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.

Mental Nerve Anterior Loop Detection in Panoramic and Cone Beam Computed Tomography Radiograph for Safe Dental Implant Placement.

Background and aim Different imaging modalities have been used as preoperative assessment tools since the emergence of dental implants. This study aimed to compare the detection and presence of mental nerve anterior loop in cone beam computed tomography (CBCT) radiograph and panoramic radiograph. Material and methods A descriptive, retrospective study was done. The optimal sample size was calculated using Epi Info software. According to the study population (795), the sample size was 259 cases which gave 95% power of the study. A previously taken CBCT and digital panoramic radiographs from the database of Taibah University Dental School and Hospital were observed by two trained and calibrated examiners to determine the presence of a mental nerve anterior loop and compare the two modalities. The mean length of the mental nerve anterior loop was also assessed.  Results Mental nerve anterior loops were detected bilaterally in 57.1% and 17.4% using CBCT and panoramic radiographs, respectively. In CBCT, the right side (20.8%) had a higher prevalence of mental nerve anterior loop than the left side (12%). The mental nerve anterior loop was not visible in 49.4% of the cases using a panoramic radiograph, while CBCT gave 10% of cases as not visible. The mental nerve anterior loop average length was 1.8 ± 0.35 mm and the width was 1.7 ± 0.28 mm. The average distance from the mental foramen to the inferior border of the mandible was 12.1 ± 0.87 mm and the average distance from the mental frogmen to the mandibular midline was 25.1 ± 0.68 mm. Conclusion As differences between CBCT and panoramic radiographs were statistically significant, CBCT is more accurate and reliable. CBCT is recommended to be used as a preoperative assessment tool to minimize nerve injury-related surgical complications during implant placement at the mandibular premolar area.

CBCT Evaluation of Unilateral Accessory Mental Foramina: Under Reported Anatomic Variant in Children

ABSTRACT: The following manuscript presents two paediatric cases with incidental finding of unilateral accessory mental foramina. Both the cases illustrate CBCT evaluation of a unilateral accessory foramina on the left side of the mandible, one of which, is a 12-year-old baby girl with pre-diagnosed medical history of precocious puberty and oral findings of supernumerary teeth and the other is an 8-year-old boy with oral bifurcation cyst. The not so frequent presence of additional foramina and canals in the mandible are frequently undervalued in clinical procedures and to our knowledge has not yet been reported in paediatric cases in the literature so far. In these case reports, authors attempt to document a rare and first of its type ever reported anatomic variant of mandible in paediatric patients in the whole literature.

RESUMEN: El manuscrito presenta dos casos pediátricos con hallazgo incidental de forámenes mentonianos accesorios unilaterales. Ambos casos se refieren a la evaluación CBCT de un foramen accesorio unilateral en el lado izquierdo de la mandíbula, uno de los cuales era una niña de 12 años con antecedentes medicos prediagnosticados de pubertad precoz y hallazgos orales de dientes supernumerarios y el otro un niño de 8 años con quiste de bifurcación bucal. La presencia no tan frecuente de forámenes y canales adicionales en la mandíbula se subestima con frecuencia en los procedimientos clínicos y, hasta donde sabemos, aún no se ha informado en casos pediátricos en la literatura hasta el momento. En esta serie de casos, los autores intentan documentar una variante anatómica rara y primera de su tipo de la mandíbula en pacientes pediátricos en toda la literatura.

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.

