Ali A M, Sharawy M
Medical College of Georgia, Augusta, USA.
J Oral Maxillofac Surg. 1995 May;53(5):544-60. doi: 10.1016/0278-2391(95)90068-3.
Clinical and autopsy studies have shown that patients with temporomandibular joint dysfunction are more likely to have enlargement and deformity of the condyle and subsequently occlusal disharmony. However, it is not known what causes this enlargement. This study was designed to test the hypothesis that surgical induction of anterior disc displacement (ADD) in the rabbit craniomandibular joint (CMJ) could lead to enlargement and deformity of the condyle.
The right CMJ was exposed surgically, and the discal attachments were severed except for the posterior discal attachment (bilaminar zone). Then, the disc was repositioned anteriorly and sutured to the zygomatic arch. The left joint served as a sham-operated control. CMJ tissues then were removed after fixation at 24 hours (5 rabbits), 1 week (10 rabbits), 2 weeks (10 rabbits), or 6 weeks (10 rabbits), processed, and stained with hematoxylineosin. Histomorphometric assessment was used to evaluate changes in condylar volume, and thickness of the fibrous, reserve cell, and condylar cartilage layers.
The results showed a progressive enlargement of the condylar volume in all experimental joints compared with controls (P < .01). The enlargement was attributable to a significant increase in the cartilage thickness and surface area of the nonarticulating portion of the condyle in the 1-week group (P < .01). In the 2- and 6-week groups, there were significant, progressive increases in cartilage thickness and surface area of the articulating portion of the condyle (P < .01). In all animals, increased cartilage thickness was associated with a decrease in the thickness of the fibrous and the reserve cell layers (P < .01).
It is concluded that surgical induction of ADD in the rabbit CMJ causes enlargement of the condyle, which is in part caused by hyperplasia of the condylar cartilage.
临床和尸检研究表明，颞下颌关节功能紊乱患者更易出现髁突增大及畸形，进而导致咬合不协调。然而，尚不清楚导致这种增大的原因。本研究旨在验证以下假说：在兔颅下颌关节（CMJ）中手术诱导前盘移位（ADD）可导致髁突增大及畸形。
通过手术暴露右侧CMJ，除后盘附着处（双板区）外，切断盘的附着。然后将盘向前重新定位并缝合至颧弓。左侧关节作为假手术对照。分别在固定24小时（5只兔）、1周（10只兔）、2周（10只兔）或6周（10只兔）后取出CMJ组织，进行处理，并用苏木精-伊红染色。采用组织形态计量学评估来评价髁突体积、纤维层、储备细胞层和髁突软骨层厚度的变化。
结果显示，与对照组相比，所有实验关节的髁突体积均逐渐增大（P <.01）。这种增大归因于1周组髁突非关节部分软骨厚度和表面积的显著增加（P <.01）。在2周和6周组中，髁突关节部分的软骨厚度和表面积有显著的、逐渐的增加（P <.01）。在所有动物中，软骨厚度增加与纤维层和储备细胞层厚度的减少相关（P <.01）。
得出结论，在兔CMJ中手术诱导ADD会导致髁突增大，部分原因是髁突软骨增生。
