Effect of Systemic Oxytocin Administration on New Bone Formation and Distraction Rate in Rabbit Mandible.

PURPOSE: The main disadvantage of distraction osteogenesis is the prolonged treatment protocol. Recently, oxytocin (OT) has been found to have anabolic effects on bone metabolism. In this experimental study, the effects of OT on the mandibular distraction gap in rabbits at 2 different distraction rates were evaluated. MATERIALS AND METHODS: This experimental study was conducted on 28 male New Zealand white rabbits. The animals were divided into 3 experimental groups and 1 control group. Group A (control group, n = 7) consisted of animals with distraction at a rate of 1 mm/day, and group B (n = 7) consisted of animals with a distraction rate of 2 mm/day; groups A and B received postoperative saline solution injection. Group C (n = 7) consisted of animals with distraction at a rate of 1 mm/day, and group D (n = 7) consisted of animals with a distraction rate of 2 mm/day; postoperative OT injection was performed in groups C and D. RESULTS: Both histomorphologic and micro-computed tomography evaluations showed increased bone healing in the OT-treated groups. CONCLUSIONS: On the basis of the evaluation of both the histomorphometric and micro-computed tomographic data, systemic OT administration was found to increase new bone formation and bone healing with distraction osteogenesis.

Oral rehabilitation with implant-supported fixed dental prostheses of a patient with cleidocranial dysplasia.

This clinical report describes the oral rehabilitation with implant-supported fixed dental prostheses in the maxilla and mandible of a patient with cleidocranial dysplasia. Cone-beam computed tomography and a tilted implant protocol in the mandible helped to establish a conservative approach for bone preservation, prevent surgical complications, enable proper implant positioning to avoid anatomic structures, and support the fixed dental prostheses.

Effects of Local Low-Dose Alendronate Injections Into the Distraction Gap on New Bone Formation and Distraction Rate on Distraction Osteogenesis.

Bisphosphonates that constrain bone resorption have a direct effect on osteoclast function. In this experimental study, the effects of low-dose local alendronate injections on the distraction gap (DG) in rabbit mandible at 2 different rates were evaluated.The experimental study was conducted on 20 male, New Zealand white rabbits. The animals were divided into 3 experimental groups and 1 control group. Group 1 consisted of animals with distraction at the rate of 1 mm/day, receiving postoperative local low-dose alendronate local injections into the DG. Group 2 consisted of animals with distraction at the rate of 2 mm/day, receiving postoperative 0.75 µg/kg of alendronate local injections into the DG. Group 3 consisted of animals with distraction at the rate of 2 mm/day, receiving postoperative 0.2 mL local saline injections into the DG. Group 4 consisted of animals with distraction at the rate of 1 mm/day, receiving postoperative 0.2 mL local saline injections into the DG. All the injections were performed immediately postoperatively and for all groups at 1, 2, 3, and 4 weeks following surgery. The distraction zones were evaluated using dual-energy X-ray absorptiometry and histological analysis.Histologically, bone healing was found to be significantly accelerated in Groups 1 and 4 compared with Groups 2 and 3 (P < 0.05). Bone healing was superior in Group 1 and the difference was statistically significant compared with Group 4. There was a significant increase in mean bone mineral density in the 1 mm daily rate groups (Groups 1 and 4) compared with the 2 mm daily rate groups (Groups 2 and 3) (P < 0.05).Local low-dose alendronate injections could be an effective way for improving bone formation in distraction osteogenesis. Furthermore, the results of this study did not support the hypothesis that injections of local low-dose alendronate may allow 2 mm/day instead of 1 mm/day of elongation in the rabbit mandible.

Effect of Platelet-Rich Fibrin on Peripheral Nerve Regeneration.

PURPOSE: This study aimed to evaluate the effect of platelet-rich fibrin (PRF) on peripheral nerve regeneration on the sciatic nerve of rats by using functional, histopathologic, and electrophysiologic analyses. MATERIALS AND METHODS: Thirty female Wistar rats were divided randomly into 3 experimental groups. In group 1 (G1), which was the control group, the sciatic nerve was transected and sutured (n = 10). In group 2 (G2), the sciatic nerve was transected, sutured, and then covered with PRF as a membrane (n = 10). In group 3 (G3), the sciatic nerve was transected, sutured by leaving a 5-mm gap, and then covered by PRF as a nerve guide (n = 10). Functional, histopathologic, and electrophysiologic analyses were performed. RESULTS: The total histopathologic semiquantitative score was significantly higher in G1 compared to G2 and G3 (P < 0.05). Myelin thickness and capillaries were significantly lower in G3 compared to G1 (P < 0.05). There was no statistically significant difference between the groups with regard to the functional and electrophysiologic results. CONCLUSION: The study results suggest that PRF decreases functional recovery in sciatic nerve injury. Further studies are required to determine the efficacy of PRF on peripheral nerve regeneration.

