Clinical Significance of Preoperative Computed Tomography Assessment During Third Molar Surgery

Tachinami, Hidetake

Clinical Significance of Preoperative Computed Tomography Assessment During Third Molar Surgery

Hidetake Tachinami DDS, Department of Oral and Maxillofacial Surgery, University of Toyama, Toyama, Japan

Kenji Nakamori DDS, PhD, Department of Oral and Maxillofacial Surgery, University of Toyama, Toyama, Japan

Makoto Noguchi DDS, PhD, Department of Oral and Maxillofacial Surgery, University of Toyama, Toyama, Japan

Kenichirou Furukawa DDS, Department of Oral amd Maxillofacial Surgery, University of Toyama, Toyama, Japan

Kayoko Niwa DDS, Department of Oral and Maxillofacial Sugery, University of Toyama, Toyama, Japan

Mutsumi Fujita DDS, Department of Oral and Maxillofacial Surgery, University of Toyama, Toyama, Japan

Sayaka Inoue DDS, Department of Oral and Maxiilofacial Surgery, University of Toyama, Toyama, Japan

Wataru Heshiki DDS, Department of Oral and Maxillofacial Surgery, University of Toyama, Toyama, Japan

Zenko Noto DDS,PhD, Department of Oral and Maxillofacial Surgery, University of Toyama, Toyama, Japan

Morphological evaluation of computed tomographic (CT) images is an important tool for preoperative assessment for surgical removal of the lower third molar (LM3). The aim of this study was to ascertain whether the findings of the inferior alveolar canal (IAC) could be used to predict inferior alveolar nerve (IAN) injury during LM3 surgery.

This retrospective study assessed subjects at a high risk of IAN injury during LM3 surgery based on orthopantomographic examination. The predictive variables included demographic (patient’s age and sex), anatomical (tooth angulation), and radiographic factors. The outcome variable was IAN injury. The relationship between the predictive and outcome variables was analyzed using Fisher’s exact test.

In this study, 49 LM3s (34 patients) were analyzed. IAN injury was observed in 4 of the 34 patients and 5 (10.2%) of the 49 LM3s. Absence of cortication between the LM3 and IAC was observed in 4 cases, while a dumbbell-shaped IAC close to the LM3 was observed in 3 of the 5 cases.

These results suggest that the cortication status and IAC shape are reliable predictive factors for IAN injury during LM3 surgery.

References

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