Prevalence of bifid and trifid mandibular canals with unusual patterns of nerve branching using cone beam computed tomography.

Lack of knowledge concerning the inferior alveolar canal anatomical variations had proven to increase the incidence of surgical complications, so the study aimed to assess the configuration and prevalence of bifid and trifid mandibular canals using cone beam CT in Egyptian subpopulation. Cone beam CT scans of 278 patients (530 hemi-mandibles) were included in the study, in which bifid and trifid mandibular canals or any other branching patterns were recorded and evaluated. Bifid canals were categorized following Naitoh classification, and the diameter of the main mandibular and accessory canals was measured. Bifid canals were detected in 181 canals (34%) while trifid canals in 46 canals (8.7%). Upon classifying the bifid canals, 78 canals showed forward type, 40 retromolar type, 33 dental type, and 7 canals showed buccolingual type. Two special bifid canals subtypes were reported in 23 canals and nine distinct patterns of trifid canals were reported in our study. In addition, unusual patterns of canal branching were reported in 5 cases. The mean diameter of the accessory canals was 1.18 ± .54 mm and the main canal was 3.98 ± 1.31 mm. This study reported a high prevalence (54%) of canal branching, which reinforces the importance of cone beam CT in pre-surgical planning.

Assessment of Gingival Thickness Using CBCT Compared to Transgingival Probing and Its Correlation with Labial Bone Defects: A Cross-Sectional Study.

PURPOSE: The aims of this study were to determine the accuracy and repeatability of CBCT for assessing gingival thickness (GT) as compared to transgingival probing and to investigate the correlation between GT and labial bone defects. MATERIALS AND METHODS: This cross-sectional study comprised 37 patients who underwent CBCT imaging. A total of 111 sites were examined, and measurements were obtained from the same points on selected index teeth. The GT was measured, and the presence of dehiscence and fenestration defects was evaluated on the CBCT scans. Transgingival probing was performed at the same points as those used on the scans. Intraexaminer reliability for clinical and radiographic measurements and interexaminer reliability for radiographic measurements were tested. Agreement between the measurement methods and the correlations between GT and labial bone defects were assessed using intraclass correlation coefficient (ICC) and chi-square test, respectively. RESULTS: The agreement between both measurement methods was excellent and statistically significant (ICC = 0.888; P < .001), with a bias of 0.04 (95% CI: 0.01 to 0.08). Significant differences in the occurrence of fenestration (P = .023) and dehiscence defects (P < .001) between the thin and thick gingival phenotypes were observed, and the defects were positively correlated with the thin gingival phenotype. CONCLUSION: CBCT demonstrated high diagnostic accuracy for GT measurements, with minimal discrepancies from the transgingival method. The presence of dehiscence and fenestration defects was positively correlated with thin gingival phenotype.

Anatomical Analysis of Mandibular Posterior Teeth using CBCT: An Endo-Surgical Perspective.

OBJECTIVE: This study sought to analyse the relationship between mandibular posterior teeth and the surrounding anatomical structures. METHODS: A total of 170 CBCT images were examined to obtain measurements regarding the following: buccolingual (BL) and mesiodistal (MD) root thickness at the standard level of resection (3 mm from the apex), the thickness of the overlying buccal and lingual bone at the same level, the proximity of the mandibular canal (MC) to the apices of the mandibular posterior teeth, as well as the horizontal location of the mental foramen (MF). RESULTS: The BL root width at 3 mm from the apex was the broadest at the mesial roots of the first molars with males: 5.33±0.99 mm and females: 5.16±0.88 mm (mean±SD). The root width was narrowest at the second premolars (males: 3.80±0.83 mm; females: 3.61±0.60 mm). At the same level; the buccal bone was thickest over the distal roots of the second molars (males: 6.92±1.85 mm; females: 6.95±1.95 mm) and thinnest over the first premolars (males: 1.73±0.93 mm; females: 1.49±1.01 mm), while the lingual bone was thickest over the distal roots of the first molars (males: 5.58±1.36 mm; females: 4.52±1.24 mm) and thinnest over the distal roots of the second molars (males: 3.13±1.50 mm; females: 2.60±1.46 mm). The nearest root apices to the MC were the distal roots of the second molars (male: 1.21±1.45 mm; female: 1.75±1.97 mm), while the furthest were the mesial roots of the first molars (male: 4.00±2.39 mm; female: 4.77±2.58 mm). The most common horizontal location of the MF was between the first and second premolars (51.8%). The lingual bone was significantly thinner over both roots of first molars in females (P<0.05). CONCLUSION: As the position of the teeth became more posterior, the buccal bone thickness increased, the lingual bone thickness decreased, and the distance to the MC became closer. CBCT analysis provides distortion- and superimposition-free images of the relevant anatomic structures.

