Analysis of the frequency of visualization of morphological variations in anatomical bone features in the mandibular interforaminal region through cone-beam computed tomography

Correlation between the presence of the median perforating canal in adults with sex, age and skeletal facial patterns: A cross-sectional study

INTRODUCTION

The aim of the present study was to evaluate the presence of the median perforating canal (MPC) and its morphometric measurements in Cone Beam CT (CBCT) scans of adult patients, correlating the findings with sex, age and skeletal facial patterns.

MATERIAL AND METHODS

717 CBCT scans were selected from a Brazilian population and the presence of the MPC was recorded. MPC diameter was measured in three points: lingual, medial and buccal. To determine the correlation between MPC presence and sex, age and ANB angle classifications the Chi-square test was performed. MPC diameters were related to sex, age and skeletal discrepancies using Mann-Whitney U and Kruskal-Wallis tests. The level of significance adopted was 5%.

RESULTS

Of the 717 CBCT scans analyzed, the MPC was present in 181 patients (25.24%), 279 (38.91%) men and 438 (61.09%) women. The mean age was 37.91 (±14.46) years old, ranging from 18 to 88 years old. There were no differences in the presence of MPC between women and men (p = 0.85), between skeletal discrepancies (p = 0.09) and age groups (p = 0.94). Regarding the MPC diameter, statistical difference was found only for the medial diameter between sexes (p = 0.04), with the highest values in men.

CONCLUSION

The MPC was detected in 25.24% of the studied population, with significant differences only for its medial diameter in men.

Assessment of the prevalence and length of the anterior and caudal loops of the mental nerve as anatomical variants of exiting the mandible at the mental foramen using cone-beam computed tomography: a systematic review and meta-analysis

OBJECTIVES

This systematic review aimed to identify the studies that performed cone-beam computed tomography analysis of the prevalence and length of the anterior loop (AL) and caudal loop (CL) of the mental nerve.

MATERIALS AND METHODS

An electronic database search was performed across PubMed, EMBASE, Web of Science, Scopus, the Cochrane library, and Google Scholar. Original studies reporting the frequency and length of the AL and CL were selected. Qualitative synthesis and meta-analysis were then conducted to assess the prevalence and length of the AL and CL and their associations with age, gender, sides, and dentition status.

RESULTS

A total of 21 studies were included in this review. The pooled prevalence of the AL (95% confidence interval) of the mental nerve at the patient and side level was 51% (31-71%) and 53% (37-69%) while the mean anterior loop length was 2.08 (1.46-2.70) mm. The pooled prevalence of the CL and mean caudal loop length were 100% and 4.73 (3.44-6.01) mm. No significant associations were found between the prevalence and length of the AL and CL and age, gender, sides, and dentition status.

CONCLUSIONS

Overall, the pooled prevalence and mean length of AL of the mental nerve varied among different populations while CL seems to be a constant anatomical landmark with a longer CL than AL.

CLINICAL RELEVANCE

Surgeons performing inter-foraminal oral surgeries like dental implant placement and genioplasty should be aware of the possible distance of the AL and CL to avoid iatrogenic mental nerve injury.

Detection Rate and Variability in Measurement of Mandibular Incisive Canal on Cone-Beam Computed Tomography: A Study of 220 Dentate Hemi-Mandibles from Italy

The mandibular incisive canal (MIC) is a small bony channel located in the interforaminal region; it represents the anterior continuation of the mandibular canal. Cone-beam computed tomography (CBCT) is the most commonly utilized radiological technique for assessing the MIC. The main purpose of this study was to evaluate the detectability and variability in measurements of the MIC on CBCT. A total of 220 dentate hemi-mandibles were retrospectively selected for this study. For each hemi-mandible, the detectability, diameter, and distance of the MIC from anatomical landmarks (cortical plates and tooth apices) were evaluated in consensus by two observers. The analysis was performed at four different levels (first premolar, canine, lateral incisor, and central incisor) and was repeated after one month. The variability of MIC measurements was expressed as the coefficient of repeatability (CR), obtained from the Bland-Altman analysis. The MIC detection rate reduced from the first premolar to the central incisor (from 82.3% to 0.5%). The CR of MIC measurements (diameter and distances from anatomical landmarks) was ≤0.74 mm. Although the MIC is difficult to detect in a non-negligible percentage of cases, the limited variability in measurements confirms that CBCT is an effective technique for the assessment of the MIC.

