China Journal of Oral and Maxillofacial Surgery ›› 2020, Vol. 18 ›› Issue (4): 314-318.doi: 10.19438/j.cjoms.2020.04.005

• Original Articles • Previous Articles     Next Articles

CBCT evaluation of second molar distal bone defects after extraction of impacted mandibular third molar

LI Chen-lin, XIE Qian-yang, XU Guang-zhou, JIANG Qian   

  1. Department of Oral Surgery, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology. Shanghai 200011, China
  • Received:2020-03-03 Online:2020-07-20 Published:2020-09-10

Abstract: PURPOSE: To explore bone defect of mandibular second molar (M2M) and its influencing factors 6 months after M3M extraction. METHODS: The preoperative and postoperative cone-beam CT (CBCT) data of 25 patients with 37 impacted M3Ms were analyzed retrospectively. IBM SPSS 25 software package was used for statistical analysis. Repeated measurement ANOVA was used to compare M2M distal osseous defect depth (ODD) before and after operation. Independent sample t test was used to analyze the influencing factors. RESULTS: M2M distal ODD decreased compared with that before extraction. Age and type of impaction before extraction were the factors influencing postoperative M2M distal bone defect. CONCLUSIONS: After removal of M3M in young patients with high risk, M2M distal bone height recovered. Age and type of impaction are the influencing factors. When M3M can be expected to be removed, early extraction may have a beneficial impact on periodontal health of M2M. When M3M is impacted deeply, bone transplantation materials should be implanted in order to achieve better bone healing.

Key words: Mandibular third molar, Extraction, Mandibular second molar, Osseous defect, Periodontal healing

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