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.

Is the Level of Nitric Oxide in the Dental Follicular Tissues of Impacted Third Molars With a History of Recurrent Pericoronitis a True Marker of Oxidative Stress?

PURPOSE: Nitric oxide (NO) is an indicator of oxidative stress in several tissues. Its role in dental follicular (DF) tissues of impacted third molars with a history of recurrent pericoronitis is not well elucidated. The present study compared NO levels between inflamed and noninflamed DF tissues of impacted third molars with a history of recurrent pericoronitis. MATERIALS AND METHODS: A cross-sectional study was designed. The study sample included inflamed DF tissues (test group) with certain local inflammatory symptoms, such as pain, tenderness, swelling, and erythema and noninflamed DF tissues (control group) without local inflammatory symptoms of impacted mandibular third molars. Each patient contributed only 1 specimen to the samples. All tissues samples were biochemically investigated for NO levels as an indicator of oxidative stress. The primary predictor variable was inflammatory status; secondary predictor variables were age and gender. The primary outcome variable was NO level. Descriptive and comparative analyses were conducted. RESULTS: The test group consisted of 57 patients (28 men, 29 women; mean age, 23.28 ± 5.16 yr) and the control group consisted of 57 patients (30 men, 27 women; mean age, 23.02 ± 5.42 yr). No relevant intergroup differences were noted for demographic findings such as age and gender. NO levels were significantly higher in inflamed DF tissues of impacted third molars than in noninflamed DF tissues (P < .05). CONCLUSION: Results of this study showed that NO might be used as an indicator of oxidative stress and the necessity to remove impacted mandibular third molars with a history of recurrent pericoronitis.

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.

Stress Analysis of Zygomatic Implants on the Augmented Maxillary Sinus: Is It Necessary to Graft?

PURPOSE: Zygomatic implants are becoming an ideal therapy with advanced implant-supported prosthetic treatment for the posterior atrophic maxilla. The purpose of this study is to examine the quantity and distribution of stress, which was caused by zygomatic implants placed using intrasinus method with or without augmentation to the atrophic posterior maxilla. MATERIALS & METHODS: In this study, 3-dimensional atrophic edentulous maxilla models with and without sinus augmentation are designed with computer-aided programs. Stress analysis was carried out on the created computer models for maxillary alveolar cortical bone, for cortical bone in the zygomaticomaxillary suture, and for zygomatic spongy bone at the apex of the zygomatic implant and for metal substructure of Von Misses stress data. RESULTS: Having augmented the maxillary sinus with graft, it was observed that after the loading especially in the posterior region, the tensile and compressive stresses on the alveolar crest was distributed more homogeneously and the stress generated on the cortical bone was reduced through the graft. CONCLUSION: Although zygomatic implants are graftless solutions for athrophic maxilla, sinus augmentation will be useful for bearing stress around the implants.

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.

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.

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.

Relationship between activity of gluthatione peroxidase and nitric oxide in synovial fluid and the progression of temporomandibular joint internal derangement.

The purposes of this study were to measure the activity of glutathione peroxidase (GPX) and nitric oxide (NO) in the synovial fluid of patients with temporomandibular joint (TMJ) internal derangement (ID) and to indicate the relationship between the activity of GPX and NO and the progress of the ID. Twenty-six patients with TMJ ID were identified and classified according to Wilkes staging through clinical and radiologic examinations. Levels of GPX were determined indirectly by a coupled reaction with glutathione reductase. Levels of NO were measured colorimetrically. The activity of GPX and NO was observed to be progressively increasing as the stage of the TMJ ID progressed. There were significant correlations between the 2 substances and the Wilkes stages. Oxidative stress may have a role in the pathogenesis of TMJ ID. In synovial fluid, GPX and NO activities are increased as the stage of the disease increased. Increase in the activities of GPX might not be enough to prevent progression of the TMJ ID.

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.

Is autogenous abdominal fat transplantation into a large temporomandibular joint defect following removal of failed alloplastic prosthesis a definitive treatment?