Frecuencia y caracterización de foramen mental accesorio en una población chilena mediante tomografía computarizada de haz cónico / Frequency and characterization of accessory mental foramen in a Chilean population using cone beam computed tomography

RESUMEN: En la práctica clínica odontológica, reconocer estructuras anatómicas es determinante en la planificación de distintos tratamientos que involucren algún riesgo. Uno de los exámenes complementarios recomendados para la planificación de diferentes tratamientos en odontología es la Tomografía Computarizada de Haz Cónico (CBCT). Con este examen, se pueden pesquisar variantes anatómicas como el Foramen Mental Accesorio (FMA), el cual es importante identificar para prevenir complicaciones. El objetivo de este trabajo fue determinar la frecuencia y caracterización de FMA en una población chilena adulta, de la ciudad de Valdivia, Chile. Este estudio es de tipo observacional descriptivo. Se revisaron 247 exploraciones de diferentes centros radiológicos de la ciudad de Valdivia, cumpliendo 143 con los criterios de selección. Este estudio fue aprobado por el Comité ético científico del Servicio de Salud de Valdivia. Se encontró presencia de FMA en el 17,48 % que corresponde a 25 pacientes de un total de 143, correspondiendo un 80 % al sexo femenino. El rango etario en que se encontró con mayor frecuencia correspondió a 18-39 años. La distancia promedio entre FMA y FM (Foramen Mental) fue de 5,76 mm, correspondiendo a 2 mm la distancia mínima y 11,5 mm la distancia máxima. La distancia promedio entre FMA y ápice dentario más cercano fue de 5,36 mm. La distancia mínima y máxima fueron de 0,8 mm y 10,2 mm respectivamente. El ápice radicular mayormente asociado al FMA correspondió al segundo premolar con una frecuencia de 60 % (n=15). Este estudio confirma la importancia de la correcta evaluación de la región mental ante procedimientos en la zona, la cual es vital para prevenir lesiones en relación a esta variante anatómica.

SUMMARY: The recognition of key anatomical structures is decisive to avoid complications in the dental clinical practice. Cone Beam Computed Tomography (CBCT) is a complementary exam recommended for the planning of different procedures in dentistry. With this exam, anatomical variants can be identified, such as the Accessory Mental Foramen (AMF). The objective of this work was to determine the frequency and characteristics of AMF in an adult Chilean population from the city of Valdivia, Chile. This is an observational study that included 247 CBCT exams from different radiological centers in Valdivia. According to the selection criteria, 143 CBCT exams were included. This study was approved by the Scientific Ethics Committee of the Valdivia Health Services. AMF was identified in 25 patients representing 17.48 %. From this result, 80 % were found in females. AMF was most frequently identified in patients from 18 to 39 years old. The average distance between AMF and Mental Foramen (MF) was 5.76 mm, which corresponds to 2 mm the minimum distance and 11.5 mm the maximum distance. The average distance between AMF and the nearest dental apex was 5.36 mm, and the minimum and maximum distance were 0.8 mm and 10.2 mm, respectively. The root apex of the second premolar was most frequently associated with the AMF, representing 60 % (n=15). This study confirms the importance of the correct evaluation of the mental region before initiating procedures in the area, which is vital to prevent injuries associated with this anatomical variant.

Detection of the Accessory Mental Foramina on Human Mandibles Using Cone-beam Computed Tomography: A Systematic Review and Meta-analysis.

INTRODUCTION: This study aimed to perform a systematic review and meta-analysis on accessory mental foramen (AMF) research using cone-beam computed tomographic (CBCT) imaging. METHODS: A systematic review was performed in PubMed, Embase, Thomas Reuter's Web of Science, Scopus, and ScienceDirect databases according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement. Articles focusing on AMF prevalence and location using CBCT imaging were selected without language restrictions. Studies reporting pooled results only or presenting any pathology in the area surrounding the mental foramen (MF) were excluded. A meta-analysis using random effects was performed. RESULTS: The present meta-analysis included a total of 46 articles involving 21,761 subjects. The overall pooled AMF prevalence was 7.87% (95% confidence interval [CI], 6.69-9.24) in subjects and 4.75% (95% CI, 3.79-5.95) in hemimandibles (n = 31,158). AMF presence was most commonly unilateral, reaching 90.15% (95% CI, 82.98-94.49). AMFs were significantly more frequent in right hemimandibles (χ2 = 5.20, P < .05) and were most commonly located posterior and inferior to the MF. However, AMFs superior to the MF were also observed in 47.43% (95% CI, 38.45-56.58) of cases. The studies conducted over the last 3 years showed significantly higher AMF prevalence levels (χ2 = 5.12, P < .05). CONCLUSIONS: Our meta-analysis demonstrates that AMF prevalence is considerable and should not be underestimated. AMFs are most frequently located in right hemimandibles. The presence of AMFs superior to the MF is frequent. Around 3% of people present superior AMFs. This fact puts those patients at greater risk for injury when performing periapical surgery in this area.

