Adaki Shridevi R, Yashodadevi B K, Sujatha S, Santana N, Rakesh N, Adaki Raghavendra
Department of Oral Medicine and Radiology, Bharati Vidyapeeth University Dental College, Sangli, Maharastra, India.
Indian J Dent Res. 2013 Mar-Apr;24(2):183-7. doi: 10.4103/0970-9290.116674.
To assess the incidence of cystic changes in the impacted lower third molar (ILTM) in which the pericoronal (follicular) space is less than 2.5 mm as measured from the radiograph. The relationship between the cystic changes and patient's age, sex, and angular position and contact of ILTM with adjacent tooth was also evaluated.
Follicular space less than 2.5 mm as measured from the panoramic radiograph was included in the study. A total of 73 tissue samples collected during the extraction ILTM were examined histopathologically. Then the data were analyzed for associations with age, sex, angular position, and contact of the ILTM with an adjacent tooth.
There were 37 male and 36 female patients, age ranging from 17 to 35 years (mean 23.95 years). Out of 73 specimens, 17 (23.3%) showed cystic changes; among them 16 (22.1%) showed dentigerous cysts and 1 (1.2%) showed odontogenic keratocysts. Most of the cystic changes occurred in the 26-30 year age range. The cystic changes showed male predominance but could not gain statistical significance. The relationship between cystic changes and angular position was statistically significant (P < 0.05). Higher probability was found in distoangular positioned ILTM. The relationship between cystic changes and communication of ILTM with the second molar was not statistically significant.
Incidence of cystic changes in ILTM justifies extraction of the impacted tooth associated with symptoms. The decision to extract or not to extract impacted third molar should be individualized, rather than generalized.
评估在全景片上测量冠周（滤泡）间隙小于2.5mm的下颌阻生第三磨牙（ILTM）中囊性改变的发生率。还评估了囊性改变与患者年龄、性别、ILTM的角度位置以及与相邻牙齿的接触之间的关系。
本研究纳入了在全景片上测量滤泡间隙小于2.5mm的病例。对73例在拔除ILTM过程中收集的组织样本进行了组织病理学检查。然后分析数据与年龄、性别、角度位置以及ILTM与相邻牙齿接触情况的相关性。
共有37例男性和36例女性患者，年龄在17至35岁之间（平均23.95岁）。在73个样本中，17个（23.3%）显示有囊性改变；其中16个（22.1%）为含牙囊肿，1个（1.2%）为牙源性角化囊肿。大多数囊性改变发生在26 - 30岁年龄组。囊性改变显示男性居多，但未达到统计学显著性。囊性改变与角度位置之间的关系具有统计学意义（P < 0.05）。远中倾斜位的ILTM发生囊性改变的可能性更高。ILTM与第二磨牙的连通情况与囊性改变之间的关系无统计学意义。
ILTM中囊性改变的发生率表明，对于有症状的阻生牙应予以拔除。拔除或不拔除阻生第三磨牙的决定应个体化，而非一概而论。
