]. In recent years, the proportion of patients with severe combined trauma has been increasing, reaching up to 10–26.4% of all trauma patients [10,34,40,43,44], resulting from motor vehicle accidents or falls from height. Midface fractures in children are frequently combined with traumatic brain injury: concussion, brain contusions of varying severity, intracranial injuries, and fractures of the cranial vault [3,4]. Several authors note an increase in the proportion of midface injuries—up to 37% in the structure of combined injuries of the brain, facial skeleton, and neurocranium [28,33,45,47,48]. Overall, in pediatric patients, midface fractures tend to be multiple and combined, and isolated zygomatic bone fractures are observed in only 3.5% of cases, while isolated maxillary fractures occur in less than 1% of cases.

Midface injuries in infants and toddlers may occur as a result of Shaken Baby Syndrome (SBS), also known as abusive head trauma (AHT). Such midface injuries may be directly part of this syndrome or develop subsequently against the background of existing manifestations and complications of SBS. Shaken Baby Syndrome is observed in children under three to five years of age. Symptoms of SBS range from subtle to life-threatening. Typically, manifestations of SBS indicate brain injury and may include vomiting, altered mental status, and other general cerebral symptoms. At the same time, visible signs of head trauma are often absent. Complications include seizures, visual impairment, cerebral palsy, cognitive deficits, and death [51]. Specific features of jaw fractures in children: such injuries most commonly result from falls from height, altercations, playground swing impacts, motor vehicle accidents, and sports activities, among others [6,12,15,36].

1.4 Features of Coding the Disease or Condition

S02.4 – Fracture of zygomatic bone and maxilla

1.5 Classification of the disease or condition

Maxillary fractures are divided into two main groups: firearm fractures (not covered in these guidelines; see clinical guidelines for firearm fractures) and non-firearm fractures.

1.5.1. Classification of non-firearm fractures of the maxilla

Classification of non-firearm fracture types of the maxillary body (Le Fort, 1901)

Le Fort type I fracture (low-level fracture), also known as Guérin's fracture or dentoalveolar fracture, characterized by the detachment of the maxillary alveolar process and hard palate from the rest of the bones of the middle third of the facial skeleton.

The fracture line extends from the base of the piriform aperture through the base of the alveolar process, the zygomaticoalveolar crest, and the maxillary tuberosity toward the pterygoid processes, as a result of which the latter is separated from the jaw, usually together with the hard palate. The fracture is typically not accompanied by significant displacement. There is a disruption in the alignment of the dental arches, mobility of the entire damaged maxillary fragment, and possible epistaxis due to injury to the mucous membrane of the maxillary sinus floor and nasal cavity.

Le Fort type II fracture (middle type), or "suborbital" fracture, is also known as a "pyramidal" fracture. In this type of maxillary fracture, a pyramidal bone fragment of the maxilla is formed, which can be displaced relative to the other facial bones. The apex of the pyramid passes just below the frontonasal suture. The fracture line is located below the junction of the nasal bones and the frontal processes of the maxilla with the nasal part of the frontal bone, then extends to the medial wall of the orbit, possibly involving the lacrimal bone, then to the inferior orbital wall, and emerges at the infraorbital margin near the zygomaticomaxillary suture. The maxilla is detached together with the nasal bones and part of the orbit from the zygomatic bone and the cranial base. This is accompanied by epistaxis, hematomas in the lower eyelid region ("spectacle hematoma"), facial edema, and malocclusion due to maxillary displacement.

Le Fort type III fracture (high type), also known as "craniofacial disjunction" or "subbasal" fracture, leads to the complete separation of the facial bones from the cranial base. Unlike types I and II, the Le Fort type III fracture also involves a fracture of the zygomatic bone. The fracture line is located below the junction of the nasal bones and the frontal processes of the maxilla with the nasal part of the frontal bone, then extends to the medial wall of the orbit, then to the floor formed by the orbital surfaces of the maxilla and zygomatic bone, passes through the lateral wall of the orbit, and emerges at its lateral margin in the region of the frontozygomatic suture.

The fracture line passes through the nasal bridge and the orbit, but unlike the second type, the zygomatic bone is detached along with the jaw; therefore, all symptoms are more pronounced.

Comments: in clinical practice, maxillary fractures that strictly correspond to the types described by Le Fort are relatively rare. A combination of several types of maxillary fractures on one or both sides is more common, for example: Le Fort type I, II maxillar fracture on the right and Le Fort type II, III on the left.

In pediatric practice, classic Le Fort fractures are observed mainly in adolescence, after 12 years of age.

Similar in clinical course to Le Fort II and Le Fort III fractures are the Wassmund fracture variants, which differ in that the nasal bones remain immobile because the fracture line extends from the upper margin of the piriform aperture to the inferomedial angle of the orbit (the so-called "medial oblique line") and then follows the fracture lines of Le Fort type II and Le Fort type III maxillar fractures.

Wassmund I – this is a Le Fort type II fracture, but without damage to the nasal bones. In Wassmund I fractures, the fracture line runs from the margin of the piriform aperture through the base of the frontal process, the infraorbital margin, and further along the orbital floor toward the medial margin of the inferior orbital fissure.

Wassmund II – this is a Le Fort type III fracture, but without damage to the nasal bones. In a Wassmund II fracture, the Wassmund I fracture line is combined with a fracture of the zygomaticomaxillary articulation.

Wassmund III – the fracture line begins as in Wassmund I, then runs horizontally along the orbital floor, extending to its lateral margin.

Sagittal (unilateral) fractures occur when only one (right or left) maxilla is fractured. Externally, the fracture line runs in a typical location, and internally (medially) – along the midline (along the palatine suture connecting both maxillae into a single upper jaw).

Fractures of the maxillary processes:

• alveolar process (a portion of the process with several teeth is fractured), frontal process (more often unilateral)

• hard palate (occurs when falling onto a protruding object).

Comments: In children, especially toddlers (under 3 years old) and less frequently preschoolers (under 6 years old), characteristic "depressed" fractures of the alveolar process and hard palate occur due to trauma from a relatively sharp, hard object (pencil, pen, paintbrush, lollipop stick) during play and falls when the child is holding the object in their mouth. As a rule, such fractures do not require surgical treatment of the bone wound.

Comminuted fractures of the anterior wall of the maxillar sinus can occur in a similar manner (by mechanism of injury). In more severe injuries resulting from motor vehicle accidents or falls from a height, as well as injuries characteristic of middle and high school-aged children caused by an unsecured soccer crossbar, comminuted fractures of the central parts of the maxilla are combined with fractures of the nasoorbitoethmoidal complex.

1.5.2. AO/ASIF classification of maxillary fractures.

Maxilla (Mx).

Category F (fracture):

• F_o – incomplete fracture;

• F1 – single fracture;

• F₂ – multiple fracture;

• F3 – comminuted fracture;

• F4 – open fracture (fracture with bone defect formation).

Category L (localization):

• L1 – disruption through the piriform aperture;

• L2 – disruption through the zygomaticomaxillary suture;

• L3 – disruption through the nasomaxillary (nasofrontal) suture;

• L – alveolar process.

Category O (occlusion):

• O0 – no occlusal abnormalities;

• O1 – dysocclusion present;

• O2 – edentulousness.

