scholarly journals Incidence and Anatomical Properties of Retromolar Canal in an Iranian Population: A Cone-Beam Computed Tomography Study

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
N. Nikkerdar ◽  
A. Golshah ◽  
M. Norouzi ◽  
S. Falah-Kooshki

Objectives. Retromolar canal (RC) is an anatomic structure, and due to increasing demand for surgical procedure in the retromolar area of the mandible, the identification of the retromolar canal has become an issue of clinical concern. It can innervate the third molar and some of the muscles around the posterior segment of the mandible, complicating surgical procedures in the retromolar area and root canal treatment of third molars. The aim of this study was to evaluate the incidence and anatomical properties of RC in a western Iranian population using cone-beam computed tomography (CBCT) images. Materials and Methods. Two hundred bilateral CBCT images were collected and screened in the three spatial planes for the presence of an RC. Anatomical properties and location of the RCs were assessed according to their course and distance from the surrounding structures. The relationship between the presence of RC and age, sex, side, and presence of second and third molars was also evaluated. Independent samples t-test, ANOVA, Tukey’s post hoc test, paired t-test, and chi-square were used to compare groups. Results. At least one RC was observed in 22% of the mandibles. Its bilateral incidence was 5.5%. Two major types of canals were detected, namely, type I, following a straight or curved course from the mandibular canal (MC) to the retromolar area (47.3%), and type II, coursing from the retromolar area to the radicular part of the third molar (52.7%). Regarding linear measurements, the mean RC diameter and the mean distance to the MC, second, and third molars were 0.68 ± 0.31, 13.7 ± 2.8, 15.3 ± 3.0, and 7.3 ± 2.3 mm, respectively. Conclusion. Based on the results of this study, RC was found in 22% of the cases; thus, it should be considered as a normal anatomical variation in the Iranian population rather than a rare finding.

2016 ◽  
Vol 10 (04) ◽  
pp. 454-458 ◽  
Author(s):  
Roberto Pippi ◽  
Marcello Santoro ◽  
Ferdinando D'Ambrosio

ABSTRACT Objective: Cone-beam computed tomography (CBCT) has been proposed in surgical planning of lower third molar extraction. The aim of the present study was to assess the reliability of CBCT in defining third molar root morphology and its spatial relationships with the inferior alveolar nerve (IAN). Materials and Methods: Intraoperative and radiographic variables of 74 lower third molars were retrospectively analyzed. Intraoperative variables included IAN exposure, number of roots, root morphology of extracted third molars, and presence/absence of IAN impression on the root surface. Radiographic variables included presence/absence of the cortex separating IAN from the third molar roots on CBCT examination, number of roots and root morphology on both orthopantomography (OPG) and CBCT. The statistical association between variables was evaluated using the Fisher's exact test. Results: In all cases of intraoperative IAN exposure, the cortex appeared discontinuous on CBCT images. All cases, in which the cortical bone was continuous on CBCT images, showed no association with nerve exposure. In all cases in which nerve impression was identified on the root surface, the IAN cortex showed interruptions on CBCT images. No nerve impression was identified in any of the cases, in which the cortex appeared continuous on CBCT images. CBCT also highlighted accessory roots and apical anomalies/curvatures, not visible on the OPG. Conclusions: CBCT seems to provide reliable and accurate information about the third molar root morphology and its relationship with the IAN.


2021 ◽  
Vol 10 (34) ◽  
pp. 2910-2914
Author(s):  
Abhishek Verma ◽  
Stuti Verma ◽  
Anushikha Dhankhar ◽  
Nitin Kumar Moral ◽  
Nidhi Nagar ◽  
...  

BACKGROUND A serious complication of surgical removal of impacted lower third molars is inferior alveolar nerve (IAN) injury. Evaluation of radiographic factors to predict IAN injury using CT and panoramic radiography includes root morphology assessment, follicular sac size, mandibular bone density, inferior alveolar nerve and vessels, condition of the overlying tissues, relation of the impacted tooth with the body and ramus of the mandible and the adjacent teeth. This study was done to evaluate the radiological features of the impacted lower mandibular teeth and their relationship with IAN through panoramic radiography and CT and to assess the most predictable radiological criteria for inferior alveolar nerve injury in impacted third molar surgery. METHODS All the patients indicated for lower third molar extraction were included in the study and pre-operative conventional panoramic radiographs (Planmeca Proline PM 2002 CC, Helsinki, Finland) and CBCT (Kodak CBCT) were taken. Any post-operative nerve injuries detected were followed up after 15 days or 1 month. Fisher’s exact test was done to find the association between the outcome variable and explanatory variables. RESULTS Only 11.4 % (N = 4) of all participants had IAN injury following surgical disimpaction. All the participants with IAN injury showed narrowing of the canal on their preoperative panoramic radiographs and presence of nerve approximation with the tooth in cone beam computed tomography (CBCT) reports (P < 0.05). CONCLUSIONS A statistically significant association exists between IAN injury and nerve exposure, radiographic signs of nerve involvement for panoramic radiograph, level of third molar impaction, and nerve approximation in CBCT. KEY WORDS Inferior Alveolar Nerve Injury, Lower Third Molar Impaction, Panoramic Radiography, CBCT


