Combined congenital and acquired defects and deformations of the maxillofacial region: clinical guidelines

List of Abbreviations

ABT – antibiotic therapy

ABP – antibiotic prophylaxis

BP – blood pressure

VTE – venous thromboembolism

SSI – surgical site infection

CT – computed tomography

FBG – fibula bone graft

INR – international normalized ratio

MRI – magnetic resonance imaging

MRSA – methicillin-resistant S. aureus

EUCAST NACs – European Committee on Antimicrobial Susceptibility Testing National Antifungal/Antimicrobial Committees

LMWH – low-molecular-weight heparin (heparin group)

NS – nutritional support

NSAIDs – non-steroidal anti-inflammatory and antirheumatic drugs

BV – blood volume

PAP – perioperative antimicrobial prophylaxis

RAG – revascularized autograft

SKAT – SKAT Program (Antimicrobial Stewardship Strategy) in inpatient medical care. Russian clinical guidelines (2018)

PE – pulmonary embolism

US – ultrasound examination

CDU – color duplex ultrasonography

Caprini score – scale for assessing the risk of venous thromboembolism in surgical patients

MFR – maxillofacial region

MFT – maxillofacial trauma

TBI – traumatic brain injury

HR – heart rate

EchoCG – echocardiography

Terms and Definitions

Intraoral approach – a type of surgical approach performed by sequential dissection of the oral mucosa, periosteum, and sometimes deeper layers of soft tissues to visualize the jaw.

Oral hygiene – a set of measures aimed at reducing the amount of dental deposits.

Closed fracture of the mandible – a type of fracture in which there is no communication between the fracture gap and the external environment through a skin wound, a wound (rupture) of the oral mucosa, or through the periodontal space of a tooth.

Surgical site infection (SSI) – an infection of a surgical wound, organ, or space occurring within the first 30 days of the postoperative period (up to 1 year if an implant is present) [5, 12, 13, 32, 40].

Perioperative antimicrobial prophylaxis (PAP) or antibiotic prophylaxis (ABP) – the prophylactic use of systemic antibacterial drugs to prevent (reduce the risk of) wound infection in the surgical intervention area.

Facial skull defect (from Lat. dēfectus - reduction, deficiency) – a symptom complex characterized by the absence or loss of a part of bone tissue substance, leading to a violation of the anatomical integrity of the facial skull structures, aesthetic and functional disorders.

Facial skull deformity (from Lat. deformatio – distortion) – a symptom complex characterized by a violation of the anatomical shape, linear and volumetric parameters of the entire bone and/or part of it, as well as the development of an incongruent ratio of the bone structures of the facial skull, leading to anatomical, aesthetic, and functional disorders, and a decrease in the quality of life.

Postoperative defects – tissue defects resulting from the treatment of epithelial malignant tumors: squamous cell carcinoma of the floor of the mouth, lower lip, mandible, adenocarcinoma of the hard palate and maxillary sinus, after surgical treatment of connective tissue tumors – sarcomas.

Post-traumatic defects – tissue defects resulting from a traumatic agent with a force exceeding the strength of bone structures, leading to the formation of a defect. Most often, such injuries occur after traffic accidents, gunshot wounds.

Jaw immobilization – the fixation of jaw fragments in a fractured state in the correct position for the period necessary for their fusion (consolidation), i.e., until the formation of a callus.

Clinical nutrition – the process of providing adequate nutrition using a number of methods other than ordinary food intake, including parenteral nutrition, enteral nutrition, or a combination thereof.

Cutaneous perforator vessel – a vessel originating from the main axial feeding trunk of the graft, supplying blood to the skin "pad" of a combined autograft.

Combined facial defect – simultaneously extensive bone and extensive soft tissue defects of the maxillofacial localization.

False joint (malunited fracture) – a variant of bone fragment fusion when, after twice the average time required for the formation of a full-fledged callus, radiological signs of consolidation are absent, and mobility of the bone fragments persists.

External approach – a type of surgical approach performed by sequential dissection of the skin, subcutaneous adipose tissue, and deeper layers of soft tissues to visualize the jaw. Osteosynthesis – the joining of bone fragments during a fracture or reconstructive surgery using various types of structures (wire suture, on-bone miniplate, etc.).

Nutritional support – a scientifically based system of diagnostic and therapeutic measures aimed at maintaining the necessary metabolic and structural-functional processes in the body, providing the latter with proper homeostasis and adaptive reserves; the process of substrate provision for patients using special methods different from ordinary nutrition, artificially created nutritional mixtures of various orientations.

Nutritional feeding – a set of measures aimed at ensuring a relatively stable trophic homeostasis in order to optimize the structural, functional, and metabolic processes of the body and adaptive reserves.

Osteomyelitis of the jaw (from Greek words: osteo from osteon – "bone"; myelo – "marrow"; -itis – "inflammation") is an acute infectious-inflammatory (or purulent-necrotic) process of an infectious-allergic nature of odontogenic or non-odontogenic origin, in which the lesion area spreads simultaneously in all structural components of the jaw bone tissue, as well as in the surrounding soft tissues, caused by pyogenic (pus-producing) bacteria or mycobacteria with the formation of an area of non-viable tissue.

Acute odontogenic osteomyelitis – an acute odontogenic infectious-inflammatory process in which the lesion zone in the bone extends beyond the dentoalveolar segment, which served as the site of localization of the entry gate for the pathogen, to the periodontium of neighboring teeth or the body of the jaw.

Osteonecrosis (ON) – a lesion of various parts of the bone of polyetiological nature, arising in response to a progressive disturbance of microcirculation in it and leading to the death of the bone marrow and trabecular bone. According to researchers at the V.A. Nasonova Research Institute of Rheumatology, by etiology, pathogenesis, or magnetic resonance imaging (MRI) data, ON is conventionally divided into 4 categories:

1. Ischemic ON (avascular aseptic necrosis), developing in response to the cessation of vascular nutrition of the bone due to vessel thrombosis. In relation to the same changes occurring in the bone marrow, the term "bone infarction" is more commonly used.

2. ON arising as a result of pathological changes associated with edema of the bone marrow or subchondral bone, most often associated with chronic arthritis, arthrosis, local and generalized osteoporosis.

3. ON of the jaw associated with the use of bisphosphonates (BPONJ) for the treatment of bone metastases in cancer patients (solid tumors, breast and prostate carcinoma).

4. Sporadic ON (Perthes disease, Hass disease, etc.).

Also considered is glucocorticoid osteonecrosis, which, together with bisphosphonate osteonecrosis, is classified as iatrogenic.

Revascularized bone autograft (from English: revascularization – connection to a new source of vascular supply), or free flap – a blood-supplied complex of autotissues, including a bone segment with adjacent muscles in the form of a sleeve, having an axial blood supply system or periosteal type of blood supply with restoration of nutrition after the creation of vascular anastomoses with recipient vessels (revascularization).

Bone fragment reposition is a procedure aimed at aligning bone fragments.

Vascular pedicle is the main vascular bundle of the graft, comprising an artery and a vein (or 2 veins), which supplies blood to the entire conglomerate of tissues that make up the autograft.

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Acquired defects and deformations of soft tissues and bones of the maxillofacial region are tissue flaws resulting from diseases, trauma, or treatment sequelae, characterized by compromised integrity of the facial bone structures and soft tissues, accompanied by scarring of the oral mucosa, nasopharynx, oropharynx, and laryngopharynx, as well as persistent impairments of masticatory and speech functions, leading to the loss of initial aesthetic appearance, deteriorated quality of life, and social maladaptation of the individual.