Category S (soft tissue):

• S0 – closed fracture;

• S1 – open fracture communicating with the oral cavity;

• S2 – open fracture communicating with the skin;

• S3 – open fracture communicating with both the oral cavity and skin;

• S4 – open fracture with soft tissue avulsion (defect).

1.5.3. Classification of maxillary (zygomatic bone) fractures depending on their duration

• Fresh (up to 14 days after injury),

• Stale (from 14 to 28 days after injury)

• Malunited (over 28 days after injury).

If more than 28 days have passed since the moment of the fracture, such a fracture does not belong to this group of diseases and is coded according to ICD as T90.2 – Sequelae of intracranial injury and skull and facial bone fractures.

1.5.4. Classification of maxillary (zygomatic arch) fractures depending on the nature of the fracture line

• linear;

• comminuted.

1.5.5. Classification of zygomatic bone fractures depending on localization and presence/absence of fragment displacement (Nizova R.F., 1967)

• zygomatic bone fractures without displacement / with displacement;

• zygomatic arch fractures without displacement / with displacement;

• simultaneous fractures of the zygomatic bone and arch without displacement / with displacement [7].

Comments: in zygomatic bone fractures, the integrity of adjacent facial bone buttresses is frequently compromised. Fracture lines may run not strictly along the bone sutures, but across adjacent bones. Zygomatic bone injuries are often combined with maxillary fractures. Since the zygomatic bone participates in the formation of the orbital walls, a fracture of the zygomaticomaxillary, frontozygomatic, or zygomaticoorbital complex is possible.

In the absence of pronounced displacement of the bone fragments of the orbital floor, it is advisable to use these clinical guidelines (ICD Code: S02.4); otherwise, clinical guidelines for the treatment of patients with orbital floor fractures should be used (ICD Code: S02.3).

1.5.6. Classification of zygomaticomaxillary complex fractures

Useful in clinical practice is the classification by P. Manson (1990), which divides trauma by energy type. It is not the primary one, but there is a clear correlation between fractures of the zygomatic bone, zygomaticoorbital, and zygomaticomaxillary complexes depending on the severity of the injury.

Manson's classification:

1. Low-energy injuries: in zygomatic bone injury, there is no displacement or minimal displacement.

2. Moderate-energy injuries: zygomatic bone fractures are accompanied by injuries along all supporting buttresses. Displacement ranges from slight to moderate. Open reduction is generally required to treat these fractures.

3. High-energy injuries: fractures are accompanied by injuries to the maxilla and zygomatic processes. Open reduction is necessary to treat this group of injuries with multiple fixation points.

1.6 Clinical presentation of the disease or condition

Non-ballistic maxillary fractures in children typically occur in typical locations, but rarely strictly correspond to Le Fort types:

1. Fracture of the maxillary alveolar process of various types.

2. Maxillofacial separation – at the junction of the jaw with the frontal and zygomatic bones.

3. Craniofacial separation – a fracture through the nasal root, orbit, and zygomatic arch.

The classic Le Fort I fracture type in children is extremely rare, possible only in adolescents over 14 years of age, whereas other types of maxillary alveolar process fractures are very common across all age groups. Any fracture of the alveolar process of the jaw is accompanied by damage to the oral mucosa, and partial or complete dislocation of one or more teeth. At the same time, during the primary dentition period (up to 6 years) and, partially, the mixed dentition period (7–11 years), dislocation or subluxation of a primary tooth occurs more frequently, without compromising its integrity. At the same time, during the permanent dentition period and partially the mixed dentition period, dislocation or subluxation of a permanent tooth is often accompanied by a breach in the integrity of the tooth structure itself (fracture of the crown or root of the tooth), and the frequency of such dental injuries increases as the child grows older.

Injured children complain of pain, impaired dental occlusion, and the inability to chew. External examination reveals an unnatural facial expression due to tension in the lips and blood-tinged viscous saliva discharging from the mouth. Speech is impaired. Examination reveals mobility of the alveolar process fragment or dislocated teeth, as well as bleeding of varying intensity from the alveolar process mucosa and tooth socket. Bruises, abrasions, or lacerated-contused wounds may be present in the lip, nose, and cheek areas. The diagnosis of an alveolar process fracture is made based on the anamnesis, complaints, and clinical symptoms observed during the examination of the injured child. An X-ray examination is performed to clarify the condition (integrity) of the teeth and their position in the area of the damaged jaw segment—detecting a tooth fracture or dislocation, and damage to surrounding structures (permanent tooth buds, etc.). Childhood is also characterized by fractures of the maxillary alveolar process with impacted dislocation of primary or permanent teeth. In this case, the tooth can embed into the alveolar process to varying depths, up to complete submersion within it, thereby damaging the underlying tooth buds or the structures of the nasal cavity and maxillary sinus. A thorough X-ray analysis is required to determine the management strategy for such an injury.

Comments: Dental injuries (subluxations and various types of dislocations), damage to the tooth structure (fractures of its coronal or root parts) are not the subject of these clinical guidelines and are discussed in the relevant pediatric dentistry manuals.

A Le Fort II maxillary fracture is the result of a severe blow and is often accompanied by closed brain injuries of varying severity. The maxillary fragment is displaced in the direction of the impact force, and downward under its own weight and the pull of the masticatory muscles. The patients' complaints, if conscious, include pain in the midface, headache, dizziness, impaired dental occlusion, and difficulty chewing, swallowing, and speaking. External examination reveals pronounced soft tissue edema of the face. Bleeding is typically detected not only in the areas of skin and oral mucosa wounds, but also from the nose. In maxillofacial, and even more so in craniofacial separation, an "elongation" of the face in the vertical position is observed. Palpation can reveal a "step" sign in the area of the infraorbital margin, zygomaticoalveolar process, and frontozygomatic suture. As a result of the displacement of the maxillary fragments, various degrees of malocclusion (most commonly open or crossbite) are observed.

Maxillary fractures are accompanied by the "raccoon eyes" sign caused by the formation of periorbital hematomas. The causes of this sign vary. When hemorrhages into the orbit are caused by damage to the facial bone structures and soft tissues, the "raccoon eyes" sign appears immediately after the trauma. In case of damage to the skull base vessels (skull base fracture), the "raccoon eyes" sign appears several hours or even 1–2 days after the trauma and always corresponds to the localization of the orbicularis oculi muscle. The color of the "raccoon eyes" is intensely crimson and does not change over time.

In addition to epistaxis, cerebrospinal fluid leak (CSF otorrhea/rhinorrhea) may be observed in cases of skull base damage. The discharge of cerebrospinal fluid is one of the most critical symptoms of a fracture of the skull base, frontal sinuses, or the petrous part of the temporal bones, accompanied by mandatory damage to the dura mater. The discharge of cerebrospinal fluid usually begins immediately after the injury and can last for up to 3 days or more. To distinguish nasal secretions from CSF, the "handkerchief test" is used. A more accurate method is the napkin test or the "double-ring sign".

Suborbital (Le Fort II) and subbasal maxillary fractures (Le Fort III) are generally accompanied by neurological disorders due to traumatic brain injuries. Changes in skin sensitivity are observed in the innervation zone of the infraorbital nerves. Affected individuals exhibit skin numbness in the infraorbital region, the alae nasi, and the upper lip on the injured side. This occurs as a result of entrapment of the infraorbital nerve during the displacement of the zygomatic bone fragments.

