An Analysis of Visibility and Anatomic Variations of Mandibular Canal in Digital Panoramic Radiographs of Dentulous and Edentulous Patients in Northern Iran Populations.
BACKGROUND
Insufficient information about the anatomical positions and structure of mandibular canal provokes unwanted damage to this important structure of mandible.


OBJECTIVE
The aim of this study was to determine the visibility and anatomical variations of mandibular canal in digital panoramic radiographs of dentulous and edentulous patients in a sample of Iranian population.


METHODS
In this retrospective-analytical research, 249 digital panoramic radiographs in dentulous group and 126 in edentulous group were studied by an expert oral and maxillofacial radiologist. In both groups, the visibility of canal borders in anterior, middle, and posterior areas were examined. In dentulous group, the distance between the canal and apex of the first and second molars were measured. Canal-to-alveolar crest distance and lower mandibular border was measured in three different points for both groups. Finally, the upper-lower positions of canals were determined.


RESULTS
In both groups, most visibility occurred in 1/3 of posterior and the least visibility was detected in 1/3 of anterior, with the intermediate being the most visible part (Type 2). There was no significant difference between the left and right sides in all cases. In dentulous group, no correlation was found between the visibility, age, and gender (p> 0.05); however, canal position was related to gender (p= 0.03 and p= 0.04 in right and left sides, respectively). High position was more frequent in females and intermediate position was more common in males. In edentulous group, no correlation was found between age, gender, and canal position (p> 0.05).


CONCLUSIONS
The most visibility of mandibular canal was in its third posterior and the least was in its third anterior part. Although the middle position of canal was more frequently visible than the high position in this study, it does not refute the possibility of damaging the mandibular canal in critical surgeries.
Dept. of Dentomaxillofacial Radiology, Dental Faculty, Guilan University of Medical Sciences, Rasht, Iran.
Somayeh
S
Nemati
Dept. of Periodontology, Dental Faculty, Guilan University of Medical Sciences, Rasht, Iran.
Anahita
A
Ashouri Moghadam
Dept. of Dentomaxillofacial Radiology, Dental Faculty, Guilan University of Medical Sciences, Rasht, Iran.
Zahra
Z
Dalili Kajan
Dept. of Dentomaxillofacial Radiology, Dental Faculty, Guilan University of Medical Sciences, Rasht, Iran.
Seyedeh Tahereh
ST
Mohtavipour
Dentist, Rasht, Iran.
Hasan
H
Amouzad
Digital Radiography; Edentulous; Jaw; Mandible; Panoramic Radiography