An Alternative Classification Scheme for Accessory Mental Foramen.

BACKGROUND: The mental foramen (MF) is an important anatomical landmark on the mandible. MFs may occur singly or with extra foramina (accessory mental foramen (AMF)). OBJECTIVE: The aim of the present study was to discuss the importance of recognition and classification of AMFs. METHODS: This study assessed CBCT images of 593 patients (208 male, 385 female) and proposed an AMF classification scheme based on three different characteristics: (1) location of the AMF with respect to the MF; (2) relationship of AMFs with tooth apices; and (3) origin of the AMF. The chi-squared test was used to compare the qualitative data as well as descriptive statistical methods when the study data were evaluated. Significance was assessed at the p < 0.05 level. RESULTS: A total of 80 AMFs were found in 71 patients. Six cases involved bilateral AMFs, whereas three cases showed double AMFs. The most common AMF location was the region posterior of the MF. Notably, all the AMFs detected in line with the mesial half of the first molar were present in female patients. Based on AMF origins, 44.5%, 48.6%, and 6.7% of the AMFs were categorized as type I, type II, and a new category identified in this study, type III. CONCLUSION: This study revealed that some foramina locations were not considered in the previous classification. Recognition and identification of these foramina might be critical to prevent possible complications. The proposed classification scheme may facilitate this objective and can be a new focus for future studies.

Accessory Mental Foramen in a Patient with Mandibular Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ) Lesion: A Case Report.

The mental nerve is a sensory nerve which traverses through mental foramen to innervate the lower lip, chin skin and the mandibular labial gingiva. Interestingly, it's variant such as the accessory mental foramen (AMF) was described as an unusual finding in the recent literature. Hereby, we reported a patient who was operated to treat the mandibular bisphosphonate-related osteonecrosis of the jaw (BRONJ) lesion. Intraoperatively, an accessory mental foramen was detected posterior to the main foramen and nerve, on the right side of the mandible. This case report highlighted the necessity for proper radiological and clinical evaluation of mental foramina in order to avoid nerve injury and postoperative paresthesia. The review of the literature and the clinical findings were also discussed in this article.

Variation in accessory mental foramen frequency and number in extant hominoids.

Nerves providing sensation to the lower face and jaw exit the mandibular canal via the mental foramen. In humans, there are many documented occurrences of additional foramina (accessory mental foramina, AMFs) on the lateral mandibular surface that may also contain nervous structures. There are large discrepancies in the literature regarding how often AMFs occur in humans, and investigations of non-human hominoid AMFs are rare. Consequently, the causes of interspecific diversity in this variable have not been explored. This project seeks to compare the frequency and number of AMFs between males and females, and among human regional groups and hominoid subspecies and species, and to investigate possible causal factors for any differences identified. No significant differences were found between males and females in any group. Gorillas and orangutans had the highest percentages of individuals with AMFs and the highest mean number of foramina, while modern humans and siamangs had the lowest figures for these variables. Significant differences (p < .05) were found for the mean number of foramina between most pairs of species. The results also showed that species with mandibles that are larger overall, have a larger area anterior to mental foramen, and a longer mandibular canal typically present more AMFs. The strongest correlation was found between the mean number of mental foramina and mandibular canal length. We suggest that these results provide preliminary support for the hypothesis that increasing mandibular canal length increases the likelihood that that nerves will ramify, leading to greater frequencies of accessory mental foramina.

