Mandibular fracture
| Classification according to ICD-10 | |
|---|---|
| S02 | Fracture of the skull and facial skull bones |
| S02.6 | Mandible fracture |
| ICD-10 online (WHO version 2019) | |
A lower jaw fracture (Latin: Fractura mandibulae , Fractura ossis mandibulae , mandibular fracture or fracture of the lower jaw , English mandibular fracture) is a broken bone of the lower jaw . The lower jaw fracture has typical courses of bone fracture lines that run along weak points in the lower jaw. The fracture can occur outside or inside the row of teeth. The lower jaw fractures are classified based on the anatomical structures involved.
Anatomical basics
- Main article: Mandible
The lower jaw (mandible) is a horseshoe-shaped bone (corpus mandibulae) with ascending branches of the lower jaw (ramus mandibulae) on both sides, which is composed of the muscle attachment of the musculus temporalis (processus coronoidus) and the articular process (processus condylaris) with the mandibular head (caput mandibulae). The tooth-bearing part of the lower jaw (pars alveolaris) interacts with the upper row of teeth, thereby influencing the occlusion and thus also influencing the position of the lower jaw .
The lower jaw bulge forms from the 1st pharyngeal arch in the 4th to 5th week of the embryo . The Merkel cartilage - a cartilage clasp belonging to the first pharyngeal arch - is also known as the mandibular arch and recedes completely in the dorsal area , apart from two small parts ( incus and malleus ). From the mesenchyme of the lower jaw bulge, most of the later, final lower jaw bone develops through desmal ossification. Only a small portion in the area of the fusion zone of the two cartilage braces ossifies enchondrally.
Causes of the lower jaw fracture
Lower jaw fractures often result from blunt force, which acts on the lower jaw with high energy. Typical causes for this trauma are traffic accidents (car, motorcycle, bicycle), sports accidents, physical disputes (very often punches), falls from a great height and falls . Lower jaw fractures as a result of gunshot wounds are less common in Germany . Tooth extraction, especially deep-set or firmly fused wisdom teeth, can iatrogenically cause a lower jaw fracture .
frequency
Approx. 70% of the facial fractures are mandibular fractures, although the numbers and the frequency of distribution can vary greatly depending on the source of the survey (trauma surgery clinic, dental clinic or oral and maxillofacial surgery clinic).
classification
The mandibular fracture is one of the fractures of the face and is divided into:
- Articular process fractures (25-30%)
- Mandibular angle fractures (20-25%)
- Fractures in the symphysis region (15-20%)
- Fractures of the alveolar ridge (20-30%)
- Fractures in the canine area (5–10%)
- Fractures in the area of the premolars (approx. 10%)
- Fractures in the molar area (7–9%)
- Fractures of the ascending mandibular branch (2–4%)
- Fractures in the area of the muscle attachment of the temporalis muscle (1%).
A classification based on therapeutic aspects has been established in the clinic.
Critique of the classification of the lower jaw fracture division
In today's clinical practice there is currently no classification that combines anatomical, clinical and therapeutic aspects.
| Soft tissue involvement | Fracture types | Localization of the fracture |
|
|
within the row of teeth
outside the row of teeth
|
diagnosis
Examination and clinical diagnosis
A distinction is made between clinical and radiological signs of a fracture. The detection of the lower jaw fracture when viewed purely from the outside is made more difficult by the massive swellings ( edema ) of the facial soft tissues, bruises , abrasions, extensive bleeding and bruises ( hematomas ) that occur postoperatively .
Possible symptoms of a lower jaw fracture are abnormal mobility of the lower jaw with no mouth closure, dislocation of the bone fragment, bone crunching ( crepitation ) when moving the bone fragment, hematomas , swellings , sensory disorders (especially mental nerve ), sprain pain, bleeding , occlusal disorders .
Clinically, the diagnosis is made by checking for certain and uncertain signs of fracture.
| Safe fracture signs | Unsafe fracture signs |
|
|
X-ray examination
Simple x-rays are indicated as the primary diagnostic tool. This includes orthopantomography (OPG) and an overview of the lower jaw according to Clementschitsch. In order to get a clear three-dimensional idea of the anatomy and extent of the fracture, the X-ray images of the various projections must be compared with one another.
With computed tomography (CT) the possibilities for imaging diagnosis of lower jaw fractures have improved considerably. The CT often shows the course of the fracture more precisely and helps with surgical planning. The higher radiation exposure compared to simple, conventional X-ray diagnostics must be taken into account.
