Fractures of the lower jaw account for about 70% of all fractures of the bones of the face. Fractures in the area of the body of the lower jaw, including the central and lateral parts, the region of the angle, are observed in almost 80% of patients. Fractures of the jaw branch are divided into fractures of the branch itself, coronoid and condylar process. Distinguish single, double (one-sided and bilateral), triple and multiple fractures of the lower jaw, without displacement and with displacement of fragments, linear, comminuted , with the presence or absence of teeth in the fracture line. When formulating the diagnosis, the anatomical localization of the fracture line must be accurately indicated (for fractures in the area of the jaw body – tooth formulas). The nature of the fracture, displacement of fragments depends on the size and direction of the traumatic force, the action of traction attached to the jaw of the masticatory muscles. Fractures in the dentition are usually open. Most often, fracture lines pass at the sites of least resistance of the lower jaw bone (“line of weakness”): the condylar process neck , jaw angle, 8 hole of the tooth, canine area, area of the chin opening , middle line.
The clinical picture. Sharp pain while chewing and talking. Spilled swelling of the soft tissues in the fracture area. The mouth is half-open, saliva is stained with blood (with fractures within the dentition with damage to the mucous membrane). Violation of the bite (graduation of the dentition). The magnitude and degree of displacement are determined in centimeters, millimeters, or the height of the tooth crown. With toothless jaws, the state of the bite is determined by the position of the frenum of the upper and lower lips. When the neurovascular bundle of the lower jaw is damaged, the sensitivity in the area of innervation of the chin nerve is impaired. Palpation of the lower jaw during a fracture of her body determines the pathological mobility of the fragments and local tenderness, which are particularly clearly defined during bimanual examination. With a fracture of the condylar process, soreness is determined in front of the tragus . The emptiness of the articular cavity when a finger is inserted into the external auditory meatus indicates a dislocation or fracture of the head of the lower jaw. A correct diagnosis is helped by an X-ray examination. So, a direct anterior panoramic radiograph of the skull gives an idea of the nature of the lesions of different localization. Side images of the body and branches of the lower jaw detail fractures in the area of premolars , molars, angle and branches. In case of fractures of the condylar processes, tomograms of both temporomandibular joints must be produced in lateral projection at a depth of 2 cm from the table surface.
X-ray fracture of the lower jaw is characterized by the presence of a line of enlightenment, which is a reflection of the plane of the fracture, which is linear in nature. The fragments are often small, not always formed. In the area of application of force, usually comminuted damage occurs with a complex pattern of the line of enlightenment. Their localization is uncharacteristic. Fragment displacement occurs not only due to muscle traction, but also under the influence of direct traumatic force. It is necessary to take into account the relationship of teeth with a fracture line, the state of periapical tissues of teeth located near the lesion zone, and periodontal bones throughout the dentition. Among single fractures of the lower jaw, injuries in the area of the angle predominate. The fracture plane is located at an angle to the middle sagittal plane of the skull, the outer and inner cortical plates are damaged at different levels, which sometimes creates a false picture of comminuted damage on radiographs . Vertical displacements prevail in the central and lateral parts of the body of the lower jaw. In case of angle fractures, the displacement is small, usually the upper fragment is pulled cranially and rotates inward. With indirect fractures in the branch area, the displacement of the upper fragment always passes cranially and outwards. A large fragment moves toward the fracture back and up. The oblique and cosvertical course of the line of enlightenment indicates damage to the branches of the lower jaw. In these cases, the fragments are shifted relative to each other in width. With a fracture of both branches, the body of the lower jaw often turns around the transverse axis. In this case, the central teeth may occupy a ventral position. Fractures of the condylar process are divided into fractures without displacement of fragments, intraarticular and extra-articular, fractures of the neck of the condylar process with displacement of fragments of a rotational nature when the upper fragment rotates inwards , and luxurious , in which the entire upper fragment leaves the articular cavity and is located almost transversely. According to x-ray data, an intra-articular fracture can be said with confidence only in fractures of the head of the lower jaw. Treatment. First aid to the victim is to prevent bleeding or to combat it, as well as asphyxia, shock, and the administration of tetanus toxoid (3000 ME).