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

PURPOSE: The aim of this study was to evaluate the frequency and location of accessory mental foramen (AMF) in a Turkish population using cone beam computerized tomography (CBCT). METHOD: CBCT images of 1005 patients were retrospectively reviewed from the archive of the Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Izmir Katip Celebi University. The prevalence, size, and localization of AMFs were assessed according to gender and age. In addition, the vertical and horizontal dimension of the mental foramen (MF) with and without AMF was measured to investigate the relationship between MF dimensions and the presence and absence of AMF. The average distance between the MF and AMF was also calculated. All measurements were then analyzed statistically. RESULTS: A total of 149 AMFs in 123 (12.23%) patients were identified on the CBCT images of the 1005 patients reviewed. There was no significant correlation between presence of AMF and gender (p = 0.152). The most common localization of an AMF with respect to the MF was posterio-inferior (n = 52; 34.89%). A statistically significant difference was also found between the vertical and horizontal dimensions of the MF with and without AMF (p < 0.05). CONCLUSION: The results of this study demonstrate the high prevalence of AMF in the studied Turkish population. Considering the high prevalence and the structures passing through it, recognition of AMF and its detection using CBCT is important to prevent complications that may occur during and after surgical procedures.

The mental foramen in dry human mandibles of adult South Africans: an anatomical study / El foramen mental en mandíbulas humanas secas de adultos sudafricanos: un estudio anatómico

The objective of the study was to investigate the position, position symmetry, shape and number of the mental foramen in a heterogeneous South African population. Knowledge of the precise position of MF in maxillofacial surgery is critical for an accurate local anaesthesia; and can provide a landmark in forensic or medico legal cases. Dry adult human mandibles (n = 325) were selected and classified by ancestry. The sample comprised male-to-female ratio of 1.2:1. Observations were made for the position, position symmetry, shape and number of the mental foramen. There was a substantial to perfect agreement (p < 0.001) for most observations, except for the shape of the MF on the right side of the mandible that had a fair agreement (K = 0.25; P > 0.05). PIV of the MF is shown as the most prevalent position. PIII and IV were commonly observed in males and females respectively. PII was commonly observed in the males of European descent, while PIII was observed in male African and Mixed descents and female European descents. There was no significant difference in the symmetric analysis of MF amongst male and female (p = 0.059) and between ancestry (p = 0.455). But also, an oval shape of MF was the most common across subpopulations and ancestries, with 2 (2 %) and 3 (0.46 %) of the AMFs present. This study is the first comprehensive description of the MF in the South African population, and could be very useful in forensic anthropology in the South Africa population.

El objetivo de este estudio fue investigar, en una población sudafricana heterogénea, la posición, simetría de posición, forma y número de forámenes mentales (FM). El conocimiento de la localización exacta del FM en la cirugía maxilofacial es crítico para una anestesia local precisa y puede proporcionar un punto de referencia en casos legales forenses o médicos. Se seleccionaron 325 mandíbulas humanas secas adultas y clasificadas por ascendencia. La muestra relación hombre-mujer fue de 1,2:1. Las observaciones fueron realizadas para la posición, simetría de la posición, forma y el número forámenes mentales. Se alcanzó la perfección de concordancia (p < 0,001) para la mayoría de las observaciones, a excepción de la forma intermedia en el lado derecho de la mandíbula el cual presentó un acuerdo justo (K = 0,25; p > 0,05). La PIV de la MF se muestra como la posición más prevalente. PIII y IV fueron observados comúnmente en hombres y mujeres, respectivamente. La PII se observó comúnmente en los varones de ascendencia europea, mientras que el PIII se observó en descendientes africanos y mixtos masculinos y descendientes femeninos europeos. No hubo diferencias significativas en el análisis simétrico del FM entre hombres y mujeres (p = 0,059) y entre ascendencia (p = 0,455). Una forma ovalada de FM fue la más común a través de subpoblaciones y ancestros, con 2 (2 %) y 3 (46 %) del con la presencia de un foramen mental accesorio. Este estudio es la primera descripción comprensiva del FM en la población sudafricana, y podría ser muy útil en antropología forense en la población de Sudáfrica.

