下顎窩の X 線学的形態に関する研究 : フーリエ級数による女性下顎窩の形態の解析

Abstract

The temporomandibular joint plays an important role in dental medicine. Therefore, studies of morphology and function of the temporomandibular joint or study of pathogenesis of temporomandibular joint dysfunction have been carried out in special field of dental medicine. In the field of radiology, some investigations have been made on morphology of the mandibular fossa from the radiological view points. In this study, the shape of the mandibular fossa revealed by lateral oblique radiograph was expressed as a single function using Fourier Progression. The study was done of 82 females (from the second decade to sixth decade) who had negative radiographic findings of temporomandibular joints. The radiographs were divided into five groups at every decade, and each group was compared on differences in the side and age. The results obtained are as follows : 1. Morphologic differences between the right and left mandibular fossae were seen in the third, fifth and sixth decade. The cause of differences are due to that the anterior part of the left mandibular fossa was deeper than the right side. 2. Morphologic differences of the right mandibular fossa, in regard to aging, were seen in the comparisons of the second and third decade, the third and fourth decade, and the fourth and fifth decade. Similar figures of morphology were seen in the other comparisons of the individual decade, except above three combinations. 3. Morphology of the mandibular fossa changes remarkably between the second and fourth decade ; i. e., the anterior part of the mandibular fossa of the third decade was shallower than the second decade, and the posterior part was deeper than the second decade. At the fourth decade the mandibular fossa was shallower than the third dedade, especially in the posterior part.