scholarly journals Accuracy of cone-beam computed tomography in defining spatial relationships between third molar roots and inferior alveolar nerve

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


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.


2014 ◽  
Vol 15 (6) ◽  
pp. 740-745
Author(s):  
Mojdeh Mehdizadeh ◽  
Navid Ahmadi ◽  
Mahsa Jamshidi

ABSTRACT Objectives Exact location of the inferior alveolar nerve (IAN) bundle is very important. The aim of this study is to evaluate the relationship between the mandibular third molar and the mandibular canal by cone-beam computed tomography. Study design This was a cross-sectional study with convenience sampling. 94 mandibular CBCTs performed with CSANEX 3D machine (Soredex, Finland) and 3D system chosen. Vertical and horizontal relationship between the mandibular canal and the third molar depicted by 3D, panoramic reformat view of CBCT and cross-sectional view. Cross-sectional view was our gold standard and other view evaluated by it. Results There were significant differences between the vertical and horizontal relation of nerve and tooth in all views (p < 0.001). Conclusion The results showed differences in the position of the inferior alveolar nerve with different views of CBCT, so CBCT images are not quite reliable and have possibility of error. How to cite this article Mehdizadeh M, Ahmadi N, Jamshidi M. Evaluation of the Relationship between Mandibular Third Molar and Mandibular Canal by Different Algorithms of Cone-beam Computed Tomography. J Contemp Dent Pract 2014;15(6):740-745.


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


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.


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