A Limited Field Cone-beam Computed Tomography-based Evaluation of the Mental Foramen, Accessory Mental Foramina, Anterior Loop, Lateral Lingual Foramen, and Lateral Lingual Canal.

INTRODUCTION: The aim of this retrospective observational study was to evaluate the cone-beam computed tomographic (CBCT)-based characteristics of the mental foramen (MF), accessory mental foramen (AMF), anterior loop (AL), lateral lingual foramen (LLF), lateral lingual canal (LLC) and to explore any relationships between their characteristics. METHODS: The location and dimension of the MF; the incidence, location, and dimension of the AMF along with its distance to the MF; the presence and dimension of the AL; and the presence, location, angle of entry of the LLF and LLC, and its relation with the mandibular canal (MC) were evaluated in 109 CBCT scans. The data were analyzed descriptively, and associations were tested using the chi-square and analysis of variance tests. RESULTS: The MF was most frequently located between the first and second mandibular premolar teeth (43.5%) or below the second premolar (34.3%). The mean horizontal dimension of the MF was 3.1 mm, the vertical dimension was 2.8 mm, and the mean vertical distance from the alveolar crest was 14.2 mm. An AMF was observed in 12.8% of cases with a mean distance of 4.1 mm from the MF. An AL was present in 47.2% of cases with a mean loop length of 3.38 mm. An LLF was present in 20.4% of cases, predominantly below the first premolar (27.3%) with a mean angle of entry of 148°. The LLC always communicated with the MC and generally not with the tooth apex. A statistically significant association existed between the presence of the LLF and AMF. CONCLUSIONS: The anatomic complexity of the MF region was confirmed; hence, CBCT-based evaluation is essential before surgical exploration of this region.

Morphological and morphometric analysis of accessory mental foramen in dry human mandibles of south indian population.

BACKGROUND: Mental foramen (MF) is an important landmark for administration of local anesthesia in surgical procedures involving the mandible. Additional mental foramina, called accessory mental foramina (AMF) transmitting branches of mental nerve, have been reported. Detection of AMFs in presurgical imaging may reduce postoperative pain in dental surgical procedures. Aim: The aim of the study was to study the incidence and morphometric analysis of accessory MF in the dry human mandibles of South Indian population. MATERIALS AND METHODS: Two hundred and sixty dry human mandibles were studied for the presence, location, shape of AMF, and its relation to MF. The horizontal diameter of AMF, and its distance from symphysis menti, the posterior border of mandible and from the base of mandible were measured and statistically analyzed. RESULTS AND CONCLUSIONS: In our study, AMF were present in 8.85% mandibles (unilateral - 7.6% [4.6% - left, 2.69% - right] and bilateral 1.6%). The most common position was below the second premolar (48.1%). AMF were round in shape (74%) and was often located either superomedial or inferolateral to MF. Their transverse diameter ranged from 0.5 to 1 mm. The AMF were situated at a mean distance of 2.96 mm from MF, 23.47 mm from symphysis menti, 11.24 mm from the lower border of the body of the mandible, and 57.35 mm from the posterior border of ramus of mandible. The knowledge of the presence of AMF and its dimensions would enable the clinicians to do mandibular procedures carefully and avoid injury to the branches of mental nerve that may be passing through it.

Five mental foramina in the same mandible: CBCT findings of an unusual anatomical variant.

