Features of the wound healing process on the face
The anatomical specifics of the maxillofacial zone ensure accelerated regeneration, but also cause a vigorous development of local reactions.
The chronology of healing is as follows:
- Tissue edema: starts in 11–16 hours, reaching a maximum by 48–72 hours.
- Demarcation: by the 5th–6th day, a clear macroscopic boundary forms between necrotic and viable tissue.
- Suppuration: infiltration and purulent inflammation actively develop from days 3 to 12. Purulent wound cleansing usually completes in 2–3 weeks.
- Scarring: the scarring period ends by the 30th day, but the final maturation and softening of the scar takes from 6 to 12 months.
Wounds in the lateral parts of the face and the submandibular region heal the most difficultly. The patient's general condition (blood loss, dehydration, swallowing disorders) acts as the leading factor determining the speed of recovery. Despite the severity of injuries, full recovery in facial fractures reaches 85%.
Pathogenesis of bone damage and sequestrum formation
In severe jaw fractures, microcirculation in the fragments is sharply disrupted, leading to the death of a bone area. The resorption process of necrotic tissue is triggered by osteoclasts.
The mechanism of this process is associated with parathyroid hormone: osteoblasts, which have receptors for parathyroid hormone, release osteoclast-activating factor. In addition, osteoblasts can deform (shrink), granting osteoclasts access to the mineralized matrix.
If the necrosis is extensive and resorption is delayed, osteoclasts massively accumulate at the demarcation line. They begin to destroy the bordering living bone, building a peculiar "trench." As a result, the dead section of the bone completely separates from the healthy mass—a sequestrum forms. In linear fractures, the situation is more favorable: by the end of the second week, capillaries from the fragments merge, fastening together with bone trabeculae.
Gunshot fractures of the maxilla
Maxillary fractures account for about a quarter of all facial fractures. In 36% of cases, the alveolar process and teeth are affected. Due to close anatomical connection with the cranial bones, reflected fractures (along bone sutures) and cranial nerve damage frequently occur.
- Through-and-through wounds: are usually caused by bullets. Their severity depends on the deviation of the wound channel. For example, damage to the piriform aperture (apertura piriformis) always results in an extensive defect. Destroyed small bone fragments and teeth act as secondary missiles, flying out of the wound and making the exit wound significantly larger than the entrance wound.
- Penetrating wounds: are usually of shrapnel origin. The projectiles penetrate deep into the tissues, often getting stuck in the infratemporal fossa (fossa infratemporalis), orbit, or pterygopalatine fossa.
Destruction of the upper wall of the maxillary sinus (sinus maxillaris) is almost always accompanied by trauma to the eyeballs, and comminuted fractures of the infraorbital region are often combined with concussion of the brain and the risk of meningitis.
Specifics of severe wound infection
The clinical picture of an infected gunshot wound depends on the type of pathogen:
- Anaerobic (gas) infection: edema significantly exceeds that of pyogenic infection. The skin is shiny from tension, and brown spots with epidermal detachment appear. Disintegrating dirty-gray tissues and gas bubbles are detected in the subcutaneous tissue.
- Putrefactive infection: occurs with penetrating wounds and lack of oral cavity hygiene. Pain is mild, edema is insignificant, but the lesion spreads totally. The wound is dry, covered with a dirty-gray coating with an ichorous (foul) odor. Severe intoxication develops (delirium, anuria), and the risk of aspiration pneumonia is high. Without proper treatment, a fatal outcome is likely on days 8–10 due to putrid gangrene of the lungs or arrosion hemorrhage.
Algorithm for primary surgical debridement (PSD)
Successful treatment directly depends on timely and correct PSD, which is performed in a strict sequence:
- Revision of the bone wound: foreign bodies, tooth roots, and secondary missiles are removed. The bone edges are nibbled with a bur or rongeurs until capillary bleeding appears. If the maxillary sinus is damaged, an anastomosis with the inferior nasal meatus is formed.
- Soft tissue management: excision of non-viable areas down to viable bleeding tissues.
- Immobilization: reliable fixation of bone fragments.
- Suturing: wounds of the oral vestibule and cavity are sutured tightly, after which sutures are applied to the external facial tissues.
In wounds of the hard palate, the main goal of the surgeon is to separate the oral and nasal cavities. This is achieved by local tissue plastics, and if it is impossible to close the defect in one stage, by manufacturing a special protective separating plate.
Briefly: answers to topical questions
What osteosynthesis methods are used for fragment immobilization in jaw fractures?
To immobilize fragments in jaw fractures, open, closed, focal, and extrafocal osteosynthesis, as well as their combinations, are used. The following methods of surgical fixation are distinguished:
- Bone suture — fixation is carried out by passing a wire ligature through bur holes on both sides of the fracture line.
- Metal mini-plates — are applied over the cortical layer across the fracture line and secured in the bone with screws.
- Osteosynthesis using a Kirschner wire — the wire is passed from one fragment into another to a depth of at least 3 cm.
- Use of staples — metal staples with predetermined properties (shape-memory materials) are used.
For stronger fixation of the mandible, a combination of a bone suture and a wire can be used.
Class and exam questions
What is the difference between entrance and exit wounds in through-and-through wounds of the piriform aperture?
The exit wound is always significantly larger than the entrance wound due to the formation of secondary missiles (bone and tooth fragments) that burst out of the wound and destroy the mass of soft tissues.
Why do vision and hearing often suffer in maxillary injuries?
The maxilla is rigidly connected to the bones of the neurocranium. Trauma is often accompanied by the destruction of orbital walls, as well as damage to cranial nerves (e.g., vestibulocochlear), leading to hearing loss.
How is a combined injury of the maxilla and nose treated?
PSD of the jaw and nose is performed, nasal bone fragments are repositioned, placing the mucosa on them. To retain tissues and prevent scar deformities, a rubber tube wrapped in iodoform gauze is inserted into the inferior nasal meatus.
What are the main causes of death of the wounded on the battlefield in facial trauma?
The most frequent causes of death in the first hours are traumatic shock, profuse bleeding, and asphyxia.
What else to study on this topic
- Mine-blast penetrating shrapnel wounds: combined burns and eye injuries
- Mechanism of cartilage tissue replacement by bone tissue under hypoxic conditions
- Classification of gunshot maxillary fractures based on Great Patriotic War experience
- Neurological complications: paresis of facial muscles and vagus nerve damage
- Principles of forming protective separating plates for the hard palate
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Other topics in the section "Chapter 11. Non-ballistic and ballistic facial injuries. Thermal and radiation lesions of the maxillofacial region (V.V. Afanasyev)"
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