The Effectiveness of Semi-Automated and Fully Automatic Segmentation for Inferior Alveolar Canal Localization on CBCT Scans: A Systematic Review

This systematic review aims to identify the available semi-automatic and fully automatic algorithms for inferior alveolar canal localization as well as to present their diagnostic accuracy. Articles related to inferior alveolar nerve/canal localization using methods based on artificial intelligence (semi-automated and fully automated) were collected electronically from five different databases (PubMed, Medline, Web of Science, Cochrane, and Scopus). Two independent reviewers screened the titles and abstracts of the collected data, stored in EndnoteX7, against the inclusion criteria. Afterward, the included articles have been critically appraised to assess the quality of the studies using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Seven studies were included following the deduplication and screening against exclusion criteria of the 990 initially collected articles. In total, 1288 human cone-beam computed tomography (CBCT) scans were investigated for inferior alveolar canal localization using different algorithms and compared to the results obtained from manual tracing executed by experts in the field. The reported values for diagnostic accuracy of the used algorithms were extracted. A wide range of testing measures was implemented in the analyzed studies, while some of the expected indexes were still missing in the results. Future studies should consider the new artificial intelligence guidelines to ensure proper methodology, reporting, results, and validation.

ASSESSMENT OF NEUROSENSORY DISTURBANCES AND RECOVERY FOLLOWING SURGICAL REMOVAL OF IMPACTED MANDIBULAR THIRD MOLAR – A PROSPECTIVE STUDY

Aim: This prospective study aim to determine the incidence and pattern of recovery of IAN and LN decits after surgery while comparing which nerve, site, side, age group and type of impaction was most likely to suffer from neurosensory disturbances and to evaluate the risk factors such as duration of surgery, proximity to inferior alveolar canal, excessive hemorrhage, clinical observation of neurovascular bundle, contributing to these postoperative neurosensory decits. Materials&Methods: This study was conducted on 30 patients who underwent surgical removal of impacted mandibular third molar between 2017-2019 in the Department of Oral and Maxillofacial Surgery, College of Dental Sciences, Davangere. Clinically, all the patients underwent objective evaluation by using pin prick test, two-point discrimination and blunt test. Sensory function was evaluated 1 week, 1, 3 and 6 months post-operatively. The areas that were evaluated are those supplied by IAN and LN. Result: The incidence of NSD in our study was 10%, the IAN 6.7% and LN decit 3.3%. No permanent NSD was observed in this study. Statistically signicant association was found between excessive hemorrhage from the socket and NSD (p=0.009). No signicant association was found between gender, age, side, type, difculty score and duration, observation of neurovascular bundle during surgery and proximity of roots to the inferior alveolar canal with NSD.

ASSESSMENT OF MANDIBULAR 3RD MOLAR APICES TO THE INFERIOR DENTAL CANAL USING CONVENTIONAL RADIOGRAPHY AND CBCT

Conventional radiographs provide only a 2 dimensional view of complicated three dimensional structures. The proximity, angulations, location of impacted teeth, related to the IAN can be adequately determined using conventional 2-D periodical and panoramic radiographs. Computed tomography necessitates the administration of a high dose radiation, especially when the slice width is shortened to increased cost are the negative aspects of computed tomography compared with conventional imaging. Cone beam computed tomographies are becoming more readily available for use in maxilla facial applications. CBCT provides better image quality of teeth and their surrounding structures, compared with conventional CT and offers high spatial resolution. CBCT seems to be more accurate data about inferior alveolar canal. Hence the present study was undertaken to assess and select roots of third molar with close proximity to inferior dental canal in panoramic radiograph having radiographic signs of darkening of root, disruption of canal cortex and canal deviation and to evaluate the same roots with CBCT using trans axial and coronal sections which is angulated parallel to long axis to tooth, axial and coronal sections for proximity of inferior dental canal with the apices of third molar root. Keywords: CBCT, IAN

Evaluation of cone beam computed tomography imaging in placed dental implants: comparison between multiplanar reconstruction and parasagittal images / Avaliação de imagens de tomografia computadorizada de feixe cônico em implantes instalados: comparação entre reconstrução multiplanar e imagens parassagitais

This study aimed to compare multiplanar reconstruction (MPR) to parasagittal images of cone-beam computed tomography (CBCT) for localizing placed dental implants concerning adjacent anatomical structures (nasal fossa floor, maxillary sinus, inferior alveolar canal and nasopalatine canal).The CBCT exams of 164 placed implants were analyzed. All tomographic images were imported to Imaging Studio software to create parasagittal image templates. The images were randomized and analyzed by two oral and maxillofacial radiologists who classified whether or not there was perforation of the anatomical structure in question.According to Kappa coefficient of agreement, the results including, all anatomical structures for inter-observer assessment was 0.81 and for intra-observer assessment, 0.79 for observer one and 0.89 for observer two. For each anatomical structure, the agreement ranged from 'substantial' to 'almost perfect' (nasal fossa floor 0.72, nasopalatine canal 0.92, maxillary sinus 0.81, and inferior alveolar canal 0.81). Based on our findings, there was substantial to almost perfect agreement when comparing MPR and parasagittal images of CBCT regarding of implant position relationship with anatomical structures. Since both modalities did not differ in implant position, and the MPR represents the complete and original volume that enables analysis in three dimensions, they can be the first-choice imaging modality to analyze placed dental implants.