The elusive retromolar foramen and retromolar canal: A CBCT study

This study aims to evaluate the presence of retromolar foramen (RMF) and retromolar canal (RMC) in the mandible using cone beam computed tomography (CBCT) in Chhattishgarh population and to correlate its possible clinical impact. 175 CBCT images were collected from which 100 bilateral CBCT images of patients were retrospectively selected from the Department of Oral Medicine and Radiology of the Chhattishgarh Dental College and Research Institute and evaluated bilaterally which were taken for diagnostic purposes from maxillofacial radiology clinic and data were statistically analyzed. This was an observational descriptive study and all the images were processed and analyzed on CS3D imaging software. The data was analyzed using chi square test. The prevalence of RMF and RMC was observed in 8.5%, of which 10 were in females and 7 in males. The RMCs traversed in different directions – horizontal, vertical and angular. Based on the subjective assessment, each of these canals was further subclassified into straight and curved canal. In the present study in 12 of the cases angular curved type was found and in 3 cases, vertical straight was noticed. The bifurcation of the inferior alveolar nerve (IAN) canal was observed in 15% of the scans and remaining 85% had single mandibular canal. The proximity of RMF from buccal and lingual cortical plates was found buccally in 16 cases and in single case was found to be lingually. Position of RMF might change with the presence and absence of third molar. The absence of third molar results in anteriorly located RMF. In majority of cases it was found that RMF was located more buccal than lingual. The parameters considered in the current study will guide the oral and maxillofacial surgeons while giving incisions in 3molar impacted cases, other pathologies and ease to preserve the retromolar foramen.

Evaluation of Retromolar Canals using Cone Beam Computer Tomography/ Avaliação do canal retromolar por meio de tomografia computadorizada de feixe cônico

The aim of this study was to evaluate the prevalence, location and clinical implications related to the presence of the retromolar canal (RMC) on cone beam computed tomography(CBCT). CBCT images of patients from Latin America Institute for Dental Research and Education - Curitiba,Pr,Brazil, was performed from June/2008 to February/2013. The interpretation was performed by a calibrated examiner, according to the criterias: presence, location and classification of the RMC variation, as well as, measurements of horizontal distances of the RMC in relation to the buccal bone cortical and diameter of these canals. A total of 751 CBCT images were interpreted: 486(64.7%) from females and 265 (35.3%) from male patients, with mean age of 54.57 (±13.23) years. The presence of RMC was observed in 58 (7.7%) patients, 23 men and 35 women. A total of 1502 hemi- mandibles were analyzed. The RMC was identified in 69(4.6%) hemi-mandibles, 44(63.8%) from females and 25(36.2%) from males. Thirty (42.8%) RMC were observed on the right side and 40 (57.2%) on the left one. The type B1 (n=33; 47.1%) was the most common, followed by the type A1 (n=18;25.7%). The mean diameter of RMC was 0.97mm (±0.44), and the mean distance between retromolar foramen and the buccal cortical of the mandible was 4.12mm (±1.35). There were no significant differences between the distances and genders, and distances and sides (p 0.05). The prevalence of RMC was 7.7% in the studied sample; they were predominantly unilateral and showed to be type B1.

The relation between the distance from mandibular retromolar foramen to mandibular angle and lower third molar using panoramic radiographs

Background: Third molars are the last to erupt in the permanent teeth series. These teeth are the most likely to be impacted this research aims to evaluate whether the distance between mandibular retromolar foramen and mandibular angle renders different results in case of absence or presence of lower third molar in both genders.Methods: A respective study conducted on 186 the distance between mandibular retromolar foramen and mandibular angle were examined on Digital panoramic radiograph (DPR). The radiographs were grouped according to Absence or presence of left lower third molar and subject gender. A logistic regression model was created using the statistically significant data.Results: The lower third molar impaction on the distance between mandibular retromolar foramen and mandibular angle was not significantly different between mean groups (absence and presence) when gender is disregard. The distance between the two was significantly increased in the male subgroup.Conclusion: The relation between the distance between mandibular retromolar foramen and mandibular angle and third molar using panoramic radiographs showed no fundamental difference in the distance between mandibular retromolar foramen and mandibular angle in case of absence or presence of lower third molar when gender is disregard.