In skull base fractures in the anterior cranial fossa region, anosmia or hyposmia may sometimes occur. Maxillary fractures are always accompanied by traumatic brain injury. Its signs include loss of vision/consciousness, nausea, vomiting, and CSF leak from the nose or ears.

In a zygomatic bone fracture, victims complain of pain, edema of the corresponding half of the face, and possible limitation of mouth opening, especially in fractures of the zygomatic arch. When the frontal process of the zygomatic bone is displaced into the orbit, pain and difficulty in eyeball movement are observed. With significant downward displacements of the zygomatic bone, diplopia is possible.

In isolated fractures of the zygomatic bone with fragment displacement, facial deformity is noted due to depression (flattening) of the soft tissues of the zygomatic region.

Comments: Tissue depression is often masked by rapidly developing soft tissue edema, which frequently spreads to the lower eyelid (up to complete closure of the palpebral fissure).

Palpation of edematous tissues may reveal subcutaneous crepitus, auscultatorily resembling the crunch of dry snow, a "step" sign in the middle part of the lower orbital margin and in the area of the zygomaticoalveolar crest, as well as the possible manifestation of the Malevich sign ("broken pot"). Hemorrhage into the mucosa of the transitional fold in the area of the upper premolars, first or second molar may be noted; numbness of the skin of the infraorbital region, lower eyelid, upper lip and upper teeth, and the nasal bridge on the injured side; hemorrhage into the orbital tissue and the sclera of the eye; as well as the occurrence of chemosis (due to damage to the orbital wall and ocular conjunctiva); epistaxis (as a result of damage to the maxillary sinus). Epistaxis from one half of the nose on the injured side is characteristic.

In an isolated fracture of the zygomatic arch, soft tissue depression may occur due to the inward and downward displacement of the arch fragments. Soft tissue depression is masked by rapidly developing edema. Limitation and pain upon opening the mouth appear, as well as difficulty with lateral movements of the mandible on the injured side. These symptoms are associated not only with the entrapment of the coronoid process of the mandible by the displaced fragment of the zygomatic arch, but also with trauma to the masseter and temporal muscles themselves.

Comments: In childhood, the aforementioned symptoms of maxillofacial injuries most often have a mild character, especially in children of younger age groups (preschool – up to 6 and early school age – up to 9–10 years). Therefore, in addition to diagnostics based on the aforementioned absolute symptoms of maxillofacial injuries, it is necessary to pay attention to relative fracture symptoms (soft tissue edema of the injury zone, pain, limitation of mouth opening, etc.), which may also be characteristic of milder injuries (e.g., facial contusions). The definitive diagnosis is made after X-ray diagnostics.

Naso-orbito-ethmoid (NOE) fracture.

In NOE fractures, rupture of the medial palpebral ligament and damage to the lacrimal apparatus are possible. It is necessary to identify fragmentation and posterior displacement of bone fragments into the ethmoid bone or upward into the anterior cranial fossa.

The Markowitz and Manson classification system classifies NOE complex fractures based on the involvement of the medial canthal tendon as follows:

Type I NOE fractures – the medial canthal tendon is intact and attaches to a single large fragment;

Type II NOE fractures – the fracture is comminuted and the medial canthal tendon attaches to a single bone fragment;

Type III NOE fractures: comminution extends to the attachment site of the medial canthal ligament on the anterior medial orbital wall at the level of the lacrimal fossa, resulting in avulsion of the ligament.

The naso-ethmoido-orbital region has a complex three-dimensional anatomy, the preservation of which plays an important role in facial aesthetics. In blunt trauma to the middle third of the face, fractures of the medial orbital wall frequently extend to the nasoethmoidal structures, leading to the formation of NEO fractures along lines of least resistance. This may result in either a single large bone fragment representing the medial parts of the orbital rim with the lacrimal crest and the attached medial canthal ligament; several sufficiently large bone fragments that can be fixed; or several smaller fragments, where the fragment to which the ligament is attached cannot be surgically fixed. Naso-ethmoido-orbital fractures often extend to adjacent areas, including the supraorbital rim, frontal sinus, infraorbital rim, and orbital floor. When the fracture extends to the frontal sinus and the dura mater is damaged, cerebrospinal fluid leak may occur.

The classic clinical signs of an NEO fracture are telecanthus and saddle nose deformity. The development of telecanthus (widening of the intercanthal distance) is caused by the displacement of the medial orbital rim together with its attached medial canthal ligament. The palpebral fissure thus becomes rounded. In contrast to orbital hypertelorism, the orbit itself is not displaced laterally. The pseudohyperteleric appearance of the orbits is accentuated by the flattening and widening of the bony nasal dorsum, resulting in widely spaced eyes. The most reliable clinical sign of an NEO fracture is the mobility of the frontal process of the maxilla upon direct finger pressure on the medial canthal ligament, accompanied by crepitus of the bone fragments. Palpation causes pain. Patients typically present with epistaxis and bilateral periorbital and subconjunctival hematomas. Saddle nose deformity presents as depression of the nasal dorsum and its shortening with an increased angle between the nasal septum (columella) and the upper lip. A naso-ethmoido-orbital fracture often leads to disruption and obstruction of the lacrimal drainage system. The most important step in the treatment of an NEO fracture is transnasal canthopexy. This procedure preserves the intercanthal distance and corrects telecanthus.

2. Diagnostics, medical indications and contraindications for diagnostic methods

Criteria for establishing the diagnosis/condition:

1. history data (presence of trauma, epistaxis, etc.);

2. history of complaints (edema, hematomas, pain, decreased facial skin sensitivity, altered facial shape, limited mouth opening, etc.);

3. physical examination (changes in facial shape and symmetry, edema, bruising, pathological mobility and crepitus of bone fragments, subcutaneous emphysema, epistaxis, nasal breathing difficulty, hypesthesia of the facial skin and maxillary teeth, characteristic sound upon percussion, etc.);

4. instrumental examination (presence of a fracture line in typical locations according to X-ray findings). Radiography of the facial bones (in axial or semi-axial projection) reveals disruption of the integrity of the inferior and lateral orbital rims, discontinuity in the zygomatico-alveolar crest and the temporal process of the zygomatic bone, and decreased pneumatization of the maxillary sinus due to hemosinus.

2.1 Complaints and Anamnesis

• In maxillary and/or zygomatic bone fractures, it is recommended to assess the patient's general condition, including consciousness (clear, confused, lethargic, unconscious), whether there was a loss of consciousness and its duration, and memory impairments (amnesia: retrograde, episodic, etc.) [31].

GR CLEL 5Grade of Recommendation C (Level of Evidence – 5).

• When taking a history in patients with suspected maxillary fracture, it is recommended to clarify the mechanism of injury, paying special attention to the circumstances of its occurrence. It is necessary to record the date and time of the injury, and the exact address or approximate location if the patient has difficulty remembering. The necessary information must be obtained from the adults accompanying the child. If the injury resulted from assault, the medical documentation should indicate who inflicted the injury (if possible); if the injury resulted from a road traffic accident, the circumstances and the state registration plate of the vehicle should be noted to facilitate subsequent legal proceedings [19,36].

GR CLEL 5Grade of Recommendation C (Level of Evidence – 5).

• When taking a history in patients with suspected maxillary and/or zygomatic bone fracture, it is recommended to ascertain whether there was dizziness, nausea, vomiting, headache, loss of consciousness, or amnesia to verify traumatic brain injury and ensure timely primary consultation by a neurosurgeon (neurologist) [32,53,54].

