Md. Abdul Hakim1, Ismat Ara Haider2, ATM Saiful Islam3, Syed Atiqur Rahman4,
Md. Mostafizur Rahman5, Mohammad Abul Kalam6
1. Assistant Professor, Department of Oral & Maxillofacial Surgery, Dental Unit, Rajshahi Medical College, Rajshahi
2. Professor & Head, Depurtraent of Oral & Maxillofacial Surgery, Dhaka Dental College & Hospital, Dhaka
3. Associate Professor, Department of Oral & Maxillofacial Surgery, Dent Dental Unit, Rajshahi Medical College, College, Rajshahi.
4. Assistant Professor, Department of Oral & Maxillofacial Surgery, Dental Unit, Sir Salimullah Medical College, Dhaka
5. Junior Consultant, Department of Oral & Maxillofacial Surgery, Dental Unit, Shaheed Suhrawardi Medical College Hospital, Dhaka
6. Dental Surgeon, Department of Emergency, Dhaka Dental College Hospital, Dhaka
Abstract
The aim of this study was to evaluate the association between panoramic radiography and cone beam computed tomography (CBCT) in patients with close relationship of the impacted lower third molars and the mandibular canal before undergoing surgical extraction to reduce post-operative complications. This study was conducted in the department of Oral and Maxillofacial Surgery of Dhaka Dental College Hospital in the period of January 2013 to December 2013. CBCT Images were taken from 47 patients having 47 impacted mandibular third molars whose panoramic radiographs showed a close relationship between the canal and mandibular third molars. The lingual course of the mandibular canal was the most frequently detected course (44.68%) in all CBCT findings. Impacted lower third molar roots were 78.72% contact with the canal and 21.28% separate from the canal. Contact of the tooth with the mandibular canal was more frequently (87.5%) observed when the combination of superimposition of the tooth roots and the interruption of the radiopaque border of the canal to the roots was seen on the panoramic radiographs. The incidence of inferior alveolar nerve injury associated with impacted mandibular third molar removal was 2.13%, CBCT provides more precise diagnostic information to determine the relationship of impacted third molars to the mandibular canal. The data acquired by CBCT can be useful in assessing the risk of the surgery and increasing patient awareness about potential anatomical complications and making decisions to undergo surgery. Adequate understanding for the anatomical relationship of impacted lower third molar with mandibular canal is of importance to reduce the risk of nerve injury. The current study reveals low incidence of nerve injury after a proper assessment by CBCT.
Key Words: CBCT, Impacted third molar, Mandibular canal, OPG, Surgical extraction