Author(s):  
Shirin Sakhdari ◽  
Sara Farahani ◽  
Ehsan Asnaashari ◽  
Sahel Marjani

Objective: This study sought to assess the frequency and severity of second molar external root resorption (ERR) due to the adjacent third molar and its correlation with the position of third molar and other related factors using cone-beam computed tomography (CBCT). Materials and Methods: This cross-sectional study evaluated 320 second molars and their adjacent impacted third molars on CBCT scans of patients over 16 years, retrieved from the archives of Azad University Radiology Department. Presence/absence of second molar ERR, its location and severity (if present), and position of adjacent third molar were determined on CBCT scans, and recorded in a checklist. Data were analyzed using a logistic regression model. Results: The frequency of second molar ERR was 33.4% in the mandible and 14% in the maxilla. The severity of ERR was significantly correlated with the involved jaw (P=0.001) but had no correlation with age, gender, or depth of impaction of adjacent third molar (P>0.05). The mesioangular and horizontal positions of impacted third molars had a significant correlation with the frequency of second molar ERR (P<0.006). Conclusion: According to the results of this study, ERR occurring in second molars adjacent to third molars is common, especially in the mandible. Mesially inclined third molars have a greater potential of being associated with ERR in second molars.


2018 ◽  
Vol 23 (1) ◽  
Author(s):  
Marcelo Bonifácio da Silva Sampieri ◽  
Danilo Da Silva Correa ◽  
Francisca Lívia Parente Viana ◽  
Thaís Sumie Nozu Imada ◽  
Josfran Da Silva Ferreira Filho ◽  
...  

Objective: it is important to evaluate the position andestablish the third molar relationship with the mandibularcanal to minimize the risk of nerve injury and assistin planning the extraction of this tooth. The panoramicradiograph is the standard diagnostic tool for this purpose.However, if it indicates a close relationship betweenthe third molar and the mandibular canal, furtherinvestigation using cone beam computed tomography(CBCT) may be recommended to check the three-dimensionalrelationship between the tooth and the mandibularcanal. Thus, this study aimed to correlate the clinicalfindings (observed in third molar surgeries) to imagingfindings (observed in panoramic radiographs andCBCT). Subjects and method: after the extraction of 20mandibular third molars, the panoramic radiograph andthe cone beam computed tomography were analyzed.Then, the surgical findings were correlated to the imagefindings. Results: It was observed that the radiographicfinding type 2 (darkening of roots) observed in the panoramicradiograph presented a greater relation to theabsence of cortical bone between the mandibular canaland the third molar (CBCT finding), with statistical significance(p


2019 ◽  
Vol 21 (5) ◽  
pp. 474-476
Author(s):  
Ana Paula Tulio Manfron ◽  
Alessandra Soares Ditzel ◽  
Flávia Gasparini Kiatake Fontão ◽  
Luciana Rei Azevedo-Alanis