PURPOSE: To evaluate the long-term clinical outcome after the removal of failed major alloplastic temporomandibular joint (TMJ) implants and the placement of an autologous abdominal fat graft. MATERIALS AND METHODS: A long-term clinical follow-up was performed in 4 patients who underwent removal of a failed alloplastic implant and insertion of an autologous abdominal fat graft under 1-stage surgical management. Postsurgical use of pain medication was documented and the vertical interincisal opening measurement was obtained at the follow-up visit. Long-term computed tomographic (CT) scans were available for 3 of 4 patients and evaluated for fat graft retention by a radiologist. Hounsfield units were used. RESULTS: The study showed long-term (average, 4.7 years) clinical success, including normal jaw function (≥30-mm vertical opening) and freedom from the use of pain-relieving medication. Long-term CT scans (average, 5 years after surgery) documented fat graft retention in 3 patients (-80 HU). CONCLUSION: Autogenous fat graft placement alone, after major TMJ alloplastic removal, provides excellent long-term clinical success.

Biomimetic dental implant production using selective laser powder bed fusion melting: In-vitro results.

Instead of a textured surface with irregular pore size and distribution as in conventional dental implants, the use of lattice structures with regular geometric structure and controlled pore size produced by selective laser powder bed fusion melting (LPDF) technique will provide more predictable and successful results regarding osseointegration and mechanics. In this study, biomimetic dental implants with 2 different pore designs were fabricated by LPDF technique and compared with conventional dental implants in terms of surface characterization and resistance to biomechanical forces. Finite element analysis, scanning electron microscopy, computed micro tomography scanning, ISO 14801 tests and detork tests were used for the comparison. The tested biomimetic implants were found to be as durable as conventional implants in terms of mechanical strength and detork values. They were also found to be 40-60% more advantageous than conventional dental implants with respect to surface area and volume. As a result, it was concluded that biomimetic dental implants with sufficient mechanical strength and complex surface geometries can be made as designed without changing the reliable base material and can be produced using a different manufacturing method.

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.

Pharyngeal airway space changes and stability following an extended LeFort-I osteotomy advancement in cleft lip and palate and non-cleft lip and palate patients: A long term comparison study.

PURPOSE: The aim of this study was to evaluate effects of extended maxillary advancement osteotomy on pharyngeal airway space (PAS) in mid-facial deficient cleft lip and palate (CLP) patients and mid-facial deficient non-CLP patients. METHODS: Pharyngeal airway space (PAS) of 10 CLP and 10 non-CLP patients with the mean age of 19 years 10 months was measured on digitized lateral cephalograms taken shortly before maxillary advancement operation with Quadrangular Le Fort I osteotomy (QLF-I) (T0), early post-operative, (T1) and long term post-operative (T2). Two way repeated analysis of variance, independent samples t-test and correlations tests were used for statistical analysis of airway and skeletal changes. RESULTS: Total PAS depth and area was significantly increased after the advancement and was stable in long term post-operative period for CLP and non-CLP patients. Nasopharyngeal and velopharyngeal airway space depth and area was statistically increased at T1 and T2 for both groups. Oropharyngeal airway depth and area showed no significant statistical difference at any of the time points. The effect of QLF-I osteotomy on (PAS) was similar in both CLP and non-CLP patients. CONCLUSIONS: Nasopharyngeal, velopharyngeal, and total pharyngeal airway space depth and area increased after maxillary advancement with the QLF-I osteotomy; this increase was stable in long term follow up. Maxillary advancement with the QLF-I technique had no significant effect on oropharyngeal airway space depth and area in both CLP and non-cleft patients.

Malondialdehyde levels in dental follicles of asymptomatic impacted third molars.

PURPOSE: Increased levels of reactive oxygen species lead to oxidative stress and tissue damage. Malondialdehyde (MDA) is one of many low-molecular-weight endproducts of lipid peroxidation that increases with oxidative stress. The aim of this study was to determine oxidative stress in dental follicles (DFs) of radiologically asymptomatic impacted third molars (ITMs) using MDA. MATERIALS AND METHODS: This study involved 40 DFs of 40 patients referred for clinically and radiographically asymptomatic ITMs. Forty healthy gingival tissues in the same patients were obtained during surgical removal of teeth as a control group. DF widths on periapical radiographs narrower than 2.5 mm were included in the study. All tissues samples were analyzed for MDA as an indicator of oxidative stress. RESULTS: Levels of MDA were significantly higher in DFs from ITMs than those from healthy gingival tissues of the same patients (P < .01). CONCLUSION: The results suggest that significant oxidative stress may occur in DFs of asymptomatic ITMs. The findings suggest that increased MDA may play an important role in oxidative stress in DFs. In light of these preliminary findings of the present study, further investigations and comprehensive studies are required to determine the role of antioxidants that scavenge free radicals in DFs.