Maxillofacial trauma in children is accompanied not only by significant damage in the acute period, but also by sequelae associated with delayed development and growth of facial and jaw tissues, causing persistent post-traumatic deformations.

Congenital defects and deformations of soft tissues and bones of the maxillofacial region in children are alterations that occur as a result of developmental anomalies, manifesting as impaired structure and function of facial tissues. These defects may involve both soft tissues (e.g., skin and mucous membranes) and bone structures.

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

Congenital defects may be caused by the following factors:

1. Genetic factors. Hereditary diseases and mutations can lead to developmental anomalies of the maxillofacial region. For example, syndromes such as Goldenhar syndrome, Patau syndrome, and others may be associated with congenital defects.

2. Environmental factors. Exposure to adverse environmental factors during pregnancy (e.g., toxic substances, radiation) can disrupt normal fetal development.

3. Infectious agents. Infections contracted by the mother during pregnancy (e.g., rubella, cytomegalovirus) can lead to anomalies in the development of the child's maxillofacial region.

4. Nutritional deficiencies. A lack of vitamins and minerals (e.g., folic acid) during pregnancy can contribute to the development of congenital defects.

Acquired defects may occur in children due to the following causes:

1. Trauma. Fractures and soft tissue injuries of the maxillofacial region resulting from accidents or trauma can lead to acquired deformations.

2. Diseases. Inflammatory processes (e.g., osteomyelitis), tumors, or other pathologies can cause the destruction of bone and soft tissue.

3. Surgical interventions. Operations in the maxillofacial region (e.g., tumor removal or tooth extraction) can lead to scarring and deformations.

4. Infections. Certain infections (e.g., mumps or herpes) can cause inflammation and damage to facial tissues.

Pathogenetic causes of congenital defects include:

1. Impaired embryonic development. As a result of genetic or environmental factors, a disruption occurs in the formation of tissues and organs in early pregnancy.

2. Cell migration anomalies. Improper cell migration during embryogenesis can lead to underdeveloped or mispositioned structures of the maxillofacial region.

3. Molecular signaling dysfunction. Disruptions in molecular signals responsible for tissue development can lead to anomalies.

Acquired defects may be caused by:

1. Secondary tissue changes. Trauma or disease leads to the destruction of normal tissue structure, causing inflammatory reactions and scar formation.

2. Compensatory mechanisms. Upon the loss of function of individual structures (e.g., teeth), changes in dental occlusion and jaw position may occur.

3. Chronic inflammatory processes. Prolonged inflammation can lead to bone tissue destruction and altered anatomy of the maxillofacial region.

In all cases, it is necessary to consider the patient's individual characteristics to choose the optimal approach for treatment and rehabilitation.

1.3 Epidemiology of the Disease or Condition

Congenital malformations of the maxillofacial system in children represent a significant problem in pediatric dentistry and maxillofacial surgery. These malformations can range from minor anomalies to severe deformations requiring comprehensive treatment. The epidemiology of congenital maxillofacial malformations shows a prevalence of approximately 1-3% among newborns, making them one of the most common developmental anomalies.

The most common congenital malformations are cleft lip and cleft palate. These anomalies can manifest either isolated or in combination with each other. Cleft lip occurs in 1 out of every 1000-1500 newborns, whereas cleft palate has a similar frequency. These malformations are more frequently observed in boys, although cleft palate can occur with equal frequency in both sexes.

Other congenital anomalies of the maxillofacial system include micrognathia, macrognathia, as well as various forms of facial dysplasia and asymmetry. Micrognathia, for instance, can be associated with syndromes such as Patau syndrome or Treacher Collins syndrome. The frequency of these anomalies varies depending on geographic region and ethnicity.

Risk factors for the development of congenital maxillofacial malformations include genetic predisposition, exposure to teratogenic factors during pregnancy (such as alcohol, illicit drugs, or certain medications), and the presence of comorbid conditions in the mother. For example, women with diabetes or obesity have an increased risk of giving birth to a child with congenital anomalies.

It is important to note that early diagnosis and a multidisciplinary approach to the treatment of such malformations can significantly improve the quality of life for children and their families. Modern imaging methods, such as ultrasound and magnetic resonance imaging, make it possible to detect some of these anomalies even before birth. After birth, a comprehensive assessment of the child's condition is necessary, involving specialists from various profiles—pediatric surgeons, orthodontists, and medical speech-language pathologists—to develop an individualized treatment plan.

Benign epithelial tumors in children are quite common, especially between the ages of 5 and 15 years. One of the most common is ameloblastoma, which accounts for about 18% of all benign tumors and tumor-like lesions of the jaws. This tumor is most frequently localized in the mandible, particularly in the angle and ramus region. Osteoblastoclastoma, although virtually absent in children under 12 years of age, can be diagnosed in adolescents and accounts for 15-20% of all benign bone tumors.

Myxoma is also one of the most common tumors of the maxillofacial region in children and adolescents, most frequently detected at the age of 10 to 30 years with equal frequency of involvement of the maxilla and mandible. The proportion of myxoma is approximately 8%. Fibrous dysplasia is detected more often during the eruption of permanent teeth and puberty, when endocrine system activation and intensive growth of the jaws and other bones of the facial skeleton occur.

Among injuries, domestic trauma is the most frequent. Boys are more prone to domestic trauma compared to girls, especially between the ages of 5 and 15 years when they are most active. Traffic injuries also occur among children, particularly in the warm season (April-September), and are more common in boys. Gunshot wounds with bone damage account for about 10-15%, but their frequency among children is significantly lower compared to adults. Occupational injuries among children are less common, but may occur in cases of industrial accidents or during vocational training.

The osteomyelitic process can develop in children of all ages, but is most frequently observed in adolescence (12 to 18 years), with osteomyelitis being more common in boys than in girls. The localization of osteomyelitis also has specific features: maxillary osteomyelitis accounts for about 15% of all cases, whereas mandibular osteomyelitis accounts for about 85%. Odontogenic osteomyelitis of the mandible is more common (68%) compared to the maxilla (32%). The incidence of bisphosphonate-related osteonecrosis among children receiving zoledronic acid-based medications** (bisphosphonates) ranges from 11 to 27%. Osteoradionecrosis of the mandible is also observed more frequently than that of the maxilla, accounting for 10% to 40% among pediatric patients who received head and neck radiation therapy.

Partial secondary edentulism (loss of teeth due to accident, extraction, or localized periodontitis) is the most common pathology, which may be accompanied by atrophy of the alveolar process (part) of the jaw. It is one of the most widespread conditions: according to the World Health Organization, up to 75% of the population in various regions of the world suffer from it, and it occurs in all age groups of patients.

1.4 Features of Coding the Disease or Condition

M19.0 Primary arthrosis of other joints

M19.1 Post-traumatic arthrosis of other joints

M19.2 Other secondary arthrosis

M19.8 Other specified arthrosis

1.5 Classification of the disease or condition

1. By etiology

1) Post-traumatic — resulting from physical factors: mechanical trauma (gunshot and non-gunshot, including occupational (industrial and agricultural) and non-occupational (domestic, street, sports, transport, surgical)); thermal (burns and frostbite); electrical injury; chemical trauma: by acids, alkalis, and other aggressive substances.

