Alveolar ridge preservation with deproteinized bovine bone graft and collagen membrane and delayed implants.

To evaluate clinically and radiographically an alveolar ridge, preservation technique with deproteinized bovine bone graft and absorbable collagen membrane and then restoration with delayed implants were done. The study included 30 patients. The trial group's sockets were filled with deproteinized bovine bone graft (Bio-Oss) and covered with absorbable collagen membrane (Bio-Gide). The control group's sockets healed without any treatment. Panoramic radiograph and computed tomography were taken immediately after graft and 3 and 6 months later to evaluate the height, width, and volume change of the alveolar ridge bone. Dental implants were inserted in all sockets at 6 months, and osseointegration condition was evaluated in the following 12 months. All sockets healed uneventfully. In the trial group, the mean (SD) height reduction of the alveolar ridge bone was 1.05 (0.24) mm at 3 months and 1.54 (0.25) mm at 6 months. The width reduction was 1.11 (0.13) mm at 3 months and 1.84 (0.35) mm at 6 months. Bone volume reduction was 193.79 (21.47) mm at 3 months and 262.06 (33.08) mm at 6 months. At the same trend, in the control group, the bone height reduction was 2.12 (0.15) mm at 3 months and 3.26 (0.29) mm at 6 months. The width reduction was 2.72 (0.19) mm at 3 months and 3.56 (0.28) mm at 6 months. Bone volume reduction was 252.19 (37.21) mm at 3 months and 342.32 (36.41) mm at 6 months. There was a significant difference in alveolar ridge bone height, width, and volume reduction in the 2 groups. The osseointegration condition had no significant difference between the 2 groups. This study suggested that the deproteinized bovine bone graft and absorbable collagen membrane were beneficial to preserve the alveolar ridge bone and had no influence on the osseointegration of delayed implant.

Secondary healing after removal of large keratocystic odontogenic tumor in the mandible: enucleation followed by open packing of iodoform gauze.

PURPOSE: The aim of this retrospective study was to present the findings of an open packing method after enucleation of large keratocystic odontogenic tumors (KCOTs) in the mandible. PATIENTS AND METHODS: We performed a retrospective case series study of 27 patients with KCOTs larger than 5 cm treated at our institution between September 2003 and September 2008. A conservative surgical treatment was applied, which involved enucleation of the primary lesion and open packing of the residual osseous defect with iodoform gauze for secondary healing. Bone regeneration, tumor recurrence, and surgical complications were observed and analyzed. We used the χ(2) test and Pearson correlation coefficient for statistical analysis. RESULTS: The postoperative follow-up time was 52.3 months on average (range, 24 to 84 months). The packing gauze was changed every 2 weeks after enucleation, and the total duration for packing was 10.2 months on average (range, 7-15 months). Bone regeneration and satisfactory secondary healing were observed clinically and radiographically after treatment. Only 1 case had a recurrence 6 months after initial treatment, which was attributed to insufficient bony unroofing during enucleation. The recurrent lesion was re-treated by the same method, and no recurrence occurred in the following 6 years. No serious complications from this method of treatment were observed. No significant variables were found to be related to the recurrence. CONCLUSIONS: Enucleation with subsequent open packing was shown to be a conservative and comfortable treatment for patients and appears to be an effective choice for the management of large KCOTs in the mandible.

Investigation of impacted permanent teeth except the third molar in Chinese patients through an X-ray study.

PURPOSE: To investigate the incidence and the local factors of impacted permanent teeth, except for the third molar, in Chinese patients through an x-ray study. MATERIALS AND METHODS: A total of 548 impacted permanent teeth from panoramic radiographs were studied and recorded according to the patients' gender and age, tooth position, and classification of impaction. The local factors contributing to impacted permanent tooth were also investigated. RESULTS: The incidence of impacted permanent teeth in the Chinese was 6.15%. The impacted tooth showed a predilection for women and was more common in the maxilla. The impaction of the canine had the greatest occurrence, 28.10% of all impacted teeth. Vertical impaction was most common (49.09%). The chief local factor for impacted teeth was the lack of interdental space (49.64%). CONCLUSIONS: All permanent teeth can occur with impaction in Chinese patients. Dentists should perform a thorough evaluation before planning suitable treatment.

Influence of preservation of the alveolar ridge on delayed implants after extraction of teeth with different defects in the buccal bone.