Spontaneous Healing of Mandibular Noncontinuous Defect Caused by Medication-Related Osteonecrosis of the Jaw.

BACKGROUND: Bisphosphonates are used throughout supportive cancer therapies for the treatment of osteoporosis and metastatic bone diseases, but they invariably induce medication-related osteonecrosis of the jaw (MRONJ). This medicational modality may induce consequential losses that can lead to spontaneous or surgical therapy related bone fractures or defects. MRONJ stages and treatment alternatives are described in the current procedures. Accordingly, treatments for stages 0 and 1 are conservative whereas the treatment for stage 3 is surgical resection of the necrotic bone. Stage III MRONJ therapy is still controversial within the scope of conceivable bone fractures or defects. When the development of MRONJ is refractory to conventional treatment modalities, surgical management can be suggested. The aim of this study was to evaluate the results of the surgical treatment of MRONJ as part of a medical patient. METHODS: A 72-year-old man was referred to our department for extensive pain of the left mandibular region that occurred after tooth extraction. It was identified in his medical history that he had received a nitrogen-containing intravenous bisphosphonate (Zometa; Novartis, East Hanover, NJ) therapy for prostate cancer. He had been administered 4 mg. IV Zolenat 9 times during the first year of therapy, followed by 2 doses of the same amount of Zolenat in the second year. RESULTS: The treatment started with a therapy that combined antibiotics and antibacterial mouth rinse with chlorhexidine for maintaining oral hygiene. After the maturity of the sequestrum was identified through radiographic examination, the patient was treated by the segmental resection of the extensive necrotic bone, resulting in discontinuity of the mandibular corpus. Two years later, spontaneous bone healing occurred along the residual defect on the mandible. CONCLUSION: Treatment options for the defects resulting from MRONJ are still under debate, and no evidence-based guidelines are available. However, due to the results displayed in this patient; it may be a sound approach to closely follow up and observe MRONJ-related bone to prevent additional complications.

Clinical Evaluation of the Use of Tibial Bone Grafting in Dentoalveolar Reconstructive Surgery.

OBJECTIVE: The aim of this study was to evaluate the efficacy of tibial autogenous bone grafting in the treatment of patients with alveolar bone defects. MATERIALS AND METHODS: The study subjects consisted of 12 patients (10 male, 2 female, age: 19-51 years) who underwent reconstructive autogenous bone-grafting procedures. The medial approach to the tibial bone was used to harvest autogenous cancellous bone grafts in all the patients. Clinical parameters (complications at the donor and recipient sites, resorption and volume of the grafts) were evaluated retrospectively. RESULTS: The mean age of the patients was 36.25 ± 0.9 years. Of the 12 patients, 5 (41.7%) received bone grafts for sinus augmentation, 3 (25%) for cyst cavity reconstruction and 4 (33.3%) for alveolar cleft reconstruction procedures. The average follow-up period was 28.4 months (range: 21-40 months). An average of 5.2 cm3 of cancellous bone was harvested for grafting procedures. All the grafting procedures were successful, and there were no surgical complications during the harvesting protocol. In all cases, pain and gait disturbance lasted less than 2 weeks. CONCLUSION: The results of this study suggest that the use of tibial autogenous bone graft harvested using a medial approach was a safe, simple and effective method for grafting various alveolar bone defects where high amounts of cancellous bone grafts were needed with low morbidity.

Stafne Bone Cavity Complicated By Periapical Infection.

Stafne bone cavity (SBC) is an uncommon lesion of the mandible; and generally found incidentally on routine radiographic examinations. The radiographic differential diagnosis of SBC includes a variety of lesions including odontogenic cysts, benign tumors, or bone metastases. In the present case, a 22-year female patient was admitted with chief complaint of pain in the right mandibular molar area. On panoramic radiographic examination, a non-specific large radiolucent lesion related to mandibular molar teeth was detected and extra-oral surgical intervention was planned. However, on examination with cone-beam CT(CBCT), a SBC was suspected due to lack of lingual cortical plate; and intraoral surgical exploration confirmed the diagnosis showing a cavity with small inflamed salivary gland tissue. Examination with CBCTon suspicious jaw lesions helps avoid unnecessary extraoral surgical interventions.

