Comparison of the accuracy of pilot-drill-guided and fully guided implant surgery with dynamic navigation. In vitro model study.

The aims of the present study are to measure and compare dental implant deviations with fully guided and pilot-drill-guided protocols using dynamic navigation systems in polyurethane models. The pilot-drill-guided group was determined to be the study group and included 12 implant applications. In this group, the pilot hole was drilled with navigation guidance, and the procedure was completed freehandedly. In the control group, all the drilling and implant placement steps were performed using the navigation system, and a total of 12 implants were placed. The pre- and postoperative images were compared to calculate the magnitude of implant deviation. The quantitative data of the two groups were compared using the independent-samples t-test and Mann-Whitney U-test. The analyses revealed that the length of the procedure significantly differed between the two groups (p < 0.001). The procedure duration was significantly shorter in the study group. The entry deviation values of the two groups were not significantly different (p = 0.079). The analysis revealed the apex deviation to be higher in the study group than in the control group (p = 0.003). However, the two-dimensional vertical apex deviation values of the implants were not significantly different between groups (p = 0.068). Angular deviation was determined to be significantly higher in the study group (p < 0.001). In the present study, all implants were successfully placed in the models using a dynamic navigation system. The results of this study may be useful for future clinical studies.

Does Guided Bone Regeneration Prevent Unfavorable Bone Shapes in Distraction Gap?

PURPOSE: Complications related to distraction osteogenesis can cause degradation of newly regenerated bone. Additionally, an unfavorable shape of the regenerated bone at the distraction gap can reduce the quantity of regenerated bone. The aim of the present study was to report on the prevention of unfavorable shapes of regenerated bone using guided bone regeneration during distraction. MATERIALS AND METHODS: Bilateral alveolar distraction was performed in 10 beagle dog mandibles. One side of the mandible formed the experimental group and the other side served as the control group. In the experimental group, guided bone regeneration was performed simultaneously with distraction osteogenesis. In the control group, only alveolar distraction was applied. At the end of a 1-week latent period, all mandibles were distracted 10 mm (1 mm/day). After the distraction period, 3 months were allowed for consolidation. After consolidation, all the dogs were euthanized, and the shape of the regenerated bone was determined to be either favorable or unfavorable. Densitometric evaluation and area measurements were performed using computed tomography scans. Statistical evaluation was performed using the independent t test, with a significance level of P < .05. RESULTS: In the experimental group, no unfavorable bone shape developed in the distraction gap, and the new bone had a surface and volume similar to those of the segments. In contrast, in the control group, 4 mandibles had an unfavorable bone shape in the distraction gap and 4 showed favorable bone healing with no defect. The surface area of the regenerating bone in the experimental group was significantly greater than that in the control group. Also, the surface area differed significantly between the experimental and control groups (P < .05). However, the densitometric values did not differ between the 2 groups (P < .05). CONCLUSIONS: Concomitant use of guided bone regeneration with distraction osteogenesis could be an optimal method for generating a favorable bone shape within the distraction gap.

Closure of Oroantral Communication With Plasma-Rich Fibrin Membrane.

Oroantral communication (OAC) is the opening between the maxillary sinus and oral cavity. It may cause oroantral fistula or maxillary sinusitis if left untreated. The surgical closure of the OAC within 48 hours was recommended to avoid the complications like sinus infections. The aim of this study is to evaluate the treatment of OACs with plasma-rich fibrin (PRF) which is safe and easy to implement in the OACs.This study was conducted with the patients, who required the treatment of the OAC, which was developed after the posterior maxillary tooth extraction in the Dental and Maxillofacial Department of the Faculty of Dentistry in Adnan Menderes University.Plasma-rich fibrin membranes were inserted in layers into the tooth socket so that they covered the OAC. Then these membranes were fixated with the sutures to the surrounding gingiva. Antibiotic (amoxicillin/clavulanic acid 1000 mg), analgesic (dexketoprofen trometamol and/or paracetamol), and oral rinse (0.2% chlorhexidine digluconate) agents were prescribed to all patients. The patients were examined in the 3rd and 7th days and 2 months after the operation.All patients tolerated PRF perfectly, and the soft tissue recovery was completed without any problem. Full epithelization was observed in the defect area in all patients. The OAC did not relapse in any patient.Plasma-rich fibrin technique is a simple and effective method, which can be used in the treatment of OACs with a diameter of 5 mm or less with a low risk of complications.

