Mandibular condyle fractures: a consensus

British Journal of Oral and Maxillofacial Surgery (1999) 37, 87–89
© 1999 The British Association of Oral and Maxillofacial Surgeons

SUMMARY. A consensus was obtained following a two-day international conference to review the management of mandibular condyle fractures. Whilst areas of disagreement still exist, there are many areas of agreement. It is hoped this editorial will stimulate debate leading to internationally accepted guidelines.

At Groningen in the Netherlands an international conference was held to examine the management of condylar fractures of the mandible. The controversycentred on the question: ‘Is there evidence to decide“if ”, “when”, and “how” treatment for fractures involving the mandibular condyle should be carried out?’ It is hoped this consensus will stimulate a debate and lead to internationally accepted guidelines. Some guidelines seem to be regrettably based on studies which are less than perfect, being based on very low percentage of follow-ups.

Presentations were made by:

Prof.dr L.G.M. de Bont Controversies of management
Dr G. Groen 3-D anatomy
Prof.dr J.M.H. Dibbets Growth disturbances after fracture
Dr H. Israel Role of mobility in temporomandibular joint function
Dr R.R.M. Bos Closed treatment of fractures
Dr E. Ellis Biological considerations
Dr dr M. Rasse The intra-oral approach
Prof.dr dr U. Eckelt Lag screw fixation
Prof.dr dr C. Krenkel Lag screw fixation
Prof.dr dr J. Reuther Lag screw fixation
Dr E. Ellis Retromandibular approach
Dr dr M. Rasse Intracapsular fracture fixation
Dr dr G. Lauer Endoscopic fixation
Dr P.U. Dijkstra Physical therapy
Prof.dr D.B. Tuinzing Secondary corrections Consensus Panel (Dr dr R.P. Ward Booth, Prof.Dr
K. Moos, Prof.dr dr C. Lindqvist)

The presentations, where appropriate, reported outcomes and in some cases comparisons between different types of treatment. A review of the literature was undertaken.

After the presentations, the Consensus Panel, with comments from the speakers, produced the following report:

• There is a need for more scientific data to determine the advantages and disadvantages of
  open reduction versus closed treatment. It is, however, recognized that ethically prospective randomized trials may not be possible.
• Certain definitions are helpful:

Closed treatment: Defined as any treatment that does not involve an open surgical exposure of the fracture.
Expressions like ‘conservative’ or ‘closed reduction’ are often inaccurate.
Open reduction: This means open reduction and fixation, although some surgeons do not always fix after open reduction.
Displacement: This is an indication of the separation between the fragments, and may be less confusing if measured in degrees of angulation.
Dislocation: Defined as when part of the condyle is displaced outside the fossa.

Other points of agreement were:

• Some reports of closed treatment show poor results.
• Some reports of open treatment show good results.
• A simple classification of ‘intracapsular’, ‘neck’ and ‘subcondylar’ seems adequate.
• Traditional predictors of good results from closed treatment in fact are unreliable: X-ray findings or plain films may miss fractures extending into the capsule, and sagittal fractures. There is not necessarily a relationshipbetween the severity of the displacement and the outcome of closed treatment.
• Fractures in growing children are predictably successfully treated ‘closed’. There is, however, no evidence that open reduction has a poor outcome, although there are few studies on this area.
  
• There seems good evidence that displaced bilateral fractures would benefit from at least one side being treated open. Such treatment may, however, increase the displacement of the other side. It has been noted that some displaced bilateral fractures can be successfully treated closed, but predicting these cases is unreliable.
  
• There seems to be some benefit in open treatment of condyle fractures if there are associated comminuted maxillary fractures so that the vertical height of the face can be established.
  
• There is evidence that, in experienced hands, the open approach has a low morbidity (less than 1%) of nerve damage as the result of the surgery. Transient facial nerve branch weakness occurs in about 10% of cases.
  
• The socioeconomic costs of open treatment must be appreciated. On one hand, open treatment involves hospitalization, operating time (about 2 h), and more experienced surgical teams. On he other hand, immediate function should be expected and perhaps could be associated with quicker return to normal activities.
  
• Reports of avascular necrosis after open reduction are of concern. It seems likely that this follows wide stripping of the proximal fragment, or applies in those cases where the fragment is removed and returned as a free graft.
  
• There is little scientific evidence that a period of rigid IMF (MMF) has any benefit, and it may adversely affect future joint function. Oedema and muscular spasm are important causes of malocclusion and time for these to resolve may be helpful. If malocclusion is to be treated by closed treatment, functional treatment with intermaxillary guiding elastics to control the occlusion seems preferable to rigid IMF (MMF).
  
• There is no evidence that posterior bite blocks to restore the vertical height are helpful.
  Consultation with an orthodontist may, however, be very helpful if there are occlusal problems.
  
• There is an inadequate evidence to recommend a single surgical approach. Those commonly used, often in combinations, are: preauricular; postmandibular; and a variation on a submandibular approach. The choice may be guided by the fixator used. The intra-oral approach has very limited use, only for very minimally displaced low fractures.
  
