Estimating the Prevalence and Variation in Anterior Loop of Inferior Alveolar Nerve with Cone-Beam Computed Tomography in North Indian Population: An In Vivo Study (original) (raw)
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Objectives: Interforaminal implant surgery requires anatomical knowledge of the area and adequate information on the location of the various landmarks of significance such as the mental foramen, the anterior loop of the inferior orbital nerve and the mandibular incisive canal using Cone beam computed tomography (CBCT). This information may be used to provide recommendations to the surgeon without access to a 3D scan of the dento-alveolar region. Materials and methods: 65 patients scanned with 'i-CAT' device for a variety of clinical indications were included. Using the device's software the gender prevalence and length of the anterior loop was assessed. Results: The results show that an anterior loop was present with a mean of 3.40 mm in males and 2.85 mm in females as identified in an Indian sub-population. There was no significant difference in the loop length between the right and left side of the mandible. Conclusion: As the anterior loop length shows a high degree of variability, these findings suggest that a CBCT for each patient is recommended in order to visualise a safety zone before placing implants close to the mental foramen.
International Journal of Oral & Maxillofacial Implants, 2013
The mental foramen is an important landmark during surgical procedures such as osseous grafting or the placement of dental implants. To avoid injuring the mental nerve, it is important both to carefully assess the location of the mental foramen and to determine whether an anterior loop of the mental nerve or the incisive canal lies mesial to it. The objective of this study was to quantify the ability of cone beam computed tomography (CBCT) to measure the length of the mental nerve loop, the length and diameter of the incisive nerve canals, and the incisive canal path. Materials and Methods: The study included 352 CBCT scans that had originally been used for preoperative planning of implant placement in the interforaminal region of the anterior mandible. For each scan, the length of the mental nerve loop and the length, diameter, and path of the incisive canal were determined. Mean values were compared between groups based on sex, right versus left side, and whether the patient was edentulous. Results: The inferior alveolar nerve loop and incisive canal had a mean length of 2.40 ± 0.93 mm and 9.11 ± 3.00 mm, respectively. The mean incisive canal diameter was 1.48 ± 0.66 mm and showed a downward path in 51.3% of CBCT images and a linear or upward path in 38.29% and 10.41% of scans, respectively. Conclusions: CBCT provides an accurate means to identify critical anatomical features in the anterior mandible during preoperative surgical planning.
2021
Background and Aim: Iatrogenic injuries to inferior alveolar nerve (IAN) are a well known complication of implant placement, osteotomies and other surgical procedures. This study was at attempted to determine the most common position of the mental foramen and to estimate difference in position of mental foramen, occurrence of anterior loop and to evaluate the variation in the location of mandibular canal using cone-beam computed tomography (CBCT) radiographs. Materials & Methods: A total of 205 north Indian subjects were selected during a period of two years. Formerly exposed CBCT images of the selected subjects were studied by ‘iCAT Vision’ and ‘Anatomage’ Software. Measurements from the mandibular canal to the root apices of the first premolar, second premolar, first molar and second molar were obtained. Likewise the distance from the inferior alveolar canal to the buccal cortical plate (BCP) and lingual cortical plates (LCP) were also studied. The estimation of the horizontal and...
International Journal of Approximate Reasoning, 2020
1. Post-Graduate Student, Department of Prosthodontics, Govt. Dental College & Hospital, Srinagar, Jammu & Kashmir, India. 2. Professor and Head, Department of Prosthodontics, Govt. Dental College & Hospital, Srinagar, Jammu & Kashmir, India. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History Received: 30 June 2020 Final Accepted: 31 July 2020 Published: August 2020 Introduction: Implant placement requires an understanding of regional anatomy and a precise knowledge of the location of important anatomic structures such as the inferior alveolar nerve and maxillary sinus. At its anterior exit the inferior nerve creates a loop before exiting through the mental foramen. The dimensions of the anterior loop of inferior alveolar nerve are variable among individuals. This study was u...
Measurement of Anterior Loop of Inferior Alveolar Nerve Using Cone Beam Computed Tomography ( CBCT )
2017
Anatomical variations in the path of the mandibular canal such as anterior loop of the mental nerve are common. In Thai population, the finding of anterior loop from panoramic radiographic was about 43% [1]. This consideration becomes important when planning surgical procedures of the anterior mandible, such as osteotomy, bone harvesting, and the placement of dental implants. Sensory disturbance has been reported as a complication in up to 37% of patients in the first 2 weeks following surgery, with 10 to 15% of patients continuing to complain of problems after 15 months [2]. Sensory disturbance occurs mostly often after placement of a mandibular fixed prosthesis between the mental foramina [3-5]. This is because biomechanical considerations dictate that the distal margin of the implants should be as close as possible to the mental foramen so as to reduce the length of the distal cantilever, which increases the risk of injury, particularly in cases where a loop of the inferior alveo...