GSI CLEL 4Grade of Recommendations C (Level of Evidence – 4).

• If history-taking in patients with suspected maxillary and/or zygomatic bone fracture reveals circumstances of illegal acts, or if the injury resulted from a road traffic accident, this is recommended to be reported immediately to law enforcement agencies in the established manner (Order of the Ministry of Health and Social Development of the Russian Federation No. 565n dated May 17, 2012 (ed. dated November 23, 2020) "On Approval of the Procedure for Medical Organizations to Notify Internal Affairs Organs of the Admission of Patients in Respect of Whom There Are Sufficient Grounds to Believe That Harm to Their Health Was Caused as a Result of Illegal Acts") [52].

GCR CLEL 5Grade of Recommendation C (Level of Evidence – 5)

2.2 Physical Examination

All patients with suspected maxillary and/or zygomatic bone fracture must undergo a mandatory physical examination to clarify the diagnosis and determine treatment tactics [8,18,19,55]:

• assessment of the patient's general condition;

• examination of the maxillofacial region, including the oral cavity;

• palpation and percussion of the maxillofacial region;

• When examining a patient with suspected maxillary fracture, it is recommended to use a needle to assess facial sensation in order to identify compression of the trigeminal nerve branches by maxillary bone fragments [18,19].

GCR CLEL 5Grade of Recommendation C (Level of Evidence – 5)

Comments: quite frequently, a decrease in skin sensitivity is observed in the innervation zone of the infraorbital nerve (lower eyelid, infraorbital region, nasal slope and upper lip, teeth on the side of the lesion). The decrease in sensitivity may be short-lived due to rapidly increasing soft tissue edema and may not indicate nerve compression by displaced bone fragments.

• When examining a patient with a maxillary fracture and suspected skull base fracture, it is recommended to use the "double-ring" or " handkerchief" test to detect cerebrospinal fluid leak [18,19].

GR CLEL 5Grade of Recommendation C (Level of Evidence – 5).

Comments: this sign is difficult to detect due to concomitant bleeding.

• When examining a patient with a maxillary fracture, it is recommended to assess enophthalmos, hypophthalmos, exophthalmos, oculomotor impairment, visual disturbances including reduced visual acuity, and diplopia to detect orbital wall fractures and retrobulbar hematoma, and to rule out/confirm superior orbital fissure syndrome [16,18,30,35,42,56].

GR CLEL 5Grade of Recommendation C (Level of Evidence – 5).

• Palpation in patients with a maxillary fracture is recommended to be performed by grasping the alveolar process in the anterior region with the index finger and thumb of one hand and gently moving the maxilla in an anteroposterior direction to determine the mobility of bone fragments. The fingers of the other hand are simultaneously placed over the projected fracture sites in the region of the nose or infraorbital rim [36,43,48].

GDR CLE 5Grade of recommendation C (level of evidence – 5)

Comments: in younger children experiencing stress, such manipulative palpation tests for bone fragment mobility should preferably be avoided whenever possible.

2.3 Laboratory Diagnostics

• Laboratory diagnostic tests sould be performed in patients with a maxillary fracture during the preparation and planning of surgical intervention to rule out contraindications to its performance [34,36].

GPR CLEL 5Level of Recommendation Consensus - C (Level of Evidence – 5)

• Laboratory diagnostic tests for ethanol (determination of blood ethanol concentration by gas chromatography or quantitative determination of urine ethanol by gas chromatography) are recommended for patients with maxillofacial trauma when acute alcohol or drug intoxication is suspected, as well as in cases involving circumstances of illegal acts or road traffic accidents [19].

GPR CLEL 5Level of Recommendation Consensus - C (Level of Evidence – 5)

Comments: Testing for ethanol and drug intoxication in children under 15 years of age is possible only with the consent of parents (legal guardians), and from the age of 15 – with the patients' own consent.

2.4 Instrumental Diagnostics

• All patients with suspected maxillary and/or zygomatic bone fracture at the diagnosis stage are recommended to undergo X-ray imaging in the following scope: radiography of the entire skull in one or more projections, axial and semi-axial projections, and, if possible, computed tomography of the facial skeleton to determine the localization and nature of the fracture [1,5,24,25,32, 64].

GCR CLOE 4Grade of Recommendation C (Level of Evidence – 4)

• Patients with a fracture of the maxilla or zygomatic bone before discharge are recommended to undergo radiography of the entire skull in one or more (on the side of the lesion) skull projections, axial or semi-axial projections, or computed tomography of the facial skeleton, if possible, with the aim of determining the stable position of bone fragments after orthopedic or surgical immobilization [9,19,24,28, 64].

GCR CLOE 4Grade of Recommendation C (Level of Evidence – 4)

Comments: For a patient with suspected maxillary and/or zygomatic bone fracture, as well as after treatment, X-ray imaging in the scope of: anteroposterior and lateral (on the side of the lesion) skull projections, axial and semi-axial projections is not always sufficient. The radiographic buttresses of the maxilla may overlap with structures of other facial bones, so both the diagnosis of fractures, especially without fragment displacement, and the assessment of treatment results may be difficult. Therefore, if necessary, it is advisable to perform CBCT or MSCT imaging [9,19,25,57].

2.5 Other Procedures

3. Treatment, including drug and non-drug therapies, diet therapy, and pain management

3.1. Conservative management

Comments: The differential approach to selecting an analgesic is determined by the pain intensity, the patient's age category, and in some cases requires the involvement of a clinical pharmacologist. The prescription of potent analgesic drugs is carried out by decision of the standing medical commission of the medical organization. Data on the use of various pain management approaches in children with maxillary and zygomatic bone fractures are limited. Dosing of drugs from the groups: opioids (N02A); opioids in combination with non-opioid analgesics (N02AJ); non-steroidal anti-inflammatory and antirheumatic products (M01A); other analgesics and antipyretics (N02B) must be carried out taking into account age contraindications. Opioids (N02A) are contraindicated in patients with traumatic brain injury [69-78].

• All patients with a fracture of the maxilla and/or zygomatic bone undergoing perioperative antibiotic prophylaxis are recommended a systemic antibacterial drug dose corresponding to the age and single dose of the given drug [61,79-85].

GR CLEL 5Grade of Recommendation C (Level of Evidence – 5).

GR CLEL 5Grade of Recommendation C (Level of Evidence – 5).

• Patients with a fracture of the maxilla and/or zygomatic bone undergoing perioperative antibiotic prophylaxis are recommended a single administration of a systemic antibacterial drug; if it is necessary to prolong prophylaxis, the drug is discontinued no later than 24 hours after surgery (except for patients with Type III wounds "contaminated wounds"), even in the presence of a drain [61].

Comments: in contaminated surgeries, systemic antibacterial drugs are administered for a period of more than 48 hours after surgery.

Comments: Currently, the number of relevant studies assessing the effectiveness of various regimens and dosing schedules for SSI prevention in the pediatric population with maxillary and zygomatic bone fractures is limited. Existing approaches to perioperative antibiotic prophylaxis are based on national guidelines determining the tactics and choice of prophylaxis regimens, on studies in populations of patients with maxillofacial fractures, temporomandibular joint surgery, dental implantation, orthognathic surgery, head and neck surgeries, as well as in populations of patients undergoing surgeries for oral and maxillofacial pathology, predominantly in the adult population. According to available limited data, the following may be recommended: J01CR Combinations of penicillins, including beta-lactamase inhibitors; J01D Other beta-lactam antibacterials; J01FF Lincosamides; J01XA Glycopeptide antibacterials [79-86].

