Wang Mei-Qing, He Jian-Jun, Li Gang, Widmalm Sven E
Department of Oral Anatomy and Physiology, Stomatological College, Fourth Military Medical University, Xian, China.
J Prosthet Dent. 2008 Feb;99(2):148-52. doi: 10.1016/S0022-3913(08)60031-1.
The temporomandibular joint (TMJ) disc is often observed to be thicker in temporomandibular disorder (TMD) patients. This clinical observation requires verification.
The purpose of this pilot study was to investigate whether the TMJ disc responds to dysfunctional occlusal changes by an increase in thickness.
Twelve cadaver heads were divided into 2 groups, 1 with physiologically balanced occlusion (BO), 7 cadaver heads and 14 joints, and the other with physiologically nonbalanced occlusion (NO), 5 cadaver heads and 9 joints. The NO group had defining traits, such as reverse articulation or tightly locked occlusion. The latter is an occlusal relationship with drifted, tilted, and/or supraerupted teeth, often seen in patients who have lost posterior teeth. Histological sections from the lateral, center, and medial parts of the joints stained with haematoxylin and eosin were used for measuring the disc thickness. Student t tests and Bonferroni correction were used to compare groups (alpha=.05).
All 9 mean thickness values were higher in the NO than in the BO group. According to the t tests, the posterior band was thicker in the lateral (P=.007) and center (P=.015) sections, and the intermediate zone was thicker in the lateral section (P=.008) in the NO than in the BO group. These differences were not significant after Bonferroni corrections.
The results suggest that the TMJ disc has the ability to adapt to alteration of the space between condyle and fossa caused by occlusal changes. Further studies from larger groups should be undertaken.
颞下颌关节（TMJ）盘在颞下颌关节紊乱病（TMD）患者中常被观察到更厚。这一临床观察结果需要验证。
本初步研究的目的是调查TMJ盘是否会通过增厚来应对功能失调的咬合变化。
12个尸头被分为2组，1组为生理平衡咬合（BO）组，7个尸头和14个关节，另一组为生理不平衡咬合（NO）组，5个尸头和9个关节。NO组具有如反向咬合或紧密锁定咬合等特征。后者是一种伴有牙齿漂移、倾斜和/或过长萌出的咬合关系，常见于后牙缺失的患者。用苏木精和伊红染色的关节外侧、中央和内侧部分的组织学切片用于测量盘的厚度。采用学生t检验和Bonferroni校正进行组间比较（α = 0.05）。
NO组的所有9个平均厚度值均高于BO组。根据t检验，NO组外侧（P = 0.007）和中央（P = 0.015）切片的后带更厚，外侧切片的中间带（P = 0.008）比BO组更厚。经Bonferroni校正后，这些差异无统计学意义。
结果表明TMJ盘有能力适应由咬合变化引起的髁突与关节窝之间空间的改变。应开展来自更大样本量组的进一步研究。
