Evaluation of the Course of Inferior Alveolar Canal and its Relation to Anatomical Factors on Digital Panoramic Radiographs.

STATEMENT OF THE PROBLEM: The inferior alveolar canal (IAC) is a bony canal that starts from mandibular foramen at the inner surface of the mandibular ramus and extends along the ramus and body of mandibular bone in forward and downward directions to the mental foramen. Inside the mandibular canal, there are lower alveolar artery and a nerve with the same name. Understanding the anatomical details of the lower alveolar canal, including position, pathway and morphology to prevent complications in surgical procedures in the lower jaw such as mandibular impacted molar surgeries, mandibular nerve block injection, or even root canal treatment of mandibular teeth is important. PURPOSE: The purpose of this study was to investigate the course and direction of IAC in mandibular bone and its relation to anatomical factors such as gonial angle and location of entrance of IAC in the mandibular ramus. MATERIALS AND METHOD: This cross-sectional study evaluated a sample of 280 digital panoramic images. All samples were Iranian. The pattern and direction of the IACs were recorded according to age and gender and the relation of these patterns to the gonial angle of mandible and the entry point of the IAC in mandibular ramus were evaluated. RESULTS: The results showed that the course of canal, the entrance point of the canal and the gonial angle were the same between different age groups and between two genders. There was no significant relation between the course of canal and the two anatomical variables mentioned (p> 0.05). CONCLUSION: Considering the increasing frequency of implant surgeries and presence of different courses of the mandibular canal and concerning the important complications such as paresthesia caused by damage to the mandibular nerve, panoramic radiography is necessary before any surgery in this area to avoid unwanted injuries to the neurovascular system if other advanced modalities are not available.

Evaluation of Root Canal Anatomy in Mandibular Incisors Using CBCT Imaging Technique in an Iranian Population.

STATEMENT OF THE PROBLEM: To perform a successful endodontic treatment, sufficient knowledge about the number of root canals and their morphology is essential. Missed normal variations may burden this treatment. PURPOSE: This study aimed to evaluate the presence of the second canal in the roots of mandibular central and lateral incisors in an Iranian population by employing CBCT images. MATERIALS AND METHOD: This cross-sectional study recruited 180 CBCT image of mandible to evaluate the number of roots as well as the number and types of root canals. Data for each sample were collected in a data collection form set and analyzed by chi-square test using SPSS17 software. RESULTS: A total of 681 permanent mandibular incisors were assessed. All samples had one root. Most of the samples (70.3%) had only one canal (type 1 Vertucci classification). The frequency of dual-canal in samples was 29.7%; the prevalence of dual-canal in mandibular lateral teeth (35%) was more than the mandibular central teeth (23.9%, p< 0.05). Following type 1 canal, type 3 (15.7%), type 5 (12.9%), type 4 (0.7%), and type 2 (0.3%) canals had the highest frequencies respectively. CONCLUSION: Based on this study, presence of a second canal in mandibular lateral teeth (35%) is more common than in mandibular central teeth (23.9 %). The most common canal type observed was type 1 (according to Vertucci classification) followed by type 3.

An in vitro study of root and canal morphology of human deciduous molars in an Iranian population.

Dental caries is the most common chronic childhood disease. Deep caries and dental trauma are the two main etiologic factors responsible for pulp involvement. Better knowledge of the morphology of the root canals of deciduous teeth can improve the outcome of pulp treatment. In this study, 90 deciduous molar teeth (27 first mandibular molars, 27 first maxillary molars, 22 second mandibular molars and 14 second maxillary molars) were prepared using the clearing technique, and then dye was injected into the pulp cavity of each tooth. The roots of the teeth were examined under a stereomicroscope at × 10 magnification from different aspects. Measurements of root length and angulation were also recorded, and the data were analyzed using SPSS-16 software. Deciduous molar teeth in all four classes showed variability in the number of roots and root canals, and also differed in mean root length and angulation. Type I and IV root canal configurations were observed in the samples, and different types of curvature were recorded for the root canals in all four classes. As deciduous molar teeth exhibit morphologic differences from permanent teeth, a thorough knowledge of the root canals in the former can improve the outcome of pulp treatment.