Level of Evidence CGrade of Recommendation 5Level of recommendation C (level of evidence – 5).

Comments: In the postoperative period, the patient should receive therapeutic doses of drugs according to the instructions for medical use, taking into account the patient's weight, age, renal and hepatic function. When choosing an antimicrobial therapy regimen, it is recommended to consider the severity of the infectious process, the risk of resistant pathogens, and local microbiological monitoring data. It is advisable to perform microbiological testing in all patients with an "infected" wound.

In institutions providing care to children with purulent-septic complications of the maxillofacial region, it is advisable to develop local protocols for antimicrobial therapy. As drugs of choice, it is recommended to use:

- J01CR ATC – Combinations of penicillins, including beta-lactamase inhibitors

- J01D Other beta-lactam antibacterial drugs

- J01EE Combinations of sulfonamides and trimethoprim, including derivatives

- J01FF Lincosamides

- J01GB Other aminoglycosides

- J01M Quinolone antibacterials

- J01XA Glycopeptide antibacterials

- J01XD Imidazole derivatives

- J01XX Other antibacterials.

• In patients with a fracture of the maxilla and/or zygomatic bone with a breach in the integrity of the maxillary sinus walls, it is recommended to prescribe medicinal products from group R01A Decongestants and other nasal preparations for local use, ATC H02A Systemic corticosteroids to reduce edema of the maxillary sinus mucosa and the ostium into the nasal cavity, in order to improve its drainage function and prevent inflammatory processes [61,88-92].

GGR CLEL 5Grading of Recommendations Assessment, Development, and Evaluation (GRADE) – C (level of evidence 5)

3.2. Temporary transport immobilization of the maxilla

Indications: suspected maxillary fracture.

Contraindications: unconscious state of the patient, nausea, vomiting (due to the risk of asphyxia).

Anesthesia: for this type of treatment, anesthesia is performed as part of symptomatic analgesic therapy.

• Patients with a maxillary fracture are recommended to undergo temporary jaw immobilization to reduce pain and bleeding from the fracture line prior to further examination and decision-making regarding the appropriateness of additional treatment methods [46,52].

GCR CLEL 5Grade of Recommendation C (Level of Evidence – 5)

Comments: application of an immobilization bandage for maxillary fractures can be performed using a roller-bandage chin-vertex dressing, Pomerantseva-Urbanskaya elastic chin sling, standard transport bandage, plaster chin-vertex bandage, elastic bandages, etc.

3.3. Orthopedic treatment method

Indications: presence of a maxillary fracture.

Contraindications: severe traumatic brain injury with unstable main hemodynamic parameters, nausea, vomiting (due to the risk of aspiration asphyxia). Presence of pronounced displacement of the maxillary fragments where orthopedic treatment is inappropriate, and surgical-orthopedic or surgical treatment is required immediately.

Anesthesia: for this type of treatment, local (topical, infiltration, regional) anesthesia is usually performed; in some cases, in younger age groups, the use of short-term combined inhalation anesthesia is recommended. Combined anesthesia is also performed as part of symptomatic therapy.

• Orthopedic treatment is recommended for patients with a maxillary fracture for reposition and immobilization of fragments in the desired position [58,61].

GCR CLEL 5Grade of Recommendation C (Level of Evidence – 5)

Comments: this treatment method consists of fixing standard arch bar splints to the teeth of the upper and lower jaws or fabricating wire splints with hook loops for securing and intermaxillary traction of the upper and lower jaw fragments. Intraosseous orthodontic 2.0 screws placed in the interradicular spaces of the alveolar processes/parts of the jaws may also be used. Elastic interarch orthodontic rings are placed between the hooks of the splints on the upper and lower jaws (or intraosseous fixation screws). With this treatment method, short-term subsequent immobilization of the jaws using an elastic chin-vertex sling bandage is sometimes additionally required.

1. When immobilizing an alveolar process fracture with tooth displacement (partial or complete tooth dislocation), it is recommended to use individually fabricated laboratory plastic splints made of medical-grade plastic on the damaged and adjacent teeth. They can be used for the entire period of therapeutic immobilization, as well as a temporary immobilization of the dentition and alveolar process, followed by the fabrication of a permanent fixed structure by a pediatric dentist or orthodontist, for example, using aramid fibers. When an individual metal splint cannot effectively counteract the displacement of the damaged fragment, which is possible in adolescents (12 years and older), one has to resort to wire splints with hook loops for securing and intermaxillary traction of the upper and lower jaw fragments and elastic interarch orthodontic rings.

2. Certain difficulties of orthopedic treatment in pediatric patients with jaw fractures are characteristic of the primary and mixed dentition periods, which is associated with:

• the conical shape of primary teeth with a wide cervical margin and conical occlusal surface, which creates difficulties for splint placement

• decreased rigidity of jaw immobilization by the dental structure due to physiological attrition of primary teeth, high prevalence of primary tooth caries, and resorption of their roots.

• insufficient stability of erupted permanent teeth

• children with dental appliances and, especially, with elastic interarch orthodontic rings are exposed to an increased risk of aspiration of gastric contents in case of vomiting, especially considering the high frequency and nature of clinical symptoms in TBI.

3.4. Surgical-orthopedic treatment method

• Surgical-orthopedic treatment is not recommended for patients with isolated maxillofacial trauma with significant displacement of the maxillary and zygotic bone fragments, leading to functional and/or pronounced aesthetic disorders in the maxillofacial region, since the method involves insufficiently precise fragment reposition and insufficiently stable fixation [36,58,60].

GCR CLEL 5Grade of Recommendation C (Level of Evidence – 5)

• The surgical-orthopedic treatment method may be recommended in patients with severe polytrauma involving craniofacial injury, due to the low invasiveness and short duration of the intervention as anti-shock measures in the first stage of "Damage Control" [36,58,60].

GCR CLEL 5Grade of Recommendation C (Level of Evidence – 5)

Comments: Surgical-orthopedic treatment techniques, indications, and contraindications for anesthesia are described in more detail in the clinical guidelines for the management of patients with multiple fractures of the facial bones.

3.5. Surgical treatment

Indications: fracture of the maxilla (zygomatic bone) with pronounced fragment displacement. Presence of functional and/or aesthetic disorders resulting from a fracture of the maxilla and/or zygomatic bone [31,33,36].

Proindications: severe diseases (injuries) of various organs and body systems in the stage of decompensation, precluding accurate open reposition and rigid immobilization of the maxilla and/or zygomatic bone. Upon improvement of the general condition after treatment, the surgery becomes possible.

Comments: In accordance with the tactics of providing specialized surgical care to patients with severe polytrauma involving shockogenic injury according to the "Damage Control" principle, open reposition and rigid immobilization of jaw fragments are indicated after stabilization of the patient's general condition, taking into account the predicted risk of purulent-inflammatory complications.

• Patients with a maxillary fracture who have fragment displacement and/or pronounced mobility are recommended to undergo open reposition and osteosynthesis using fixation plates for craniofacial surgery (non-resorbable and resorbable) [11,16,17,29,30,65].