Symphyseal bone cylinders tapping with the dental implant into insufficiency bone situated esthetic area at one-stage surgery: a case report and the description of the new technique.

Periodontal defects and trauma at the anterior maxillary region can cause a severe alveolar ridge deficiency resulting in an unesthetic view. Ideal implant positioning can be compromised by inadequate alveolar bone in terms of height and width. Reconstruction of osseous defects with autogenous bone allows ideal implant positioning and creates a more natural soft and hard tissue profile, which influences esthetic crown anatomy at the anterior maxillary region. In this case report, an alveolar ridge defect due to periodontally compromised tooth extraction was filled with autogenous bone cylinder and dental implant at one-stage surgery. In the presented case, a new technique was described which included bone reconstruction of the defects at the anterior maxillary region and simultaneous placement of the dental implant.

Surgical and prosthodontic rehabilitation in a patient with Freeman-Sheldon syndrome.

Dental and prosthetic rehabilitation possess significant challenges in patients who have Freeman-Sheldon syndrome. Microsomia is one of the main diagnostic criteria for Freeman-Sheldon syndrome, and it creates difficulty in working in the intraoral cavity. Most patients with small orifice often have difficulties in oral hygiene maintenance, and it gives rise to loss of some of the teeth. It incurs the need for dental and oral treatment. In the presented study, the patient with limited mouth opening that disabled the dentists to perform dental treatment was given prosthodontic therapy after having commissuroplasty and implant placement simultaneously.

Effects of alendronate on rate of distraction in rabbit mandibles.

PURPOSE: Bisphosphonates are used for inhibiting bone resorption in several diseases. In this experimental study, the effects of alendronate on the mandibular distraction gap in rabbits at 2 different rates were evaluated. MATERIALS AND METHODS: The study was performed using 15 New Zealand white rabbits. Group 1 consisted of animals with distraction at the rate of 1 mm/day. Group 2 consisted of animals with distraction at the rate of 2 mm/day. These experimental groups had a postoperative alendronate injection during the first 3 days of their distraction phase. Group 3 consisted of animals with distraction at the rate of 1 mm/day, without alendronate injections. Distraction was performed on only the left sides of all animals until a gap of 10 mm was achieved. On postoperative day 45, the animals were sacrificed, and the mandibles of all animals were evaluated radiographically and histologically, and with dual-energy x-ray absorptiometry (DEXA). Radiographic images were also evaluated using transmission densitometry (TD). RESULTS: Histologically, bone healing was found to be significantly accelerated in groups 1 and 2 compared with group 3 (P < .05). Bone healing was superior in group 2, but the difference was not statistically significant compared with group 1. The TD results revealed no statistical difference between experimental groups, whereas the results for group 2 showed significantly denser osteogenic formation in the distraction gap compared with group 3. There was a significant increase in mean bone mineral density in the experimental groups compared with the control group. CONCLUSION: Histologic, TD, and DEXA results showed that alendronate injections during the distraction phase may be effective in accelerating new bone formation in the distraction gap in rabbit mandibles. The TD results also support the concept that an administration of alendronate may allow a 2 mm/day elongation instead of 1 mm/day in the rabbit mandible.

Tumor necrosis factor-alpha levels in the synovial fluid of patients with temporomandibular joint internal derangement.

PURPOSE: The purpose of this study was to investigate the level of tumor necrosis factor-alpha (TNF-α) in the synovial fluid (SF) of patients with temporomandibular joint (TMJ) internal derangement and to show the relationship between the level of TNF-α and the severity of the disease. MATERIALS AND METHODS: Arthrocentesis was performed on 32 female and five male patients (aged between 17 and 45) referred to our clinic with the complaint of TMJ pain and discomfort. TNF-α levels were determined in the SF samples obtained during arthrocentesis. As a measure of pain, visual analog scale (VAS) scores were also evaluated. RESULTS: There were statistically significant differences in VAS scores between the stages. VAS scores were found to be elevated as the stage of disease progressed. Increased levels of TNF-α were found in progressive stages of internal derangement. CONCLUSION: In our study, both SF TNF-α levels and pain levels (VAS scores) were found to be increased in patients with internal derangement as the stage of the disease progresses. TNF-α might contribute to the pathogenesis of synovitis and the degeneration of the TMJ cartilage and bone.