Transport (temporary) immobilization requires the use of dressings that fix the lower jaw to the upper or to the cranial vault: gauze round and sling-like ; elastic on Urban ; rigid standard chin slings; standard transport, consisting of a chin sling and a soft head cap; gypsum sling . If you have separate teeth, you can apply ligature dressings made of bronze-aluminum wire with a diameter of 0.4-0.5 mm, silk or nylon thread, polyamide or nylon core. The basic rules for applying: the bandage should cover two teeth standing next to each other (it is not applied to teeth standing on the fracture line), it is applied on both sides of the fracture line, as well as on the corresponding teeth-antagonists of the upper jaw; the ligature is twisted along the midline of the tooth crown clockwise, without injuring the gum. Ligatures made of wire should be applied for 2-3 days, for a longer period they can be left according to special indications. Ligature continuous bonding with polyamide yarn according to Baronov can be used as a method of permanent immobilization. The reduction of fragments should be carried out only under local anesthesia (guiding, infiltration) at the site of attachment of the masticatory muscles; general anesthesia – according to indications. Therapeutic immobilization. There are conservative (orthopedic) and operational methods of immobilizing fragments of the lower jaw. When conservative methods use tires of laboratory and laboratory production. The latter include various complex prostheses, Vsber , Vankevich , Yadrova and other tires , devices, devices used for complex, chronic fractures, most often with a jaw bone defect. In 75% of patients, various types of intraoral tires are used to treat fractures of the lower jaw , which are divided into fixing, reponing and mixed. The most common intraoral tires are all kinds of bent tooth wire tires. The fixing tires include: smooth tire-bracket, used for fractures without displacement; a tire with a spacer in the absence of teeth in the fracture line; Rarog splint for fixing toothless fragments in case of a defect in the central part of the lower jaw; Michelson’s Z-scan tire for defects in the teeth or alveolar bone of the lower and upper jaw (it is better to make it from steel wire). Resonating tires: bent tooth tires with hook loops made of aluminum wire; intermaxillary fixation with polyamide thread; standard tooth band spikes with Vasiliev hook hooks; plastic tires in various modifications. The most common are tooth bent aluminum Tigerstedt tires , which are made individually for each patient. For splinting the patient necessary: tools for applying tires, aluminum wire with a diameter of 2 mm, a length of 20-25 cm to 8 g; bronze-aluminum wire with a diameter of 0.4-0.5 mm, length up to 10 cm to 9 g; rubber elastic tube for rubber rings. In the presence of teeth, the application of bent tooth wire rails is not difficult. The splint is bent in the shape of a dental arch and fixed to all teeth with bronze-aluminum wire. Tire making should begin with the bend of the ring, hook or stud on the last teeth. They must be well fitted to the teeth and fixed. In the presence of a bone defect or absence of teeth, a spacer loop is bent in magnitude of the defect. Hook loops on the tire, if necessary, maxillary traction is made as follows. First, make a hook or tenon at the end of the wire and hold the latter in a horizontal plane with your left hand. Crampon forceps hold it, and with the fingers of the right hand make a bend at the very cheeks of the forceps at a right angle to the horizontal. Without changing the horizontal position of the wire, mix the tongs to the very corner of the bent wire and make a 180 ° bend with your right hand. Then both ends of the wire are straightened in one plane, clamping the tongs at the base of the long end of the wire and straightening the wire with your right hand. The last moment is compression of a curved loop. The manufactured tire is checked in the patient’s mouth and fixed to the teeth with bronze-aluminum wire. The tire should not injure the mucous membrane of the lips and cheeks, gums. After fastening the tire on the loop for intermaxillary traction, rubber rings are put on, the diameter of which should be 2 times less than the distance between the base of the loops that they bind. The direction of traction is determined by the degree and nature of the displacement of the fragments. Surgical treatment methods. Indications: insufficient or complete absence of teeth; tooth mobility (with periodontal disease); fractures outside the dentition (angle, branch, condylar process); large displacement of fragments with interposition of soft tissues; jaw bone defects; multiple fractures; combined lesions. The following methods of osteosynthesis according to Dunaevsky et al .
