The Effect of Different Doses of Extracorporeal Shock Waves on Experimental Model Mandibular Distraction.

OBJECTIVE: Distraction osteogenesis (DO) is widely used treatment for the bone deformities. In addition extracorporeal shock wave therapy (ESWT) is a new perspective on noninvasive modalities of management of the bone regeneration. We examined the effects of 2 different single doses of ESWT on the consolidation period of DO of the rabbit mandible using stereological, radiological and immunohistochemical methods in the present study. METHODS: DO was performed unilaterally in the mandible of 18 New Zealand rabbits (6 months' old, weighing between 2.5 and 3 kg). The distraction zone of the mandible has received no treatment as controls. Group 2 (ESWT 500) received ESWT (single dose of 500 impulses 0.19 mJ/mm energy flux intensity and 2155 mJ totally) were applied on the first day of the consolidation. Group 3 (ESWT 1000) treated with ESWT (single dose of 1000 impulses0.19 mJ/mm energy flux intensity and 4310 mJ totally) were applied on the first day of the consolidation period. After the sacrification, radiologically bone mineral density, new bone formation, new fibrous tissue, and new vessel formation were analyzed using unbiased stereological methods. RESULTS: It was found a statistically significant difference between the study groups and control group in the bone mineral density measurements and the highest values were in the ESWT1000 group. In terms of stereological analysis, there was a significant difference between the study groups and control group (P = 0.00). The new capillary volume was highest in the E1000 group. Additionally, significant differences were found in point of the capillary volumes between the groups control and ESWT500 (P = 0.001), control and ESWT1000 (P = 0.000), ESWT500 and ESWT1000 (P = 0.040), respectively. CONCLUSIONS: A total of 1000 impulses ESWT may induce the growth factors to enhance the newly formed bone regeneration.

The Use of Sequential VEGF- and BMP2-Releasing Biodegradable Scaffolds in Rabbit Mandibular Defects.

PURPOSE: Promising developments have materialized in reconstructive surgical procedures with the applications of tissue engineering. In our study, we used tissue scaffolds fabricated from polylactic acid-polyethylene glycol (PLLA-PEG) copolymers to ensure different release rates of selective growth factors recombinant human bone morphogenetic protein 2 [rhBMP-2] and vascular endothelial growth factor (rhVEGF165) in the repair of mandibular bone defects. MATERIALS AND METHODS: In our experimental study, 54 New Zealand rabbits were used. The rabbits were separated into 4 groups: group I (control group), PLLA-PEG scaffold only; group II, PLLA-PEG scaffold plus rhBMP-2 application; group III, PLLA-PEG scaffold plus VEGF165 application; and group IV, PLLA-PEG scaffold plus rhBMP-2 and VEGF165 applications. The rabbits were killed at 4 and 8 weeks postoperatively, and histopathologic and immunohistochemical assessments were performed. RESULTS: The greatest bone volume was observed in rhBMP-2-containing groups, the greatest vessel volume was observed in VEGF165-containing groups; however, the scaffold containing rhBMP-2 and VEGF165 provided the best outcomes in conjunction with increased remodeling of the new bone. CONCLUSIONS: The use of polymer tissue scaffolds that release rhVEGF165 and rhBMP-2 in coordination and mimic the natural healing process in the regeneration of especially complex tissues, such as bone, is a promising treatment alternative in the field of reconstructive surgery.

Therapeutic Effects of Sildenafil on Experimental Mandibular Fractures.

OBJECTIVES: No previous studies have examined the effect of sildenafil on fracture healing. This study was designed to investigate the effect of sildenafil on the fracture healing process. METHODS: Thirty-six female Sprague-Dawley rats (3-month-old) were used in this study. Animals were randomly divided into 2 groups based on treatment duration (1 week versus 4 weeks) and each group was then divided further into 2 subgroups, control (C) and study (S) groups. Group C (C1, C2) was treated daily with saline solution and group S (S1, S2) was treated daily with 10 mg/kg of sildenafil. Histologic, histomorphometric, radiological, and immunohistochemical analyses were performed at 1 week and 4 weeks after a fracture. RESULTS: The sildenafil group showed a significant increase in fracture healing scores (P = 0.00). The authors observed a transition from fibrous callus to cartilage tissue and immature bone tissue in group S1; and an increased transition of cartilage tissue to completely immature bone tissue in group S2, both of which were administered sildenafil. The strong expression of bone morphogenetic protein 2 and col-1 was observed in the fibrous matrix and osteoblasts within areas of new bone formation, especially in group S1. This group also showed an increase in bone density measurements at 1 week that was statistically significant (P = 0.03). CONCLUSIONS: Sildenafil accelerates fracture healing and can be used as a supporting factor in the improvement of fracture healing under various conditions.

