Cone-beam computed tomographic evaluation of accessory mental foramen in a Turkish population

Systematic review and meta-analysis of mandibular canal variations on cone beam computed tomography

OBJECTIVE

The purpose of this systematic review was to evaluate the mandibular canal (MC) variations and their anatomical incidences using cone-beam computed tomography (CBCT).

DESIGNS

Related articles on the anatomical variations of the MC using CBCT were searched through PubMed, Cochrane, and China National Knowledge Infrastructure (CNKI) to identify all relevant articles eligible for inclusion. Data extracted included incidences of the anatomical variations of the MC including the accessory mental foramen (AMF), retromolar foramen (RMF), mandibular lingual foramina (MLF), and the bifid mandibular canal (BMC).

RESULTS

In total, 16 descriptive cross-sectional studies (one low quality and fifteen high quality) were included in the meta-analysis analyzing 8862 MC. The meta-analysis performed with a random-effects model showed that the incidence of AMF was 9.54% (95% CI 6.39-12.69%), the incidence of RMF was 23.64% (95% CI 14.44-32.84%). MLF was found in almost all adults studied, and the incidence of BMC was about 38.0%.

CONCLUSIONS

The foramina and canals branched from the MC presented significant anatomical variations among individuals. CBCT-based study on the anatomical variations of the MC could provide guidance for clinical practice.

Evaluation of accessory mental foramen and accessory infraorbital foramen with cone-beam computed tomography in Turkish population

It was aimed to evaluate the frequency of accessory mental foramen (AMF) and accessory infraorbital foramen (AIOF) and analyse the correlation between these two foramina using cone-beam computed tomography (CBCT). The retrospective study reviewed the CBCT images of 1020 patients. The rates of AMF and AIOF were evaluated according to sex and age distributions. Correlations between the localizations of AMF and AIOF in the right and left jaws and the correlations between the occurrences of these foramina were evaluated. In the CBCT images of the 1020 patients, AMFs were detected in 48 patients, among which 14 were in the right half jaw, and 34 were in the left half jaw. AIOFs were detected in 143 patients, among which 65 were in the right half jaw, and 78 were in the left half jaw. Recognising and detecting AMF and AIOF with CBCT is important in terms of preventing complications that may occur in surgical procedures.

Anatomy of the accessory mental foramen in a Saudi subpopulation: A multicenter CBCT study

Aim

The aim of this is to evaluate the prevalence and location of the accessory mental foramen (AMF) in a Saudi population using cone-beam computed tomography (CBCT).

Methodology

CBCT data were retrieved from two dental facilities at two universities located in two different cities and filtered over a period of four years. The scans were aligned when the AMF was noticed, and then the size of both the AMF and mental foramen (MF), its location, and the distance from the AMF to the MF were recorded. The AMF measurements were compared between males and females and between the two sides of the mandible.

Results

In total, 603 CBCT scans were investigated. The percentage of scans with an AMF was 9.95% (n = 60), and AMFs were almost equally distributed on both sides. Only four cases (0.66%) of a second AMF were detected among the scans. The MFs on both sides were significantly larger in males than in females (P > 0.05), but they showed no differences in the sizes of the AMFs. The AMFs were most commonly located inferior and posterior to the MF. The distance between the MF and AMF ranged from 2.32 to 5 mm.

Conclusions

The prevalence of the AMF in this Saudi population was 9.95%, and it was significantly more prevalent in males than in females. Its proximity to the MF makes it clinically important to conduct proper detailed planning prior to performing any procedure that might risk the vital structures.

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.

Evaluation of the Posterior Superior Alveolar Artery Prior to Sinus Floor Elevation via Lateral Window Technique: A Cone-Beam Computed Tomography Study

Aim:

To evaluate the prevalence, diameter, localization of the posterior superior alveolar artery (PSAA) and the relationship between PSAA and the floor of the maxillary sinus and the thickness of the maxillary sinus lateral wall using cone-beam computed tomography (CBCT).

Material and Methods:

In this retrospective study, more than 500 CBCT images were retrieved. Out of them 156 CBCT images were related to the sinus floor elevation, among which 120 CBCT images were enrolled in the study based on the inclusion criteria, and 36 CBCT images were excluded. A total of 120 CBCT images of the PSSA from 60 patients comprising 32 (53.3%) men and 28 (46.7%) women were analyzed. Statistical data were analyzed using SPSS for Windows version 22. Descriptive statistics (mean, standard deviation, frequency) were used for the analyses.

