Z-shaped Miniplates vs Conventional Miniplates for Fixation of Mandibular Parasymphyseal Fractures.

AIM: The aim of this study was to evaluate a clinically and radiographically Z-shaped miniplate for the fixation of the parasymphyseal fractures. PATIENTS AND METHODS: Twenty patients (10 patients in each group) who had parasymphseal mandibular fractures were randomly selected for this study. In this study, open reduction and internal fixation were performed for mandibular parasymphyseal region fractures using two miniplates as group I, and open reduction and internal fixation were performed for mandibular parasymphyseal region fractures using a newly designed Z-shaped miniplate as group II. Clinical and radiographic evaluations were made. Each patient was evaluated: (1) clinically evaluated preoperatively and postoperatively for operating time, ease of placement of the miniplate, and occlusion and (2) radiological: postoperative reduction of fracture was evaluated radiologically at 5-day, 1-month, 2-month, and 3-month intervals with orthopantomogram, and lingual splaying was evaluated by cone-beam computed tomography (CBCT) immediately postoperatively and at an interval of 3 months. The collected data were subjected to statistical analysis. Data analysis was performed by SPSS software, version 25 (SPSS Inc., PASW statistics for Windows version 25). Chicago: SPSS Inc. RESULTS: There was a statistically significant difference (p < 0.001) between the mean intraoperative time. This indicates that group I had a longer time for fracture fixation than group II. Group I had a longer time elapsed for plate adaptation and definitive fixation than group II. Occlusion and reduction stability in both groups were similar. There was a statistically significant difference in postoperative lingual display control after 5 days and 3 months between the studied groups. This indicates that lingual display control in group II is better than in group I. CONCLUSION: The Z-shaped miniplate is effective and provides three-dimensional stability for the fixation of parasymphyseal fractures, ease of use, easily adapted in cases of fractures near the mental nerve reduced operative time, and better control of lingual splaying than conventional miniplates. CLINICAL SIGNIFICANCE: The newly designed Z-shaped miniplate is a valuable option for fixation parasymphysis fractures that need open reduction and internal fixation instead of using conventional miniplates, which are less successful in controlling lingual splaying.

Evaluation of Two Computerized Methods for Presurgical Volumetric Analysis in Secondary Alveolar Cleft Bone Grafting: A Prospective Study.

AIM: The purpose of this study is to evaluate presurgical computerized volumetric analysis in secondary alveolar cleft bone grafting (SABG) and the time taken for calculation using cone-beam computed tomography (CBCT) via two different software programs. MATERIALS AND METHODS: Twelve patients with unilateral alveolar clefts were investigated using CBCT. Two independent investigators did presurgical volumetric analysis for each patient's CBCT data using two different methods. Method A involved On-Demand 3D software (Cybermed Inc., Korea), while method B involved InVesalius 3 software (CTI, Brazil). The volume outcomes and time spent for measurements were compared between both software programs. Interobserver reliability and descriptive and t-test statistics were computed, and statistical significance was considered when p ≤ 0.05. RESULTS: There was not a statistically significant difference between clefts' volumetric measurements by the two methods via both investigators (p = 0.186 and 0.069). However, the difference in time taken for these measurements between the two methods was statistically significant (p < 0.001). Intraclass correlation coefficient (ICC) values indicated excellent interobserver reliability for measurements by method A (ICC ~ 0.998), and moderate reliability for method B (ICC ~ 0.626). CONCLUSIONS: Both software programs used in this study had comparable volumetric computation. Method B took much less calculating time than method A. The interobserver reliability was high for both methods. CLINICAL SIGNIFICANCE: These both investigated software programs may show a clinical implication for presurgical alveolar cleft volume measurement, thus reducing the surgical operating time and adequately selecting a donor site with a congruent sufficient amount of bone grafts.

Experimental study on penetration of dental implants into the maxillary sinus at different depths.

OBJECTIVE: The purpose of this study was to investigate the effect of the dental implant penetration into the maxillary sinus cavity in different depths on implant and sinus health in a dog model. MATERIALS AND METHODS: The study sample included eight titanium dental implant placed in four female dogs immediately after extraction of the first maxillary molar in the palatal socket and assigned into four groups according to the protruding of implant tips (control group A = 0 mm, and study groups B, C, and D with protrusion of 1, 2, and 3 mm, respectively). The bone blocks of the implants were harvested 5 months postoperatively and evaluated by cone beam computed tomography (CBCT) and histological analysis. RESULTS: The whole groups showed no signs of inflammation during the 5-month period of the study. The tips of the implants in group B with penetrating depths of 1 mm were found to be fully covered with newly formed bone. The tips of the implants in group C with penetrating depths of 2 mm were exposed in the sinus cavity and showed partially new bone coverage, while depths of 3 mm in group D were found to have no bone formation and the dental implant fixture sites were communicated with the sinus cavity. No significant differences were found among the groups regarding implant stability. CONCLUSION: Despite the protrusion extents, penetration of dental implant into the maxillary sinus with membrane perforation does not compromise the sinus health and the implant in canine.