The Radiological and Stereological Analysis of the Effect of Low-Level Laser Therapy on the Mandibular Midline Distraction Osteogenesis.

OBJECTIVE: The aim of this study was to evaluate the effect of low level laser therapy (LLLT) on bone mineral density by using high-resolution computerized tomography (HR-CT) and stereology in patients subjected to mandibular midline distraction. METHODS: Nine patients between the ages of 13 and 16 years with mandibular transverse deficiency (>5 mm) were evaluated. Mandibular midline distraction osteogenesis was performed for all the patients. The patients were divided into 2 groups: the control group (n = 4) and the laser group (n = 5). GaAlAs, 830 nm wavelength, power of 40 mW, energy of 8.4 J/cm2 dose per spot, was directly applied from 2 points on the mandibular midline. The laser was applied in 8 treatment sessions at 48-hour intervals. Bone mineral density and volume of the newly formed bone were analyzed using HR-CT and stereological methods. RESULTS: A higher bone mineral density rate was found in the laser group (P < 0.05). A higher newly formed immature bone rate was found in the control group (P < 0.001). These findings suggest that more mature bone may also have a greater mineral organization than that of immature newly formed bone, which is shown by HR-CT and stereological results. CONCLUSIONS: The retention period can be shortened and mineralization may be increased by using LLLT in mandibular distraction osteogenesis.

Trigger point injection therapy in the management of myofascial temporomandibular pain.

OBJECTIVES: Myofascial pain is the most common temporomandibular disorder. The objective of this study was to compare the effectiveness of combined treatment modalities in the management of myofascial temporomandibular pain. METHODS: Fifty patients (44 female, 6 male) clinically and radiologically diagnosed with myofascial temporomandibular disorder (TMD) were selected for the study and randomly assigned to two groups of 25 patients. Group 1 patients were treated with stabilization splint (SS) and Group 2 patients were treated with trigger point injection combined with SS therapy. RESULTS: Positive improvement in overall signs and symptoms with statistically significant differences was observed in both groups. Group 2 showed significant reduction in visual analogue scale (VAS) scores, and statistical analysis revealed a significant difference between the VAS scores of Group 1 and Group 2 at the 4th and 12th weeks of treatment follow-up (p<0.001). CONCLUSION: Our results indicate that trigger point injection therapy combined with splint therapy is effective in the management of myofascial TMD pain. Further research, especially randomized controlled trials, should be carried out to ascertain its effectiveness over other treatment modalities.

Retrospective analysis of impacted first and second permanent molars in the Turkish population: a multicenter study.

OBJECTIVES: The purpose of the present study was to retrospectively analyze 170 case series of patients with 200 impacted first and second permanent molars. STUDY DESIGN: Records of 104.408 patients were retrospectively screened in this multicenter study. The chosen study population consists of 170 patients who presented with impacted or retained first and second permanent molar. All patients with impacted first or second permanent molar had undergone clinical and radiographic examinations. The following factors were analyzed: age and gender, frequency, distribution, location, position, the number of impacted tooth, primary and secondary retention, degree of infraocclusion, associated pathologic conditions and treatment method. RESULTS: There were a total of 170 patients (male: 91, female: 79, mean ages 22.69 ± 8.99 years ranging from 13 to 66 years of age) with 200 retained or impacted permanent molars in 104.408 patients. In this study, 200 impacted teeth which were analyzed were 125 molars (62.5%) vertical position, 17 (8.5%) horizontal, 38 (19%) mesioangular, 12 (6%) distoangular, and 7 (3.5%) buccolingual inclination There were 52 primarily retained (26%) and 32 secondarily retained (16%) molars. 137 (68.5%) molars were asymptomatic. Cystic formation was present in 13 (6.5%) cases. CONCLUSIONS: Although the impactions of first and second permanent molars do not occur frequently, it is important to make an early diagnosis in order to start treatment at the optimal time.

