ABSTRACT
INTRODUCTION AND AIMS: Violations of the mandibular canal (MC) and mental foramen (MF) and subsequent injuries to their neurovascular bundle have been reported after surgical and nonsurgical dental procedures. Besides using advanced technologies such as cone-beam computed tomography (CBCT), clinicians should be aware of the anatomy and location of MC and MF in different populations. This study aims to describe the morphologic characteristics of the MF, MC, and its intrabony location in relation to the apices of mandibular posterior teeth in an Emirati subpopulation using CBCT. METHODS: A total of 3700 CBCT scans were screened, and 154 scans that met the inclusion and exclusion criteria were randomly selected. The scans were assessed using 3-dimensional multiplanar imaging for the following structures: the location of MF and the MC course, its intrabony location, and its relationship to the apices of the mandibular posterior teeth. The data were analysed statistically using SPSS software. RESULTS: The MC ran lingually and inferiorly at the posterior region and became more buccal and superior towards the MF. The distal root of the mandibular second molar was found to be the closest root to the MC (2.06 ± 1.83 mm). Moreover, the most common location of the MF was distal to the contact area between the 2 premolars (0.83 ± 1.84 mm) with a significant negative correlation to age (with and increase in age, the MF moves distally). The distance between the root apices and the MC was statistically significantly affected by age (positive correlation) and gender (male patients had a greater distance). CONCLUSIONS: The common course of the MC is lingual and inferior posteriorly and becomes more buccal and superior towards the MF, which is located mostly between the mandibular first and second premolars. Furthermore, the distal root of the mandibular second molar is the closest to the MC and has a positive relationship with age.
ABSTRACT
OBJECTIVES: To conduct a literature review and assess the current strength of evidence of the available studies and to investigate factors important for treatment choice. METHODOLOGY: Structured electronic and hand searches were performed, restricted to English records for all age groups. Only cohort studies comparing spontaneous eruption and surgical and orthodontic extrusion were assessed. Risk of bias assessment was made by the method introduced by the Cochrane collaboration and the Newcastle-Ottawa quality assessment scale for cohort studies, and the body of evidence was assessed by the GRADE approach. RESULTS: One hundred seventeen studies were identified, but only three were suitable for inclusion; these were not meta-analyzed because of methodological and clinical heterogeneity. Spontaneous eruption had a low failure rate of 5-12%. CONCLUSION: Given that infection can be controlled by endodontic therapy, it appears that spontaneous eruption results in the fewest complications in immature teeth, regardless of the degree of intrusion. Furthermore, there appear to be no significant differences between surgical and orthodontic extrusion in terms of adverse outcomes. Limitations of the majority of current cohort studies include selection bias (no confounding adjustment and no demonstration that outcomes were absent at the start of the study), reporting bias, and no information on whether investigators were blinded from the outcomes assessed. Furthermore, there is a serious indirectness in the current body of evidence regarding each outcome. Therefore, guidelines for treatment are currently not based on strong evidence.