Differential diagnosis
In terms of differential diagnosis , subluxations of teeth, contusions of the temporomandibular joint, dentitio difficiles, hematomas and edema in the area of the temporomandibular joint should always be considered.
Accompanying injuries
Lower jaw fractures occur in both severe and mild trauma. Therefore, the search for further damage is always mandatory. Possible obstructions of the airways can be acutely life-threatening, e.g. B. by the sinking back of the tongue base in double-sided paramedian mandibular fractures. The external auditory canal must also be inspected, as the spatial proximity of the temporomandibular joint and the external auditory canal can result in traumatic injury to the latter. One possible indicator of this is bleeding from the external ear canal.
Functional failures (= uncertain signs of fracture) can also serve as clues for the localization of the fracture - e.g. B. Sensitivity disorders in the area of the lower lip, lack of thermal vitality of the lower teeth.
therapy
The lower jaw fracture is treated by repositioning, fixation, retention and immobilization. Both conservative and surgical therapy are possible here. The surgical care is carried out by an oral surgeon, oral and maxillofacial surgeon or trauma surgeon.
The dislocated fragment is repositioned and fixed by means of mini-plate osteosynthesis ( osteosynthesis ). In the area of the temporomandibular joint head, the fragments can also be stabilized using interosseous screws. Before the advent of plate osteosynthesis, fixation was carried out using wire osteosynthesis.
Initial treatment
The accident care must first ensure the vital functions . If the airways cannot be exposed, the dislocated mandibular fragment must be repositioned as an emergency and the base of the tongue prevented from sinking again. If this is not possible, a tracheotomy or cricothyrotomy may have to be performed to secure the airway.
Lower jaw fractures are often caused by traumatic events (such as brutality offenses, traffic accidents) and can be accompanied by further, potentially life-threatening injuries. The diagnosis of the mandibular fracture is then not in the foreground during the initial phase of treatment.
surgery
Surgical treatment tries to eliminate the defects, restore the continuity of the lower jawbone and achieve an aesthetic reconstruction of the face. This involves attaching the unstable bone fragments to the stable parts of the lower jaw. An important therapy goal is the restoration of normal tooth occlusion, the chewing function and the speech function.
Since the occlusion must be checked intraoperatively, oral intubation via the mouth is not an option. Instead, nasal intubation is used or an existing tracheostoma is used for intraoperative ventilation.
Reduction
Displacement of fragments due to muscle pull, as occurs especially in fractures in the extremity area, can also be observed in mandibular fractures. The muscles that attach to the lower jaw cause a dislocation of the fragments, e.g. B. Coronoid process with the muscle attachment of the temporalis muscle. These fragment shifts due to muscle pull can make repositioning difficult. Furthermore, a fragment displacement often occurs due to the great force applied during the fracture and the fracture edges can often stand in the way of a reduction, as they can be strongly jagged and have a complicated three-dimensional course.
Technique of operative fixation
In operative care, a distinction is made between functionally stable and exercise-stable care. Osteosynthesis plates, mini osteosynthesis plates, wire suspensions and lag screws can be used for surgical treatment.
Operative access:
- for paramedian / median lower jaw fracture: oral vestibule
- for fractures in the tooth-bearing molar area: oral vestibule, submandibular
- for fractures in the area of the ascending lower jaw branch: oral vestibule, submandibular, pre-auricular / retro-auricular
- for fractures in the area of the temporomandibular joint: oral vestibule, pre-auricular / retro-auricular
The main aim is to achieve a stable splint (plate osteosynthesis) of the fragment and rigid immobilization of the fracture. An exception are fractures in the area of the temporomandibular joint, where early mobilization is sought to avoid ankylosis and the fixation of very small fragments is not always possible.
The best cosmetic results with regard to the scars are achieved by two-layer seam closure to reduce the tension on the skin and thus achieve a smaller scar. The intraoral sutures are removed after approx. 10 days, whereas the extraoral sutures are removed after approx. 5–7 days.
Maxillo-mandibular fixation
Maxillo-Mandibular Fixation (MMF) of the rows of teeth of the lower and upper jaw is used in the treatment of the lower jaw fracture. The established name of "intermaxillary fixation" (IMF) is incorrect because it is not two maxillae that are connected, but the mandible and the maxilla. Correctly, the name is increasingly changing to Maxillo-Mandibular Fixation. The fractured jaw is immobilized both preoperatively (as an immediate measure) and intraoperatively after the reduction of fragments. The fixation splints the fracture on the healthy jaw.
