A Retrospective Cone Beam Computed Tomography (CBCT) Study of the Assessment of the Length of the Anterior Loop of the Inferior Alveolar Nerve (original) (raw)
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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.
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.
Dental Journal of Advance Studies
Purpose The present in vivo study aimed to estimate the prevalence and variation in anterior loop of inferior alveolar nerve (IAN) in relation to mental foramen to assess the safe zone in anterior part of mandible for implant placement with cone-beam computed tomography (CBCT) in North Indian population. Materials and Methodology To conduct this study, 70 patients were selected and radiographically evaluated. All CBCT scans were made from Genoray Papaya 3D Plus. CBCTs were evaluated in CDSee software for anterior loop and height measurement anterior to mental foramen. Four parameters of prevalence of loop length and height anterior to mental foramen on right and left side each and four parameters of variation in loop length and height on right and left side each were recorded with the help of descriptive statistical analyses (mean, median, mode, and range) and paired t-test. Level of significance (p) was also calculated. Result Paired t-test value for comparison on both the right an...
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...
PloS one, 2015
The maxillary incisive canal connects the roof of the oral cavity with the floor of nasal cavity and has the incisive and nasal foramina respectively at its two opposite ends. Its close proximity with the anterior incisors affects one's ability to place immediate implants in ideal position. To avoid causing complication, variations in their dimensions were studied. Images of ninety Mongoloids patients examined with i-CAT Cone Beam Computed Tomography were included. The sizes of the nasopalatine foramen, the incisive canal and foramen, and anterior maxillary bone thickness were measured. The direction and course of the canals were assessed. The mean labiopalatal and mesiodistal measurements of the incisive foramen were 2.80mm and 3.49 mm respectively, while the labiopalatal width of the nasal foramen was 6.06mm. The incisive canal was 16.33mm long and 3.85 mm wide. The anterior maxillary bone has an average thickness of 7.63 mm. The dimensions of the incisive foramen and incisive...
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...
The portion of inferior alveolar nerve (IAN) existent anterior to the mental foramen, before parting the canal, is referred to as the anterior loop (AL) of the IAN. The presence of AL is important when placing the implant interforaminal area of the mandible. These anatomical discrepancies can be assessed by cone-beam computerized tomography (CBCT), for evaluating its position and exact location. Mandibular neurovascular canal contents may be vulnerable to damage during mandibular surgical procedure. Greater knowledge of the location and configuration of the mandibular canal can help in the safe performance of these procedure in the dental clinic. Cross-sectional CBCT imaging is a good modality for studying the course, location, configuration and accessory branches of the mandibular canal. Advanced cross-sectional imaging modalities especiallly CBCT is a suitable tool for observing anatomic characteristics of mandibular canal to preserve this vital structure in surgical procedure.
Assessment of the anterior loop of the mandibular canal: A study using cone-beam computed tomography
Imaging Science in Dentistry, 2016
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.
British Journal of Oral & Maxillofacial Surgery, 2018
The anterior loop of the inferior alveolar nerve (IAN) is an important landmark to consider during dental implant surgery in the anterior mandible. The purpose of this study was to determine the prevalence and length of IAN loops using reformatted computed-tomography (CT) scans. Materials and Methods: CT scans of 188 consecutive patients, complying with inclusion criteria, were reformatted using specialized software. The prevalence and length of IAN loops were assessed for dentate subjects. Results: Eighty four per cent of cases had at least one anterior loop present; 59% of cases had bilateral loops. The mean length of the loops in third quadrant (Q3) was 1.4 mm (SD: 0.7; 95% CI: 1.3-1.6; Minimum: 0.3; Maximum: 4.0). The mean length of the loops in fourth quadrant (Q4) was 1.5 mm (SD: 0.9; 95% CI: 1.4-1.6; Minimum: 0.3; Maximum: 5.5). In total 21% of cases had loops greater than 2 mm, in both the Q3 and Q4. Conclusions: CT images, reformatted with specialized software may be a useful to identify IAN loops, especially in settings where recent CBCT devices are not freely available. The prevalence of IAN loops is high while the length of the loop remains variable, requiring meticulous individual assessment prior to implant placement.