Prevalence and extension of the anterior loop of the mental nerve in different populations and CBCT imaging settings: A systematic review and meta-analysis

Purpose

Materials and Methods

Results

Conclusion

Mental Foramen and Anterior Loop Anatomic Characteristics: A Systematic Review and Meta-analysis of Cross-sectional Imaging Studies

INTRODUCTION

The present study aimed to review the epidemiologic, topographic, and morphometric aspects of the mental foramen (MF) and anterior loop (AL) on cone-beam computed tomographic imaging studies.

METHODS

An International Prospective Register of Systematic Reviews (PROSPERO)-registered systematic review (CRD42018112991) was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two reviewers independently performed data extraction from observational studies that evaluated MF and AL on 7 electronic databases. MedCalc (MedCalc Software bv, Ostend, Belgium) software was used to perform a meta-analysis with a 95% confidence level.

RESULTS

Of 1545 articles, 66 met the inclusion criteria, totaling 14,233 patients from 5 continents, with a total of 6655 females and 5884 males (some studies did not report sex), with an age range between 8 and 89 years. The most prevalent shapes of MF were oval (48.72%) and circular (44.36%), and the most frequent horizontal positions were between premolars (43.66%) and in line with the long axis of the second premolar (43.12%).

CONCLUSIONS

Based on the articles that assessed AL, the mean prevalence was 43.18%, with most studies reporting bilateral localization as the most prevalent.

Systematic review and meta-analysis of lingual foramina anatomy and surgical-related aspects on cone-beam computed tomography: a PROSPERO-registered study

PURPOSE

This study aimed to summarize the evidence regarding lingual foramen (LF) characteristics using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

A registered systematic review (#42,019,145,962) was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statements. An electronic search without date or language restrictions was performed in five databases, including grey literature (Google Scholar and ProQuest). The Meta-Analysis of Statistics Assessment and Review Instrument was used to evaluate the selected studies.

RESULTS

A total of 6641 articles were identified, and 26 studies (8255 CBCT scans) were selected after a three-step selection process. There was a female predominance, and age ranged between 10 and 93 years. A total of 4336 LFs were observed among men (n = 2042) and women (n = 2294). Of this LF-related sample, 43.5% of the studies were from Asia, followed by Europe (33.5%), North America (14%), and South America (9%). Different distances from the LF to the alveolar crest (11.04-20.4 mm), buccal (4.73-4.91 mm), and lingual (8.75 mm) cortices and the inferior border of the mandible (8.48-26.59 mm) were evaluated.

CONCLUSION

In summary, this systematic review found that LF is an anatomical structure with a high prevalence among the included studies (greater than 90%), regardless of the population evaluated. The occurrence of at least one LF was the most common pattern.

Evaluation of Mental Foramen with Cone Beam Computed Tomography: A Systematic Review of Literature

Purpose

The aim of this systematic review is to assess whether the anatomy of mental foramen is precisely evaluable with cone beam computed tomography (CBCT) before implantation in humans.

Methods

A systematic review was carried out to evaluate the anatomy of mental foramen (size, position, symmetry, anterior loop, and accessory mental foramen or multiple mental foramina). According to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, an electronic search of three databases (Medline, Web of Science, and Cochrane Library) was undertaken until June 2020 and was supplemented by manual searching. Two reviewers will independently perform the processes of study inclusion, data extraction, and quality assessment. Systematic reviews, studies about children, and case reports were excluded. Only studies using CBCT to do preoperative evaluation were selected.

