[Effect of bone grafting on the repair of distal alveolar bone defect of the second molar after extraction of mandibular impacted third molar].

PURPOSE: To observe the effect of bone grafting during the extraction of mandibular third molar on repair of distal alveolar bone defect distal to the second molar. METHODS: The risks of the distal alveolar bone defect in the second molar were estimated after removal of the impacted teeth according to the position of the third molar and second molar before operation. It was divided into three groups: low risk group, medium risk group and high risk group. The medium risk group and high risk group were further divided into bone graft subgroup (group A) and non-bone graft subgroup (group B). There were 36 cases in group A and 45 cases in group B. Postoperative re-examination indicators included subjective perception of the patients, depth of probing and height of alveolar bone in the distal molar of the second molar by X-ray examination. The data were analyzed with SPSS 19.0 software package. RESULTS: Six months after operation, in mediun risk group, 0 cases in group A had subjective feelings of cold and heat stimulation; in group B, the number was 6 cases, the difference was significant (P<0.05). Distal periodontal probing depth of the second molar was (2.93±0.34) mm in group A and (2.95±0.50) mm in group B. There was no significant difference between 2 groups (P=0.931). X-ray examination of the alveolar bone height increment of the second molar Δh: (3.31±1.02) mm in group A, (3.10±1.72) mm in group B, the difference was not significant (P=0.794). In high risk group, 4 cases in group A had subjective feelings of cold and heat stimulation; in group B, the number was 10 cases,the difference was significant (P<0.05). Distal periodontal probing depth of the second molar was (3.08±0.37) mm in group A and (3.24±0.41) mm in group B. There was no significant difference between 2 groups(P=0.931). X-ray examination of the alveolar bone height increment of the second molar Δh: (5.21±1.79) mm in group A, (2.99±2.42) mm in group B, the difference was significant (P<0.05). CONCLUSIONS: Risk classification of the second molar distal bone defects after extraction of the impacted teeth is essential, which is helpful to determine whether bone grafting is needed during operation. Autologous bone mixed with Bio-Oss artificial bone powder can promote recovery of the alveolar bone height of the second molar, especially in high risk group, and discomfort caused by exposure can be reduced.

[Clinical evaluation of simple maxillary sinus elevation with simultaneous implant in patients with serious posterior maxillary deficiency].

PURPOSE: To evaluate the clinical effect of simple osteotome sinus floor elevation without bone grafting in the posterior maxilla area with less bone height. METHODS: Twenty eight cases with posterior maxillary bone deficiency were included.Their residual alveolar bone height (RBH) was less than 7 mm. 40 ITI implants were implanted. Among them, 6 implants were implanted in the sites with RBH less than 4 mm (group 1), 34 were implanted in the sites with RBH between 4 to 7 mm (group 2).16 implants were inserted with bone graft, while 24 implants were inserted without bone graft. 6-12 months after operation, the alveolar bone height were measured and recorded. SPSS19.0 software package was used for data analysis. RESULTS: All 40 implants in 28 patients had good initial stability and good osseointegration, the success rate was 100%. RBH in group 1 and group 2 was (3.44±0.57) mm, (5.50±1.00) mm, respectively; postoperative bone increase was (7.91±1.06) mm in group 1, (8.77±1.15) mm in group 2, respectively (P>0.05).Preoperative RBHin bone graft group was (5.37±1.24) mm and (5.07±1.19) mm in patients without bone graft. Postoperative bone increase was (8.47±1.18) mm in bone graft group, and (8.89±1.13)mm in patients without bone graft, responsively (P>0.05). CONCLUSIONS: Maxillary sinus elevation can be successfully performed in patients with RBH<4 mm, and the effect is similar to that of conventional maxillary sinus lifting. Simple osteotome sinus floor elevation without bone grafting, which is with less trauma and lower cost, is effective in improving bone height in posterior maxillary region.

[Cone-beam CT evaluation of volume and surface area changes of impacted upper central incisors before and after orthodontic treatment].

PURPOSE: The purpose of this study was to quantitatively evaluate root resorption by cone-beam computer tomography (CBCT) after orthodontic treatment of impacted upper central incisors. METHODS: Ten patients (12 impacted incisors and 8 contralateral corresponding teeth) were included in this study. With self-designed modified nance arch and straight wire arch, the impacted incisors were treated by combined orthodontics and surgery approach. CBCT images of all patients were taken before and immediately after the treatment. Mimics software was used to build three-dimensional images. The upper central incisors were isolated. Volumes of teeth and superficial area were calculated. The difference between pre- and post- treatment was statistically evaluated with paired samples t test using SPSS13.0 software package. RESULTS: Significant difference in volume and superficial area was found between pre- and post- treatment (P<0.05). The average whole dental volume increase was (9.67±10.86) mm3, and the superficial area increase was (28.97±14.36)mm2. Statistical significance was achieved among 12 impacted incisors. The average whole dental volume increase of the control group was（12.38±10.22）mm3, and the superficial area increase was（30.64±16.74）mm2. There was no significant difference between the impacted and the control group in dental volume and superficial area before and after treatment (P>0.05). CONCLUSIONS: The treatment by combined orthodontics and surgery approach could promote tooth development for impacted incisors without causing root absorption, which can be safely performed.

[Application of research-based learning for bachelor intern students of stomatology].

PURPOSE: To apply research-based learning in education of bachelor intern students of stomatology and evaluate its role in promoting the comprehensive quality of the students. METHODS: Sixty students from grade 2007 and 2008 in school of stomatology, Wenzhou Medical University were enrolled in this study. Thirty of them were randomly selected into a group for research-based learning, while the others were taught with traditional teaching mode. Survey and assessment of the teaching effect was performed after the course. Independent t test was employed to evaluate the differences with SPSS16.0 software package. RESULTS: No significant difference of exam results was revealed between the two groups. Questionnaire survey showed a good evaluation for the teaching mode and the teachers in the group research-based learning, but the evaluation of mastering research capability was lower. CONCLUSIONS: Research-based learning mode promotes the study interest and comprehensive quality of the students. No evidence of interference with mastering clinical skills is disclosed.

Effects of huangqi and bear bile on recurrent parotitis in children: a new clinical approach.

OBJECTIVE: To evaluate the pharmacological effects of traditional Chinese medicine, bear bile capsule and Huangqi granule, on recurrent parotitis in children. METHODS: In this prospective, controlled, and randomized study, a total of 151 young children were divided into three groups: Group A included massaging the children's parotid region and melting vitamin C in their mouth daily; Group B included swallowing bear bile capsule and Huangqi granule daily; and Group C included massages and vitamin C as prescribed in Group A, and traditional Chinese medicine as prescribed in Group B. Children were treated individually for one month and then a follow-up study was conducted for 1 to 3.5 years. Analysis of variance (ANOVA) and Ridit analysis were employed for statistical analysis. RESULTS: The recurrence rate decreased in every group, but was significantly more in Groups B and C when compared to Group A. The recurrences significantly decreased (P<0.01) in Group B and their recovery rate was as high as 63%, significantly better than those of the other groups (P<0.01). CONCLUSIONS: Huangqi and bear bile could be a novel clinical approach for treating recurrent parotitis in children.