Detection of buccal perimandibular neurovascularisation associated with accessory foramina using limited cone-beam computed tomography and gross anatomy

Prevalence of accessory mental foramen and lateral lingual foramen using cone beam computed tomography: A single-center cross-sectional study

PURPOSE

This study aimed to assess the prevalence, dimensions, and positions of accessory mental foramen (AMF) and lateral lingual foramen (LLF) in an Iranian population using cone beam computed tomography (CBCT).

METHODS AND MATERIALS

In this cross-sectional study, CBCT images of 2082 patients were retrospectively reviewed based on inclusion criteria, including images from the mandibular region taken in the past five years with accurate demographic data. Exclusion criteria included images with significant pathologies, fractures, or poor quality. CBCT images were captured, and AMF and LLF presence (primary outcome variable), dimensions, and positions (secondary outcome variables) were recorded relative to the mental foramen and adjacent teeth. Data analysis was performed using the Chi-square test with a 5% significance level.

RESULTS

A total of 2082 CBCT samples (46.54% females and 53.46% males) with a mean age of 48.30 ± 12.70 years were examined. Among these, 246 AMFs were observed in 222 individuals with a prevalence at the foramen level of 11.815%, with 24 having two AMFs. AMF was mostly observed unilaterally, with bilateral occurrence noted in 10.81% of patients with AMF. Additionally, 86 patients were found to have LLF with a prevalence at the foramen level of 5.907%. There were no significant differences between genders in AMF and LLF prevalence.

CONCLUSION

AMF and LLF were detectable using CBCT in the selected Iranian population. AMF was commonly situated posterior and superior to the mental foramen, while LLF was often found near the first premolar. This knowledge is crucial for preventing nerve injury during surgery and ensuring effective nerve block procedures.

Lobular capillary hemangioma with an intraosseous feeder vessel through an accessory buccal foramen in the mandible: A unique case report

The aim of this case report is to present a unique and rare finding in a 29-year-old male with the chief complaint of swelling in the gums related to the back teeth of the lower left jaw, since 20 days. In the absence of any alarming findings on the intraoral periapical radiograph and blood profile, an excisional biopsy of the provisionally diagnosed pyogenic granuloma was planned with a high-power diode LASER (Light Amplification by Stimulated Emission of Radiation). Following the excision, an unusual amount of bleeding was encountered from a single point on the buccal cortical plate between the teeth #35 and #36. On reevaluating the left face with advanced radiodiagnostic methods, an accessory buccal foramen was reported distal to #35 which housed a thin, tortuous, and aberrant branch of the inferior alveolar artery. The swelling was histopathologically diagnosed as lobular capillary hemangioma, and the aberrant artery was labeled as its feeder vessel. The patient had no episode of recurrence until 2 years of follow-up.

Cone-beam-computed tomography evaluation of mandibular nutrient canals in patients with periodontal diseases

Background and Aim

The aim of this study was to evaluate radiographically the prevalence of mandibular nutrient canals (NCs) in patients with/without periodontal bone loss with aging and to correlate the number of NCs with the severity of bone loss using cone-beam-computed tomography (CBCT).

Patients and Methods

CBCT examinations of 208 patients were evaluated retrospectively of all patients, 114 had periodontal bone loss, whereas 94 patients were control subjects. Alveolar bone loss investigations were performed according to the Progressive Rate Index.

Results

NCs were observed in 55% of the control group and 86% of the periodontitis patients. NCs were more prevalent in the elderly age group with periodontal bone loss. In the study group, the NCs were statistically more frequent than in the control subjects (P > 0.05).

Conclusion

Statistical analysis showed a significant difference between the age groups and the prevalence of NCs increased in patients with periodontal alveolar bone loss with aging (P < 0.05).

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.

PECULIARITIES OF THE SOURCES OF ORIGIN AND MORPHOGENESIS OF THE HUMAN MANDIBLE

OBJECTIVE

The aim: To determine the sources and terms of origin, developmental peculiarities and dynamics of ossification of the mandible during the prenatal period of human ontogenesis.

PATIENTS AND METHODS

Materials and methods: The research was carried out on the specimens of 30 embryos, 30 pre-fetuses and 60 human fetuses at the period from the 9th to the 12th weeks of the intrauterine development, which were studied by microscopic examination. Three-dimensional computer reconstructions of the human pre-fetal head were made.