Results:

The ages of the participants ranged between 26 and 76 years and the mean age was 54.48 ± 10.92 years. The PSAA was detected on the right side in 95% of the CBCT scans and on the left side in 85% of the maxillary sinuses. At the first detection point (FDP) and last detection point (LDP), the mean values of the distance between the inferior border of the PSAA and the floor of the maxillary sinus were 9.54 ± 4.27 mm and 7.91 ± 4.75 mm, respectively. The mean diameters of the PSAA at the FDP and LDP were 1.36 ± 0.46 mm and 1.12 ± 0.35 mm, respectively.

Conclusion:

Detection of the characteristics of the PSAA by using CBCT is crucial for handling the sinus floor elevation procedures uneventfully.

Evaluation of pneumatic cavities surrounding temporomandibular joint by cone beam computed tomography

OBJECTIVE

The purpose of this study was to detect the prevalence and characteristics of pneumatization in the roof of the glenoid fossa (PRGF) and articular eminence (PAT) by using cone beam computed tomography (CBCT) images.

MATERIAL AND METHOD

CBCT images of 378 patients (756 TMJ) were analyzed to determine the PRGF and PAT. Twenty-eight patients were excluded due to some reasons such as trauma, degeneration, previous surgical operation of temporomandibular joint (TMJ). Pneumatization was detected in 297 of 350 patients, but not pneumatization in 53 patients. Age, gender, laterality (unilateral, bilateral) and lacunarity (unilacunar, multilacunar) were recorded. Unilateral types were also noted as right and left localization. Chi-square test was used to evaluate relationship between pneumatization and gender, lacunarity and laterality.

RESULTS

PRGF and/or PAT were diagnosed in 491 (70%) TMJ components whom 178 (51%) were male and 172 (49%) were female with mean age of 40.38±18.34 years. In total, 103 (35%) of the patients had unilateral and 194 (65%) patients had bilateral pneumatization.

CONCLUSION

CBCT provides reliable and precise images to detect pneumatization surrounding TMJ structure in comparison to 2D images. Evaluation of TMJ components accurately before surgical intervention is crucial to prevent complication or increase the success of therapy.

Localization of the Mandibular Canal in a Turkish Population: a Retrospective Cone-Beam Computed Tomography Study

Objectives

The aim of this study was to determine the location of the mandibular canal at the mental foramen region that is essential in order to prevent injuries to the inferior alveolar neurovascular bundle during mandibular surgical procedures.

Material and Methods

The position of the mandibular canal was analysed using cone-beam computed tomography images from 300 Turkish patients, who were referred to Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Izmir Katip Celebi University for various complaints. The distances of the mandibular canal to the outer superior (D1), inferior (D2), buccal (D3), and lingual (D4) cortical margins were measured at 2 mm distal to the mental foramen.

Results

There were 148 (49.3%) males and 152 (50.7%) females with ages ranging from 15 to 74 years (39.15 [SD 17.8]). D1 was significantly greater than D2 and D3 was significantly greater than D4 on both left and right sides. While the mean D1, D2, and D4 in males were significantly greater than in females on both left and right sides. There was no significant difference between D3 in males and females on both left and right sides.

Conclusions

The results showed that the mandibular canal was vertically located nearer to the inferior cortical border and horizontally nearer to the lingual cortical border of the mandible at the mental foramen region. Knowledge of the distances of mandibular canal to the outer cortical margins at this region of the mandible will be helpful for surgical procedures.

A rare anatomic variation: Triple mental foramina

Multiple mental foramina (MF) are rarely found in the human mandible. We report on the case, as documented using cone beam computed tomography (CBCT), of the triple MF that were identified on the right hemimandible of a 28-year-old female patient. The distal foramen was located on the mandible between the apices of the second premolar root and the first molar mesiovestibular root, being reached by a thin canal that left the mandibular canal. A pair of mesial foramina were identified between the apices of the premolar teeth. Thus, the three foramina corresponded to a surface area of 23.49mm² of the mandible. On the opposite side, a single mental foramen had a surface area of just 13.25mm². On each side, retromolar canals that opened into the retromolar fossae were also found. The anatomic possibility of multiple MF increases the surface area at risk during surgical procedures, increases the risk of neurovascular damage and obscures the common tooth-related location of the mental foramen. Practitioners should, therefore, consider a personalised and imaging-documented approach so as to avoid treatment failure.