Comparative Efficacy of Spiral Computed Tomography and Orthopantomography in Preoperative Detection of Relation of Inferior Alveolar Neurovascular Bundle to the Impacted Mandibular Third Molar
Purpose
To assess the relationship of the inferior alveolar neurovascular canal (IANC) and the impacted mandibular third molar on spiral computed tomography (SCT), determine the validity of this assessment, and compare it with that for an orthopantomogram (OPG).
Materials and Methods
Patients visiting the Oral and Maxillofacial outpatient department at the Government Dental College and Hospital, Nagpur, India, were chosen as the subjects for our study. Patients were operated on and the actual clinical findings were compared with the SCT findings. Sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve were determined as a part of ROC analysis. The values for both the diagnostic modalities were then compared using a χ2 test.
Results
Objective evaluation of the SCT showed that the number of positive clinical findings (marking on tooth surface, visualization of the neurovascular bundle, intraoperative excessive hemorrhage, and IAN paresthesia) were significantly more in patients with no measurable distance between the tooth and the canal. Also, the positive clinical findings were observed significantly more in patients who had the following features observed on spiral CT: lack of cortication of the canal and lingual or intraradicular course of the inferior alveolar neurovascular bundle (IANB). ROC analyses of both these diagnostic modalities have shown that the SCT performed better than OPG, although the difference is not statistically significant (P = .9871; χ2 test).
Conclusions
The spiral CT images definitely enhanced the visualization of the relation of the tooth to the IANB, which might provide a higher level of intrasurgical safety and safeguard the interests of both the surgeon and the patient.
⁎Senior Resident, Oral and Maxillofacial Surgery, Maulana Azad Institute of Dental Sciences, New Delhi, India
†Dean, Professor, and Head, Department of Oral and Maxillofacial Surgery, Dr D.Y. Patil Dental College, Pune, India
‡Associate Professor and Head, Department of Oral and Maxillofacial Surgery, Government Dental College and Hospital, Nagpur, India
§Associate Professor and Head, Department of Oral and Maxillofacial Surgery, Maulana Azad Institute of Dental Sciences, New Delhi, India
Address correspondence and reprint requests to Dr Jhamb: SFS-111, Rajouri Apts., Rajouri Garden, New Delhi 110064, India
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