Efficacy of platelet rich fibrin in the reduction of the pain and swelling after impacted third molar surgery: randomized multicenter split-mouth clinical trial.

BACKGROUND: Impacted third molar removal is a routine procedure in oral and maxillofacial surgery. Platelet-rich fibrin (PRF) is a second generation platelet concentration which is produced by simplified protocol. The aim of this study was to assess the effectiveness of PRF in the healing process by evaluating the changes in pain and swelling after third molar surgery. METHODS: Fifty-six patients (23 male, 33 female) who provide the inclusion criteria were selected to participate in this study. The evaluation of the facial swelling was performed by using a horizontal and vertical guide. The pain was evaluated in the postoperative period using a visual analog scale (VAS) of 100 mm. RESULTS: Horizontal and vertical measurements showed more swelling at the control side (without PRF) in 3th day postoperatively (p < 0.05). There were no statistically significant differences regarding pain among the groups. CONCLUSION: As a conclusion, PRF seems to be effectiveness on postoperative horizontal swelling after third molar surgery. PRF could be used on a routine basis after third molar extraction surgery.

Finite-Element Analysis of a New Designed Miniplate which is Used via Intraoral Approach to the Mandible Angle Fracture: Comparison of the Different Fixation Techniques.

The mandible is the largest facial bone as well as the most commonly fractured bone in the maxillofacial region. Despite numerous studies conducted to identify optimal treatment modalities and plates configurations for intraoral and transoral approaches, no definitive conclusion has been reached. This study used finite element analysis (FEA) to assess 4 scenarios for treatment of an angle fracture (6-hole noncompression miniplate; 6-hole single plate/Champy's technique, 3D strut plate; 2 parallel 4-hole noncompression miniplates). Analysis included segmental displacement and Von Mises Stress evaluations of a 3D reconstruction of a human mandible. Von Mises Stress values for plates did not vary significantly among treatment groups. Moreover, no significant differences were observed in cumulative displacement of segments subjected to vertical and horizontal loads, with all treatment configurations demonstrating clinical acceptability.

Piezosurgery versus conventional surgery in radicular cyst enucleation.

OBJECTIVE: This study compared the use of piezosurgery and conventional surgery in radicular cyst enucleation. STUDY DESIGN: The study was conducted with 29 patients who were radiologically and cytologically prediagnosed with radicular cysts in the jaw region. Nineteen patients were treated using piezosurgery, and 10 were treated using conventional surgical procedures. Surgical procedures were evaluated according to the following criteria: hemorrhage, soft-tissue damage, manipulation complexity, major perforation areas on the enucleated cyst tissue, and approximate operation duration. Patients were monitored postoperatively and evaluated for hemorrhaging at 24, 48, and 72 hours following surgery. Follow-up was conducted to check for recurrences and ranged from 5 to 24 months. RESULTS: No complications were observed in any of the 20 patients treated using piezosurgery, although the duration of surgery was longer than expected. Of the 10 patients treated using conventional methods, hemorrhaging that affected the operation occurred in 3 cases, perforation of the cyst epithelium and difficulties in enucleation occurred in 5 cases, postoperative hemorrhage occurred in 2 cases, and recurrence was observed in 2 cases. CONCLUSIONS: Piezosurgery may be considered effective in procedures such as enucleation that require sensitive manipulation, despite the increase in the length of the overall surgical procedure. Given the results of the present study and the current lack of information in the literature regarding postoperative pain, infection, and long-term success rates associated with the use of piezosurgery in cyst enucleation, further study in this area is recommended.

Correction of postsurgical alveolar ridge defect with vertical alveolar distraction of the onlay block graft.

Alveolar bone augmentation for dental implant rehabilitation is one of the greatest challenges for oral and maxillofacial surgeons. Bringing out an inadequate quantity of vertical bone during augmentation compromises correct implant positioning and the resulting prosthetic restoration. Alveolar distraction osteogenesis is now generally used in correcting alveolar ridge atrophy due to trauma, congenital defects, or periodontal defects. Onlay block grafting is a suitable method for restoring the alveolar bony defects. However, it sometimes can become a complicated procedure to repair the horizontal defect accompanying a vertical defect using only bone blocks. This clinical report presents a successful reconstruction of a severe anterior mandibular alveolar bony defect as a result of impacted teeth extraction and periodontal problem in a 50-year-old healthy female patient. The defect was reconstructed with symphysis graft and platelet-rich fibrin in the first step. Vertical alveolar distraction was performed on the grafted site to maintain the suitable bony height 3 months later. Grafted bony segment distraction and the treatment options in similar cases were also discussed in this clinical report among with the literature.