GCR CLOE 4Grade of Recommendation C (Level of Evidence – 4)

• Patients with linear fractures of the zygomatic bone with fragment displacement are recommended to undergo minimally invasive reposition of the zygomatic bone via a puncture below the zygomatic bone to restore the anatomical shape of the bones of the middle third of the face [19,36,58].

GPR CLEL 5Level of Recommendation Consensus - C (Level of Evidence – 5)

Comments: Performing a minimally invasive zygomatic bone reposition with a bone hook is possible only if the fracture is conditionally linear. If during the zygomatic bone reposition surgery it was not possible to achieve the correct position of the fragments, or if the reposition was unstable and the fragments displace again, it is advisable for the patient to undergo zygomatic bone osteosynthesis surgery.

• Patients with comminuted fractures of the zygomatic bone with fragment displacement, as well as in the absence of the possibility of their stable fixation during reposition using an elevator (reusable bone lever/elevator), are recommended to undergo osteosynthesis surgery to restore the anatomical shape of the bones of the middle third of the face [11,16,21,22,37].

GPR CLEL 5Level of Recommendation Consensus - C (Level of Evidence – 5)

Comments: During osteosynthesis of the maxilla and zygomatic bone in children, various fixation devices (craniofacial fixation plates [non-resorbable and resorbable], screws, etc.) can be used. Biodegradable plates can be installed in areas of low functional load, typically in younger and middle-aged children [46]. Miniplates are usually placed in the main buttress areas of the zygomatic bone: the frontozygomatic suture and/or the infraorbital margin, and/or the zygomaticoalveolar crest, as well as the zygomatic arch, if necessary. The most optimal zone for bone immobilization using biodegradable materials in children is the infraorbital margin, as well as, if necessary, for the reconstruction of the zygomatico-frontoorbital complex. In multiple fractures of the bone structures of the middle and lower facial zones, along with the aforementioned fixation sites using biodegradable materials, it is possible to use non-resorbable craniofacial fixation plates or meshes in areas of increased functional load.

The type and number of surgical approaches to perform this surgical intervention are determined by the surgeon individually for each patient depending on the nature of the fracture and the surgeon's qualifications. The following approaches are usually used:

• in the frontozygomatic suture area

• lower palpebral

• middle palpebral

• subciliary

• transconjunctival (in adolescents only)

• intraoral

Comment: in cases of combined zygomatic bone fracture with multiple fractures of the upper and middle facial tiers, a bicoronal approach is used.

• All patients with maxillary and/or zygomatic bone fractures are recommended to undergo follow-up imaging (skull radiography in one or more projections, or computed tomography of the facial skull) to confirm the reduction and alignment of bone fragments in the anatomically correct position and their stability [20,27,52].

GCR CLEL 5Grade of Recommendation C (Level of Evidence – 5)

3.6. Pain management

• Patients with displaced maxillary and/or zygomatic bone fractures are recommended to undergo reduction and osteosynthesis under total intravenous anesthesia [58,59,60].

Level of Evidence CGrade of Recommendation 5Level of recommendation – C (level of evidence – 5)

3.7. Diet therapy

• Patients with a maxillary fracture who have impairment of all components of the food intake act (chewing and swallowing) are recommended the first jaw diet: feeding severely ill patients via a nasogastric feeding tube [36,58,61].

GCR CLEL 5Grade of Recommendation C (Level of Evidence – 5)

Comments: In this case, introducing food into the mouth is not only useless, but also dangerous due to the risk of aspiration. Food can be quickly minced using a meat grinder, blender, or rubbed through a dense sieve and even strained to prevent hard-to-grind particles (plant fiber, meat veins, etc.) from getting into it. The cream-like consistency of the food allows it to pass freely directly into the stomach via a nasogastric feeding tube inserted through the nose or mouth. If necessary, even greater dilution of the food can be achieved by adding broth, milk, or boiled water. For patients with an upper jaw fracture who retain swallowing and sucking functions, the second jaw diet is recommended. In younger children, the mashed food can be administered by parents or medical staff using a 10-20 ml syringe with a flexible tube, which is carefully inserted between the dental arches and the cheek.

Food in this type of diet is brought to a purée consistency by passing it through a meat grinder or blender, and diluted with broth, milk, or even warm boiled water to a sour cream-like consistency for the necessary thinning. Such food easily passes through a rubber drainage tube attached to the spout of a drinking cup.

The difference between the first and second jaw diets lies solely in the degree of comminution of the components.

Comments: In children of younger age groups, most often preschool age (up to years old) with severe polytrauma involving traumatic brain injury and an unstable general condition, independent feeding may be difficult or even impossible. In such cases, the possibility of prolonged partial or total parenteral nutrition or the placement of a nasogastric tube through the nose or mouth should be considered.

• In patients with a zygomatic bone fracture in the pre- and postoperative periods, it is recommended to exclude food from the diet that requires significant chewing load (meat, nuts, crackers, etc.) to prevent the displacement of bone fragments due to muscle traction and to reduce painful afferentation [58,61].

Level of Evidence CGrade of Recommendation 5Level of recommendation – C (level of evidence – 5)

4. Medical Rehabilitation and Sanatorium-Resort Treatment

• All patients who have undergone surgical treatment for a zygomatic bone and maxillary fracture are recommended to undergo rehabilitation measures aimed at the complete social and physical recovery of the patient [36,58].

SOR CLoE 5Strength of Recommendation – C (Level of Evidence – 5

Comment: The need for patient rehabilitation is due to maxillofacial trauma. The presence of postoperative wounds (disruption of integrity) in this aesthetically significant anatomical area, their healing, pain syndrome of varying severity, and possible disorders of facial muscle function, masticatory function, as well as neurological disorders can lead to significant social maladjustment and reduce the quality of life of these patients. A medical rehabilitation program for a long period of time after trauma is especially relevant in a growing organism to avoid post-traumatic maxillofacial deformities and functional disorders in a child.

General principles of rehabilitation after surgical treatment of maxillary and/or zygomatic bone fractures:

• Comprehensive assessment of the patient's baseline condition and formulation of the rehabilitation program;

• Drawing up a plan of diagnostic and therapeutic measures necessary for rehabilitation;

• Multidisciplinary principle of organizing rehabilitation care;

• Monitoring the effectiveness of the ongoing therapy during the course of restorative treatment and at the end of the rehabilitation program.

Stages of patient rehabilitation after surgical treatment:

Stage 1 – early rehabilitation, from the 7th to the 10th day after surgery. During this period, the patient undergoes inpatient rehabilitation treatment for 3–5 days, after which further rehabilitation takes place on an outpatient basis for 10–15 days.

The most important tasks of stage 1 rehabilitation are the study of primary vascular-platelet hemostasis, the wound healing process, and the relief of postoperative pain, as well as the treatment of concomitant pathology if present.

Stage 2 – from the 15th to the 45th day after surgery, aimed at accelerating reparative processes, preventing postoperative complications, maxillary sinusitis, extraarticular contracture of the mandible, and visual analyzer pathology.

• Restoration of masticatory function: one of the important components of postoperative rehabilitation at an early stage is the normalization of masticatory function. The patient is given recommendations regarding dietary restrictions, and the dynamics of normalization of the range of mandibular motion are monitored.

• Pain relief: the severity of pain sensations depends on the degree of intraoperative trauma and individual pain threshold. Systemic agents for pain relief are selected individually by the attending physician depending on the intensity of pain and the severity of psychoemotional disorders.

