Gupta Saurabh K, Saxena Payal
Department of Conservative Dentistry and Endodontics, Government College of Dentistry, Indore, Madhya Pradesh, India.
J Investig Clin Dent. 2013 Nov;4(4):240-6. doi: 10.1111/j.2041-1626.2012.00154.x. Epub 2013 Jan 25.
The aims of the present study were to determine the prevalence of cusp 7 in permanent mandibular first molars in an Indian population, and to comparatively evaluate the variations in occlusal morphology of these teeth, including the difference in the number of cusps and fissure patterns.
A total of 1123 Indian participants from the Government College of Dentistry, Indore, Madhya Pradesh, India, were selected for the study. For the analyses of cusp 6 and cusp 7 in permanent mandibular first molars, the Arizona State University Dental Anthropology System was used. Groove patterns were analyzed and classified as Y, +, X, and Ұ.
Of the 1123 individuals, 132 (11.75%) were found to have cusp 7, while 78 (6.95%) had cusp 6. Thus, a total of 210 participants had the six-cusped mandibular first molars, 98 (8.73%) had the four-cusped mandibular first molars, and two had the seven-cusped variant. Overall, the most common fissure pattern was the Y pattern (50.36%), while the least common was the X pattern (1.25%). Mandibular first molars with cusp 7 demonstrated a highly significant (P < 0.05) dominance of the Ұ pattern (36.80%) over the Y (30.74%), + (27.71%), and X (4.46%) fissure patterns.
A significant prevalence of cusp 7 (11.25%) in permanent mandibular first molars was found in the present study in an Indian population.
本研究的目的是确定印度人群中恒牙下颌第一磨牙的第七尖发生率，并比较评估这些牙齿的咬合形态变化，包括牙尖数量和沟型差异。
从印度中央邦印多尔政府牙科学院选取了1123名印度参与者进行研究。对于恒牙下颌第一磨牙的第六尖和第七尖分析，使用了亚利桑那州立大学牙科人类学系统。对沟型进行分析并分类为Y型、+型、X型和Ұ型。
在1123名个体中，发现132人（11.75%）有第七尖，而78人（6.95%）有第六尖。因此，共有210名参与者有六尖下颌第一磨牙，98人（8.73%）有四尖下颌第一磨牙，两人有七尖变异型。总体而言，最常见的沟型是Y型（50.36%），最不常见的是X型（1.25%）。有第七尖的下颌第一磨牙显示Ұ型（36.80%）在Y型（30.74%）、+型（27.71%）和X型（4.46%）沟型中占高度显著优势（P < 0.05）。
本研究在印度人群中发现恒牙下颌第一磨牙中第七尖的发生率显著（11.25%）。