Results

From 728 potentially eligible articles, 72 were included in the qualitative analysis and quantitative synthesis. This systematic review provided an assessment of the anatomy of the mental foramen. The mental foramen was located mostly between the two premolars (between 50.4% and 61.95%) or apically to the second premolar (from 50.3% to 57.9%). The mean diameter of the mental foramen was bigger in males than in females; the difference between them could reach 0.62 mm. The anterior loop seemed to be longer in males (between 0.87 ± 1.81 and 7.25 ± 2.02 mm) than in females (between 0.81 ± 1.18 and 6.52 ± 1.63 mm) and with the presence of teeth (from 0.91 ± 1.18 to 2.55 ± 1.28 for dentate people and from 0.25 ± 0.61 to 2.40 ± 0.88 mm for edentate population). The anterior loop and the accessory mental foramina were detected more frequently with CBCT than panoramic X-ray: only between 0.0 and 48.6% AMFs detected with CBCT were also seen with panoramic images. Clinical Significance. The mental foramen (MF) is an important landmark for local anesthesia and surgical and implantology procedures. Its location, morphology, and anatomical variations need to be considered to avoid mental nerve injury. The aim of this review is to evaluate the mental foramen using CBCT through a systematic literature review to improve knowledge of this complex area for the clinician.

Identification of anterior loop in different populations to avoid nerve injury during surgical procedures-a systematic review and meta-analysis

Exact recognition of the anterior loop is very important to avert any injury to the neurovascular bundle during surgical procedures. The purpose of this review was to evaluate the prevalence and length of the anterior loop in different populations. A comprehensive search of Medline/Pubmed and Cochrane database was done. The focused question was the presence of anterior loop (including loop length) of the inferior alveolar nerve in mental foramen region in CBCT images of the various subjects. Articles related to the presence of anterior loop (including loop length) were only included. Initial literature search resulted in 3024 papers, after removing duplicate articles, 2821 articles were left. Two thousand seven hundred eighty-four articles were further excluded by the reviewers after screening the abstracts which resulted in 37 studies. Hand searching resulted in 2 additional papers. Seven full-text articles were excluded for not fulfilling the inclusion criteria. Finally, 32 articles were included in the review. Two thousand five hundred three subjects with anterior loop were found, which approximates 38% with 48.4% bilateral, 27.8% right side, and 23.8% left side. The loop distribution in males and females was also found to be different. There was highly significant (P < 0.001; I² = 98.81%) heterogeneity found in the included studies. Variations were found in the prevalence, length, gender, and side distribution of anterior loop in various populations. This systematic review highly recommends not relying on any average values and the clinician should compulsorily make use of imaging modalities available in each and every case, wherever surgical procedure is to be performed near mental foramen region.

Cone-beam CT assessment of implant-related anatomy landmarks of the anterior mandible in a Chinese population

PURPOSE

To investigate the prevalence, location, and morphology of the mandibular lingual foramen (MLF), mandibular incisive canal (MIC), and anterior loop of the inferior alveolar canal (ALC) in a Chinese population using cone-beam CT (CBCT).

MATERIALS AND METHODS

From 2014 to 2016, CBCT images from patients with various scanning purposes were obtained from the database of the Affiliated Stomatology Hospital of Kunming Medical University, China. Imaging analyses of the MLF, MIC, and ALC were performed via the NNT viewer software. The prevalence, location, length, classification of MLF, and its distances to the alveolar crest and the lower border of mandible were investigated, and the prevalence and length of MIC and the prevalence of ALC were also studied.

RESULTS

This study examined 1008 subjects, 521 (51.7%) males, and 487 (48.3%) females. 916 (90.9%) subjects showed the medial lingual foramina (LF), a single medial LF with the supraspinous-type predominating. Lateral LF were observed in 547 (54.3%) subjects mostly located in the premolar areas. 876 (86.9%) subjects had the MIC on the left side, whereas 877 (87.0%) had the MIC on the right side. The ALC was present in 147 (14.6%) subjects.

CONCLUSIONS

This study showed a high prevalence of LF and MIC in the Southwest Chinese population. Therefore, caution should be taken during the implant treatment at the anterior mandible region.