New method to increase inter-alveolar height with preservation of crestal cortical bone for implant treatment.

The aim of this technique is to provide adequate interocclusal distance (3 mm) allowing preprosthetic management. A bone block was cut with piezosurgery and extracted, leaving the crestal cortical bone intact. The free crestal alveolar bone was fixed to the maxilla with 2 dental implants. After 3 months of follow-up, abutment surgery was performed and osseointegration was evident with adequate interocclusal height (7 mm) allowing prosthetic management.

Evaluation of the effects of guided bone regeneration and periosteum on newly formed bone in a distraction gap.

We determined the causes of bone resorption within a distraction gap and determined whether it could be prevented via guided bone regeneration during distraction. Another goal was to determine the effect of periosteum in bone healing in a distraction gap.Twelve sheep mandibles were bilaterally distracted. One side of the 6 sheep mandibles formed the control group; the other side was the study group, from which the periosteum was excised and distraction was performed. In the other 6 sheep, on the study side, guided bone regeneration was applied with distraction; on the other study side, guided bone regeneration was applied, and the periosteum was excised at the distraction. At the end of a 1-week latent period, all subjects were distracted 10 mm (1 mm/d), and we waited 3 months for consolidation. At the end of this period, all animals were killed, and radiologic evaluations of the newly formed bone within the distraction gap were conducted.The surface area of the regenerating bone in the membrane groups was significantly higher than in the groups without a membrane. However, no additional effect of the periosteum on the bone surface area was observed. No significant difference between the groups in densitometric values was observed.Concomitant use of guided bone regeneration with distraction osteogenesis may be the optimal way to generate a flat bone surface within a distraction gap.

A comparative evaluation of parasymphyseal fracture fixation in edentulous patients performed using dynamic navigation systems and Herbert screws with the conventional two-plate method: A study on models.

PURPOSE: The investigators performed this study to compare the rigidity outcomes for minimally invasive fixation of edentulous mandibular parasymphyseal fractures without flap creation using Herbert screws with a dynamic navigation system and the conventional two-plate method. METHODS: The investigators implemented an in-vitro study design, and 20 polyurethane edentulous mandibular models covered with flexible plastic to simulate the gingiva were used. Parasymphyseal fractures were created in all models using a reciprocal saw. In the study group, the fracture segments in each model were planned to be fixed using two 30-mm Herbert screws. The Herbert screws were placed using a screwdriver with the dynamic navigation system guiding the process. In the control group, to simulate open reduction, the fracture fragments were fixed using two 4-hole straight titanium plates and 6-mm titanium screws. All mandibular models on the prepared platform were attached to the biomechanical testing machine. They were subjected to a continuous linear compression until plastic deformation occurred. Displacement resistance was measured once for every model when the displacement reached 1, 3, 5, 10, and 15 mm. Furthermore, the maximum breaking forces that the models could withstand before deformation were measured. Data were analyzed using independent samples t-test. A value of p < .05 was considered statistically significant. RESULTS: Manual examination of the models did not reveal any mobility between the fragments. In all evaluated displacement steps, the models fixed using Herbert screws showed significantly higher resistance to mechanical loading compared to the models fixed using parallel miniplates. CONCLUSION: In present study, parasymphyseal fracture of edentulous mandible models were fixed successfully using Herbert screws with the dynamic navigation system. The results of this study may encourage future clinical studies.

Propofol based total intravenous anesthesia versus sevoflurane based inhalation anesthesia: The postoperative characteristics in oral and maxillofacial surgery.