For the time in which the maxillo-mandibular fixation is worn (approx. 4–8 weeks), normal nutrition is possible to a limited extent. A vomiting ( emesis ) during fixation poses an increased risk of aspiration of vomit. Initially, if necessary, nutrition via a nasal feeding tube should be ensured. In an emergency, the elastic bands connecting the upper and lower jaws can be cut to open the mouth. The patients therefore always have to carry scissors with them during the fixation period.
Complications
Permanent deformities can remain as complications after mandibular fractures.
Despite proper healing "on the X-ray", pseudoarthroses, sensory disorders in the area of the lower lip and teeth - the mental nerve, lingual nerve, inferior alveolar nerve - can develop ( Vincent symptom ). Furthermore, there is a risk of infections, which are favored by extensive soft tissue defects, hematomas, open fractures and comminuted fractures.
The best prospects for good functional and aesthetic results are given with early surgical intervention.
Replacement osteotomies
In osteotomies to adjust the occlusion in the case of mandibular facial deformities, for example after fractures that have healed in malposition or mandibular growth disorders (orthognathic surgery), the lower jaw bone is divided along the external oblique line in the area of the 2nd molar and lingually above the mandibular foramen . The lower jaw nerve running there (N. alveolaris inferior) is spared and the front, drawer-shaped lower jaw fragment is moved forwards or backwards and fixed in the new position with the help of osteosynthesis plates . This surgical method practiced today is the Obwegeser operation modified from Dal-Pont.
literature
- Thomas W. Sadler: Head and Neck. In: Thomas W. Sadler (Ed.): Medical Embryology. 10th corrected edition. Thieme Verlag, 2003, ISBN 3-13-446610-4 .
- Karl Heinz Austermann: Fractures of the facial skull. In: N. Schwenzer, M. Ehrenfeld (Hrsg.): Tooth-mouth-jaw medicine. Volume 2: Special Surgery. Thieme Verlag, 2001, ISBN 3-13-593503-5 .
- Andreas Neff, Christoff Pautke, Hans-Henning Horch: Traumatology of the facial skull. In: Heinz-Henning Horch (Ed.): Oral and maxillofacial surgery . Urban & Fischer at Elsevier, 2006, ISBN 3-437-05417-1 .
Web links
Individual evidence
- ↑ Norbert Schwenzer: Tooth-Oral-Maxillofacial Medicine - Special Surgery (Volume 2), textbook for training and further education . Thieme Verlag, Munich
- ↑ PN Bochlogyros: A retrospective study of 1,521 mandibular fractures. In: J Oral Maxillofac Surg. 1985 Aug, 43 (8), pp. 597-599, PMID 3859609
- ^ F. Carinci, L. Arduin, F. Pagliaro, I. Zollino, G. Brunelli, R. Cenzi: Scoring mandibular fractures: a tool for staging diagnosis, planning treatment, and predicting prognosis. In: The Journal of Trauma . 2009 Jan, 66 (1), pp. 215-219, PMID 19131829 .
- ↑ R. Cenzi, D. Burlini, L. Arduin, I. Zollino, R. Guidi, F. Carinci: mandibular condyle fractures: evaluation of the Strasbourg Osteosynthesis Research Group classification. In: J Craniofac Surg. 2009 Jan, 20 (1), pp. 24-28, PMID 19164983 .
- ↑ CH Buitrago-Téllez, L. Audigé, B. Strong, P. Gawelin, J. Hirsch, M. Ehrenfeld, R. Ruddermann, P. Louis, C. Lindqvist, C. Kunz, P. Cornelius, K. Shumrick, RM Kellman, A. Sugar, B. Alpert, J. Prein, J. Frodel: A comprehensive classification of mandibular fractures: a preliminary agreement validation study. In: Int J Oral Maxillofac Surg. 2008 Dec, 37 (12), pp. 1080-1088. Epub 2008 Jul 30, PMID 18672348 .
- ↑ B. Spiessl: Osteosynthesis in sagittal osteotomy using the Obwegeser-Dal Pont method. In: Fortschr Kiefer face shield. 1974, 18, pp. 145-148, PMID 4534071 .