2) Postoperative — following the removal of benign and malignant tumors and tumor-like formations;

3) Post-infectious — following past infections (nonspecific and specific purulent-inflammatory processes of the soft tissues and bones of the facial skeleton) and tissue necrosis resulting from marked circulatory disorders;

4) Following radiation exposure to the tissues of the maxillofacial region;

5) Bone (osteonecrosis or bisphosphonate-associated) necrosis of the jaws;

6) Following aseptic inflammation;

7) Congenital defects of the maxillofacial region.

2. By localization

There are numerous classifications describing mandibular defects, developed by various authors (Dunaevsky V.A., 1957; Pavlov B.L., 1972; Khodorkovsky M.A., 1999; Matyakin A.E., A.A. Uvarov et al., 1993; David d et al., 1989; Carion J.L., Payement G. et al., 1994). These classifications were created in the context of using avascular bone grafts, but some of them remain relevant today.

The choice of the donor site for harvesting a vascularized bone graft depends on the localization of the mandibular defect, which makes it necessary to use a system dividing the jaw into sectors. The most widely used classification is that of J.B. Boyd et al. (1991), which is based on the size of the lesion and the involvement of "key zones" (condylar process, mandibular angle, and mental region) in the defect. The aesthetic and functional results of the surgery largely depend on the precise reconstruction of these areas.

The J.B. Boyd classification is based on the system proposed by B.L. Pavlov in 1972 and distinguishes three sectors of the mandible (Figure 1):

H — lateral defects of any length in the region of the ramus with the articular head, angle, and half of the chin (includes 1, 2, or 3 "key zones");

L — defects similar to sector H, but without the condylar process (includes 1 or 2 "key zones");

C — defects of the central segment containing 4 incisors and 2 canines (includes 1 "key zone").

Combinations of these designations are possible (e.g., a defect from angle to angle is designated as LCL). From the perspective of surgical tactics, this division allows for the precise determination of the number of required osteotomies.

Figure 1. J.B. Boyd classification

In 1993, J.B. Boyd and co-authors proposed supplementing the classification with designations for lost perimaxillary soft tissues: "c" — skin defect, "m" — mucosal defect, "sm" — skin and mucosal defect.

Some surgeons note a shortcoming of the J.B. Boyd classification in that it does not account for the many possible variants of mandibular defects within a single class and does not provide information on the localization of soft tissue defects that often accompany bone defects in cancer patients. However, this disadvantage can be viewed as an advantage that simplifies the classification. For example, in the case of a tumor in the floor of the mouth requiring mandibular hemiresection in an oncological patient, it is necessary to fashion a fibular flap with a large soft tissue component for the successful reconstruction of both the bony structure of the mandible and the soft tissues of the oral cavity. Similar principles apply to other tumor localizations and the choice of the most appropriate graft.

Currently, the most widespread classification for assessing maxillary defects is that of J.S. Brown and R.J. Shaw (2010) (Figure 2), which, in addition to the defect of bony structures, additionally takes into account all its components: integumentary tissues, oropharynx, skull base, dura mater. The following symbols are proposed to designate defects:

— maxilla — MXD,

— integumentary tissues and skin — S,

— pharynx — Ph,

— skull base — Bs,

— dura mater — Dm.

This approach is necessary to determine reconstruction tactics and select the autograft depending on the components of the defect.

Figure 2. Modified classification of maxillary defects by J.S. Brown and R.J. Shaw.

Figure 3. Classification of maxillary defects proposed in 2010 by Z. Durrani et al. (adapted from [14]): a — alveoectomy, b, c, d, e — subtotal, total, radical, combined maxillectomy, respectively.

1.6 Clinical presentation of the disease or condition

In both acquired and congenital defects of the maxillofacial region, the following disorders may occur:

1. Impairment of tissue integrity. Congenital and acquired defects can manifest as anomalies such as cleft lip or cleft palate, as well as other changes affecting both soft and bone tissues.

2. Functional disorders. Children with such conditions may encounter difficulties in chewing, swallowing, and speech articulation. This is due to the fact that anomalies in the structure of the jaw and face can interfere with the normal functioning of the oral cavity.

3. Aesthetic changes. Congenital and acquired defects can significantly affect a child's appearance, which may cause self-doubt and difficulties in communicating with other children.

4. Quality of life. Children with such conditions may experience discomfort and limitations in their activities, which can affect their play and interaction with peers.

Acquired and congenital defects of the maxillofacial region can cause a number of serious disorders affecting both the physical and psychological state of the child. One of the most prominent aspects is the impairment of tissue integrity. Congenital anomalies, such as cleft lip or cleft palate, are examples of changes that can affect both soft and bone tissues. These defects can vary in severity and localization, which in turn influences the approaches to their treatment and reconstruction.

Functional disorders are also an important component of the problem. Children with such conditions frequently encounter difficulties in chewing, swallowing, and speech articulation. Anomalies in the structure of the jaw and face can hinder the normal functioning of the oral cavity, leading to difficulties in performing basic life functions. These functional limitations can negatively affect the child's nutrition and socialization capacity.

Aesthetic changes caused by congenital or acquired defects also play a significant role in a child's life. Appearance can change significantly due to facial structural anomalies, which may lead to reduced self-esteem and self-doubt. Children with such conditions may experience difficulties in communicating with peers, which can exacerbate their social isolation and lead to emotional problems.

The quality of life of children with maxillofacial defects may also suffer significantly. They may experience discomfort and limitations in their activities, affecting their ability to participate in play and interact with other children. These limitations can lead to reduced activity levels and a general deterioration of the child's psycho-emotional state.

Thus, congenital and acquired defects of the maxillofacial region represent a complex problem requiring an interdisciplinary approach for the effective treatment and rehabilitation of children. The necessity of taking all these aspects into account underlines the importance of early diagnosis and timely intervention to minimize negative consequences for the child's health and quality of life.

2. Diagnostics, medical indications and contraindications for diagnostic methods

2.1 Complaints and Anamnesis

Diagnosis of maxillofacial defects is based on collecting anamnesis, complaints, and a clinical examination of the patient. If the existing complaints are caused by any pathological processes in the maxillofacial region (including trauma, oncological diseases, congenital defects), or are the consequence of previously performed treatment or other interventions in this area, the possibility of reconstructive-plastic treatment and rehabilitation should be considered. Thus, children with acquired and congenital defects of the maxillofacial region often present with diverse complaints that can vary depending on the type and severity of the defect. The main complaints include:

1. Difficulties with chewing and swallowing. Children may report pain or discomfort while eating, as well as difficulty swallowing food. This may be due to improper jaw closure or anomalies in the structure of the maxillofacial system.

2. Speech problems. Parents often note that the child has difficulty pronouncing certain sounds or words. This may be due to insufficient mobility of the soft palate or structural anomalies of the lips and tongue.

3. Esthetic complaints. Children may express dissatisfaction with their appearance, especially if the defects lead to noticeable changes in facial shape. This can cause self-doubt and social isolation.

4. Pain and discomfort. Some children may complain of periodic pain in the jaw, face, or ears, which can be associated with malocclusion or inflammatory processes.

5. Limitations in physical activity. In some cases, children may experience limitations in games and physical activity due to discomfort or fear of injury.

Taking an anamnesis in children with acquired and congenital maxillofacial defects is a complex process involving both medical and social aspects. Anamnesis and complaints should be gathered not only from the sick child, but additional information should also be obtained from accompanying persons and relatives. In the case of congenital anomalies, special attention is paid to the presence of similar problems in parents or other family members, which may indicate a genetic predisposition. It is also important to consider the pregnancy history, including potential infections, toxicosis, and medication use, as these factors can play a significant role in the development of defects.

