Objectives: To review the aetiology and management of progressive condylar resorption (PCR) after orthognathic surgery.

Methods: Medline search (1966- 2003), keywords "progressive ", "condylar", "resorption", "atrophy", and "orthognathic surgery". Hand searching of key journals. Bibliographies of all publications identified were scanned to identify any other relevant studies.

Results: Research into the aetiology and management of PCR is generally poor. Most publications are case reports or retrospective case series. Only one study has a retrospective case-control but there are no prospective studies. The literature does report a number of patient and surgery related risk factors but in many instances it is difficult to determine the true extent of their role due to weak research. Theories proposed to explain PCR include the effect of hormones, avascular necrosis, condylar torquing and changed biomechanics, but individually they are unable to fully account for PCR. Conservative treatment appears to be successful in almost 50% of cases. Further surgery is offered to the remainder but objective indications and timing are unclear. Following repeat surgery only half of the patients appear to have a satisfactory result.

Conclusions: 1. Females with mandibular deficiency and high mandibular plane angle planning to undergo orthognathic surgery, especially bimaxillary and mandibular advancement osteotomies, should be warned of the risks of PCR. 2. A multifactorial aetiology is most likely. 3. Initial management should be conservative. Repeat surgery is unpredictable