The mental foramen is an important anatomic landmark located on the buccal aspect of the mandible, typically near the apex of the second premolar. Mental foramina exhibit many anatomical variations, including differences in size, shape, position, and number. The most frequent type of variation in number is the presence of double mental foramen, which has a reported incidence ranging from 1.4 to 12.5%. The incidence of triple mental foramen ranges from 0.7 to 1.2%. The frequency of accessory mental foramina varies among ethnic groups, with a low incidence in white Caucasian populations. At present, cone beam computed tomography (CBCT) is the diagnostic tool of choice for examining the maxillofacial region, and the high spatial resolution of CBCT allows accurate three-dimensional analysis of mental foramen variations. The present report describes an unusual case of five mental foramina in a 24-year-old white European male diagnosed by CBCT.

Mental foramen and lingual vascular canals of mandible on MDCT images: anatomical study and review of the literature.

The mental foramen and lingual vascular canals are related to vessels and nerves in the mandibular body. The aim of the present study was to determine the number and location of these structures and to make measurements of them. The archived Multidetector Computed Tomography images of 100 adult (15- to 70-year-old) patients were evaluated retrospectively. The diameters of the mental foramens and their distances from the front, back, upper and lower reference points were measured. The distribution of mental foramens with respect to the teeth was also researched. The presence of lingual vascular canals, and the number of median and lateral canals was determined, and the length of the median lingual vascular canals measured. All measurement parameters were analyzed by gender, side and age group. Eleven patients demonstrated a total of 15 accessory mental foramen. Median lingual vascular canals were observed in 100% of cases, with lateral lingual vascular canals determined in 32%. Significant differences were observed in the results of different gender groups (P < 0.05); in contrast, no significant difference was observed related with age or side. Accessory mental foramen was determined mostly in males, and unilaterally on the right side; also, the distances of mental foramen, except the distance from the back border of the mandible (P < 0.05), were found to be higher, bilaterally, in males. Variation of mental foramen, as well as the presence, position and size of lingual vascular canals can be clearly investigated by multidetector computed tomography. A preoperative knowledge of the positions of neurovascular and bone structures is very important for preventing complications that may occur during or after operations.

Detection and characterization of the accessory mental foramen using cone-beam computed tomography.

OBJECTIVE: This study aimed to investigate the frequency and characteristics of accessory mental foramina (AMFs) and their bony canals in a selected Chinese population using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Reconstructed CBCT images of the mandible in 784 Chinese patients (305 males and 479 females) were retrospectively analysed to identify the AMF. The presence, dimension and location of the AMF as well as the origin and course of the associated bony canal were evaluated and classified. Variations in these characteristics were analysed according to gender, side and age. RESULTS: A total of 66 AMFs were found in 57 (7.3%) of the 784 patients. The frequency of AMFs was significantly influenced by gender and side of the mandible (p < .05). Most AMFs were located apically between apices of the first and second premolars. The high-position AMFs (above the mental foramen) accounted for 54.5% of the total. The mean horizontal and vertical diameters of the AMF were 1.38 ± 0.47 and 1.23 ± 0.37 mm, respectively. Two typical types of the bony canal leading to the AMF were identified according to their bifurcation site from the mandibular canal. Most bony canals originated from the anterior loop of the mental canal (56.1%) and coursed posterosuperiorly (36.3%). The mean length of the bony canals was 5.78 ± 2.31 mm. CONCLUSIONS: This study presents a considerable frequency of AMFs in a Chinese population. The high-position AMF and the associated bony canal coursing in the oblique upward direction appear frequently. Thus, clinicians should be alert to the presence of the AMF to avoid neurovascular complications especially when dental procedures require periosteum detachment and implant insertion in the mental region.

3D CBCT morphometric assessment of mental foramen in Arabic population and global comparison: imperative for invasive and non-invasive procedures in mandible.