RESULTS

Results: During the 7th week of development the maxillary processes maximum approach the lateral and medial nasal ones; in pre-fetuses 20,0 mm of PCL they join the frontal spindle forming the facial structures (upper jaw and lip, vestibule of the oral cavity, rudiments of dental laminas, and rudiments of dental buds in its distal portions). Osteogenous islets, rudiments of the mimic and masticatory muscles, blood vessels are formed. During the 8th week of development the osseous tissue of the mandible is formed, the alveolar processes are formed. The oral and nasal cavities are isolated in 9-10-week pre-fetuses, the mass of the osseous tissue increases in both jaws, the enamel organs are detached, the angles and rami formed by the hyaline cartilaginous tissue of the mandible are determined, the rudiments of the temporomandibular joints are already seen. During the 11th week of development the osseous base of both jaws become formed. Till the end of the 12th week the osseous tissue begins to replace the hyaline cartilage of the mandibular rami, and the articular heads are formed in the portion of their proximal ends.

CONCLUSION

Conclusions: The mandible in its development is known to be characterized by intra-cartilaginous formation of the bone which starts from the ends of the cartilage gradually displaced by the osseous tissue. It is indicated that both jaws in pre-fetuses 37,0 and 42,0 mm of PCL are presented by the typical cartilaginous tissue, and in pre-fetuses 45,0-50,0 mm of PCL the osseous tissue is already available replacing the cartilaginous one.

Characteristics of Mandibular Canal Branches Related to Nociceptive Marker

It is difficult to correlate the direction of mandibular canal branches (MCBs) with altered sensation in dental treatments. In contrast, calcitonin gene-related peptide (CGRP) is related to vasodilation, bone formation, and the interaction with the peripheral nervous system. Therefore, we investigated the detailed morphological characteristics of MCBs using cone-beam computed tomography (CBCT) and observation of the CGRP distribution around the MCB. The MCB measurements were evaluated using principal component analysis (PCA) to identify morphological correlations. A total of 168 sides of mandibles from 84 cadavers were analyzed in this study. Most of the MCBs were primarily in the direction of the clock model from X to XI in sagittal sections and XII to I in coronal sections of the mandible. The structure of the MCB was divided into the fine canal branch (60.4%, 223/369), partial branch (24.4%, 90/369), and no canal branch (15.2%, 56/369). PCA indicated that the measurement element with the MCB and its structures were correlated in contrast to tooth factors. Positive CGRP reactions were clearly observed in the no-canal branch group compared to other groups. These data provide useful suggestions for MCB dynamics and information for clinical dental treatment.

The mandibular incisive foramen, a false mental foramen

BACKGROUND

The mandibular incisive foramen (MIF) is an opening on the external surface of the dentate mandibular body, medial to, and facing the mental foramen (MF). There is actually scarce evidence of such MIF.

CLINICAL PRESENTATION

A retrospective Cone Beam CT (CBCT) study of the archived files of a 56 y.o. male patient was documented anatomically for dental medical purposes. In the 2^nd premolar region of the left hemimandible were found two adjacent foramina facing one each other: the distal one was opened medially, while the medial one was oriented distally. On axial CBCT slices the mandibular canal was detected to open at the distal foramen in the outer cortical plate of the mandible. The medial foramen in that cortical plate served as entrance to the mandibular incisive canal, thus being a MIF.

CONCLUSION

CBCT accurately distinguishes the canals opening on the outer cortical plate of the mandible thus is of use to differentiate a MIF from a MF. Such adjacent foramina expose at risk not just the mental nerve, as in cases with true multiple MF, but also the IAN and the mandibular incisive nerve.

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.

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.

Accessory Mental Foramen and Maxillofacial Surgery

Accessory mental foramens should be considered in surgical procedures performed in mandibular body and symphysis. Location and content of these foramina has significant impact on the result of surgery.Lip numbness is the catastrophic result if these foramina are violated while their content is nerves that carry sensory inputs from lower lip. Examples of interferences with dental implant, orthognathic, and periapical surgeries are presented and it is discussed in which conditions they complicate oral surgical procedures.

Accessory mandibular foramen during dental implant placement: case report and review of literature

Accurate knowledge of vital anatomical structures, such as the inferior alveolar nerve, mental nerve, and mental foramen, is critical to achieve favorable results during oral surgical procedures and dental implant placement. Although uncommon, variations in mandibular foramina have been reported and if unnoticed and, as a result, injured, may lead to patient morbidity, neurosensory disturbances, and other undesired complications. We present a case report of identification of an accessory mandibular foramen (AMF) encountered during placement of 2 dental implants for a mandibular implant-retained overdenture and demonstrate appropriate management. In addition, we propose a more reasonable terminology for such accessory foramina so as to facilitate communication through common terminology among health care providers. As conventional radiography (periapical and panoramic films) may not allow for proper identification of such anatomical variations, cone-beam computed tomography may be useful in the diagnosis of AMF during treatment planning of dental implants in the mandible.

