Yang Il-Hyung, Moon Beom-Seok, Lee Seung-Pyo, Ahn Sug-Joon
Seoul National University Dental Hospital, Jongro-Gu, Seoul, Korea.
J Oral Maxillofac Surg. 2012 May;70(5):e349-60. doi: 10.1016/j.joms.2011.08.027. Epub 2011 Dec 9.
The present study was designed to analyze the skeletal differences in patients with temporomandibular joint (TMJ) disc displacement (DD), according to the sagittal jaw relationship.
We implemented a cross-sectional study design and enrolled a sample of Korean women older than age 17 years. The subjects were classified into 3 groups according to the magnetic resonance images of the bilateral TMJs: bilateral normal disc position (BN), bilateral disc displacement with reduction, and bilateral disc displacement without reduction. Each group was subdivided into 2 groups using the mandibular body length to anterior cranial base ratio as a sagittal jaw parameter: normal-size mandible (NM) and oversized mandible (OM). Seventeen variables from the lateral cephalograms were analyzed using 2-way analysis of variance to analyze the differences in skeletal characteristics with respect to the mandible size and TMJ DD status.
The subjects with TMJ DD generally had a short ramus height and clockwise rotation of the ramus and mandible compared with those with BN in both OM and NM groups. However, significant differences were present in the skeletal characteristics of the TMJ DD patients between the NM and OM groups. Significant backward positioning and rotation of the ramus and mandible were found between BN and bilateral disc displacement with reduction or bilateral disc displacement without reduction in the OM group, while those of the ramus and mandible were found between BN and bilateral disc displacement with reduction or bilateral disc displacement without reduction in the NM group.
The results of our study suggest that the skeletal characteristics associated with TMJ DD are differently represented according to the sagittal jaw relationship.
本研究旨在根据矢状位颌骨关系分析颞下颌关节（TMJ）盘移位（DD）患者的骨骼差异。
我们采用横断面研究设计，纳入了17岁以上的韩国女性样本。根据双侧颞下颌关节的磁共振图像，将受试者分为3组：双侧盘位置正常（BN）、双侧可复性盘移位和双侧不可复性盘移位。每组再根据下颌体长与前颅底比值这一矢状位颌骨参数分为2组：正常大小下颌骨（NM）和超大下颌骨（OM）。使用双向方差分析对侧位头影测量片上的17个变量进行分析，以分析下颌骨大小和颞下颌关节盘移位状态在骨骼特征方面的差异。
在OM组和NM组中，与BN组相比，TMJ DD患者的下颌支高度通常较短，下颌支和下颌骨呈顺时针旋转。然而，NM组和OM组中TMJ DD患者的骨骼特征存在显著差异。在OM组中，BN组与双侧可复性盘移位或双侧不可复性盘移位之间发现下颌支和下颌骨有明显的向后定位和旋转，而在NM组中，BN组与双侧可复性盘移位或双侧不可复性盘移位之间发现下颌支和下颌骨有明显的向后定位和旋转。
我们的研究结果表明，与TMJ DD相关的骨骼特征根据矢状位颌骨关系有不同表现。