Immunohistochemical analysis of reconstructed sheep mandibles: transport distraction osteogenesis versus autogenous bone grafting.

PURPOSE: Although many studies have been conducted that related to growth factor expression in mandibular distraction osteogenesis, to our knowledge, no study comparing the immunohistochemical outcomes of autologous bone grafting (ABG) and transport distraction osteogenesis has been conducted up to now. The aim of this study was to histologically and immunohistochemically analyze newly formed bone in the resected mandible reconstructed by transport distraction osteogenesis and iliac crest bone grafting in a sheep model. MATERIALS AND METHODS: Mandibular discontinuity defects created in the jaws of sheep were reconstructed by distraction osteogenesis (n = 7) and bone grafting (n = 7) and allowed to heal for 3 mos. The animals were then sacrificed and their jaws resected and prepared for decalcification. Histological and immunohistochemical examinations of transforming growth factor-beta 1 (TGF-ß1) and bone morphogenetic protein (BMP) -2, -4 were performed in the newly formed bone in the defect area. RESULTS: Positive staining for BMP-2, -4, and TGF-ß was observed in the cells and matrix components. BMP is present in both processes, but the expression of BMP-2, -4, and TGF-ß in the distraction regenerate is stronger when compared with bone graft healing. CONCLUSIONS: The only limitation of the present study was that it evaluated the role of BMP-2, -4, and TGF-ß expressions in bone repair process at 3 mo postoperatively. Determination of growth factor expression at more than 1 time point would be ideal in elucidating the role of these factors during bone healing.

Comparison of ketamine-diazepam with ketamine-xylazine anesthetic combinations in sheep spontaneously breathing and undergoing maxillofacial surgery.

The objective of this study was to choose a suitable anesthetic combination for use in experimental surgical models by comparing the anesthetic and cardio-respiratory changes. Fourteen healthy male sheep were randomly assigned to two different drug regimens. In Group 1 the sheep were anesthetized with ketamine + xylazine (22 mg/kg im. + 0.2 mg/kg i.m., respectively). Anesthetic combination of ketamine + diazepam (22 mg/kg im. + 0.4 mg/kg i.m., respectively) was used in Group 2. Heart rate, respiratory rate and mean arterial pressures were evaluated before anesthesia, after induction of anesthesia up to 30 minutes in 5 minute intervals and during recovery. In all sheep, duration of anesthesia induction, duration of anesthesia and duration of recovery were recorded. Quality of induction, anesthesia, analgesia and recovery were evaluated. Cardio-respiratory parameters decreased below baseline values after anesthesia induction in both groups. However, no profound effects on cardio-respiratory functions were observed during study. In Group 2, it was observed that; anesthesia induction time was longer, the depth of anesthesia was inadequate during the osteotomy stage of the surgical procedure and recovery time was longer in comparison to Group 1. Otherwise the quality of anesthesia induction, anesthesia, analgesia and recovery was better in Group 1 than Group 2. These findings indicate that both drug combinations can provide short time anesthesia for minor surgical procedures. Ketamine+xylazine combination can be used as a more suitable anesthetic combination in experimental surgical procedures such as maxillofacial surgery than ketamine+diazepam combination, in sheep.

Stereologic analysis of bone produced by distraction osteogenesis or autogenous bone grafting in mandible.