For children with acquired defects, it is necessary to gather information about injuries, surgeries, or diseases that could have led to changes in the jaw and facial structure. For example, head or facial injuries can cause serious anatomical changes requiring further intervention. It is also important to assess the child's overall development, including physical, emotional, and social development. The presence of developmental delays may indicate more serious problems and require additional attention.

The child's social adaptation is another important aspect of the anamnesis. It is necessary to find out how they cope with their condition in the social environment: whether they have friends, how they communicate with peers, and whether they experience difficulties at school. These factors can significantly influence the child's psycho-emotional state and quality of life.

In addition, information about previous surgical interventions or orthodontic treatment is important for planning further care. A thorough collection of complaints and anamnesis is an essential stage of diagnosis and the development of an individualized approach for each patient, taking into account their unique needs and circumstances. This allows physicians not only to more accurately assess the child's current health status, but also to develop an optimal treatment strategy to achieve the best outcomes.

2.2 Physical Examination

When examining children, the principle of maximum informativeness with minimum invasiveness must be followed. All children with maxillofacial defects must undergo a physical examination to clarify the diagnosis and determine the treatment tactics, including:

1. assessment of the patient's general condition;

2. examination of the maxillofacial region and oral cavity;

3. palpation of the maxillofacial region.

Comments: The somatic status in patients with acquired defects and deformations of the maxillofacial region should be characterized by a satisfactory general condition, with no complaints. The general condition of the patients should not be impaired, and body temperature should be within the physiological norm.

Comments: An external examination of patients with acquired defects and deformations of the maxillofacial region reveals a violation of facial configuration due to the presence of a postoperative (or post-traumatic) defect localized in the area of the bone structures of the mandible (maxilla), zygomatic bones and arches, nasal bones, perimaxillary soft tissues, mucous membrane, and oral cavity tissues. The skin should be of physiological color and capable of being pinched into a fold. Cicatricial changes may be present in patients after prior surgical interventions or trauma. Upon palpation, regional lymph nodes are not enlarged. In patients with an oncological origin of maxillofacial defects who have undergone prior surgery, several palpable lymph nodes may be present, painless upon palpation, without signs of abscess formation and metastasis. Signs of cicatricial contracture of the masticatory muscles may be noted when the jaw defect or perimaxillary soft tissues are localized in the area of the masticatory muscles. Food intake and swallowing may be difficult.

Comments: During palpation in patients with acquired defects and deformations of the maxillofacial region in the localization zone of the bone structures or perimaxillary soft tissues and/or mucous membrane, attention is drawn to the presence of a communication between the oral cavity and the maxillary sinus, the localization and degree of displaceability (the ability to move into an orthotopic position) of the preserved mandibular stumps, the range of mouth opening, and the ability to close the lips and eyelids [59; 72; 76].

Comments: When examining patients with acquired defects and deformations of the maxillofacial region, restricted mouth opening may be caused by the localization of tissue defects in the area of the masticatory muscles, leading to their cicatricial contracture.

Comments: During the examination of patients with acquired defects and deformations of the maxillofacial region, tooth percussion should be painless. The oral cavity must be sanitized prior to scheduled surgical intervention.

Comments: When examining a patient with acquired defects and deformations of the maxillofacial region, pathological tooth mobility should not be detected. The oral cavity must be sanitized prior to scheduled surgical intervention.

Comments: The symptom of hypesthesia of areas of the skin, mucous membrane, and/or perimaxillary soft tissues is caused by a mechanical disruption of the integrity of the nerve passing through the section of the jawbone in the defect zone, which innervates the corresponding area of the perimaxillary soft tissues and/or mucous membrane.

Comments: the general practitioner assesses the patient's general somatic status, clarifies the diagnosis of comorbid conditions, and determines the indications for additional diagnostic methods (echocardiography, 24-hour blood pressure monitoring [ABPM], internal organ ultrasound, etc.) [11].

Comments: The ophthalmologist performs fundus biomicrophotography using a fundus camera, fundus biomicroscopy, and identifies signs of optic atrophy, papilledema, and visual impairments that may indicate the development of intracranial pathology.

Comments: the neurologist assesses neurological status and determines the indications for further examination if complications are suspected. If trigeminal nerve neuropathy develops, the neurologist performs an examination, recommends further diagnostic workup, clarifies the diagnosis, and prescribes treatment.

Comments: the otorhinolaryngologist assesses the condition of the ENT organs, clarifies the diagnosis, adjusts the complex treatment plan, and draws up a schedule of measures to prevent ENT complications during and after surgical intervention for acquired maxillofacial defects and deformities. Special attention should be paid to patients in the postoperative period if prolonged nasal intubation (up to 3–5 days) is performed and/or a nasogastric tube is placed due to the existing risks of purulent-inflammatory complications in the paranasal sinuses and "ascending" intracranial complications [45].

Comments: The choice of anesthesia technique is determined by the patient's general condition and the scope of the planned surgical intervention for acquired maxillofacial defects and deformities. Reconstructive head and neck surgeries are often associated with significant blood loss and require intraoperative blood transfusion.

2.3 Laboratory Diagnostics

Comments: all patients with maxillofacial defects and deformities must undergo: 1) a complete blood count (CBC) with differential; 2) determination of ABO blood groups and Rh factor (D antigen); 3) general general-medical biochemical blood test including alanine aminotransferase and aspartate aminotransferase activity, blood glucose, hepatitis B virus surface antigen (HBsAg), hepatitis B virus core antigen (HBcAg), hepatitis C virus antigens, hepatitis C virus antibodies, HIV-1 antibodies (IgM, IgG), and HIV-2 antibodies (IgM, IgG) to assess general status; 4) a coagulogram (screening hemostasis test) (activated partial thromboplastin time [APTT], plasma fibrinogen, platelet aggregation and adhesion, international normalized ratio [INR], D-dimer concentration, antithrombin-III activity) for laboratory monitoring of pharmacotherapy; 5) serum total protein, albumin, transferrin, and C-reactive protein; 4) urinalysis, urine urea [7, 14, 15, 35, 46]. These tests are performed as part of the patient's preoperative preparation based on the initial consultation by the anesthesiologist-resuscitator before surgery and during inpatient postoperative treatment to assess dynamics and/or adjust treatment.

2.4 Instrumental Diagnostics

Comments: orthopantomography of the jaws in patients with acquired maxillofacial defects and deformities is performed preoperatively when computed tomography (CT) of the facial skull is technically unavailable [12].

Comments: in a comprehensive examination for more accurate diagnosis, computed tomography of the facial skeleton with intravenous bolus contrast enhancement, multiplanar, and three-dimensional reconstruction is used, allowing to establish and determine changes in bone tissue. This research method makes it possible to obtain a clear image of the cortical layer, evaluate the condition of surrounding soft tissues, determine the presence, and visualize in detail. The CT protocol should be agreed upon with specialists in radiology, IT technologies, and engineers of radiology departments; together with them, special CT protocols should be developed, the results of the study evaluated, and surgical intervention planned and modeled using a virtual three-dimensional head model [7;8;12;13;15;23;32;72;88;94].

