Bo-Yeon Seo1, Jung-Sub An2, Min-Seok Chang1, Kyung-Hoe Huh3, Sug-Joon Ahn4. 1. Graduate student, Department of Orthodontics, School of Dentistry, Seoul National University, Seoul, Korea. 2. Clinical professor, Department of Orthodontics, Seoul National University Dental Hospital, Seoul, Korea. 3. Professor, Dental Research Institute and Department of Oral and Maxillofacial Radiology, School of Dentistry, Seoul National University, Seoul, Korea. 4. Professor, Dental Research Institute and Department of Orthodontics, School of Dentistry, Seoul National University, Seoul, Korea. Electronic address: titoo@snu.ac.kr.
Abstract
OBJECTIVES: The aim of this study was to investigate the condylar dimensions of the temporomandibular joint (TMJ) with respect to disk displacements and sex by using computed tomography (CT) and magnetic resonance imaging (MRI). STUDY DESIGN: Disk displacements were divided into 3 groups based on MRI findings: normal disk position (NR), disk displacement with reduction (DDR), and disk displacement without reduction (DDNR). After the angular and linear condylar dimensions were calculated from CT images, differences in condylar dimensions with respect to disk displacements and sex were analyzed with 2-way analysis of variance. RESULTS: Condylar depth and condylar height were significantly smaller in condyles with DDNR compared with those with NR or DDR (NR = DDR > DDNR). Condylar width gradually decreased significantly from NR to DDNR (NR > DDR > DDNR). The anterior condylar angle was significantly larger in condyles with NR compared with those with DDR or DDNR (NR > DDR = DDNR). Condyles with DDNR exhibited significantly larger horizontal condylar angles than those with NR or DDR (NR = DDR < DDNR). Altered condylar dimensions associated with disk displacement were not significantly different between men and women. CONCLUSIONS: Condylar dimensions may be significantly associated with disk displacements of the TMJ, irrespective of sex.
OBJECTIVES: The aim of this study was to investigate the condylar dimensions of the temporomandibular joint (TMJ) with respect to disk displacements and sex by using computed tomography (CT) and magnetic resonance imaging (MRI). STUDY DESIGN: Disk displacements were divided into 3 groups based on MRI findings: normal disk position (NR), disk displacement with reduction (DDR), and disk displacement without reduction (DDNR). After the angular and linear condylar dimensions were calculated from CT images, differences in condylar dimensions with respect to disk displacements and sex were analyzed with 2-way analysis of variance. RESULTS:Condylar depth and condylar height were significantly smaller in condyles with DDNR compared with those with NR or DDR (NR = DDR > DDNR). Condylar width gradually decreased significantly from NR to DDNR (NR > DDR > DDNR). The anterior condylar angle was significantly larger in condyles with NR compared with those with DDR or DDNR (NR > DDR = DDNR). Condyles with DDNR exhibited significantly larger horizontal condylar angles than those with NR or DDR (NR = DDR < DDNR). Altered condylar dimensions associated with disk displacement were not significantly different between men and women. CONCLUSIONS: Condylar dimensions may be significantly associated with disk displacements of the TMJ, irrespective of sex.