Temporomandibular Joint Morphology and Disc Position in Mandibular Prognathism Patients With and Without Asymmetry

Sotobori, Megumi

Temporomandibular Joint Morphology and Disc Position in Mandibular Prognathism Patients With and Without Asymmetry

Megumi Sotobori DDS, Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering,University of Yamanashi, Chuo-city Yamanashi, Japan

Koichiro Ueki DDS, PhD, Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering,University of Yamanashi, Chuo-city Yamanashi, Japan

Kohei Marukawa DDS, PhD, Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering,University of Yamanashi, Chuo-city Yamanashi, Japan

Masatoshi Higuchi DDS, Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering,University of Yamanashi, Chuo-city Yamanashi, Japan

Ryuichi Nakazawa , Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering,University of Yamanashi, Chuo-city Yamanashi, Japan

Akinori Moroi DDS, PhD, Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering,University of Yamanashi, Chuo-city Yamanashi, Japan

Yuri Ishihara DDS, Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering,University of Yamanashi, Chuo-city Yamanashi, Japan

Hiroumi Ikawa DDS, Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering,University of Yamanashi, Chuo-city Yamanashi, Japan

Ran Iguchi DDS, Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering,University of Yamanashi, Chuo-city Yamanashi, Japan

Akihiko Kosaka DDS, Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering,University of Yamanashi, Chuo-city Yamanashi, Japan

Purpose; The purpose of this study was to investigate the relationship between temporomandibular joint (TMJ) morphology, including the angle of articular eminence and discal tissue in patients with or without asymmetry.

Material and methods; The subjects consisted of 66 Japanese patients diagnosed with mandibular prognathism with and without asymmetry. They were examined with lateral, frontal and axial cephalograms and divided into 2 groups (33 symmetric patients and 33 asymmetric patients). By using magnetic resonance imaging (MRI) the 132 joints could be classified into four types on the basis of disc position and shape: anteriorly 1:displacement type, 2:anterior type, 3:fully-covered type and 4:posterior type. Furthermore, the angle of articular eminence that is the angle between the line connecting the lowest point of the articular eminence (point A) and the squamotympanic fissure and a line connecting the pointA and highest point of the glenoid fossa of the 132 TMJ joints was measured.

Results: Disc displacement was observed in15 /66 (22.7%) of the asymmetry group and 17/66 (25.8%) of the symmetry group. Of deviation side in the asymmetry group was 10/33 (30.3%) and non-deviation side was 5/33(15.2%). In the angle of articular eminence, there was significant difference between deviation side and non-deviation side of asymmetry group (p=0.0064), and between symmetry group and asymmetry group of non-deviation side (p=0.0068). Further, it was tend to larger in anterior type and smaller in posterior type.

Conclusion: These results suggest the angle of articular eminence was related to disc position and symmetry or asymmetry in mandibular prognathism.

References: Ueki K1, Moroi A, Sotobori M, Ishihara Y, Marukawa K, Yoshizawa K, Kato K, Kawashiri S.: Changes in temporomandibular joint and ramus after sagittal split ramus osteotomy in mandibular prognathism patients with and without asymmetry.

J Craniomaxillofac Surg. 2012 Dec;40(8):821-7. doi: 10.1016/j.jcms.2012.03.003. Epub 2012 Apr 14.

Ueki K1, Marukawa K, Nakagawa K, Yamamoto E.: Condylar and temporomandibular joint disc positions after mandibular osteotomy for prognathism. J Oral Maxillofac Surg. 2002 Dec;60(12):1424-32; discussion 1432-4.