Comments: in the preoperative period in patients with defects and deformations of the facial bones, if there is an indication and technical feasibility, the use of additive technologies is indicated. At the same time, together with a radiologist, radiology specialist, and IT technology specialist, the size, localization, and configuration of the defect are clarified using CBCT or MSCT images of the donor and recipient zones, the true dimensions of the bone defect are determined, the parameters of the optimal graft are calculated, and a "virtual" surgical intervention is planned and performed, during which the bone graft is modeled to the shape of the lost jaw segment and positioned in the defect area to restore the anatomical integrity of the facial bones. When performing surgery in patients with oncological pathology, simultaneous primary replacement of a maxillofacial defect using vascularized grafts is planned. Initially, the extent of the pathological tumor process is assessed, and the resection margins of pathologically altered tissues are planned. Next, based on CT data in a special computer environment (Amira 5.4.5, Visage Imaging, Germany), virtual planning of the reconstructive stage of the operation is carried out according to the protocol described above. Then, the results of the study performed on a spiral computed tomograph are converted into a set of 100–150 tomograms with a step of 0.1–0.8 mm, which are input into a personal IBM-compatible computer in DICOM format. Further, using the 3Dview software package, the series of tomograms is converted into a three-dimensional computer model in STL format, which is generally accepted for the software of stereolithography units for the manufacture of prototyped graft, jaw, and template models for intraoperative modeling. The CT scan protocol should be agreed upon with specialists in radiology, IT technologies, and engineers of radiology departments; together with them, special CT protocols should be developed, the results of the study evaluated, and surgical intervention planned and modeled using a virtual three-dimensional head model [12,23;29;40;67;72;87;89;90;94].

Comments: evaluation of the cardiovascular system in the preoperative period is mandatory as part of preoperative preparation.

Comments: targeted chest radiography allows for the diagnosis of pathological changes in the skeleton, lung tissue, the state of the pleural cavity, and the assessment of the size and shape of the heart shadow and adjacent vessels.

Comments: blood flow velocity in vessels, their diameter, and the degree of potential narrowing due to atherosclerotic lesions are studied. Despite the fact that direct lower extremity artery angiography remains the "gold standard" in lower limb artery research and is widely used in leading medical institutions of the Russian Federation, it is advisable to use new methods according to indications [5;7;12;13;15;23;28;29;31;46;76;94]. In the recommendations of cardiovascular surgeons for preoperative evaluation of lower extremity arteries to determine the feasibility of free fibular transfer, multidetector computed tomographic coronary angiography is the preferred and most objective method of investigation for the following three conditions: abnormal pedal pulse, significant prior lower leg trauma, and suspected vascular disease. The effectiveness of this study has been demonstrated in surgical planning by the majority of pediatric surgeons [2;3;38;114;104;101].

Comments: special attention is paid to atherosclerotic vascular lesions and congenital vascular anomalies. In the recommendations of cardiovascular surgeons for preoperative evaluation of lower extremity arteries to determine the feasibility of free fibular transfer using multidetector computed tomographic coronary angiography, it is the preferred and most objective research method for the following three conditions: abnormal pedal pulse, significant prior lower leg trauma, and suspected vascular disease [17;44;100], and the effectiveness of this study has been demonstrated in surgical planning.

2.5 Other Procedures

Comments: a joint consultation is necessary for planning the orthopedic structure and the position of dental implants. In complex clinical situations, stereolithographic models may be required (reconstruction of the cranial bones and facial skeleton using stereolithography) [15,23,28,69,87,88].

Comments: microbiological test results are especially important when performing repeat surgical interventions and in cancer patients who have received complex antitumor treatment, as well as in cases of postoperative complications for an objective assessment of the patients' treatment dynamics [14]. If necessary, biomaterial can be sampled from the wound intraoperatively to study the microbiota and its sensitivity to systemic antibacterial drugs and antiseptics (antiseptics and disinfectants) in the form of a biopsy specimen in order to monitor ongoing ABP or, if necessary, to prescribe and adjust antibacterial therapy dynamically [16; 22; 48; 77; 80; 102].

Comments: morphological examination of tissues (biopsy specimens) obtained during surgery is mandatory to clarify the diagnosis and for differential diagnosis with other nonspecific, specific inflammatory diseases and neoplasms of the maxillofacial region [96].

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

3.1 Drawing up a treatment plan, including orthodontic rehabilitation. Preparation for microsurgical reconstruction or fabrication of custom-made prostheses.

The necessity of restoring the anatomical integrity of the mandible and its functional adequacy in children is in most cases beyond doubt, but the choice of reconstruction method remains a controversial issue.

Comments: Currently, mandibular reconstruction in children remains a challenging issue despite the ongoing improvement of surgical techniques, planning methods, and rehabilitation [1]. The gold standard for mandibular reconstruction in adults is microsurgical reconstruction using free flaps [2], but this method, like reconstruction with static prostheses, is not always optimal in pediatric practice due to the continuous growth of the child [3, 4, 5]. The use of 3D modeling makes it possible to achieve more accurate reconstruction results, making its use necessary in reconstructive surgeries on the maxillofacial system in children [6].

For young children, the optimal reconstruction method appears to be the use of custom-made "growing" prostheses [7]; for older patients (from 12 years of age), in addition to classical "adult" microsurgical reconstruction [8], options for combined reconstruction using custom endoprostheses with an artificial joint and free fibular flap plasty can be offered. According to the literature, the aforementioned method is used in adult practice, but the experience of its use is limited [9].

Comments: To achieve an optimal outcome and enable the patient's final rehabilitation, including permanent dental prosthetics, it is necessary to consider further options for orthodontic prosthetics already at the planning stage. First of all, it is necessary to assess the cross-sectional area of the potential bone graft during microsurgical reconstruction, and if its volume is insufficient (taking into account possible degradation without physiological loading), alternative reconstruction options should be considered.

Comments: When the integrity of the bone structures of the maxillofacial region is completely disrupted, restoring the original contours can be difficult, especially in the absence of surgical templates and with a small surgical field. Achieving correct reposition of bone fragments is facilitated by using custom metal structures with specific positioning markers on the bone structures for fixation.

3.2 Surgical treatment, including corrective surgical interventions

Indications for surgical treatment of bone defects in the maxillofacial region in children can be determined based on clinical, radiological, and functional data. The main indications include:

- Presence of significant bone defects: Surgical intervention is indicated for pronounced bone defects that may result from trauma, infectious processes (e.g., osteomyelitis), tumor diseases, or congenital anomalies.

- Functional impairments: If there are impairments in chewing, speech, or breathing functions caused by bone deformations or bone tissue insufficiency, surgical restoration of the anatomical structure is indicated.

- Aesthetic indications: In cases where bone defects lead to pronounced aesthetic impairments (facial asymmetry, jaw deformation), surgical treatment may be indicated to improve the patient's appearance and psycho-emotional state.

- Ineffectiveness of conservative therapy: If there is no positive trend from conservative treatment (orthodontic, physiotherapeutic, etc.) within a set period of time, it is advisable to consider surgical intervention.

- Preparation for orthodontic treatment: In cases where prior bone tissue restoration is required for successful orthodontic correction (e.g., in the presence of alveolar bone deficiency), surgical treatment becomes a necessary stage.

- Prevention of complications: Surgical intervention may be indicated to prevent the progression of the pathological process or the occurrence of complications such as secondary infections or deformations.

Each case requires an individual approach taking into account the patient's age, general health status, and the specifics of the clinical situation. The decision on the necessity of surgical intervention should be made by a multidisciplinary team of specialists taking into account all the above factors.