Incidence of the retromolar foramen in dry mandibles and its significance for dental surgical procedures

O forame retromolar, assim como o canal retromolar, são variações anatômicas da mandíbula que se apresentam na região do trígono retromolar. Esse forame e canal contêm estruturas neurovasculares que fornecem inervação adicional aos molares inferiores e à área bucal. Objetivou-se verificar a incidência e ocorrência entre os sexos do forame retromolar em mandíbulas da Coleção de Ossos Contemporâneos da Universidade Federal de Pernambuco. Foram analisadas 61 mandíbulas secas, sendo 37 masculinas e 24 femininas. Das 61 mandíbulas, 18 apresentaram o forame retromolar (29,5%), sendo 12 mandíbulas apresentando o forame unilateralmente (19,67%). As mandíbulas masculinas apresentaram uma maior incidência comparada às femininas, tendo totalizado 12 (32,43%) mandíbulas com forame retromandibular. A população analisada mostra uma alta incidência do forame retromolar, especialmente para o lado direito. A identificação dessa variação anatômica auxilia no planejamento de cirurgias e durante os procedimentos anestésicos.

Double retromolar foramen during an inferior third molar extraction: a rare case report

Objetivo: O objetivo do presente estudo foi relatar a ocorrência de um forame retromolar duplo durante a exodontia de um terceiro molar inferior. Relato de Caso: Um paciente de 20 anos do sexo masculino foi encaminhado à clínica odontológica da Universidade Federal de Alagoas para realizar extração dos terceiros molares do lado esquerdo, por motivos ortodônticos. Um forame retromolar duplo foi identificado perioperativamente durante o descolamento muco-periosteal na região do trígono retromolar, distalmente ao terceiro molar inferior esquerdo, onde houve hemorragia moderada, a qual foi controlada utilizando compressão local com gaze embebida em solução de anestésico local com vasoconstritor. A ocorrência dessa variação da normalidade foi registrada por fotografias. Antes da realização do procedimento, a radiografia panorâmica do paciente sugeria a presença dessa estrutura anatômica. Conclusões: O conhecimento acerca da ocorrência de um forame retromolar duplo apresenta importância clínica para exodontia de terceiros molares inferiores e pode auxiliar o dentista na prevenção e no manejo de acidentes e complicações durante esse procedimento cirúrgico

Risk factors for anesthesia failure in the mandible.

Local anesthesia is a common procedure in the daily dental practice, however, there are multiple factors affecting the effectiveness of this procedure. Correct identification of the causes of the failure is essential at the time of taking the necessary measures to achieve the anesthetic success. Most problems in the anesthesia of the mandible are due to limited access and anatomical variants, such as: bifid Inferior Alveolar Nerve, Retromolar Foramen, Accessory Mental Foramen, Accessory innervations and Cross Innervations. Moreover, inflammation increases the absorption of anesthetic, reducing its concentration at the site of action. The several techniques available for mandibular anesthesia does not guarantee 100% effectiveness, plus each individual techniques presents indications and complications. Psychological phenomena such as anxiety and fear to the dentist can also increase the perception of pain. The clinician should all aspects involved but also the psychological variables that negatively affect dental patient care in anesthetic procedures.

Anatomical description of retromolar foramina in dry human mandibles: incidence, morphometry, and topography

ABSTRACT Objective: To carry out morphometric, topographic, incidence analysis of retromolar foramina in dry adult human mandibles, and relate the findings to Dental practice. Methods: 265 mandibles were evaluated simultaneously by two researchers. With the aid of metal wires, each retromolar foramen was classified regarding diameter. Foramina with a diameter smaller than 0.5mm were not taken into account. Results: Retromolar foramina were observed in 23.4% of cases, with a higher bilateral incidence (with distinction of both antimeres), and up to 4 of them located in the same mandible. Furthermore, most foramina had a diameter between 0.5 and 1mm. Conclusion: The retromolar foramina are clinically relevant findings and should never be underestimated by clinicians.