What are the retromolar and bifid/trifid mandibular canals as seen on cone-beam computed tomography? Revisiting classic gross anatomy of the inferior alveolar nerve and correcting terminology

Author(s):  
Joe Iwanaga ◽  
Yohei Takeshita ◽  
Yuki Matsushita ◽  
Mi-Sun Hur ◽  
Soichiro Ibaragi ◽  
...  
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.


2021 ◽  
Vol 24 (2) ◽  
Author(s):  
Claudemir de Souza Júnior ◽  
Ricardo Machado ◽  
Renee Ashley Batts ◽  
Lucas da Fonseca Roberti Garcia

The filling material should be restricted to the root canal, and not extend to the periradicular tissues. Overextension occurs when there is an overflow of gutta-percha and sealer, whereas overfilling refers to the overflow only of sealer beyond the apical foramen. Both may cause several negative clinical consequences. Nevertheless, an accurate diagnosis of where they occurred cannot always be performed by conventional radiographic examination, because of the two-dimensional aspect of the image. This paper describes a clinical case of labiomandibular paraesthesia after overfilling into the mandibular canal (MC), as diagnosed by cone-beam computed tomography (CBCT), later used to perform the treatment planning. A 34-year-old Caucasian female patient sought a private dental clinic complaining of pain in the right mandibular posterior region. After taking the anamnesis and performing clinical and radiographic exams, the patient was diagnosed with pulp necrosis in the second right mandibular molar, and underwent root canal treatment. The final radiography showed overextension or overfilling, probably into the MC. About 2 hours after the procedure, the patient reported paraesthesia of her lower right lip and chin. A CBCT confirmed a small overfilling into the MC. For this reason, vitamin B12 was prescribed as the first treatment option. After 7 days, the patient reported a significant decrease in paraesthesia, and was completely normal after 15 days. This case report shows that CBCT is an effective radiographic diagnostic tool that can be used as an alternative in clinical cases of labiomandibular paraesthesia caused by overextension or overfilling.   Keywords Endodontic treatment; Overfilling; Paraesthesia; Conebeam computed tomography.


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


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.


Author(s):  
Baratollah Shaban ◽  
Amin Khajavi ◽  
Nasim Khaki ◽  
Yones Mohiti ◽  
Tahere Mehri ◽  
...  

2019 ◽  
Vol 13 (1) ◽  
pp. 544-550
Author(s):  
Silvan Correa ◽  
Rogério H. Lopes Motta ◽  
Milena B. Fellipe Silva ◽  
Sidney R. Figueroba ◽  
Francisco C. Groppo ◽  
...  

Purpose: The mandibular foramen, located on the internal surface of the mandibular ramus, is an important anatomical landmark for the success during the inferior alveolar nerve block. This cross-sectional retrospective study aimed to evaluate the location of the mandibular foramen through Cone-Beam Computed Tomography (CBCT) in different facial shapes. Materials and Methods: The determination of the location of the mandibular foramen was performed using CBCT of mesocephalic, dolichocephalic and brachycephalic patients (n=40 each). The ramus width (W), the distance from the mandibular foramen to the deepest point of the anterior border of the mandibular ramus (D), the distance from the mandibular foramen to the lowest point of the mandibular notch (V) and the distance from the inferior border of the mandible to the lowest point in of the mandibular border (R), as well as the ratios W/D and V/R, were measured. ANCOVA, two-way ANOVA and Chi-square tests were used to analyze the variation among the facial shapes. Results: The ramus width (W) was greater (p<0.0001) in the brachycephalic (28.4±0.5 mm) than in both mesocephalic (26.8±0.36 mm) and dolichocephalic (25.5±0.39 mm) patients. D (p=0.0433) and R (p=0.0072) were also greater in the brachycephalic (17.7±0.36 mm; 43.4±0.75 mm, respectively) than dolichocephalic (16.5±0.3 mm; 40.3±0.63 mm, respectively), but both did not differ from mesocephalic (17.3±0.36 mm; 41.8±0.66 mm, respectively) patients. The other measurements (V, W/D and R/V) did not significantly differ among facial shapes. Conclusion: The localization of the mandibular foramen was, in the horizontal direction, more posterior in the brachycephalic patients and, in the vertical direction, higher in the dolichocephalic patients, when compared to the other groups analyzed. Thus, the anatomic data found in this study may help dentists to increase the success of the inferior alveolar nerve block and prevent surgical complications.


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