Comments: When choosing a method for skin grafting, the primary consideration should be the feasibility of local tissue plasty by advancing the skin surrounding the defect. All plastic surgical procedures are based on the biological property of tissues—separated from their donor site while remaining attached via a vascular pedicle—to engraft in a new location. Adequate blood inflow and sufficient venous and lymphatic drainage are of paramount importance for tissue engraftment at the site of the defect being replaced. Good blood supply, rapid restoration of innervation, and healing by primary intention can prevent the development of atrophy in the transplanted tissues. Functional restoration of organs formed from the transferred flap is facilitated by functional loading.

Comments: The most frequent indication for free skin grafting is the presence of an extensive granulating surface ($5\text{ cm}^2$ ² or more). The optimal method of autologous skin grafting is considered to be the transplantation of an isolated skin flap. Depending on the thickness of the harvested skin layer, full-thickness (complete) and split-thickness grafts are distinguished. A full-thickness skin graft consists of the skin proper (epidermis and dermis). Its thickness allows transplantation only onto a well-vascularized wound and in the absence of infection risk. Transplantation of a full-thickness graft is possible for small wounds and is used in facial surgery or for closing defects of the palmar surface of the hand and fingers. The advantage of a full-thickness skin graft is its resistance to secondary retraction (shrinkage) and autolysis.

Comments: A split-thickness skin graft consists of the epidermis and a portion of the dermis. One of the advantages of a split-thickness skin graft is the ability to cover extremely extensive skin defects through "mesh" autologous skin grafting, where the harvested graft is perforated with a specialized device to create staggered stab incisions. This allows its surface area to be expanded by 3 to 6 times when stretched. Another advantage is the elimination of the need to suture the donor site. A specific feature of split-thickness skin grafts is their tendency toward primary shrinkage due to the contraction of collagen fibers; the thinner the graft, the more pronounced this property is.

Comments: Instead of small separate grafts, skin areas incorporating the epidermis down to the papillary dermis are used, matching the dimensions of the defect, with a width of 2–3 cm and a length of 4–5 cm. The most common donor sites for harvesting a free skin graft used to repair head and neck defects, depending on the size of the defect, are: the retroauricular region, the anterior or medial surface of the thigh, and the medial surface of the arm. The graft is immobilized in the wound bed for 7–10 days.

Comments: The type of flap and its method of transposition are chosen depending on the area, shape, volume of the defect, and its blood supply. For skin flap defects resulting from surgical interventions, trauma, tumor processes, as well as congenital absence of an organ, a single- or double-pedicled skin or musculocutaneous/fasciocutaneous flap is used with rotation.

Comments: elimination of soft-tissue cicatricial deformities and restoration of the skin cover by plasty using expanded skin from an adjacent (nearby) region.

Comments: Currently, in patients with facial skeleton defects and deformities, surgical approaches to organs are being developed without large incisions on the face, or within "hidden" areas (scalp, retroauricular region) [7,14,15,35,46].

The repair of maxillofacial defects using revascularized flaps with microsurgical techniques must be performed in hospitals equipped with a surgical microscope, necessary surgical instrumentation, and a technologically equipped intensive care unit.

Operations are performed by maxillofacial surgeons proficient in microsurgical techniques and the technical nuances of maxillofacial surgeries. It is well known that currently, it is possible to repair defects of the mandible or maxilla of any extent and location (total, subtotal, combined with defects of perimaxillary soft tissues and/or oral mucosa). The maxillofacial surgeon's arsenal includes a wide range of vascularized bone and soft-tissue autografts: revascularized (rib, scapular, fibular, iliac crest, radial); vascularized pedicled flaps (latissimus dorsi, pectoralis major) [7; 8; 12; 13; 29; 30; 56; 59; 60; 61; 62; 63; 67; 68; 94].

A typical algorithm for selecting a vascularized graft takes into account: 1) the localization of the mandibular defect (according to classifications such as Boyd J.B., 1991, or other functional classifications); 2) the extent of the mandibular defect; 3) the presence and volume of defects in the perimaxillary soft tissues and oral mucosa; 4) the characteristics of the vascular system in the recipient site; 5) anatomical variants of the donor site vascular system; 6) the blood supply characteristics of each bone graft. When planning mandibular or maxillary reconstruction and functional rehabilitation of patients, a "team" approach to treatment is required, adhering from the patient's very first visit to the principle of "reverse" planning—starting from the final treatment outcome—with mandatory "virtual surgical intervention" and "virtual dental prosthetic planning." It is essential to account for: 1) vascular anomalies in both donor and recipient sites; 2) concurrent general somatic pathology in the patient [8; 28; 29; 88].

Comments: the use of a fibular autograft in patients with acquired maxillofacial defects of categories I, III, and V is the method of choice [13; 22; 28; 29; 54].

Comments: the use of an iliac crest or rib autograft in patients with isolated acquired maxillofacial defects of category III or IV is the method of choice [7, 14, 15, 35, 46].

Comments: the use of a fasciocutaneous-osseous forearm flap including a fragment of the radius or a fibular autograft in patients with category II and IV defects combined with extensive hard palate defects is the method of choice [1;5;7;8;28;29;31;67;68].

Comments: at the first stage, it is necessary to reconstruct an adequate soft-tissue lining that reliably isolates the oral and nasal cavities from the external environment. Microsurgical bone autotransplantation can be performed after 6-8 months. This approach eliminates the potential negative aspects of single-stage reconstruction: tissue deficit, difficulties in positioning the bone component of the autograft and vascular pedicle, and hematoma formation leading to secondary infection of the flap bone component.

Elimination of maxillofacial defects using revascularized flaps with microsurgical techniques is performed in 4 stages:

I. The stage of harvesting the revascularized flap is performed by a team of reconstructive plastic surgeons. If necessary, the graft is shaped to match the lost jaw segment in the donor site while preserving blood supply. If indicated and/or technically feasible, previously manufactured preoperative stereolithographic surgical guides and models are used.

II. The stage of osteosynthesis in the recipient site (using a rib graft as an example).

After transferring the rib graft to the recipient site, it is adapted in the wound by connecting it to the mandibular stumps. Previously manufactured stereolithographic surgical guides and models are used for this purpose.

Osteosynthesis of the end of the rib graft with the mandibular stumps is performed using internal fixation devices (miniplates with screws).

The vascular pedicle of the graft is brought out to the zone of vascular anastomosis creation, toward the recipient vessels.

III. When the mandibular defect is localized in the body region, if indicated and/or technically feasible, the third branch of the trigeminal nerve is sutured using microsurgical technique.

In this procedure, the stumps of the mandibular nerve are prepared on both sides (proximally on the bone "platform" – the inferior alveolar nerve; distally in the soft tissues – the mental nerve). Next, the segments of the trigeminal nerve are coapted with an intercostal nerve autograft of the required length using an end-to-end technique. Interrupted perineurial sutures are applied using an operating microscope or loupes (2.5x magnification).

IV. The microsurgical stage of the operation.

1. Preparation for anastomosing donor and recipient vessels.

2. Creation of the arterial anastomosis.

3. Creation of the venous anastomosis.

4. Release of blood flow through the anastomoses.

Currently, intraoral or combined approaches for creating vascular anastomoses are being developed.

When performing microsurgical reconstruction of the mandible with a free (revascularized) fibular flap in children aged 3-10 years, there is a lack of increase in bone graft thickness as the child grows, ultimately making permanent dental prosthetics impossible due to insufficient volume of the graft's bone component. Furthermore, these patients often exhibit mandibular deformation and dental arch abnormalities due to retarded longitudinal growth of the free flap bone part compared to the intact part of the jaw, which makes this type of reconstruction inappropriate in this age group. [7]

Comments: The method for restoring the mandible after segmental resection in the young age group is the use of titanium implants for osteosynthesis or custom-made prostheses, whereas at an older age, planned microsurgical reconstruction with a vascularized flap followed by prosthetics is recommended [6].