• Regulated wound healing process: one of the important aspects of postoperative patient recovery that allows avoiding the development of late postoperative complications (scar deformation, prevention of inflammatory complications in the area of the postoperative wound and maxillary sinus, etc.).

Proper management of the wound process, starting from the 2nd day after surgery until complete healing of soft tissue wounds, involves: regular treatment of the wound area with antiseptic solutions, dressings with ointment applications (the composition of the ointment depends on the stage of the wound process); dynamic monitoring by a maxillofacial surgeon; microbiological control (if purulent-septic complications and wound infection are suspected).

Comments: An important role in ensuring the early postoperative period in a child is played by compliance with oral hygiene. To ensure oral hygiene measures using wiping of teeth and oral mucosa with antiseptic swabs, rinsing, and the use of mechanical (from a syringe) or electrical hydroirrigators of various types, parents or medical personnel must be involved.

During regular dressings of the patient performed by a doctor or nurse, thorough cleaning of all intraoral structures (wire and ribbon splints, cap splints, plugs-spacers – individual structures made of medical rubber, protective plates) and teeth from food debris is necessary by irrigation and rinsing of the oral vestibule with antiseptic solutions (ATC group D08A: Antiseptics and disinfectants: chlorhexidine**, etc.). Baking soda (1 tablespoon per 1 liter of liquid) is added to these solutions to facilitate washing away greasy food particles. Rinsing is performed either manually by removing the removable intraoral structure (splint, etc.) from the oral cavity or by irrigating them with a stream of antiseptic from a syringe inside the oral cavity. During dressings, it is necessary to monitor the position of the splint, other intraoral structures, and orthodontic rings.

If there are pressure ulcers from intraoral structures on the mucous membrane of the lips, gums, or cheeks, it is necessary to adjust them (grinding, bending, etc.) into a comfortable and safe position. Elastic intermaxillary orthodontic rings are recommended to be replaced as they weaken, but at least once every 3–4 days.

• In order to accelerate reparative processes and reduce the inflammatory reaction, it is recommended to perform physiotherapeutic procedures upon the recommendation of a physical therapy doctor [58,62,63].

Level of Evidence CGrade of Recommendation 5Level of recommendation – C (level of evidence – 5)

Comments: in patients with traumatic brain injury, physiotherapeutic procedures are not recommended.

• When using fixation plates for craniofacial surgery, non-resorbable titanium miniplates and screws during surgical treatment, the question of the advisability of their removal after consolidation of the maxilla and zygomatic bone fragments is recommended to be decided individually and strictly according to indications [36, 58, 59, 61].

Level of Evidence CGrade of Recommendation 5Level of recommendation – C (level of evidence – 5)

Comments: Removal of on-bone metal fasteners in children is indicated no earlier than 4–6 months after the osteosynthesis surgery. Moreover, while in adolescents older than 14–15 years in certain cases (at the request of the patient or parents) it is permissible to leave metal structures on a permanent basis, in younger children under conditions of ongoing facial bone growth, it is necessary to insist on the removal of metal structures to avoid post-traumatic deformations of bone structures, including disruption of the occlusal relationship of the jaws.

5. Prevention and Dispensary Observation

Dispanserization is necessary for all children throughout childhood until the completion of facial bone growth.

Following any fractures of the facial bones, a consultation and, if necessary, treatment by an orthodontist and a pediatric dentist are required.

• According to indications, for the prevention of postoperative complications in the ENT organs, visual organs, and nervous system upon discharge, a follow-up dispensary appointment (examination, consultation) by an otorhinolaryngologist, ophthalmologist, and neurosurgeon (neurologist) may be recommended [61, 66, 67].

GCR CLOE 4Grade of Recommendation – C (Level of Evidence – 4)

• All patients are recommended to undergo follow-up panoramic radiography of the maxilla/zygomatic bones 4 weeks after surgery to confirm the alignment of fragments in the correct position, stability of fragment fixation, and to rule out a post-traumatic inflammatory process in the maxillary sinus [58, 61].

Level of Evidence CGrade of Recommendation 5Level of recommendation – C (level of evidence – 5)

Comments: Rehabilitation of children who have suffered maxillofacial bone fractures combined with craniomaxillofacial trauma does not end with inpatient treatment. Dynamic follow-up is necessary at 2–4 weeks, 3 months, 6 months, and 1 year. Dentition prosthetics using removable plate dentures should occupy an important place in the rehabilitation program, and upon completion of the patient's growth – the use of dental prostheses on dental implants. Early orthodontic treatment with removable appliances is indicated when necessary. These measures are aimed at preventing the development of dentomaxillofacial deformities.

6. Organization of Medical Care

Indications for emergency hospitalization in a medical organization:

1. Radiologically confirmed diagnosis of maxillary fracture.

2. Presence of a zygomatic bone fracture with fragment displacement

3. Presence of a zygomatic bone fracture without fragment displacement in preschool and early school-age children.

In younger age groups, symptomatic drug therapy, physiotherapy, as well as dynamic monitoring and adherence to a restricted physical activity regimen to prevent displacement of facial bone fragments in the early post-traumatic period are indicated to be performed in an inpatient setting.

Indications for planned hospitalization in a medical organization: none.

Facial bone fractures are an emergency condition; all injured children should be examined in a multidisciplinary hospital and, if necessary, hospitalized on an emergency basis.

If more than 28 days have passed since the injury, this condition does not belong to this group of diseases and is coded according to ICD-10 as T90.2 – Sequelae of skull and facial bone fractures.

Indications for patient discharge:

1. in the absence of indications for further inpatient treatment (uneventful postoperative period, satisfactory position of fragments, absence of progressive purulent-inflammatory maxillofacial diseases of traumatic origin);

2. if there is a need to transfer the patient to another medical institution;

3. at the request of the patient or their legal representative;

4. in cases of non-compliance by the patient with prescriptions or the internal regulations of the hospital, provided this does not threaten the patient's life or the health of others.

7. Additional Information

Negative factors affecting treatment outcomes include:

1. Development of infectious complications.

2. Pressure on the maxilla and/or zygomatic bone.

3. Non-compliance with oral hygiene.

4. Non-compliance by the patient with the diet and masticatory activity restrictions.

5. Non-compliance with exercise therapy recommendations in the postoperative period.

6. Participation in contact sports within 3 months.

7. Failure to attend follow-up examinations.

8. Non-compliance with other recommendations of the attending physician.

Criteria for Evaluating the Quality of Medical Care

References

Appendix A1. Working Group Composition

1. Semyonov Mikhail Georgievich. – Doctor of Medical Sciences, Professor, Member of the Association of Specialists in Maxillofacial Surgery.

2. Kulakov, A. A. – Academician of the Russian Academy of Sciences, MD, Professor, President of the Association of Maxillofacial Surgery Specialists LLC.

3. Brailovskaya T. V. – Doctor of Medical Sciences, Professor, Executive Secretary of the Association of Specialists in Maxillofacial Surgery.

4. Bayrikov, I. M. – Corresponding Member of the Russian Academy of Sciences, MD, Professor, Member of the Association of Maxillofacial Surgery Specialists LLC.

5. Ivanov S.Yu. – Corresponding Member of the RAS, MD, Professor, Board Member of the Association of Maxillofacial Surgery Specialists.

