Koca-Ceylan Gozlem, Taskaya-Yilmaz Nergiz, Guler Ahmet U, Incesu Lutfi, Aksoz Tolga
Department of Prosthodontics, Ondokuz Mayis University, Turkey.
Saudi Med J. 2003 Dec;24(12):1352-9.
Teeth and muscles play a very important role for occlusal equilibrium and function. When tooth loss begins, it may also affect the function of the muscle tissues.
The thickness of the masseter and anterior temporalis muscles were measured bilaterally in 30 healthy fully dentate adults and in 30 unilateral edentulous patients by using ultrasonographic imaging. All scans were carried out by the same radiologist to eliminate the inter-observer difference, using a real time scanner (Toshiba SSA- 270 A Japan). A 7.5 MHz linear transducer was used. The transducer was held against the cheek with light pressure. The effect of age, sex, duration of the partial edentulism, unilateral chewing habits of the individuals to the muscle thickness were also evaluated. In all subjects, facial proportion index was also determined.
No study has been found in the literature concerning the masticatory muscle thickness in unilateral partial edentulous patients. Therefore, the main purpose of this study was to compare and establish the differences of the muscle thicknesses between dentate and edentulous sides in unilateral partial edentulous patients with ultrasonography and to test whether the variation in the thickness of the muscle is related to the variation in the facial morphology using the facial proportional indices in the study groups. In the present study, ultrasonography revealed a large variation in the thicknesses of the masseter and temporalis muscles in experimental and control groups, during both relaxed and contracted conditions. The thicknesses of the muscles in females during both relaxed and contracted conditions were less than those in males in both control and experimental groups. In experimental group, a high negative correlation was found between the thickness of the masseter muscle and Facial proportion Index (FPI) in females, however, the statistical analysis showed no significant difference in males. Also, a high negative correlation was found in control group, especially in females. There was no statistically significant relationship between thicknesses of the muscles and age of the subjects in both groups. There was no statistically significant relationship between unilateral chewing habits and muscle thickness. In this study, the duration of partial edentulism did not affect the thickness of the muscles.
Further research is required to study muscular atrophy for comparison with total edentulism.
牙齿和肌肉对咬合平衡及功能起着非常重要的作用。牙齿缺失开始时，也可能影响肌肉组织的功能。
通过超声成像对30名健康的全口牙齿健全成年人及30名单侧无牙患者双侧咬肌和颞肌前部的厚度进行测量。所有扫描均由同一位放射科医生使用实时扫描仪（日本东芝SSA - 270 A）进行，以消除观察者间差异。使用7.5 MHz线性换能器。将换能器轻轻按压在脸颊上。还评估了年龄、性别、部分无牙的持续时间、个体的单侧咀嚼习惯对肌肉厚度的影响。在所有受试者中，还测定了面部比例指数。
文献中未发现有关单侧部分无牙患者咀嚼肌厚度的研究。因此，本研究的主要目的是通过超声检查比较并确定单侧部分无牙患者有牙侧和无牙侧肌肉厚度的差异，并使用研究组中的面部比例指数测试肌肉厚度的变化是否与面部形态的变化相关。在本研究中，超声检查显示，在实验组和对照组中，无论是在放松还是收缩状态下，咬肌和颞肌的厚度都有很大差异。在对照组和实验组中，女性在放松和收缩状态下肌肉的厚度均小于男性。在实验组中，女性咬肌厚度与面部比例指数（FPI）之间存在高度负相关，然而，统计分析显示男性无显著差异。在对照组中也发现了高度负相关，尤其是在女性中。两组中肌肉厚度与受试者年龄之间均无统计学意义上的关系。单侧咀嚼习惯与肌肉厚度之间无统计学意义上的关系。在本研究中，部分无牙的持续时间不影响肌肉厚度。
需要进一步研究肌肉萎缩情况，以便与全口无牙情况进行比较。