Bone regeneration and graft material resorption in extraction sockets grafted with bioactive silica-calcium phosphate composite (SCPC) versus non-grafted sockets: clinical, radiographic, and histological findings.

PURPOSE: The purpose of the present study was to evaluate the effect of silica-calcium phosphate composite (SCPC) granules on bone regeneration in extraction sockets. METHODS: Ten patients were selected for a split-model study. In each patient, bone healing in SCPC-grafted and control ungrafted sockets was analyzed through clinical, radiographic, histomorphometric, and immunohistochemical assessments 6 months postoperatively. RESULTS: A radiographic assessment using cone-beam computed tomography showed minimal ridge dimension changes in SCPC-grafted sockets, with 0.39 mm and 1.79 mm decreases in height and width, respectively. Core bone biopsy samples were obtained 6 months post-extraction during implant placement and analyzed. The average percent areas occupied by mature bone, woven bone, and remnant particles in the SCPC-grafted sockets were 41.3%±12%, 20.1%±9.5%, and 5.3%±4.4%, respectively. The percent areas of mature bone and woven bone formed in the control ungrafted sockets at the same time point were 31%±14% and 24.1%±9.4%, respectively. Histochemical and immunohistochemical analyses showed dense mineralized bundles of type I collagen with high osteopontin expression intensity in the grafted sockets. The newly formed bone was well vascularized, with numerous active osteoblasts, Haversian systems, and osteocytes indicating maturation. In contrast, the new bone in the control ungrafted sockets was immature, rich in type III collagen, and had a low osteocyte density. CONCLUSIONS: The resorption of SCPC granules in 6 months was coordinated with better new bone formation than was observed in untreated sockets. SCPC is a resorbable bone graft material that enhances bone formation and maturation through its stimulatory effect on bone cell function. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03897010.

Dose reduction in head and neck organs through shielding and application of different scanning parameters in cone beam computed tomography: an effective dose study using an adult male anthropomorphic phantom.

OBJECTIVES: The aim of this study was to determine the effect of shielding and scanning parameters on radiation dose reduction to the organs in the head and neck region in cone beam computed tomography (CBCT). STUDY DESIGN: An anthropomorphic phantom and optically stimulated luminescent dosimeters were used to calculate the changes in effective or equivalent doses to 9 anatomic structures through the addition of a thyroid collar, radiation safety glasses, and a radiation safety cap and by using different scanning protocols on a CS 9300 CBCT unit. RESULTS: The thyroid collar alone yielded dose reductions of 46% to the thyroid gland and at least 38% to the esophagus, but no more than 12% to the salivary glands. The radiation safety cap significantly reduced doses to the brain and the pituitary gland. Full shielding resulted in dose reductions of at least 50% to the thyroid gland, at least 47% to the esophagus, and approximately 35% to the brain and the pituitary gland. Significant dose reductions were recorded for all tissues with the "low dose" setting compared with the standard setting. CONCLUSIONS: Increased protection of the organs in the head and neck regions can be achieved by using various forms of shielding in CBCT imaging, with selection of the most appropriate scanning parameters based on the purpose of the examination.

Osteoma Cutis and Tonsillolith: A Cone Beam Computed Tomography Study.