2021
Objective: The aim of this study was to evaluate the size, shape and location of the mental foramen (MF) and anterior loop (AL) in the Brazilian population through the analysis of cone beam computed tomography (CBCT) and panoramic radiography (PR). Method: We analyzed the location, shape and size of the MF, the distance between the upper wall of the MF and the alveolar crest (AC), the size of the AL and the presence of lingual anastomosis. Results: Fifty PR and CBCT exams were analyzed. In relation to the MF, the most common location was between premolars (56%), the most common shape was the oval shape (83%) and the average size in the PR was 3.63 mm and in the CBCT was3.66 mm. The average distance from the MF to the AC in the PR was 17.29 mm and in the CBCT was 11.48 mm. The average AL size was 3 mm, the smallest being 1 mm and the largest being 5 mm. Static analysis was performed to verify the relationship between the distance from the foramen to the AC with the values that were...
Journal of Oral and Maxillofacial Surgery, 2009
To measure and compare the anterior loop length (ALL) for the mandibular canal and the mandibular incisive canal diameter (ICD) at its origin in cadavers using anatomy and cone beam computed tomography (CBCT) to safely install endosseous implants in the most distal area of the interforaminal region. Materials and Methods: The ALL and ICD were measured using CBCT in 4 cadavers, and using anatomy in 71 cadavers. Results: The ranges and mean Ϯ SD for the anatomic measurements were: ALL, 0.0 to 9.0 mm and 1.9 Ϯ 1.7 mm; ICD, 1.0 to 6.6 mm and 2.8 Ϯ 1.0 mm. The average discrepancies between CBCT and anatomic measurements were 0.06 mm or less for both the ALL and the ICD, which were less than the resolution of CBCT. Conclusions: Because large variations in measurements were observed, both for ALL and ICD, no fixed distance mesially from the mental foramen should be considered safe. The ALL and the ICD can be estimated from the CBCT measurement. The preoperative CBCT measurement yields important information for each case.
Journal of International Society of Preventive and Community Dentistry, 2019
Purpose: Sufficient area in the interforaminal region is required for dental implant placement, and the anterior loop of the mandibular canal is located within the limits of this area. The aim of this study was to evaluate the prevalence and extent of the anterior loop in a Brazilian sample population using cone-beam computed tomography (CBCT). Materials and Methods: CBCT images from 250 patients (500 hemimandibles) obtained for various clinical indications were randomly selected and evaluated to determine the presence and length of the anterior loop. The length of the anterior loop was then compared based on gender, age, and the side of the mandible. The data were analyzed using the Pearson chi-square test and linear regression analysis. results: An anterior loop was identified in 41.6% of the cases, and its length ranged from 0.25 mm to 4.00 mm (mean, 1.1±0.8 mm). The loop had a greater mean length and was significantly more prevalent in males (p = 0.014). No significant differences were found between the right and left sides regarding length (p = 0.696) or prevalence (p = 0.650). conclusion: In this study, a high prevalence of the anterior loop of the mandibular canal was found, and although its length varied greatly, in most cases it was less than 1 mm long. Although this is a prevalent anatomical variation, safety limits for the placement of implants in this region cannot be established before an accurate evaluation using imaging techniques in order to identify and preserve the neurovascular bundles.
Surgical and Radiologic Anatomy, 2018
Purpose This study aimed at identifying the course of the mandibular canal, the presence of anterior loop and accessory mental foramen, as well as verifying the association between these variables through the analysis of cone beam computed tomography (CBCT) exams. Methods CBCT images were analyzed to identify the type of mandibular canal path, classified into three types: (I) catenary; (II) progressive descending; and (III) straight. In addition, the presence of anterior loop and accessory mental foramen was analyzed. The variables were summarized by measures of absolute frequency, relative, mean and standard deviation. The Chi square and Fisher's exact tests were used in the comparative analysis of the frequency distribution. The level of significance was 5%. Results The most frequent mandibular canal course was straight type (74.4%), followed by catenary (19.4%) and finally the progressive descending (6.2%). It was observed a prevalence of 10.2% for anterior loop and 7.9% for accessory mental foramen. There was no association between the presence of anterior loop (P = 0.798) and accessory mental foramen (P 0.480) with the mandibular canal course pattern, as well as no association between the anterior loop and the presence of the accessory mental foramen (P = 0.407). Conclusions The CBCT analysis is the best methodology for the investigation and localization of mandibular anatomical variations, which provides a good image quality of the bone tissue and details of the anatomical structures, reducing the risk of injury to the lower alveolar vascular-nervous bundle and, consequently, cause paralysis and hemorrhage in the anterior region of the mandible and adjacent structures.