BACKGROUND: Recent advancements in clinical dentistry have increased the possibilities of surgical procedures in the mental region. A detailed knowledge of mental foramen (MF) morphometry is significant to preserve integrity of the mental nerve trunk in surgical interventions such as orthognathic surgery, implant placement and anaesthetic block. OBJECTIVE: The aim of this study was to determine the most accurate position of the mental foramen by using new assessment approach in a sample of dental patients presenting to the specialist dental clinic, College of Dentistry, Al Jouf University, Saudi Arabia. STUDY DESIGN: A retrospective study was performed using cone beam computed tomography (CBCT) of 600 patients (40.1 ± 11.78 years old). Following inclusion and exclusion criteria, 395 CBCT were finally obtained and analyzed for the most accurate position of the mental foramen (MF) by OnDemand 3D software (Seoul, Korea). Prevalence of shape of MF and accessory MF were also assessed. Pearson chi-square test was employed to test significant differences between genders and races. RESULTS: The most common horizontal and vertical position of the mental foramen was in line with the long axis of 2nd premolar (41.3%) and below the root apex level (93.2%), respectively. The most common shape of MF was round type (72.66%). The prevalence of accessory 2MF and 3MF was 2.28% and 0.25%, respectively. CONCLUSION: New information about MF presented in this article can help anatomists, prosthodontists, orthodontists, surgeons, forensic odontologists and paleoanthropologists to predict the position of the MF and perform safer surgeries.

The assessment of accessory mental foramen in a selected polish population: a CBCT study.

BACKGROUND: Accessory mental foramen (AMF) is a rare anatomical variation. When accessory mental foramen is present, the nerves and vessels that go through the mental foramen (MF) must follow alternative courses and special care must be taken during dental treatment planning. The purpose of this study was to evaluate the occurrence and the location of AMF in a selected Polish population using cone-beam computed tomography (CBCT). METHODS: Two hundred CBCT (105 males and 95 females) examinations were evaluated for the presence of AMFs. The location and side of AMFs were reported. The mean distance between MF and AMF was also calculated. The vertical size of MF on the side with and without AMF was measured. The obtained variables were statistically analyzed. RESULTS: AMFs were observed in 7% of the patients. There was no statistically significant difference between the appearance of AMF and sex (p > 0.05). We found no significant difference in the vertical size of MF between individuals with and without AMFs (p < 0.05). CONCLUSION: Twenty-eight AMFs (7%) were observed from 400 sides of 200 patients. AMFs occurred more often in males (18 AMFs) than in females (10 AMFs). Twenty AMFs (71.4%) were located anteriorly, and eight (28.6%) - posteriorly. Fifteen AMFs (53.6%) were on the right side and thirteen (46.4%) - on the left.

Changes in bite force after orthognathic surgical correction of mandibular prognathism: a systematic review.

Patients requesting treatment for mandibular prognathism seek functional and aesthetic improvements. Improvements in bite force and efficiency are generally used as measures of better function. It is unclear what effect the surgical correction of mandibular prognathism will have on the patient's occlusal forces. The literature was searched using medical subject heading (MeSH) and key word terms 'bite force', 'osteotomy', 'orthognathic surgery', and 'prognathism'. A total of 17 articles were included in this review. These included a total of 697 patients, who ranged in age from 15 to 44 years. Male patients outnumbered female patients in only one study. Five hundred and thirty-two patients underwent bilateral sagittal split osteotomy, 108 patients underwent intraoral vertical ramus osteotomy, and 24 patients underwent extraoral vertical ramus osteotomy (approach unspecified). In general, masticatory efficiency at 3 months after surgery was greater than that found pre-surgically; the increase was significant at 6 months after surgery. The occlusal contact area and points tended to increase from 3 months after surgery, and there was a significant increase at 12 months after surgery. Occlusal forces, although improved, will be lower in corrected prognathic patients than in normognathic patients even at 2 years after surgery.