In this study, we report a rare case of osteoma cutis (OC) and tonsillolith, diagnosed using cone beam computed tomography. The dystrophic calcifications in the face and tonsils were incidentally found during examination of the patient's scan with no relation to the main chief complaint. The diagnosis was OC, combined with dystrophic calcification of the tonsils. It is important to mention that OC is a rare soft-tissue ossification of cutaneous tissue, typically on the face and clinically asymptomatic. It may be primary but the majority of cases are secondary. Incidental finding of OC and tonsilloliths on a two-dimensional dental radiograph does not provide sufficient information concerning the location of these calcifications. Thus, cone beam computed tomography (CBCT) provides critical information for the diagnosis of asymptomatic OC lesions not available through any other means of clinical detection.

Radiographic Diagnosis of a Central Giant Cell Granuloma Using Advanced Imaging: Cone Beam Computed Tomography.

Central giant cell granuloma (CGCG) is a benign non-neoplastic, proliferative intraosseous lesion of the jaw with an unknown etiology often diagnosed during the first two decades of life. The true nature of this lesion is controversial and remains elusive. Here, we report a case of central giant cell granuloma, diagnosed using cone-beam computed tomography (CBCT). A 21-year-old female presented to the clinic complaining of a painless swelling involving the right side of the mandible that had started one year previously. A CBCT scan revealed a well-defined, multilocular radiolucent lesion on the right side of the mandible extending from the molar region to the ramus with wispy septations. Wispy septations and undulating borders are some of the characteristic radiographic features of a central giant cell granuloma. The patient underwent an excisional biopsy. The biopsy revealed multinucleated giant cells in a fibrous stroma confirming our radiographic diagnosis of a central giant cell lesion.

An Immature Ten-year Long-standing Case of Ossifying Fibroma.

Ossifying fibroma is a rare benign bone neoplasm common in middle age, with definite female predominance. Here, we describe a case of an ossifying fibroma in a 36-year-old female, with a right facial deformity. The lesion had been present for almost 10 years. The panoramic image showed a multilocular appearance with scattered radiopacities. Advanced imaging revealed an expansile multilocular lesion with multiple small radiopaque foci and a few dense radiopaque masses. A histopathological examination confirmed the diagnosis. The case represents a non-aggressive form of an immature ossifying fibroma.

Effect of altering the reciprocation range on the fatigue life and the shaping ability of WaveOne nickel-titanium instruments.

INTRODUCTION: The purpose of this study was to investigate the effect of altering the reciprocation range of the WaveOne instrument (Dentsply Maillefer, Ballaigues, Switzerland) on its fatigue life and shaping ability regarding tendency for canal transportation, the canal centering ratio, and preparation time. METHODS: Thirty primary WaveOne instruments were divided into 3 equal groups according to the reciprocation range used: G1: 150 counterclockwise (CCW)-30 clockwise (CW), G2: 120 CCW-30 CW, and G3: 90 CCW-45 CW. They were activated in a cyclic fatigue testing device until fracture. The time to fracture and the length of the fractured tip were recorded and registered. To assess the shaping ability, 30 mesiobuccal canals of mandibular molars were prepared using the same reciprocation ranges. Canals were scanned using cone-beam computed tomography scanning before and after preparation to evaluate root canal transportation and the canal centering ratio at 1, 4, and 7 mm from the apex. The time taken to complete canal preparation was also recorded. The mean ± standard deviation values were analyzed using analysis of variance and the Tukey post hoc test. The significance level was set at P < .05. RESULTS: The time to fracture recorded increased as the reciprocation range decreased, and this was significant for the 90 CCW-45 CW group (P < .05). Regarding preparation time, it increased significantly as the reciprocation range was decreased (P < .05). Results for canal transportation and the canal centering ratio showed that at 1 mm from the apex there were no significant differences between the experimental groups. For the other studied levels, the 150 CCW-30 CW group had the highest mean for canal transportation and the lowest mean for the canal centering ratio, which was statistically significant in comparison with the other experimental groups (P < .05). CONCLUSIONS: Decreasing the reciprocation range of WaveOne instruments resulted in an increased cyclic fatigue resistance with less canal transportation and more centered preparations but with longer preparation times.