Accuracy of implant placement with a combined use of static and dynamic computer-assisted implant surgery in single tooth space: A randomized controlled trial.

OBJECTIVE: To compare implant accuracy of combined static and dynamic (SD) computer-assisted implant surgery (CAIS) with static (S), dynamic (D) CAIS, and freehand surgery (FH) for single implant placement. MATERIALS AND METHODS: One hundred and twenty patients were randomized into four groups. Implants were placed using both stereolithographic surgical guide and dynamic navigation in the SD group, stereolithographic surgical guide in S group, dynamic navigation in D group, and conventional freehand in FH group. Analysis of deviation between planned and final implant position, as well as K means analysis was conducted for implant deviation at platform, apex, and angle (primary outcomes) and directional distribution at platform and apex (secondary outcome). RESULTS: Significant differences were found among the four groups (p < .001): The 3D deviation at the platform (mm) of SD, S, D, and FH groups was 0.62 ± 0.50, 1.06 ± 0.67, 1.02 ± 0.45, and 1.48 ± 0.68, respectively, at apex (mm) was 0.75 ± 0.57, 1.40 ± 0.71, 1.28 ± 0.50, and 2.18 ± 0.95, respectively, and angle (degrees) was 1.24 ± 1.41, 3.18 ± 2.04, 3.28 ± 1.57, and 7.50 ± 4.06, respectively. Deviation at the platform of FH group was significantly more toward mesial (p = .026) and coronal (p = .014) direction, while at the apex, toward distal (p = .004) and lingual (p = .002) than SD group. CONCLUSION: The use of combined static and dynamic CAIS provided significantly higher accuracy than the two alone and freehand surgery for single implant placement.

Ghost cell odontogenic carcinoma: A case report.

Ghost cell odontogenic carcinoma (GCOC) is a rare malignant neoplasm characterized by the presence of ghostcells. It is considered to originate from either a calcifying odontogenic cyst (COC) or a dentinogenic ghost cell tumor(DGCT). Its clinical and radiographic characteristics are non-specific, including slow growth, locally aggressivebehavior, and eventual metastasis. This case report describes a 43-year-old Thai man with plain radiographs and cone-beam computed tomographic images revealing a unilocular radiolucency with non-corticated borders surrounding an impacted left canine associated with radiopaque foci around the cusp tip. Based on the microscopic findings, the lesion was diagnosed as GCOC. Partial maxillectomy of the right maxilla was performed, and radiotherapy was administered. An obturator was made to support masticatory functions Three years later, the lesion showed complete boneremodeling and no signs of recurrence, and long-term follow-up was done regularly.

Scatter-to-primary ratio in dentomaxillofacial cone-beam CT: effect of field of view and beam energy.

OBJECTIVE: The aim of this study was to evaluate the effect of field of view (FOV) and beam energy on the scatter-to-primary ratio (SPR) in dental cone-beam CT (CBCT). METHODS: An anthropomorphic phantom representing an adult male (ATOM Max 711-HN, Norfolk, VA, USA) was scanned using the 3D Accuitomo 170 CBCT (J. Morita, Kyoto, Japan) using 11 FOVs. During each scan, half of the X-ray beam was blocked. Each scan was performed at three exposure settings with varying beam energy and equal radiation dose: 90 kV 5 mA, 77 kV 7.5 mA and 69 kV 10 mA. The SPR was estimated by measuring the grey values in the blocked and non-blocked regions of the RAW data. The effect of FOV on SPR was evaluated using Dunn's multiple comparison test, and the effect of the exposure settings was compared using a Wilcoxon signed rank test. RESULTS: Larger FOVs showed increased scatter. FOVs with a shorter isocenter-detector distance showed a particularly high SPR. Most intercomparisons between FOVs were statistically significant. The largest difference was found between 17 × 12 cm and 6 × 6 cm (lower jaw), with the former showing a 4.9-fold higher SPR. The effect of beam energy was relatively small and varied between FOV sizes and positions. CONCLUSION: While the choice of FOV size and position is determined by the diagnostic region of interest, the image quality deterioration for large FOVs due to scatter provides another incentive to limit the FOV size as much as possible.

A split-mouth randomized clinical trial to evaluate the effect of local and systemic administration of vitamin C on extraction wound healing.

