Bifid mandibular condyle with associated temporomandibular joint ankylosis: a computed tomography study of the patterns and morphological variations.
OBJECTIVE
Bifid mandibular condyle (BMC) with associated temporomandibular joint ankylosis (TMJA) is extremely rare with only four cases reported. We present the first case series of BMC with TMJA in an attempt to elucidate the morphological pattern in this rare condition.


METHODS
Retrospective examination of CTs over a period of 6 years revealed 37 patients with TMJA, of whom 10 had BMC. Clinical and CT features of these were analysed. Patients were grouped according to sides of involvement and orientation of condyles.


RESULTS
The male:female ratio was 1:1. Nine were post-traumatic and one post-infectious. The aetiology was sustained in childhood in all patients. Six patients had unilateral BMCs and four had bilateral. One patient had bilateral BMCs with bilateral TMJA. This was anteroposterior (AP) in orientation. Three patients had bilateral BMCs with unilateral TMJA, among which one was AP and two mediolateral (ML). Six patients had unilateral BMC with ipsilateral TMJA; all of the ML anterior condylar process was ankylosed in joints with AP BMC and TMJA. Lateral condylar process was ankylosed in post-traumatic ML BMC with TMJA, while the medial condylar process ankylosed in the post-infectious patient. In general, ankylosed heads were found to be larger, sclerotic and often mushroom shaped compared with non-ankylosed heads.


CONCLUSIONS
This series attempts to elucidate patterns of ankylosis and CT morphology in BMC with associated TMJA. Also included are hitherto unreported cases such as bilateral AP BMC with TMJA and post-infectious BMC with TMJA.
Department of Radiology, Christian Medical College, Vellore, India. taj_ar@yahoo.com
T A
TA
Rehman
S
S
Gibikote
N
N
Ilango
J
J
Thaj
R
R
Sarawagi
A
A
Gupta
D000293:Adolescent; D000328:Adult; D000844:Ankylosis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008335:Mandibular Condyle / Q000002:abnormalities*; D012189:Retrospective Studies; D013704:Temporomandibular Joint; D014057:Tomography, X-Ray Computed; D055815:Young Adult