6. Drobyshev A. Yu. – Doctor of Medical Sciences, Professor, Vice-President of the Association of Specialists in Maxillofacial Surgery.

7. Yaremenko, A.I. – MD, Professor, Vice-President of the LLC "Association of Specialists in Maxillofacial Surgery".

8. Roginsky V.V. – MD, Professor, Member of the Association of Maxillofacial Surgery Specialists.

9. Belchenko V.A. – MD, Professor, Board Member of the Association of Maxillofacial Surgery Specialists.

10. Topolnitskiy O. Z. – MD, PhD, Professor, Board Member of the Association of Maxillofacial Surgeons.

11. Botsarova S. A. - Member of the Association of Specialists in Maxillofacial Surgery.

12. Sysolyatin P. G. – Doctor of Medical Sciences, Professor, Board Member of the Association of Specialists in Maxillofacial Surgery.

13. Durnovo E. A. – MD, PhD, Professor, Board Member of the Association of Maxillofacial Surgeons.

14. Lepilin A. V. – MD, PhD, Professor, Board Member of the Association of Maxillofacial Surgeons.

15. Tarasenko S. V. – MD, PhD, Professor, Member of the Association of Maxillofacial Surgeons.

16. Epifanov S. A. – MD, PhD, Associate Professor, Member of the Association of Maxillofacial Surgeons.

17. Pankratov A. S. Doctor of Medical Sciences, Professor, Member of the Association of Specialists in Maxillofacial Surgery.

18. Bagnenko A.S. – Candidate of Medical Sciences, Associate Professor, Member of the "Association of Specialists in Maxillofacial Surgery".

19. Baranov, I.V. – PhD in Medical Sciences, Member of the LLC "Association of Specialists in Maxillofacial Surgery".

20. Sviridenko, A.D. – Member of the LLC "Association of Specialists in Maxillofacial Surgery".

21. Stolyarenko, P.Yu. – PhD in Medical Sciences, Associate Professor, Member of the LLC "Association of Specialists in Maxillofacial Surgery".

All members of the working group are members of the All-Russian Public Organization "Association of Specialists in Maxillofacial Surgery". There is no conflict of interest.

Appendix A2. Methodology for Developing Clinical Guidelines

Target audience of these clinical guidelines:

1. Maxillofacial surgeons

2. Trauma and orthopedic surgeons

3. Neurosurgeons

4. Otolaryngologists

5. Ophthalmologists

6. Physiotherapists

7. Oral and Maxillofacial Surgeons

8. Paediatric dentists

9. Mid-level medical personnel

10. Healthcare organizers

11. Medical insurance experts (including conducting medical and economic expertise)

12. Medical students, residents, postgraduate students.

Table 2. Scale for grading levels of evidence validity (LEV) for diagnostic methods (diagnostic interventions)

Table 3. Scale for assessing levels of evidence (LE) for prevention, treatment, and medical rehabilitation methods, including those based on natural therapeutic factors (preventive, therapeutic, rehabilitation interventions)

Table 4. Scale for assessing grades of recommendation (GR) for prevention, diagnostic, treatment, and medical rehabilitation methods, including those based on natural therapeutic factors (preventive, diagnostic, therapeutic, rehabilitation interventions)

Procedure for updating clinical guidelines.

The mechanism for updating clinical guidelines provides for their systematic revision - at least once every three years, as well as upon the emergence of new evidence-based medicine data regarding the diagnosis, treatment, prevention, and rehabilitation of specific diseases, or in the presence of justified additions/comments to previously approved clinical guidelines, but no more frequently than once every 6 months.

Appendix A3. Reference Materials

These clinical guidelines were developed taking into account the following regulatory and legal documents:

1. Article 76 of Federal Law of the Russian Federation No. 323-FZ dated November 21, 2011 "On the Fundamentals of Healthcare Protection in the Russian Federation", regarding the development and approval of clinical guidelines (treatment protocols) for the provision of medical care by medical professional non-profit organizations;

2. Order of the Russian Ministry of Health No. 422n dated June 14, 2019 "On Approval of the Procedure for Providing Medical Care in the Profile 'Maxillofacial Surgery'";

3. Federal Law of the Russian Federation No. 326-FZ dated November 29, 2010 (as amended on October 29, 2024) "On Compulsory Medical Insurance in the Russian Federation";

4. Order of the Russian Ministry of Health No. 203n dated May 10, 2017, "On Approval of Criteria for Assessing the Quality of Medical Care".

5. Federal Law No. 178-FZ dated July 17, 1999 (as amended on May 29, 2024) "On State Social Assistance".

6. Federal Law No. 124-FZ dated July 24, 1998 "On the Basic Guarantees of the Rights of the Child in the Russian Federation"

7. Order of the Ministry of Labor and Social Protection of the Russian Federation No. 585n dated August 27, 2019 (as amended on October 6, 2021) "On Classifications and Criteria Used in Carrying Out Medical and Social Expertise of Citizens by Federal State Institutions of Medical and Social Expertise" (Registered with the Ministry of Justice of Russia on November 18, 2019, No. 56528)

Appendix B. Physician Action Algorithms

1. Maxillary fracture

2. Zygomatic bone fracture

Appendix C. Patient Information

Pediatric traumatology is a serious problem that leads to injuries of varying severity, up to life-threatening conditions. As a child grows older, the risk of maxillofacial trauma increases, especially when the child begins to move independently. Various stabbing and cutting objects cause serious injuries to children of all ages due to improper use. The main cause of accidents is adult negligence. Furthermore, maxillofacial trauma leads to severe anatomical, functional, and neurological disorders that may require a series of reconstructive surgeries.

When sustaining a maxillofacial injury accompanied by wounds, tissue defects, or loss of consciousness, immediate medical assistance must be sought by calling an ambulance team.

Parents should be aware that visible clinical and radiological recovery upon discharge from the hospital or completion of active outpatient treatment does not rule out the possibility of delayed complications. All children who have suffered maxillofacial trauma must be placed on dispensary follow-up.

The maxilla and zygomatic bone are among the many bones that make up the facial skeleton. A fracture typically occurs in the area where these bones join adjacent bones.

Maxillary fractures occur when the traumatic force is directed at the middle third of the face. Fractures of the zygomatic complex occur when the traumatic force is directed at the zygomatic prominence (the most prominent point below the eye).

Injuries most frequently involve damage not only to the maxilla or zygomatic bone, but also to adjacent bones.

A fracture of the maxilla or zygomatic bone with fragment displacement can lead to facial deformity, impaired chewing and vision, altered facial sensitivity, and nasal breathing disorders.

Complications arising after a zygomatic bone fracture:

• Enophthalmos and downward displacement of the eyeball, double vision.

• Inflammation of the maxillary paranasal sinus, so-called sinusitis.

• "Numbness" of the maxillary teeth and the skin in the area of the nose, lip, and lower eyelid on the affected side.

• Limited mouth opening and restricted lateral jaw movements, which cause difficulty and pain during eating.

• Traumatic brain injury of varying severity, hemorrhages, cerebrospinal fluid leakage, etc.

Zygomatic bone fractures without displacement and functional impairment are treated conservatively and require short-term hospitalization for examination.

Maxillary and/or zygomatic bone fractures with fragment displacement require surgical treatment.

Appendix G. Assessment Scales, Questionnaires, and Other Evaluation Tools

Absent