AbstractThe retromolar canal is an anatomical variation of the mandibular canal. Its neurovascular bundle may extend to areas of the temporalis tendon, and areas of buccinator muscle insertion in the alveolar process at lower third molar region, beside the retromolar fossa. The observation of the retromolar canal in conventional radiographs is limited by the presence of increased bone condensation in the region due to overlapping anatomical structures. The use of three-dimensional imaging techniques, such as cone beam computed tomography can contribute significantly for the treatment planning.Some complications may occur in surgical procedures involving the retromolar area when the retromolar canals are present, such as hemorrhage, failure in anesthesia and injuries to nerve branches. This study reported an unusual case of a double retromolar canal on the left side of the mandible, that led  to the change of the treatment planning in a 54-year-old male patient. Furthermore, the clinical and surgical consequences of these findings in oral rehabilitation were discussed. The cone beam computed tomography was  an important diagnostic tool in the observation of the presence and the exact location of retromolar canal. Retromolar canals may be detected on a panoramic radiograph. However, more precise information about the anatomical variation can be shown on cross sectional cone beam computed tomography images. Keywords: Anatomic Variation. Mandible. Cone-Beam Computed Tomography. ResumoO canal retromolar é uma variação anatômica do canal da mandíbula. Seu feixe vásculo-nervoso pode se estender para áreas do tendão do músculo temporal, áreas de inserção do músculo bucinador e no processo alveolar na região do terceiro molar inferior, além da fossa retromolar. A observação do canal retromolar em radiografias convencionais é limitada pela presença de condensação óssea com sobreposição de estruturas anatômicas. Devido a esse fato o uso de técnicas de imagem tridimensionais, como a tomografia computadorizada de feixe cônico, contribuem significativamente para o planejamento do tratamento. Algumas complicações podem ocorrer em procedimentos cirúrgicos envolvendo a região retromolar quando o canal retromolar está presente, como hemorragia, falha na anestesia e lesões aos ramos nervosos. Este estudo relatou um caso incomum de canal retromolar duplo, do lado esquerdo da mandíbula, causando alterações no planejamento clínico do tratamento de um paciente do sexo masculino de 54 anos de idade. Além disso, as consequências clínicas e cirúrgicas desses achados na reabilitação bucal foram discutidas. Atomografia computadorizada de feixe cônico apresentou-se como importante ferramenta diagnóstica na observação da presença e localização exata do canal retromolar. Canais retromolares podem ser detectados em uma radiografia panorâmica. No entanto, informações mais precisas sobre esta variação anatômica podem ser mostradas em imagens de tomografia computadorizada de feixe cônico. Palavras-chave: Variação Anatômica. Mandíbula. Tomografia Computadorizada de Feixe Cônico.AbstractThe retromolar canal is an anatomical variation of the mandibular canal. Its neurovascular bundle may extend to areas of the temporalis tendon, and areas of buccinator muscle insertion in the alveolar process at lower third molar region, beside the retromolar fossa. The observation of the retromolar canal in conventional radiographs is limited by the presence of increased bone condensation in the region due to overlapping anatomical structures. The use of three-dimensional imaging techniques, such as cone beam computed tomography can contribute significantly for the treatment planning.Some complications may occur in surgical procedures involving the retromolar area when the retromolar canals are present, such as hemorrhage, failure in anesthesia and injuries to nerve branches. This study reported an unusual case of a double retromolar canal on the left side of the mandible, that led  to the change of the treatment planning in a 54-year-old male patient. Furthermore, the clinical and surgical consequences of these findings in oral rehabilitation were discussed. The cone beam computed tomography was  an important diagnostic tool in the observation of the presence and the exact location of retromolar canal. Retromolar canals may be detected on a panoramic radiograph. However, more precise information about the anatomical variation can be shown on cross sectional cone beam computed tomography images. Keywords: Anatomic Variation. Mandible. Cone-Beam Computed Tomography. ResumoO canal retromolar é uma variação anatômica do canal da mandíbula. Seu feixe vásculo-nervoso pode se estender para áreas do tendão do músculo temporal, áreas de inserção do músculo bucinador e no processo alveolar na região do terceiro molar inferior, além da fossa retromolar. A observação do canal retromolar em radiografias convencionais é limitada pela presença de condensação óssea com sobreposição de estruturas anatômicas. Devido a esse fato o uso de técnicas de imagem tridimensionais, como a tomografia computadorizada de feixe cônico, contribuem significativamente para o planejamento do tratamento. Algumas complicações podem ocorrer em procedimentos cirúrgicos envolvendo a região retromolar quando o canal retromolar está presente, como hemorragia, falha na anestesia e lesões aos ramos nervosos. Este estudo relatou um caso incomum de canal retromolar duplo, do lado esquerdo da mandíbula, causando alterações no planejamento clínico do tratamento de um paciente do sexo masculino de 54 anos de idade. Além disso, as consequências clínicas e cirúrgicas desses achados na reabilitação bucal foram discutidas. Atomografia computadorizada de feixe cônico apresentou-se como importante ferramenta diagnóstica na observação da presença e localização exata do canal retromolar. Canais retromolares podem ser detectados em uma radiografia panorâmica. No entanto, informações mais precisas sobre esta variação anatômica podem ser mostradas em imagens de tomografia computadorizada de feixe cônico. Palavras-chave: Variação Anatômica. Mandíbula. Tomografia Computadorizada de Feixe Cônico.


2014 ◽  
Vol 08 (03) ◽  
pp. 389-394 ◽  
Author(s):  
Koray Halicioglu ◽  
Mevlut Celikoglu ◽  
Suleyman Kutalmis Buyuk ◽  
Ahmet Ercan Sekerci ◽  
Faruk Izzet Ucar ◽  
...  

ABSTRACT Objectives: The aim was to investigate mandibular third molar (3M)’s maturation in the crossbite and normal sides by two- and three-dimensional analyses using cone beam computed tomography (CBCT). Materials and Methods: A retrospective study was performed using CBCT of 25 patients (16 females and 9 males; mean age: 16.8 ± 2.9 years) with unilateral posterior crossbite. The formation stages and the volume of the mandibular 3Ms were evaluated by means of CBCT data of the patients without knowing the crossbite side of the patients. Results: Statistically no significant differences were found in the development of the 3Ms between the crossbite and the control sides, whereas the volume of 3M was found to be less in the crossbite side than in the normal side (P = 0.021). Conclusions: A volume of 3M was found to be less in the crossbite side than in the normal side.


