Analysis of epidemiological characteristics of impacted mandibular third molars next to inferior alveolar canal
KOU Zheng-wei
ZHAO Zhi-jun
XUE Yang
HU Kai-jin
Abstract：Objective To study the epidemiological characteristics of impacted mandibular third molar (IMTM) next to inferior alveolar canal (IAC),and to guide the risk evaluation and the surgical procedure of IMTM extraction.Methods A retrospective analysis was made among the patients who underwent IMTM extraction in the Department of Oral Surgery,School of Stomatology,the Fourth Military Medical University since Jan.1,2015 to Dec.31,2016.Only the IMTMs next to IAC,which were confirmed by cone-beam computed tomography (CBCT),were finally included.And then,the type of impaction and the relative position between IMTM and IAC were analyzed.Results Three hundred and four IMTMs from 214 patients were included.Among which,226 (74.34％) IMTMs protruded into IAC,while 78 (25.66％) IMTMs contacted with IAC.According to the Pell & Gregory classification,median impaction was the most common in both the protruding group [99 (43.81％) and the contacting group 40 (51.28％)];in accordance with the Winter's classification,horizontal impaction was the most common in both the two groups [90 (39.82％) vs.34 (43.59％)].Further analysis of the relative position between IMTM and IAC showed that both in the protruding group and the contacting group,most IAC were located next to the root of IMTM [118 (52.21％) vs.63 (80.77％)].Conclusion This study demonstrates the impaction type of IMTM next to IAC and the relative position between these IMTM and IAC.Furthermore,it provides guidance for the extraction surgery planning and how to prevent inferior alveolar nerve damage in the absence of CBCT.
Keywords：cone-beam CTimpacted mandibular third molarinferior alveolar canal
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 153-157 )