Singh Bishnupati, Chandra Subhash, Sourabh Kumar, Shahi Ajoy K, Sharma Swati, Kumar Sandeep
Department of Prosthodontics, Dental Institute, Rajendra Institute of Medical Sciences, Ranchi, Jharkhand, India.
Department of Orthodontics, Dental Institute, Rajendra Institute of Medical Sciences, Ranchi, Jharkhand, India, Phone: +91 9955393983, e-mail:
J Contemp Dent Pract. 2020 Jan 1;21(1):97-104.
The aim of this study is to establish a proportion between the inferior border of mandible and lower edge of the mental foramen and inferior border of mandible to occlusal plane for dentulous subjects and to evaluate the validity of this proportion in orienting the occlusal plane for edentulous subjects.
The occlusal plane was evaluated in the selected 50 dentulous and edentulous subjects for its relation to the mental foramen and inferior border of the mandible. The orthopantograms obtained were traced with the markings and the measurements were tabulated under different headings. After measuring the distances, the proportion between the distances was determined. The mean proportions of dentulous, edentulous, male, and female subjects were evaluated. Then the proportion of male subjects was compared with that of female subjects and dentulous subjects with that of edentulous subjects. Comparison of proportion between the different groups was done by using unpaired test. The mean and standard deviation (SD) were determined for each group separately and were compared within each group. From the calculated "" value, "" the probability for error was found out.
In dentulous subjects, the proportion ranged from 1:3.53 to 1:4.40. The mean was 1:3.90. In edentulous subjects, the proportion ranged from 1:3.50 to 1:4.15. The mean was 1:3.84. On comparison, the difference between both the groups was 0.06. The difference was statistically insignificant ( = 0.14). In the comparison of dentulous male and female subjects, the difference obtained was 0.02. The difference was statistically insignificant ( = 0.77). The comparison of edentulous male and female subjects and the difference obtained was 0.03. The difference was statistically insignificant ( = 0.51).
The derived proportion of 1:4 between the inferior border of mandible and mental foramen and inferior border of mandible and occlusal plane in edentulous patients as measured on an orthopantogram may yield a plane of occlusion similar to that existing in the dentulous state.
The above-drawn proportion between the inferior border of the mandible to the lower edge of the mental foramen and between the inferior border of the mandible and the occlusal plane in edentulous patients may yield a plane of occlusion which is oriented similar to that existing in the dentulous state. The proportions derived radiographically in this study can serve as a basis for future studies to establish the occlusal plane for edentulous subjects.
本研究旨在确定有牙颌受试者下颌骨下缘与颏孔下缘之间以及下颌骨下缘与咬合平面之间的比例关系，并评估该比例关系在无牙颌受试者咬合平面定位中的有效性。
在50名有牙颌和无牙颌受试者中评估咬合平面与颏孔及下颌骨下缘的关系。对获得的曲面断层片进行标记追踪，并将测量数据按不同标题列表。测量距离后，确定距离之间的比例。评估有牙颌、无牙颌、男性和女性受试者的平均比例。然后比较男性受试者与女性受试者以及有牙颌受试者与无牙颌受试者的比例。通过使用非配对检验对不同组之间的比例进行比较。分别确定每组的均值和标准差（SD），并在每组内进行比较。根据计算出的“t”值，找出误差概率。
在有牙颌受试者中，该比例范围为1:3.53至1:4.40。均值为1:3.90。在无牙颌受试者中，该比例范围为1:3.50至1:4.15。均值为1:3.84。比较发现，两组之间的差异为0.06。差异无统计学意义（P = 0.14）。在有牙颌男性和女性受试者的比较中，获得的差异为0.02。差异无统计学意义（P = 0.77）。无牙颌男性和女性受试者的比较及获得的差异为0.03。差异无统计学意义（P = 0.51）。
在曲面断层片上测量得出的无牙颌患者下颌骨下缘与颏孔及下颌骨下缘与咬合平面之间1:4的比例，可能产生与有牙颌状态下相似的咬合平面。
上述得出的无牙颌患者下颌骨下缘与颏孔下缘之间以及下颌骨下缘与咬合平面之间的比例，可能产生一个定位与有牙颌状态下相似的咬合平面。本研究通过影像学得出的比例可为未来建立无牙颌受试者咬合平面的研究提供基础。
