Objective. This study assessed the canal configuration of mandibular molars according to Vertucci’s classification of a Saudi population using cone-beam computed tomography (CBCT). Methods. A total of 290 first and 367 second mandibular molars were analyzed. The CBCT images were evaluated in three sections to inspect the number of roots and canals and canal system. The data are presented as frequencies and percentages. The chi-squared test was used to assess differences between both sides. SPSS was used for analysis, with a significance level of α ≤ 0.05. Results. Among the first molars, 95.4% of the teeth had two roots, and 64.5% had three canals. Approximately 57.9% showed Vertucci type IV mesial roots. Between the second molars, 89.6% of teeth had two roots and 80.4% had three canals. The frequency of Vertucci type IV (39.4%) was the highest in mesial roots. The first molars showed a high prevalence of 3-rooted teeth (5.5%). Both the right and left sides showed teeth with similar external and internal anatomy p < 0.05 . Conclusion. Most of the mandibular first and second molars had two roots and three canals. In the first mandibular molars, similar to the second mandibular molars, the majority of the mesial canals had Vertucci type IV, while the distal canals had Vertucci type I.

Background. This study aimed to assess the prevalence of missed canals in endodontically treated teeth and their association with apical periodontitis in a Saudi Arabian population using CBCT. Materials and Methods. A total of 208 CBCT radiographs were investigated. For each tooth, radiographs of axial, coronal, and sagittal segments were acquired to appraise the external as well as the internal structure of the root canal system and apical area. In root canal-treated teeth, unfilled canals appearing from the cementoenamel junction to the apex were defined as missed untreated canals; and a periapical lesion was considered when disruption of the lamina dura was detected, and the low-density area associated with the radiographic apex was at least twice the width of the periodontal ligament space. The data were presented as frequencies and percentages. The Z-test was used to analyze the differences in proportions with the significance level set at P value <0.05. Results. The overall prevalence of missed canals among endodontically treated teeth was 18%. The prevalence of missed canals was higher in maxillary first molars with 40.6%. The overall prevalence of apical periodontitis among teeth with missed canals was 90%. It was 84.2% in the maxilla and 100% in the mandible. The second mesiobuccal canal in the maxillary first molars and mesiobuccal and distobuccal canals in mandibular teeth were the most missed canals. Conclusion. Apical periodontitis in root canal-treated teeth with missed canals was high (90%), with most identified missed canals in maxillary and mandibular first molars.

Aim: There is an inadvertent alteration of the occlusal surface after dental treatment. However, research concerning the effect of these iatrogenic disturbances on the temporomandibular joint (TMJ) is scarce. Hence, the present study aimed to investigate the relationship between sudden iatrogenic occlusal disturbance and its effect on the myogenous temporomandibular disorder (TMD). Materials and methods: A cross-sectional observational study was conducted among 30 female subjects aged 18 years to 38 years who received treatment (direct and indirect restorations altering the occlusal surfaces of teeth, and oral prophylaxis) in the students' clinics at the College of Dentistry Jazan University. The preoperative assessment included a patient interview, a baseline occlusal record, and bite force analysis. All the assessments were repeated 2 weeks after the treatment. Descriptive statistics were calculated. Results: As there was no change observed in bite force as well as occlusal disturbances in the control group, no comparative tests could be applied. The treatment-induced occlusal disturbances were observed in 80% of the participants. The mean change in occlusal force on the treated teeth was found to be 5.6 ± 1.1 Newtons. None of the patients reported any symptoms related to pain or restriction in function in the TMJ. Conclusion:No relation was observed between the abrupt changes in the occlusal force due to dental treatment and the development of the myogenous TMD. Clinical significance: Iatrogenic occlusal interferences may cause/exacerbate TMDs; hence, extreme caution should be exercised by the clinicians to avoid causing harm to the patients.