Our aim was to evaluate the influence of preservation of the alveolar ridge on delayed implants with different defects in the buccal bone. We enrolled 60 patients who had one posterior mandibular tooth extracted. Cone-beam computed tomography (CT) was used to measure the buccal bone defects in the alveolar ridge before the tooth was extracted (level A=3 to 5 mm, and level B=more than 5 mm). After the tooth had been extracted, the socket either had the alveolar ridge preserved (trial group) or it was left to heal spontaneously (control group). The changes in the dimensions of the alveolar ridge from preoperatively to 6 months postoperatively were evaluated by cone-beam CT. Suitable implants were inserted 6 months later, and their length and diameter recorded. The implant stability quotient was evaluated for the following 3 months. The dimensions of the bone in the alveolar ridge in the trial group were significantly less than those in the control groups in both levels. Fifty-seven patients required implants (except 3 in level B in the control group). There were more longer and wider implants in the trial group than in the control group in Level B. 3 months after implantation, there were no significant differences in implant stability quotients between the groups, though in the control group, Level B, the mean (SD) value was 69.50 (1.00) while in the other groups values were all above 70 at 3 months. We conclude that when the defect in the buccal bone was more than 5mm, the alveolar ridge preservation demonstrated a remarkable effect in preserving the alveolar ridge dimension and delayed implantation.

Improved sedation for dental extraction by using video eyewear in conjunction with nitrous oxide: a randomized, controlled, cross-over clinical trial.

OBJECTIVE: The purpose of this study was to investigate the effect of a portable video eyewear entertainment system used in conjunction with nitrous oxide/oxygen sedation during the removal of impacted lower third molars. STUDY DESIGN: Thirty-eight patients had their bilateral third molars removed under local anesthesia and nitrous oxide/oxygen inhalation sedation in 2 visits. On one side, video eyewear was used (group NE). On the other side, the tooth was removed without the use of video eyewear (group N). Vital signs were monitored. Overall behavior and the outcome of treatment were assessed. RESULTS: All 38 patients completed the study. The mean scores on behavior rating in group NE were significantly higher than those in group N (P < .05). The majority of patients (92.1%) preferred nitrous oxide with video eyewear. CONCLUSIONS: The use of video eyewear appeared to augment the effectiveness of nitrous oxide sedation in dental extraction patients.

Matrix metalloproteinase and its inhibitor in temporomandibular joint osteoarthrosis after indirect trauma in young goats.

Our aim was to examine the change in expression of matrix metalloproteinases (MMP-13), matrix metalloproteinases-3 (MMP-3), and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in the articular cartilage of goats with experimentally-induced osteoarthrosis of the temporomandibular joint (TMJ) at various times. Osteoarthrosis was induced in 20 goats in the bilateral TMJ and 5 goats acted as controls. There were 5 goats in each group, and a group was killed at 7 days, and 1, 3, and 6 months postoperatively. The samples were collected, and the joints evaluated histologically. Immunofluorescence was used to detect the presence of MMPs and TIMP-1 in the articular disc and condylar cartilage. The ultrastructure of the articular disc and condylar surface at 1 month was examined with scanning electron microscopy (SEM). Osteoarthrosis of the TMJ progressed gradually over time. MMP-13, MMP-3, and TIMP-1 were expressed strongly in the TMJ soon after injury; MMP-13 became gradually weakened, and MMP-3 strengthened later. None of these were expressed in the normal condyle. After a month the surface of the arthrotic condyle was uneven, and the underlying collagen fibrils were exposed in irregular fissures on the surface. The secretion of TIMP-1 was related closely to the changes of MMPs during osteoarthrosis of the TMJ. The unbalanced ratio between them caused degradation of the matrix of the cartilage and might be the cause of osteoarthrosis of the TMJ.

[Surgical orthodontic technique for the treatment of maxillofacial deformities and dysfunction of occlusion after maxillofacial fractures].

OBJECTIVE: To evaluate a new technique to treat severe maxillofacial deformity and dysfunction of occlusion after the maxillofacial fractures. METHODS: Thirty-four consecutive patients, with delayed maxillofacial deformities and dysfunction of occlusion after the maxillofacial fractures, were treated by the use of x-ray cephalometric analysis, model surgery, open reduction and rigid internal fixation. RESULTS: Thirty-three patients were successfully corrected the maxillofacial deformities, facilitated normal occlusal relationship. Only one patient with severe damage of the brain was presented a mild occlusion dysfunction one year after the operation. CONCLUSIONS: The above-mentioned technique may be a viable and effective option for the management of the deformities of the face and dentition after the maxillofacial fractures.