高、低角型骨性安氏Ⅲ类错颞下颌关节凹位置及形态的对比研究

A Cephalometric Study on Glenoid Fossa Position and Shape in Different Vertical Skeletal Types of Skeletal Malocclusion Class Ⅲ

目的:对比骨性安氏Ⅲ类错高、低角型颞下颌关节凹的位置及形态。方法:选取骨性安氏Ⅲ类错低角型及高角型患者,每组20例,对其许氏位片上关节凹的位置及关节凹的前斜面进行比较分析。结果:颞下颌关节凹的位置在Ⅲ类骨面型的低角型患者离前颅底最远,偏向后方,关节凹的位置最低,关节凹的前斜面较陡峭。在Ⅲ类骨面型的高角型中离前颅底最近,偏向前方,关节凹的位置最高,关节凹的前斜面较平滑。结论:颞下颌关节凹的位置及关节凹形态变化与下颌骨生长方向有关。颞下颌关节凹的位置变化为骨性安氏Ⅲ类错不同垂直骨面型的表征之一。

Objective： To analyse the position of the glenoid fossa in subjects with different sagittal and vertical skeletal features. Methods： A eephalometrie study was carried out on a sample of 40 subjects who were divided into two groups（20 subjects each ） according to skeletal vertical relationships. Cephalometrei analysis comprised both sagittal and vertical measurements for the assessment of the position of the glenoid fossa in relation to surrounding skeletal structures, as well as the shape of the glenoid fossa. Results： As for sagittal measurements , TMJ position was more posterior in low angle type of skeletal class Ⅲ in contrast with high angle type. In the vertical plane, the position of the glenoid fossa relative to cranial base was more caudal in low angle subjects when compared with subjects with high angle vertical relationships. Conclu- sion： In the aspect of variety, it＇ s more steep on the frontier wall of the glenoid fossa in low angle type. Both the podition and the shape of the glenoid fossa may be used as reference structures for the assessment in diagnosis and treatment planning of skeletal Malocclusion class Ⅲ.