Timely fabrication of full-fledged dental, maxillofacial, and facial prostheses is an important component of the rehabilitation measures in patients with jaw defects. A similar approach is optimal for traumatic maxillofacial injuries. Orthopedic appliances vary in design and are subdivided into: splinting, repositioning, stabilizing, correcting, replacing, and forming devices.

Prostheses for cranio-maxillofacial surgery are divided into: dentoalveolar; jaw; facial; combined; post-resection (following jaw resection). Immediate, early, and delayed prosthetics are distinguished. Accordingly, prostheses are subdivided into surgical and postoperative. Replacing devices also include orthopedic appliances used for palatal defects: protective plates, obturators, etc. For facial and jaw defects, prostheses are fabricated when there are contraindications to surgical interventions or when patients refuse reconstructive surgery. In cancer patients, removable dental prostheses are the most optimal designs [23;28;53;76;79;99;103].

3.3 Prevention of Surgical Site Infections

Comments: The choice of regimen and protocol for perioperative antibiotic prophylaxis (PAP) is based on national and international guidelines for the prevention of SSI [24,68,69,70,71].

Comments: in case of a high risk of complications, prolongation of antibiotic prophylaxis for 24-48 hours in the postoperative period is permitted. Prolonging antibiotic prophylaxis after the end of surgery does not increase its efficacy, but increases the risk of selecting antibiotic-resistant strains and complications, in particular, C. difficile-associated antibiotic-induced diarrhea. For type IV wounds ("infected wound") in case of old trauma, prior infection, presence of purulent discharge, or non-viable tissues, antibiotic therapy is indicated [23,68,69,70,72,73,74]. Type IV wounds include old traumatic wounds with non-viable tissues, as well as postoperative wounds in the area of a pre-existing infection. This implies that microorganisms capable of causing surgical site infections (SSIs) were present in the surgical site before the operation. Thus, antibiotic prophylaxis may be prolonged for more than 48 hours, in combination with the prevention of dysbiosis [23,68,69,70,71].

Table 1. Systemic antibacterial drugs for AMP in patients with maxillofacial defects

¹ Contraindication: neonatal period up to 1 month, including premature infants.

² allergy to beta-lactam antibacterial drugs: penicillins, high risk of MRSA. [200]

³ 120 minutes before incision. [80]

Comment: A single dose of antibiotics for AMP in pediatric surgery is calculated for each child individually, depending on their body weight.

#Clindamycin** For children, in a single dose of 10 mg/kg. Route of administration: IV. [200]

3.4 Pain Management

Comments: Operations for repositioning and osteosynthesis of the mandible are usually performed under general combined endotracheal anesthesia with nasal endotracheal intubation or combined anesthesia; for other maxillofacial surgeries, interventions with oral intubation are permissible.

3.5 Diet therapy

Comments: Taking into account the involvement of structures participating in the grinding, propulsion, and swallowing of the food bolus, oral nutrition may be inadequate to meet the patient's nutritional requirements (including due to pain syndrome during eating) or lead to an increased risk of surgical wound dehiscence or compromised osteosynthesis stability. In such cases, it is advisable to use either sparing dietary options (pureed diet, sip feeding, or enteral formula supplements), more severe cases require tube feeding, and when oral nutrition is impossible for a long period, gastrostomy placement should be considered (Gastrostomy). Parenteral nutrition may be considered as a supportive option, but is not indicated as the sole source of nutrients in the absence of pathology of the esophagus and lower gastrointestinal tract.

4. Medical Rehabilitation and Sanatorium-Resort Treatment

Comments: in the early postoperative period, balanced infusion therapy must be prescribed; nutrition is parenteral for the first 5 days, followed by pureed and minced food. The trophism of the transplanted flap is assessed by the condition of the skin paddle, using both objective characteristics and examinations with portable and stationary ultrasonic Doppler devices (Medical ultrasonic diagnostic equipment) [74;92;97].

After 6 months, patients undergo the first stage of dental implantation followed by the placement of gingiva formers and orthopedic structures.

In some cases, patients require corrective surgeries aimed at increasing or decreasing the soft tissue volume of the previously operated area, eliminating color mismatch, and correcting soft tissues surrounding the flap.

In the comprehensive rehabilitation of patients with extensive transfacial defects of the mandible reconstructed with revascularized grafts, to achieve a long-term predictable functional rehabilitation outcome, an action algorithm and timeframes are proposed for all stages of the comprehensive rehabilitation of this category of patients:

1. stage of comprehensive treatment: surgery to reconstruct the mandibular bone defect with a vascularized autograft;

2. stage of comprehensive treatment: preliminary prosthetics with a removable laminar denture with clasp retention (2-3 months after reconstruction of the mandibular bone defect with a vascularized autograft);

3. stage of comprehensive treatment: orthodontic treatment (if necessary, before the surgery to reconstruct the mandibular bone defect with a vascularized autograft, or 2-3 months after) to prevent dental arch deformations;

4. stage of comprehensive treatment: increasing the height (and width, if necessary) of the vascularized autograft in the position of the restored alveolar part of the mandible using free blocks from the iliac crest (or fibula, scapula) 0.5 years after mandibular bone defect reconstruction [9;23;28;33;42;76].

5. stage of comprehensive treatment: repeated preliminary prosthetics with a removable laminar denture with clasp retention 2-3 months after the surgery to increase the height (and width, if necessary) of the autograft;

6. stage of comprehensive treatment: placement of dental implants and simultaneous vestibuloplasty (so-called "vestibuloplasty") 0.5 years after increasing the height (and width, if necessary) of the autograft;

7. stage of comprehensive treatment: uncovering of dental implants, placement of gingiva formers, and adaptation of the temporary denture 4-6 months after dental implant placement;

8. stage of comprehensive treatment: definitive prosthetics 2-3 weeks after placement of gingiva formers, with preliminary prosthetics using a removable laminar denture with clasp retention 2-3 months after reconstruction of the mandibular bone defect with a vascularized autograft [23;28;76].

Comments: The goal of comprehensive surgical and orthopedic treatment of patients is functional and aesthetic rehabilitation, which can be achieved only through close cooperation between the maxillofacial surgeon, prosthodontist, and dental surgeon. Furthermore, in patients with jaw tumors, the collaborative work of these specialists should begin at the surgical planning stage, jointly agreeing not only on the extent of resection but also determining the method of prosthetic care. However, each patient requires an individual, personalized approach to dentition and maxillofacial prosthetic designs depending on the severity of aesthetic and functional impairments, as well as the size and localization of the resulting defect [7; 8; 9; 10; 12; 13; 23; 28; 29; 53; 58; 59; 60; 61; 62; 63; 76].

Comments: The purpose of prosthetic support during surgical interventions in patients with maxillary defects is primarily to isolate the oral cavity from the nasal and maxillary sinus cavities, temporarily close the resulting defects, and restore breathing, speech, and masticatory functions [5; 15].

Comments: Reconstruction using facial ectoprostheses is a unique technology that allows for the rapid correction of facial defects that in most cases are not amenable to plastic surgery. A patient with a craniofacial defect achieves social rehabilitation, an aesthetically harmonious appearance, and facial symmetry.