To our knowledge, in the literature, any other investigation that numerically compared osteoblasts retrieved from transport distraction osteogenesis and bone grafting procedures using stereological methods is not reported. The purpose of this study was to compare the total number of osteoblast cells at 3 months in bone produced by distraction osteogenesis and that in autogenous bone graft. A total of 19 growing sheep (male aged 7 or 8 mo; weighing between 21 and 28 kg) were used in this study. Mandibular discontinuity defects created in mandibles of sheep were reconstructed by transport distraction osteogenesis and iliac crest bone graft and allowed to heal for 3 months. The animals were then killed, and the jaws were resected and prepared to be decalcified. Stereological and histologic examinations were performed. Intramembranous ossification and osteoid and trabecular formations were observed in both groups. In the distraction group, the mean +/- standard deviation (SD) numerical density of the osteoblasts was found to be higher (0.0004866 +/- [0.000044])when compared with those of both the graft (0.0003458 +/- [0.000030]) and control groups (0.0002714 +/- [0.000022]). Statistically significant differences were found among the groups (P < 0.05). Stereologic evaluation of bone in the sheep model demonstrated significantly greater osteoblast density in bone formed through transport distraction osteogenesis when compared with bone grafting and the control. Therefore, further studies should be conducted to evaluate the differences in both osteoblastic and osteoclastic cellular activities at different time points in distraction osteogenesis and autogenous bone grafting to assess the healing process of bone for clinical applications.

Ultrasonographic evaluation of disc displacement of the temporomandibular joint compared with magnetic resonance imaging.

PURPOSE: We compared high-resolution ultrasonography with magnetic resonance imaging (MRI), as the gold standard, to evaluate lateral and anterior capsule-condyle distances to detect disc displacement of the temporomandibular joint. MATERIALS AND METHODS: This study included 28 patients (19 female and 9 male; age range, 16-51 years; mean age, 32.82 years), and in total, 56 joints were assessed with ultrasonography and MRI. Measurements were obtained for anterior capsule-condyle and lateral capsule-condyle distances in both open- and closed-mouth positions with high-resolution ultrasonography. These findings were also compared with those of MRI taken as reference. Receiver operating characteristic curve analysis was performed to assess our results. We assessed sensitivities, specificities, accuracies, and positive and negative predictive values for both open- and closed-mouth positions. RESULTS: Diagnostic accuracy of ultrasonographic anterior capsule-condyle distance in the closed-mouth position to detect MRI-positive disc displacement (area under receiver operating characteristic curve, 0.689; P = .015) was the highest. CONCLUSIONS: The measurement of the distance between the most anterior point of the articular capsule and the most anterior point of the condyle can be used to assess disc displacement in diseased joints. However, it is necessary to determine the most accurate threshold value and to set cutoff values. These findings need to be confirmed by further research in a large number of patients to test the interexaminer agreement and the reproducibility of this method.

Study of mandibular alveolar distraction osteogenesis using a three-dimensional computed tomography measurement method: report of four patients, a preliminary study.

OBJECTIVE: This study was conducted to show dimensional and volumetric changes after vertical alveolar distraction osteogenesis using a three-dimensional computed tomography measurement method. MATERIALS: Four patients with mandibular alveolar ridge atrophy were evaluated. Three-dimensional computed tomography reconstructions were obtained 2 weeks before and 3 months after the operation. The results of the three-dimensional computed tomography measurements were used for preoperative planning and for quantitative assessment of the mandibular alveolar distraction. The results of the preoperative and postoperative three-dimensional computed tomography measurements were compared statistically using paired t-test. RESULTS: The increase in distracted mandibular segment volume and surface area, height, and width of each slice after distraction were statistically significant (P < 0.001). CONCLUSION: In atrophic jaw cases, the dimensions of the present alveolar bone were clearly measured so that the amount of augmentation needed could be estimated. Three-dimensional computed tomography provided better understanding of the effects of distraction osteogenesis on the anterior mandible. Newly formed bone can be viewed as close to its real dimensions after distraction osteogenesis.

Maxillary myxoma: surgical treatment and reconstruction with buccal fat pad flap: a case report.

Myxoma is a benign tumor that arises from mesenchymal tissue and is found less commonly in the bone than in soft tissue. The majority of bony myxomas occur in the jaws. When compared with other odontogenic tumors, myxoma of the jaws is a rare entity. Numerous types of treatment have been used for these tumors including simple curettage, enucleation, curettage with peripheral ostectomy, and en bloc resection with or without immediate reconstruction. The buccal fat pad (BFP) is a lobulated mass of fatty tissue in the oromaxillofacial region, which has long been a source of grafts in facial augmentation. A case of an odontogenic myxoma in the left maxillary molar area of a 34-year-old female that was treated by curettage and peripheral ostectomy is presented. The surgical defect was successfully repaired with a pedicled BFP flap.