Evaluation of root and its canal morphological variations in mandibular premolars in Malaysian subpopulation using a novel classification system: a CBCT study

This is a retrospective study that analysed CBCT scans of patients treated in UMDH (Universiti Malaya Dental Hospital), to classify and compare the root and its canal morphology of mandibular premolars in the clearly defined Malaysian subpopulation using the novel classification system. In total, 479 mandibular premolars were included in this study (227 first- and 252 second premolars) and categorised according to their demographic variables (ethnicity, gender, and age group). The data was analysed using SPSS for descriptive analysis. Generalised Estimating Equations (GEE) were performed using Python 3 to analyse the association between the complexity of root and its canal morphology and the demographic variables. Single- and double-rooted mandibular first premolars (FPs) were seen in 88.5% and 11.5% of the examined samples, respectively. Whereas, all mandibular second premolars (SPs) exhibited a single root. 1 FP 1 (56%), followed by 1 FP 1–2 (33.3%), were the most common configurations in the mandibular first premolars. 1 SP 1 (85.3%) and 1 SP 1–2 (10.3%) were the most prevalent configurations in mandibular second premolars. Pertaining to the anomalies, FPs had a prevalence rate of 11.5%, 10.1%, and 8.4% for supernumerary roots, “C”-shaped canals, and deep proximal grooves of the examined teeth, respectively. Mandibular premolars showed a wide range in the root canal configurations based on the novel configuration system in this clearly defined subpopulation of patients who attended UMDH. There was no significant association between the complexity of root canal morphology and their demographic variables ( P > 0.05). However, there was a significant association between the complexity of root canal morphology and FPs (OR = 0.11, 95% CI: 0.07–0.17, P < 0.001). These findings can facilitate the clinician’s evaluation of the case difficulty based on the root anatomy and its canal configurations prior to the root canal treatment.