A CBCT Based Three-Dimensional Assessment of Mandibular Posterior Region for Evaluating the Possibility of Bypassing the Inferior Alveolar Nerve While Placing Dental Implants

Abstract

A high rate of nerve injury and related consequences are seen during implant placement in the posterior mandibular arch. An approach has been proposed to avoid nerve injury by dodging the inferior alveolar nerve (IAN) while placing an implant. A prospective study with a total of 240 CBCT (cone beam computed tomography) images of patients with three dentate statuses, namely, edentulous (group I), partially edentulous (group II) and dentate (group III) were included in the study. The nerve path tracing was done on CBCT images with On-demand 3D software. The three dimensions, i.e., the linear distance from the outer buccal cortical plate to the inferior alveolar nerve (BCPN), linear distance from the outer lingual cortical plate to the inferior alveolar nerve (LCPN) and linear distance from the midpoint of the alveolar crest to the inferior alveolar nerve (ACN) were assessed. The data were presented and analyzed between variables using one-way ANOVA and independent t-test in SPSS version 21.LCPN of the right 1st premolar region (p < 0.05) was significantly different among the groups with edentulous subjects recorded with the minimum value (6.50 ± 1.20 mm). Females were found to have significantly (p < 0.05) less available bone (6.03 ± 1.46 mm) on the right side of the mandibular jaw compared to males in edentulous group of patients. On comparing age groups for partially edentulous subjects, LCPN of the right 1st premolar region had significantly (p < 0.05) less available bone (6.03 ± 0.38 mm) in subjects with age ≥54 years. The IAN follows a lingual course in the molar region and later flips to the buccal side in the premolar region. The LCPN dimension in the 1st and 2nd premolar region was found to be more than 6 mm irrespective of age, gender and side of the jaw. Thus, it can be considered as a suitable site for placing implants while bypassing the IAN with CBCT assessment remaining as the mainstay in the pre-surgical phase.

Evaluation of Neurosensory Deficits Following the Use of Computer Assisted Surgical Guide for Inferior Alveolar Nerve Bypass versus Inferior Alveolar Nerve Lateralization (Randomized Controlled Trial)

“…IAN bypassing technique ( Group B) in accordance with the previous studies (14)(15)(16) which considered the use of computer guided surgical stent for IAN bypassing technique can be optimized with reducing the possibilities of inferior alveolar nerve injury.…”

“…Planning to place the implant in either buccal or lingual directions with the aid of a surgical guide stent provided that sufficient bone width is available between 5 -6 mm, minimizes the risk of plate perforation. (11)(12)(13)(14) Recently computer-guided implant placement procedure with stereolithographic templates has become popular use. surgical planning was provided in both virtual and 3D environments, thus allowing the surgery to be performed virtually in an accurate prosthesis-driven manner and exact transition of virtual planning by computer-aided surgical stent.…”

Morphometric Analysis of the Mandibular Canal, Anterior Loop, and Mental Foramen: A Cone-Beam Computed Tomography Evaluation

“…Orthopantomogram was recommended as an initial investigation to predict IAN injuries following extraction surgery for lower impacted wisdom teeth while CBCT scans were considered by many practitioners as a keystone in pre-implantation assessment to plan minimally invasive surgery, conduct mocks for planned surgeries, and avoid iatrogenic injuries [ 39 , 40 ]. Also, CBCT can be used to assess the skeletal deformation in congenital diseases [ 41 ] This study emphasizes the importance of using the appropriate imaging modality on an individual basis to locate these structures before performing implantation or other surgical procedures related to the mandible.…”

A CBCT aided assessment for the location of mental foramen and the emergence pattern of mental nerve in different dentition status of the Saudi Arabian population

“…In the current study, we have used SCANORA ® 3Dx CBCT machine (Nahkelantie 160, Tuusula, Finland) for generating scans of the mandibular region of patients. We adopted the specifications of the machine, exposure settings, image acquisition protocol and display software from Sghaireen et al [21].…”