China Journal of Oral and Maxillofacial Surgery ›› 2014, Vol. 12 ›› Issue (1): 39-44.

• Clinical Articles • Previous Articles     Next Articles

Analysis of the mandibular condylar fracture type leading to temporomandibular joint ankylosis in adults

CAI Yi-hua, LU Chuan, HE Dong-mei, YANG Chi   

  1. Department of Oral Surgery, Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology. Shanghai 200011, China
  • Received:2013-06-20 Revised:2013-07-20 Online:2014-02-10 Published:2014-02-10
  • Supported by:
    Supported by Research Fund of Science and Technology Committee of Shanghai Municipality (08DZ2271100,13XD1402300), Program for Innovative Research Team of Shanghai Municipal Education Commission, Scientific Research Foundation of Ministry of Education for Returned Overseas Scholars and Research Fund of the Ministry of Health of China (201002017).

Abstract: PURPOSE:To analyze the mandibular condylar fracture type leading to temporomandibular joint ankylosis in adults. METHODS: Patients diagnosed with ankylosis caused by condylar fracture who had CT scans from injury to ankylosis in our department from 2010 to 2012 were reviewed. According to the relationship between the mandibular stump of the ramus and TMJ fossa, the condylar fractures were divided into 3 grades. Grade 0: the stump of the ramus was in the fossa without contact to it; Grade 1: the stump of the ramus was in the fossa with contact to it; Grade 2: the stump of the ramus was superolaterally displaced out of the fossa. The type of condylar fracture, the degree of fracture fragment displacement, the position of the disc and other fractures of the mandible were also analyzed for ankylosis development. RESULTS: Thirteen patients with 24 joints had completed CT scans diagnosed with TMJ ankylosis caused by condylar fracture were included in the study. The types of the condylar fracture caused to ankylosis were all intracapsular fractures with type B fracture accounting for 70%. Among the relationship between the stump of the ramus and TMJ fossa, grade 0 in 0 joint; grade 1 in 10 joints, accounting for 41.7%; grade 2 in 14 joints, accounting for 58.3%. The discs were all displaced with the fracture fragment and ruptured in the posterior band in grades 1 and 2. There were 77% of the condylar fractures had combined symphysis fracture which caused widening of the mandibular arch. CONCLUSION: The relationship between the ramus stump and TMJ fossa plays an important role in the prognosis of condylar fracture. Grade 0 is less easy to cause ankylosis; grade 1 is easy to cause ankylosis and is the relative indication for surgery; grade 2 is most likely to cause ankylosis and is the absolute indication for surgery. Other risk factors are type B intracapsular condylar fracture and combined mandibular fracture with arch widening.

Key words: Temporomandibular joint ankylosis, Mandibular condyle fracture, Fracture type