Multiple accessory foramina of the mandibular ramus: risk factor for oral surgery

A 27-year-old female was referred to our hospital with a chief complaint of removal of an impacted right mandibular third molar. Panoramic radiography showed two small circular radiolucencies on the right mandibular ramus. Computed tomography revealed that one of the radiolucencies was an accessory foramen located lateral to the mandibular ramus, and the other radiolucency was an accessory foramen located medial to the ramus; it was also connected to the mylohyoid groove. Continuity with the mandibular canal was confirmed for both accessory foramina. After explaining the risks of extraction, the patient decided against surgery and the impacted tooth was left in situ. Most patients have at least one or more accessory foramina in the mandible; however, accessory foramina of the lateral aspect of the mandibular ramus have not been reported. The high resolution of cone-beam computed tomography and three-dimensional reconstructed images enable improved detection of accessory foramina. Therefore, additional accessory foramina that are similar to those found in the present case could be found in the future using such imaging modalities.

The effectiveness of articaine in mandibular facial infiltrations

Four percent articaine local anesthetic has been successfully used to attain local anesthesia for dental procedures. Mandibular block anesthesia may consume longer time to attain and have a higher failure of local anesthesia compared to infiltration. Mandibular facial infiltration has been reported to successfully attain effective local anesthesia for dental procedures. This study involved only several tooth sites and found that 1.8 cc of 4% articaine facial infiltration in the mandible may be effective when the facial mandibular cortex is <2.0–3.0 mm. A waiting time of 5–10 minutes may be required for effective anesthesia. An additional 1.8 cc of dose may be required to attain anesthesia if an initial 1.8 cc of dose fails. The need for additional anesthetic may be predicted by a measurement of the facial cortex using cone beam computerized tomography. A study of mandibular sites is needed to delineate the anatomical dimensions, density of cortical bone, and apical neural location for ensuring successful local anesthetic infiltration.

Number of accessory or nutrient canals in the human mandible

OBJECTIVES

The aim of the study was to assess the presence, location and the number of accessory or nutrient canals in the body of the mandible by means of cone beam CT images, obtained with the Planmeca ProMax® 3D Max device.

MATERIAL AND METHODS

Seventy-four cone beam images of the mandible from adult patients (37 males and 37 females) who were imaged for dental implantology planning or third molar extraction were used to assess the number and location of accessory or nutrient canals. All images were taken with the same machine (Planmeca® ProMax 3D Max) at 200-, 400- or 600-μm resolution. Distinction was made between canals entering or exiting the mandible superior or inferior of the inferior alveolar canal and between similar canals superior or inferior of the genial tubercula.

RESULTS

The number of accessory canals varied between nil to 11. No statistical significant difference between males and females was found with regard to the number or location of accessory canals in the mandible. Only 5.4% of patients had no accessory canals. One to five accessory canals were found in 71.6%, and 23% of patients had more than five accessory canals. The majority (81%) of patients had between two and six accessory canals.

CONCLUSION

It seems that subjects showing no accessory canals whatsoever should be considered exceptional as more subjects with than without accessory canals in the body of the mandible were found.

CLINICAL RELEVANCE

These results are clinically relevant for mandibular surgery and mandibular local anaesthesia.

Detection and characterization of the mandibular accessory buccal foramen using CT

OBJECTIVE

To investigate the frequency and characteristics of the mandibular accessory buccal foramen (ABF) with CT.

METHODS

A retrospective study was carried out using the CT records of 504 patients referred to the Erciyes University Medical School (Kayseri, Turkey) between 2007 and 2010. Presence, location, diameter, area and number of ABFs and their continuity with mandibular canal and distance to the mental foramen were evaluated using axial, sagittal and three-dimensional CT images. Statistical analysis was performed using SPSS® v. 15 (SPSS Inc., Chicago, IL), and t-tests were used for statistical analysis.

RESULTS

14 ABFs were observed in 10 (2%) of 504 patients. The frequency of ABFs was found to be 2.6% in males and 1% in females. The mean distance between the ABF and the mental foramen was 5.0 mm [standard deviation (SD) ± 2.48]. The mean long axis of the ABFs was 1.4 mm (SD ± 0.4) and the mean area of them was 1.5 mm(2) (SD ± 0.8). The mean area of the mental foramen on the side with the ABF was 4.1 mm(2) (SD ± 2.71).

CONCLUSIONS

This study presents a relatively lower frequency of ABFs than that in the literature. These foramina could have more complex neurovascular structures than was previously thought. Thus, in special cases where a direct surgical exploration during the planned surgery is not indicated, CT or cone beam CT examination to determine the possible presence of ABFs may be indicated.