• There is inadequate evidence to recommend a single type of fixator. Those which have been used are: lag screws, plates (these must be strong mandibular plates, or two plates), and external fixators. The selection will probably be made on the basis of operator’s experience with any given system.
  
• Open reduction and internal fixation of intracapsular fractures is still experimental.
  
• Closed treatment will normally consist of (if possible) a delay while swelling and spasm settle, followed by IMF (MMF) with elastic guidance, not rigid, for 1–6 weeks.
  
• The Strasbourg Osteosynthesis Research Group recommendations for removal of hardware em sensible. They state that all non-functional material should be removed unless there is significant morbidity from removal, e.g. where a second general anaesthetic is needed or where there will be a risk of surgical trauma or nerve damage.
  
• In the absence of clear preoperative indicators to identify which fractures will have a poor outcome with closed treatment, a protocol is suggested:

1. If surgery can be delayed, function, especially occlusion, should be assessed at about 5 days. If there is poor function, then treatment should be considered.
   
2. If surgery cannot be delayed and there are indications which are absolute or relative, e.g. displaced bilateral fractures or severe unilateral displacement, then an open reduction and fixation should be considered. A minimal or undisplaced fracture would be a very low indication for open treatment, if observation over a few days is not possible.
   
3. If the medical condition is unsuitable for open reduction, e.g. unfit for a general anaesthesic, or immunocompromised, closed treatment should be considered.
   
4. Open reduction and fixation should only be used by those surgeons who feel ‘comfortable’ with and have experience of the techniquues.

The measurable definitions of ‘successful’ outcome are poorly defined. This is partly due to a lack of information on pre-injury status.Whether a successful outcome should be the same as pre-traumatic function is questionable. The following criteria are suggested but are not exclusive.

• return to the pre injury occlusion;
• normal jaw opening (about 40 mm)
• pain-free joint, or no worse than pre-injury;
• absolutely minimal morbidity of surgery, e.g. no damage to the branches of the facial nerve, good hidden scars, no anaesthetic complications.

As a scientifically justified randomized comparative clinical study between closed treatment and any other kind of open reduction and internal fixation does not seem to be ethical, a prospective multi-centre condylar fracture audit seems to be desirable.

Suggestions for further reading

Becking AG, Tuinzing DB. Correction of post-traumatic malocclusion by orthognathic surgery. J Cranio Maxillofac Surg 1992;20(1):65.

Dibbets JMH, Enlow DH. Facial Growth, 3rd edn. Philadelphia: WB Saunders, 1990:149–163.

Eckelt U. Zugschraubenosteosynthese bei Unterkiefergelenkfortsatzfrakturen. Dtsch Z Mund Kiefer Gesichtschir 1991; 15(1):51–57.

Ellis E, Carlson DS. The effects of mandibular immobilization on the masticatory system. Clin last Surg 1989;16(1):133–146.

Ellis E, Dean J. Rigid fixation of mandibular condyle fractures. Oral Surg Oral Med Oral Pathol 1993;76:6–15.

Hall MB. Condylar fractures: surgical management. J Oral Maxillofac Surg 1994;52:1189–1192.
Haywood JR, Scott RF. Fractures of the mandibular condyle. J Oral Maxillofac Surg 993;51:57–61.

Krenkel C. Treatment of mandibular condyle fractures. Atlas of the Oral and Maxillofacial Surgery Clinics of North America 1997;5(1):127–155.

Rasse M, Berk H, Futter M. Ergebnisse nach konservativer und operativer Versorgung von Gelenkfortsatzfrakturen des Unterkiefers. Z für Stomatologie 1990;87/5:215–225.

Rasse M. Diakapituläre Frakturen der Mandibula: Eine neue Operationsmethode und erste Ergebnisse. Z für Stomatologie 1993;90/8:413–428.

Thiele RB, Marcoot RM. Functional therapy for fractures of the condyloid process in adults. J Oral Maxillofac Surg 1985;43:226–228.

Walker RV. Condylar fractures: nonsurgical management. J Oral Maxillofac Surg 1994;52:1185–1188.

Ziccardi VB, Schneider RE, Kummer FJ. Wurzburg lag screw plate versus four-hole miniplate for the treatment of condylar process fractures. J Oral Maxillofac Surg 1993;55:602–607.

Temporomandibular bone and posterior cranial fossa. CD-ROM & CD-i. Editor: B. Hillen, Elsevier Science, Amsterdam, 1994.

Rudolf R.M. Bos DDS PhD, Associate Professor, Department of Oral and Maxillofacial Surgery University Hospital, Groningen

R. Peter Ward Booth FDS FRCS, Consultant, Regional Maxillofacial Unit, The Queen Victoria Hospital NHS Trust, East Grinstead, UK

Lambert G. M. de Bont DDS PhD, Professor and Chairman, Department of Oral and Maxillofacial Surgery, University Hospital Groningen, Groningen, The Netherlands