Briefly explore the relationship between sagittal fracture types of mandibular condyle and displacement of temporomandibular joint disc

Abstract

Objective To analyze the relationship between fracture types and disk displacement in the cases of sagittal fracture of mandibular condyle (SFMC) . Methods A total of 74 cases (74 sides) of type A, B, and C of SFMC were diagnosed by CT examination and had magnetic resonance imaging (MRI) checked to confirm the position of temporomandibular joint (TMJ) discs. The correlation between fracture types and disk displacement was evaluated by chi-square test. Results Among 74 cases of SFMC (type A, B, C) , 26 cases (57.69%) of anterior disc displacement without reduction was more common in type A fracture, while 24 cases (62.50%) of anterior disc displacement with reduction was more frequently seen in type B fracture. And 24 cases (50%) of normal condyle-disc position, it was more common in type C fracture. Statistical difference was found between fracture type and condyle-disc positions (χ2= 29.555, P= 0.000) by chi-square test (P<0.05) . Conclusions In cases of FSMC, the discs are likely to displace. And different displacements are closely related to certain types of displacement. Anterior displacement is the most frequent displacement. With the increase of injury degree, the anterior disc displacement without reduction is more likely to occur. Key words: Mandibular condyle; Sagittal fractures; Temporomandibular joint disk; Displacement