Assessing the Prevalence and Morphological Characteristics of Bifid Mandibular Canal Using Cone-Beam Computed Tomography - A Retrospective Cross-Sectional Study

An evaluation of mandibular canal variations: a systematic review and meta-analysis

The inferior alveolar nerve and vessels are carried via the mandibular canal, which extends bilaterally from the inferior alveolar foramen to the mental foramen. Bifid and trifid mandibular canals result from abnormal fusions of nerve canals. The purpose of this study was to provide an up-to-date and comprehensive analysis of the prevalence of mandibular canal variations among healthy adults, and to identify any potential ethnic, sex, or laterality predilections. The prevalence of the bifid mandibular canal was 18.87% and that of the trifid canal 1.3%. Unilateral variants were three times commoner than bilateral. Each mandibular half had four canals emanating from separate openings on the lingual surface of the mandibular ramus. Retromolar and forward canals were the predominant subtypes, followed by dental; buccolingual were the least frequent. The mean length and diameter of the bifid mandibular canal were 13.62 mm and 1.63 mm, respectively. The possibility of a bifid mandibular canal is a crucial consideration in dental medicine. Because anatomical variations of the mandibular canal are fairly common, awareness of them is essential for anatomy teachers and for surgeons who operate in the oromaxillofacial region.

Bifid Mandibular Canal: A Proportional Meta-Analysis of Computed Tomography Studies

Introduction

Growing body of evidences showed different grades in prevalence of bifid mandibular canals. Because the previous reviews focused solely on patient-level occurrence, hemi-mandible-level prevalence, bilateral symmetry, length, and diameter of bifid mandibular canals were required to be estimated collectively. The research question of this meta-analysis was "What is the prevalence of bifid mandibular canal among patients seeking computed tomography examinations"?

Materials and Methods

In vivo, computed tomography, and cross-sectional studies were eligible. Studies, with less than 100 subjects or anatomic site restriction or controlled class of bifid mandibular canal, were excluded. Joanna Briggs Institute (JBI) critical appraisal tool for prevalence studies was used to assess methodological quality of all included studies. Random effect meta-analyses for proportion of bifid mandibular canal were done.

Results

40 studies met the inclusion criteria. All studies were selected for both systematic review and meta-analyses. Totally, 17714 patients and 31973 hemi-mandibles were included. All eligible studies showed moderate risk of bias on average. Resulting from the random effect model, more than 20% of patients seeking computed tomographic examinations had bifid mandibular canals (BMCs) which penetrated into slightly more than 14% of hemi-mandibles. Of the patients having bifid mandibular canals (BMCs), nearly 23% exhibited such anatomy on both sides of their mandibles. Estimated mean length and diameter of the accessory canals of bifid mandibular canals were 12.17 mm and 1.54 mm, respectively.

Conclusion

The geographical locations, classifications, reliability test, and voxel size of computed tomography were all implicated in the prevalence of bifid mandibular canals along with gender and laterality, although considerable heterogeneity and bias were detected.

Prevalence of Bifid Mandibular Canal: A Systematic Review and Meta-analysis

Objectives

The aim of this study was to evaluate the prevalence of bifid mandibular canal (BMC) using cone-beam computed tomography (CBCT) and panoramic images through meta-analysis.

Methods

Databases of Scopus, PubMed, and Web of Science were searched to find the relevant studies. Studies the met the inclusion criteria were selected. Variables of prevalence, side, length and diameter of BMC and sex were assessed. Data was analyzed using STATA software version 17.

Results

Of the 1164 articles initially selected, 36 were enrolled. A total of 38077 patients were considered. The overall prevalence of BMC was 18.0%. Studies that evaluated CBCT images reported higher prevalence of BMC compared to panoramic images (25.0% vs 3.0%). The prevalence of BMC was higher in men than women and slightly higher in right side than the left side of the jaw, but none of those differences were significant.

Conclusion

The results have shown a total prevalence of 18.0% for BMC. Detection power of CBCT images were higher than panoramics. There was no significant relation between prevalence of BMC with sex or side of the jaw.

Prevalence and Characterization of bifid mandibular Canal Using Cone Beam Computed Tomography: A Retrospective Cross-Sectional Study in Saudi Arabia

Aim

The purpose of this study is to determine the prevalence and morphological characteristics of the bifid mandibular canal in a Saudi Arabian subpopulation, to aid in preventing surgical complications near the mandibular canal.

Patients and Methods

Using CBCT images obtained from the Radiology unit database in a University Hospital Clinics. A total of 488 CBCT images were investigated (244 Female – 178 Male). In the present study, the Naitoh classification was used to categorize the bifid mandibular canal into the following types: 1) Retromolar canal; 2) Dental canal; 3) Forward canal (with or without confluence); and 4) Buccolingual canal. Additional variation (Trifid canal) was included. All CBCTs were assessed in coronal, sagittal, axial, as well as panoramic views using specialized software.

Results

The prevalence of BMC was 28.7% (95% CI, 24.5 to 33.2), Gender (p = 0.404) and age (p = 0.654) had no statistical significances, laterality of BMC, patients with unilateral BMC were significantly older than those with bilateral BMC (mean ± SD ages of 40.5 ± 13.5 and 32.9 ± 13.8, respectively, p = 0.009). About two-thirds (67.5%) of the investigated BMC cases were found unilateral. The most common reported type of BMC was retromolar canal.

Conclusion

The incidence of bifid mandibular canal using CBCT is considered relatively high in Saudi Arabian subpopulation, with the most common type was the retro-molar canal.

Normal Variants of the Oral and Maxillofacial Region: Mimics and Pitfalls

A normal variant is defined as an incidental, often asymptomatic, imaging finding that mimics a true pathologic condition. Given the complex anatomy and wide variety of normal variants in the oral and maxillofacial region, a thorough understanding of commonly encountered normal variants in this region is essential to avoid misinterpretation and unnecessary further imaging or interventions. Moreover, familiarity with normal variants that are known to become symptomatic at times is necessary to facilitate further workup and guide the treatment plan. Intraoral radiography and panoramic radiography, which are unique to oral and maxillofacial radiology, provide two-dimensional (2D) images. Hence, the overlapping of structures or the displacement of the tomographic layer on images can confuse radiologists. It is crucial to understand the principle of 2D imaging to avoid being confused by ghost images or optical illusions. In addition, understanding the normal development of the maxillofacial region is essential when interpreting maxillofacial images in children or young adults because the anatomy may be quite different from that of mature adults. Knowledge of changes in the jaw bone marrow and each tissue's growth rate is essential. It is also necessary to know when the tooth germ begins to calcify and the tooth erupts for diagnostic imaging of the maxillofacial region. The authors describe imaging findings and clinical manifestations of common normal variants in the oral and maxillofacial region, divided into four parts: the maxilla, mandible, tooth, and temporomandibular joint, and discuss the imaging approach used to differentiate normal variants from true pathologic conditions. Online supplemental material is available for this article. ^©RSNA, 2022.

Radiographic Evaluation of Prosthodontic Patients

This article focuses on radiographic imaging with regard to planning, treating, and maintaining partially and completely edentulous prosthodontic patients with dental implants. Cone-beam computed tomography (CBCT) is the preferred imaging method for pretreatment dental implant treatment planning. Radiographic guides containing radiopaque materials and/or fiducial markers transfer both the proposed prosthesis design and desired implant location for appropriate radiographic evaluation. The three-dimensional CBCT analysis provides information on the adjacent relevant anatomy, bone volume of the edentulous sites, and restorative space assessment.