Analysis of Root and Canal Morphology of First Permanent Molars in a Selected Tanzanian Population Using Cone Beam Computerized Tomography

Abstract

Background: Knowledge of tooth morphology is critical and necessary in clinical dental practice. It is of paramount importance for clinicians to be well versed in disparities in tooth morphology due to anatomical differences in roots and root canals. Lack of detailed information about internal root morphology remains one of the core causes of post-endodontic diseases due to missed canals that clinicians may have left unprepared. Knowing the root and canal morphology in the Tanzanian population will contribute to achieve successful endodontic therapy. Study objective. To determine root and root canal morphology in first permanent molars among a selected Tanzanian population using Cone beam computerized tomography. Study design. This was an in vitro descriptive cross-sectional study with an analytical component. Study area. The study was conducted in eight health facilities in the Tabora region for easy data collection in the western part of Tanzania, which provides oral health services across the region. Study population. Three hundred and thirty-five extracted teeth first permanent maxillary and mandibular molars teeth obtained from the Tanzanian population aged 16-40 years attending seven health facilities in the Tabora region, Western Tanzania Material and methods. A total of 335 teeth which met inclusion criteria were chosen for this study. The number of roots and their external root morphology were visually examined. The tooth lengths were measured using a standardized measuring caliper. The number of canals and their configurations were analyzed by CBCT scanner after exposing the mounted teeth on study cast using beading wax. Sequential axial, coronal, and sagittal CBCT images were evaluated continuously from the floor of the pulp chamber to the apex. Analysis of the type of root canals configuration was carried out based on Vertucci’s (1984) root canal classification. T-test and fisher exact tests were carried out to determine the frequency and relationship between certain variables. Ethical approval was sought and granted from KNH-UoN Ethical Research Committee (Approval No. P757/09/2021). Results. All maxillary first permanent molars had three roots while majority (96.6%) of mandibular first permanent molars had two roots. Root fusions were more common in maxillary than mandibular first permanent molars with fusion between mesiobuccal and distobuccal roots being the commonest pattern. There was statistically significant association between root fusion and first permanent molars (Fishers = 11.460, df = 1, p

= .002. Mesiobuccal root of maxillary first permanent molars had higher (60.8%) occurrence of root curvature in the distal direction while distobucal root had higher (65.5%) occurrence of root curvature in mesial direction. Both mesial and distal root of the first permanent mandibular molar were more distally curved, 94.8% and 90.9% respectively. The mean root lengths of first permanent mandibular molars were 20.46mm (±1.76) and 19.63mm (+1.68 SD) for the mesial and distal roots respectively. The mesiobuccal, distobuccal and palatal roots of the first maxillary permanent molars had mean root lengths of 19.29mm (+1.50 SD) 18.66 mm (+1.69 SD) and 19.91 mm (+1.62 SD) respectively. Unpaired t-test showed males had significantly longer first permanent molar mesial and distal root lengths than the females (P<0.05) The mesiobuccal root of the maxillary first permanent molar was found to have the most varied number of canals, 42 (50.0%) had one canal, 41(48.8%) two canals and three canals (1.2%). The mesial and distal roots had the most varied root canal configurations among the mandibular first permanent molars. Root canal configurations type I (78.1%) and IV (71.3%) identified as the most predominant in the distal and mesial roots respectively. Root canal configurations type VI (48.8%) and I (98.8%) identifies being the most predominant on the mesiobuccal and palatal roots respectively. Further, these roots had the most varied canal configurations. CONCLUSION Root and root canal morphology of maxillary and mandibular first permanent molars in selected Tanzanian population showed some degree of complexity and variations from those of previous studies in other populations. The mesiobuccal root of the maxillary first permanent molars and mesial root of the mandibular first permanent molars presented with the most varied canal configurations RECOMMENDATION A larger sample size should be done in various regions of the country to obtain data, which is more representative and generalizable to the Tanzanian population Careful evaluation of radiographs and the anatomy of the pulp chamber are essential to achieve a successful root canal therapy. Clinicians should focus on each case individually in addition to their anatomical knowledge.