OBJECTIVE: Total intravenous anesthesia and inhalation/volatile anesthesia are the main general anesthesia procedures used in all surgical applications. The aim of this study was to compare sevoflurane anesthesia and total intravenous anesthesia with propofol in terms of postoperative complications, especially after oral and maxillofacial surgeries. MATERIAL AND METHODS: Each patient was taken to the recovery room following extubation, and the pulse rate, non-invasive blood pressure (NIBP) and oxygen saturation were monitored. Presence of hypoxia, tachycardia, bradycardia, hypertension and hypotension were determined as vital sign complications. RESULTS: The risk of complications related to vital functions were low for both anesthesia methods, and no statistically significant difference between the groups. The incidence of nausea and vomiting was found to be significantly higher in the patients undergoing both major (p = 0.011) and minor (p = 0.021) surgeries in the IA-S group. The recovery time was found to be significantly longer in the TIVA-P group compared to the IA-S group in the patients undergoing both major (p = 0.026) and minor surgery (p = 0.018). CONCLUSION: TIVA and IA methods, which are considered safe in terms of vital signs, should be preferred according to patient characteristics. Despite the fact that inhaled anesthetics require PONV premedication for long term interventions, we believe that they could be preferred due to shorter recovery time compared to intravenous anesthetics.

Biomechanical evaluation of hybrid fixation method of sagittal split ramus osteotomy in mandibular advancement.

PURPOSE: In this study, eight different fixation methods applied after sagittal split ramus osteotomy (SSRO) were compared experimentally. MATERIALS AND METHODS: SSRO was performed to 48 sheep hemimandibles in eight groups of 6 each. Group A- a four hole standard miniplate; Group B- a four hole standard miniplate and one bicortical screw; Group C-a four hole locking plate; Group D-a four hole locking plate and one bicortical screw; Group E-a six hole straight miniplate; Group F-a six hole straight miniplate and one bicortical screw; Group G- a sliding plate, which was specifically designed for SSRO; Group H- sliding plate and one bicortical screw. RESULTS: In terms of measured values of displacement, the highest degrees of displacement were observed in decreasing order in Groups G, C, A, and E. The least displacement values were detected in Groups H, F, D and B with values being very close to each other. For linear force applied up to 70N, 3 mm or higher displacement values were not seen in any fixation system. CONCLUSION: According to the results of study, all systems are suitable for clinic usage. However, intermaxillary fixation or functional elastics may be needed for sliding plate systems during the healing period of hard tissue.

Comparison of Bovine Bone-Autogenic Bone Mixture Versus Platelet-Rich Fibrin for Maxillary Sinus Grafting: Histologic and Histomorphologic Study.

Numerous grafting materials have been used to augment the maxillary sinus floor for long-term stability and success for implant-supported prosthesis. To enhance bone formation, adjunctive blood-born growth factor sources have gained popularity during the recent years. The present study compared the use of platelet-rich fibrin (PRF) and bovine-autogenous bone mixture for maxillary sinus floor elevation. A split-face model was used to apply 2 different filling materials for maxillary sinus floor elevation in 22 healthy adult sheep. In group 1, bovine and autogenous bone mixture; and in group 2, PRF was used. The animals were killed at 3, 6, and 9 months. Histologic and histomorphologic examinations revealed new bone formation in group 1 at the third and sixth months. In group 2, new bone formation was observed only at the sixth month, and residual PRF remnants were identified. At the ninth month, host bone and new bone could not be distinguished from each other in group 1, and bone formation was found to be proceeding in group 2. PRF remnants still existed at the ninth month. In conclusion, bovine bone and autogenous bone mixture is superior to PRF as a grafting material in sinus-lifting procedures.

Implants in children with hypohidrotic ectodermal dysplasia: an alternative approach to esthetic management: case report and review of the literature.

Ectodermal dysplasia (ED) is a rare congenital disease that affects several ectodermal structures. Children with ED may have various manifestations of the disease that differ in severity. In addition to its other symptoms, ED causes anadontia and hypodontia of the primary or permanent teeth, impacted teeth, malformed and widely spaced peg-shaped teeth, and underdeveloped alveolar ridges. Since the oral rehabilitation of these cases is often difficult, particularly in pediatric patients, treatment should be provided by a multidisciplinary team. Dental implants are the treatment of choice when growth has stabilized, and implants can be used to support, retain, and stabilize the prosthesis. The purpose of this paper was to present a case report of implant placement in a 7-year-old girl with hypohidrotic ectodermal dysplasia and review the current literature to discuss the use of dental implants in such patients.