Mental foramen morphometry in a population from Khyber Pakhtunkhwa (KP) Pakistan / Morfometría del foramen mental en una población de Khyber Pakhtunkhwa (KP) Pakistán

Knowledge of variations in MF location, size and shape is important when anesthetizing nerves of the mandibular region in dental procedures. The location, shape and position of the MF were determined in 119 human mandibles of unknown age and sex from different KP medical institutions. Parameters determined were: MF length and width; accessory mental foramen (AMF) width; MF and AMF to midline (MF-ML) (AMF-ML), upper (MF-UM) (AMF-UM) and lower mandibular margins (MF-LM) (AMF-LM) and posterior border of the mandibular ramus (MF-PRM) (AMF-PRM). AMF position in relation to the MF was also noted. MF were mainly oval and situated below the second premolar. MF mean length and width were: 2.4 ± 0.89 (right) and 2.4 ± 0.727 mm (left), and 3.0 ± 0.80 (right) and 2.9 ± 0.94 mm (left) respectively. MF-ML, MF-UM, MF-LM and MF-PRM distances on the right and left sides were: 29.1 ± 2.19 mm and 28.1 ± 2.12 mm; 11.0 ± 3.99 mm and 11.2 ± 3.98 mm; 13.1 ± 1.83 mm and 12.8 ± 1.74 mm; and 69.3 ± 5.52 mm and 68.7 ± 5.02 mm, respectively. Double mental foramen (DMF) were observed on both sides (10.9 % right, 12.6 % left) with length and width 0.7 ± 0.42 mm and 0.9 ± 0.34 mm (right) and 0.8 ± 0.32 mm and 1.0 ± 0.47 mm (left): they were mainly oval (5.8 % right, 7.56 % left). DMF-MF distance was 8.9 ± 4.58 mm on the right and 6.6 ± 4.11 mm on the left. An oval accessory mental foramen was observed in one mandible. There was no difference between right and left MF; however differences in the parameters measured were observed in relation to other populations indicating the need to be aware of such differences when undertaking surgical procedures around the MF.

El conocimiento de las variaciones del foramen mental (FM), su ubicación, tamaño y forma es importante al momento de anestesiar los nervios de la región mandibular en procedimientos dentales. La ubicación, forma y posición del FM se determinó en 119 mandíbulas humanas, de edad y sexo desconocidos, de diferentes instituciones médicas de Pakistan. Los parámetros determinados fueron: longitud y ancho; ancho del foramen mental accesorio (FMA); MF y AMF a la línea mediana (FM-LM) (FMA-LM), margen superior (FM-MS) (FMA-MU) y margen inferior (FM-MI) (FMA-MI) y el margen posterior de la rama mandibular (FM-RMP) (FMA-RMP). También se observó la posición del FMA en relación con el FM. La forma del FM fue principalmente ovalada y situado por debajo del segundo premolar. Los datos de longitud y anchura del FM fueron: 2,4 ± 0,89 (derecha) y 2,4 ± 0,727 mm (izquierda), y 3,0 ± 0,80 (derecha) y 2,9 ± 0,94 mm (izquierda), respectivamente. Las distancias FM-LM, FM-MS, FM-MI y FM-MRP en el lado derecho e izquierdo fueron: 29,1 ± 2,19 mm y 28,1 ± 2,12 mm; 11.0 ± 3.99 mm y 11,2 ± 3,98 mm; 13,1 ± 1,83 mm y 12,8 ± 1,74 mm; y 69,3 ± 5,52 mm y 68,7 ± 5,02 mm, respectivamente. Se observaron foramenes mentales dobles (FMD) en ambos lados (10,9 % derecho, 12,6 % a la izquierda) con una longitud y ancho de 0,7 ± 0,42 mm y 0,9 ± 0,34 mm (derecha) y 0,8 ± 0,32 mm y 1,0 ± 0,47 mm (izquierda): fueron principalmente ovalados (5,8 % derecha, izquierda 7,56 %). La distancia FMD-FM fue de 8,9 ± 4,58 mm a la derecha y 6,6 ± 4,11 mm en el izquierdo. Se observó un foramen mental accesorio ovalado en una mandíbula. Hubo diferencia entre FM derecho e izquierdo. Sin embargo, las diferencias en los parámetros medidos fueron observados en relación con otras poblaciones que indican la necesidad de ser conscientes de estas diferencias al realizar procedimientos quirúrgicos en todo el MF.