Comments: As a child grows, the maxillofacial skeleton enlarges, which may significantly outpace the growth of free flaps or titanium prostheses. To compensate for this, corrective surgeries must be performed, including the use of distraction devices, or staged activation should be carried out to increase the horizontal/vertical dimension of the growing endoprosthesis.

5. Prevention and Dispensary Observation

Comments: There is no specific prevention for the described pathologies.

Comments: If there is suspicion of recurrence, secondary deformity, or deterioration of the patient's local, neurological, ophthalmological, or other status, a computed tomography (CT) scan of the maxillofacial region, magnetic resonance imaging (MRI) of the soft tissues of the head, electroencephalography (EEG), and other studies are indicated based on the clinical presentation.

6. Organization of Medical Care

Indications for emergency hospitalization to a medical organization:

Indications for emergency hospitalization may arise in the event of complications.

Indications for planned hospitalization in a medical organization:

1. The need to perform instrumental diagnostic methods under anesthesia.

2. The need to perform a surgical intervention.

Indications for patient discharge:

1) in the absence of indications for further inpatient treatment (uneventful postoperative period, satisfactory fragment alignment, no progressive purulent-inflammatory diseases of the maxillofacial region of traumatic origin);

2) if the patient needs to be transferred to another medical facility;

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

4) in cases where the patient violates medical orders or internal hospital regulations, provided this does not threaten the patient's life or the health of others [7, 14, 15, 35, 46].

7. Additional Information

Negative factors affecting treatment outcomes include:

1) Development of infectious complications.

2) Non-compliance with the attending physician's recommendations.

3) Participation in contact sports for 3 months.

4) Failure to attend follow-up appointments.

It is necessary to accompany daily dressings with hygienic procedures in children with mandibular fractures to clean the oral cavity, teeth, and splints from food debris [59, 76, 78, 79]. Professional oral care consists of thoroughly cleaning splints and teeth from food debris by irrigating and rinsing the oral vestibule with antiseptic and disinfectant solutions. Rinsing is performed by spraying antiseptics and disinfectants from a syringe. After rinsing, splints are cleaned of food debris trapped between the splint, teeth, gums, ligatures, and rubber rings. During dressings, it is necessary to check the position of the splint, traction loops, and the condition of the wire ligatures. If there are pressure sores caused by the loops on the mucosa of the lips, gums, or cheeks, they must be adjusted to the appropriate position. Loose ligatures are tightened and tucked against the teeth.

Children with a mandibular fracture and their caregivers should be instructed in individual oral and dental hygiene, with the selection of appropriate hygiene products and tools to clean the oral cavity, teeth, and splints from food debris [21,59,79].

The patient should rinse the mouth with antiseptics (antiseptic and disinfectant agents), including the use of oral irrigators, not only after every meal, but also between meals and before bedtime. The patient should brush their teeth with a toothbrush and toothpaste, using interdental brushes to remove remaining food debris after brushing.

Criteria for Evaluating the Quality of Medical Care

References

Appendix A1. Working Group Composition

1. Nikolay S. Grachev, D.Sc. in Medicine, Professor, General Director of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Russian Ministry of Health, member of the Federation of Specialists in Treatment of Head and Neck Diseases.

2. Andrey V. Lopatin, D.Sc. in Medicine, Professor, Deputy General Director for Scientific and Clinical Work at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Russian Ministry of Health.

3. Nikolay M. Markov, D.Sc. in Medicine, Professor, Head of the Laboratory of Maxillofacial Rehabilitation, Dentistry and Orthodontics at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Russian Ministry of Health.

4. Igor N. Vorozhtsov, Ph.D. in Medicine, Head of the Head and Neck Surgery and Reconstructive-Plastic Surgery Group at the Scientific Department of Surgery and Anesthesiology of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Russian Ministry of Health, Head of the Department of Pediatric Oncology, Head and Neck Surgery and Neurosurgery at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Russian Ministry of Health, member of the Federation of Specialists in Treatment of Head and Neck Diseases.

5. Natalya V. Babaskina, pediatric oncologist at the Department of Pediatric Oncology, Head and Neck Surgery and Neurosurgery of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Russian Ministry of Health, junior researcher at the Head and Neck Surgery and Reconstructive-Plastic Surgery Group of the Scientific Department of Surgery and Anesthesiology of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Russian Ministry of Health, member of the Federation of Specialists in Treatment of Head and Neck Diseases.

6. Kapitolina D. Starokorova, pediatric surgeon at the Department of Pediatric Oncology, Head and Neck Surgery and Neurosurgery of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Russian Ministry of Health.

Appendix A2. Methodology for Developing Clinical Guidelines

Target audience for these clinical guidelines:

1. Pediatric surgeons

2. Maxillofacial surgeons

3. Pediatric oncologists.

4. Plastic surgeons

5. Dentists

6. Otolaryngologists

7. Healthcare organizers

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

9. Medical students, residents, postgraduate students.

Table. Scale for grading levels of evidence (LE) for diagnostic methods (diagnostic interventions)

Table 1. Scale for grading levels of evidence (LE) for prevention, treatment, and medical rehabilitation methods, including those based on natural therapeutic factors (preventive, therapeutic, and rehabilitative interventions)

Table 3. Scale for evaluating the levels of recommendation certainty (LRC) for prevention, diagnostic, treatment, and medical rehabilitation methods, including those based on natural healing factors (preventive, diagnostic, therapeutic, and 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 on 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 legal documents:

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

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 Field of 'Maxillofacial Surgery'";

3. Federal Law of the Russian Federation No. 326-FZ dated November 29, 2010, "On Compulsory Medical Insurance in the Russian Federation";

4. Order of the Russian Ministry of Health No. 203n dated April 14, 2025, "On Approval of Criteria for Assessing the Quality of Medical Care";

5. Order of the Russian Ministry of Labor No. 374n dated July 26, 2024, "On Approval of Classifications and Criteria Used in Carrying Out Medical and Social Assessment of Citizens by Federal Medical and Social Assessment Institutions";

6. Federal Law No. 178-FZ dated July 17, 1999, "On State Social Assistance".

7. Order of जहाज of the Russian Ministry of Health No. 664n dated June 24, 2021, "On Approval of the Procedure for Medical Organizations to Notify Internal Affairs Bodies in Cases Established by Paragraph 5 of Part 4 of Article 13 of the Federal Law 'On the Fundamentals of Protecting the Health of Citizens in the Russian Federation'";

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

Appendix B. Physician Action Algorithms

Initial appointment (examination, consultation) by an orthodontist

Appendix C. Patient Information

Maxillofacial defects in children can be either congenital or acquired – resulting from trauma, tumor resection, or as complications of surgical interventions. This can lead to both aesthetic disorders (such as facial asymmetry or disproportion), which complicate the child's social adaptation, and functional problems, including impairment of breathing, nutrition (chewing, swallowing), and speech. Even minor changes and defects of the maxillofacial skeleton can become much more pronounced as the child grows, so one should never delay a visit to a specialist to develop an optimal plan for correction, rehabilitation, and, if necessary, staged surgical treatment. Taking into account the child's age, the optimal reconstruction option will be selected – this can be either an individualized "growing" prosthesis for bone defects of the jaws (typically used in younger children) or microsurgical reconstruction using the child's own vascularized bone graft (usually recommended for children aged 14 and older). It should be remembered that the process of maxillofacial restoration always involves multiple stages and spans over time – at least throughout the entire period of active child growth.

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

Not applicable.