A split-mouth single-blind randomized-controlled clinical trial study was designed to investigate the effect of local and systemic vitamin C administration on extraction wound healing. Thirty patients who underwent bilateral premolar extraction were randomly divided into three group pairs; group 1: control and systemic administration (Con/CSA), group 2: control and a combination of local and systemic administration (Con/CLSA), and group 3: systemic and a combination of local and systemic administration (CSA/CLSA). The vitamin C (600 mg) was taken by swallowing (systemic administration) or slow oral dissolution (combined local and systemic administration). The socket size and radiographic density were evaluated immediately after extraction, and 7 days and 21 days later. The results demonstrated that the percentage radiographic density of new bone formation in the socket did not differ significantly within each group. However, in the CSA and CLSA group there was an improvement of soft tissue healing based in terms of socket depth reduction at 21 days after extraction compared with the control (P < 0.05).

Dentofacial Deformity Caused by Bulky Osteochondroma: Report of an Unusual Case and the Importance of Cone Beam Computed Tomography.

INTRODUCTION: Osteochondroma of mandibular condyle is a rare benign tumor. CASE REPORT: This case report described clinical, radiographic features, differential diagnosis, histopathologic correlation and treatment of condylar osteochondroma. CONCLUSION: Conebeam computed tomography (CBCT) is an alternative modality to CT or MRI that should be performed in all cases of suspected osteochondroma of the mandibular condyle.

Anatomical considerations of the Thai fibula used as a fibula osteocutaneous free flap in mandibular reconstruction and dental implant placement.

OBJECTIVE: Although the fibula osteocutaneous free flap has many proven advantages in restoring mandibular defects, the dimension of available fibula is one of its limitations. The present study aimed to investigate the suitability of dimensions and the quality of harvested fibulae for mandibular reconstruction and dental implant placement in Thais. MATERIAL AND METHOD: One hundred fourteen fibulae of 57 adult Thai cadavers were dissected. Total fibular length and the length of harvested fibula were measured. Dimensions of the fibula cross sections available for dental implant placement were recorded. Additionally, the cortical bone thickness and densities of cortical and spongy bones of 60 fibulae were assayed using cone beam computed tomography scan images. RESULTS: Mean total fibular length and mean length of harvested fibulae were 34.2 +/- 2.3 cm and 18.2 +/- 2.3 cm, respectively. A dental implant length of 7 to 10 mm could be placed in the fibula. The mean cortical bone thickness was 2.2 +/- 0.6 mm. The mean densities of the cortical and spongy bones were 614.4 +/- 148.8 HU and -600.6 +/- 228.7 HU, respectively. CONCLUSION: The present study suggests that, in Thais, a harvested fibula of 16 to 20 cm in length is sufficient to provide bone for reconstructing defected mandible and the dental implant placement is 7 to 10 mm in length. The mean cortical and spongy bone densities of fibula are less than that of the mandible in previous reports. The result supports the clinical experience using the fibula as donor site for the mandibular reconstruction and dental implant placement.

Oral and radiographic findings in patients undergoing continuous ambulatory peritoneal dialysis.

OBJECTIVE: To compare the oral status, cortical and spongy bone density of the mandible, and dental pulp calcification between the patients undergoing continuous ambulatory peritoneal dialysis (CAPD) and age- and sex-matched healthy controls. MATERIAL AND METHOD: Thirteen end stage renal disease patients undergoing CAPD and 17 age- and sex- matched healthy volunteers were enrolled. The questionnaires, oral radiography, and intraoral examination, including number of decayed teeth, filled teeth, missing teeth, plaque index, gingival index, calculus index, and oral hygiene index were performed in both groups. Two views of oral radiology, comprising panoramic and bite-wing radiographs, were taken to evaluate mandibular bone density and pulp calcification. The data were analyzed with t-test and Mann-Whitney U tests. RESULTS: Both groups were similar in baseline demographics, including age, sex, and education. Plaque index, calculus index, and oral hygiene index of the CAPD patients were significantly worse than the controls' (p = 0.025, 0.015, and 0.014, respectively). Percentage of decayed teeth and missing teeth of the CAPD patients had a trend to be higher than control. The percentage of filled teeth, decayed missing filling tooth (DMFT) index, sum of percentage DMFT, gingival index, average of spongy and cortical bone densities, and the percentage of pulp calcification were comparable in both groups. CONCLUSION: CAPD had poorer oral hygiene than the healthy; however; DMFT pulp calcification, and bone density were not differenct from the healthy. This urges the medical personnel to examine all CAPD patients in order to prevent hematogenous spreading of occult oral infection.