2021 ◽  
Vol 10 (6) ◽  
pp. e55710615659
Author(s):  
Magno Vincíus Silva Batista ◽  
Joel Motta Junior

Objective: This study aims to establish the anatomical relationship between the mandibular canal and the third molars, based on analysis by Cone Beam Computed Tomography. Methodology: Computed Tomography analysis of 67 third molars was performed using Blue Sky Plan 4 virtual planning software. The anatomical dispositions of the third molars and mandibular canal were evaluated, as well as the factors that favor the contact between these structures. Result: There was a prevalence of 76.1% for biradicular third molars, 52.2% for class 1 and 71.6% class A. Vertical and mesioangulated teeth had a higher prevalence, with 38.8% and 35.8% respectively. Sicher and Tandler's classification presented 41.8% of the canals as type I, while in the buccal-lingual positioning, 89.5% of the canals were located through the buccal. 44.8% of the teeth had contact with the canal and the factors with statistical significance were: female gender (p = 0.019), number of roots (p = 0.019), class 3 (p = 0.004) and C (p = 0.012) teeth and lingual positioning of the mandibular canal (p = 0.016). About the anatomical delimitations, the mean diameter of the canal was 3.14 mm and the distances related to the dental roots, lingual, buccal and inferior cortical bony were 2.77, 3.53, 4.56 and 8.32 milimeters, respectively. Conclusion: Therefore, the assessment of third molars by computed tomography is essential during preoperative planning, as it identifies anatomical relationships that favor contact between the tooth and the mandibular canal and helps to reduce the incidence of sensorineural disorders.


2020 ◽  
Vol 12 (4) ◽  
pp. 136-141
Author(s):  
Marouf Noruzi ◽  
Maryam Mostafavi ◽  
Aysan Ghaznavi ◽  
Amir Ardalan Abdollahi

Background: Determining the incidence and anatomic features of accessory mental foramen (AMF) in the Iranian population is of vital importance. This study investigated the prevalence and anatomic characteristics of AMF using cone-beam computed tomography (CBCT) in a selected Iranian population. Methods: A total of 853 CBCT images from 440 women and 413 men were examined in this cross-sectional retrospective study. The images were evaluated by two independent observers using reconstructed 3-dimensional, cross-sectional, and panoramic views. Several parameters were assessed, including the location of AMF relative to mental foramen (MF), size and the point of canal bifurcations, and the distance between the main and accessory canals. Finally, statistical differences in the AMF prevalence in terms of gender and direction and its location were evaluated by the Mann-Whitney U test (P<0.05). Results: The prevalence of AMF was 10.55%, which was more frequently located in the posterior inferior area relative to the main MF, and its nerve was more frequently originated from the anterior loop (P=0.001). There were no statistically significant differences in gender (P=0.26) and direction (P=0.4). The mean distance of AMF was 7.62 mm. The mean height of MF and the AMF vertical height were 13.65 mm and 52.12 mm in those with AMF on one side, respectively, and this difference was statistically significant (P=0.001). The sizes of the MF and AMF were 3.2 mm (large diameter), 2.3 mm (small diameter), and 1.4 mm (large diameter), and 1.1 mm (small diameter), respectively. Conclusions: Based on the findings of the present study, the prevalence of AMF according to hemi-mandibular was 5.80% in the selected Iranian population. Thus, AMF might branch from any section of the inferior alveolar nerve and the mandibular canal.


2016 ◽  
Vol 9 (4) ◽  
pp. 220
Author(s):  
Mahmuda Akter ◽  
Quazi Billur Rahman ◽  
Md. Wares Uddin ◽  
Gokul Chand Kundu ◽  
Samir Banik ◽  
...  

<p class="Abstract">The aim of this study was to assess the proximity and relation of impacted mandibular third molar and inferior alveolar canal on orthopantomogram and cone beam computed tomography (CBCT). Sixty impacted mandibular third molars having close proximity with the  inferior alveolar canal were included. CBCT images were done to determine the exact location and relationship of impacted third molar tooth and inferior alveolar canal. We assessed the radiographic signs from orthopantomogram, the course of  inferior alveolar canal and proximity to the third molar tooth in CBCT. The buccal course of  inferior alveolar canal was most frequently detected (n=36) in CBCT findings. The impacted lower third molar roots were 55% contact with the  inferior alveolar canal and 45% separate from the canal. On orthopantomogram, the following signs were strongly correlated with actual contact: Superimposed relationship between the third molar and the inferior alveolar canal. CBCT is useful as a presurgical planning in patients with impacted mandibular third molar showing close proximity to the  inferior alveolar canal.</p>


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