Methods of direct osteosynthesis:
1. Intraosseous – pins, rods, spokes, screws.
2. Bone – glue, circular ligatures, coupling halves and grooves.
3. Intraosseous- bony – bone suture with various materials, including titanium nitride wire with shape memory; osseous plates on the screws; bone seam with bone knitting needles; intraosseous- bony tires (T-beam); chemical osteosynthesis using quick-hardening plastics; mechanical osteosynthesis with U-shaped staples using bone- suturing apparatus.
Methods of indirect osteosynthesis:
1. Intraosseous- Kirschner spokes , pin extraoral devices without compression and with a compression device.
2. Bone – the hanging of the lower jaw to the upper, circular ligatures with supragingival splints and prostheses, extraoral terminal devices (clamps), extraoral terminal devices with a compression device ( Rudko , Zbarga , Ermolaev – Kulagova ).
Fractures in children are often without displacement according to the type of “green branch” in the region of the central, lateral departments, condylar process. Apply mouthguards made of quick-hardening plastic, sling-like dressings of various modifications, according to indications of orthodontic appliances. During the period of milk and shift bite, the use of metal tires is not recommended. If necessary, their imposition is better to use steel wire. Extraoral fixation and surgical methods are rarely used in children because of the risk of damage to the dental follicles. Complications of the condylar process fractures : microgenia , secondary malformation of the bite.
General methods of treatment. Before carrying out permanent immobilization, the question of the fate of the tooth in the fracture line should be resolved, and surgical readjustment of the oral cavity was performed. Intact teeth should be observed using electroodontodiagnosis . The teeth are removed in the presence of periapical inflammatory foci, pronounced inflammatory phenomena in the periodontium, ruptures of the mucous membrane and gum tissue, as well as dislocated, mobile, fragmented, interfering with the reduction of fragments when the tooth is wedged into them. Depending on the severity of the injury, the nature and location of the fracture, patients are prescribed anti-inflammatory (antibiotics), hyposensitizing , stimulating, general strengthening therapy (vitamins, balanced nutrition). Special oral care is needed. The use of hyperbaric oxygenation , physiotherapy exercises, physiotherapy, and functional methods of patient management is important . Among the physical factors, the UHF electric field and magnetotherapy are widely used . The exposure to the UHF electric field is prescribed on the 2nd – 3rd day after fixation of the fragments of the lower jaw with tooth sutures and on the 3rd – 3rd day after osteosynthesis with wire in the treatment of fractures of the bones of the lower jaw. Magnetotherapy is carried out on the 4th-5th day after osteosynthesis or splinting . The magnetic field induction in the first two procedures is 9-10 mT , in the next 12-19 mT . A sinusoidal current is applied continuously. The first two procedures are carried out for 10 minutes, the next 15 minutes. In bilateral fractures, exposure is performed using two direct-core inductors, which are located on both sides of the face. The number of procedures depends on the clinical picture (on average 5-10 procedures). Starting from the 2-3rd procedure, a marked decrease in tissue edema and tenderness in the fracture area is noted. The presence of metal inclusions is not a contraindication to the appointment of magnetotherapy in the indicated dosages. To improve the consolidation of fragments on the 12-14th day after immobilization, calcium electrophoresis is performed on the affected half of the face. For this purpose, a 2-5% solution of calcium chloride is used. An active electrode with calcium chloride (anode) is applied to the skin of the face at the site of the projection of the former fracture, and a second electrode (cathode) is placed on the forearm of the right or left hand. The duration of the procedure is 20 min, the current strength is 3-5 mA. The course of treatment consists of 12 treatments every other day.
Prevention of complications (traumatic osteomyelitis): early tooth extraction from the fracture line according to indications, suturing of the socket tightly after removal; timely and rational immobilization; general therapy.