[Clinical analysis of muscle function intensifier in treatment of 40 patients with maxillary protrusion].

PURPOSE: To investigate the clinical effects of combined muscle functions intensifier and straight wire appliance in the treatment of maxillary protrusion. METHODS: Forty patients with maxillary protrusion were randomly divided into 2 groups (group A and group B). Straight wire appliance and muscle function intensifier were used in group A, while patients in group B received straight wire appliance only. X-ray projection was conducted to measure relative maxillary index (labial inclination of upper or lower incisor, SNB angle, ANB angle, FMA, maxillary plane angle, NA-PA, U1-FH, U1-PP, forward moving distance of U6) before and 6 months after treatment. The efficacy was analyzed and evaluated using SPSS 20.0 software package. RESULTS: After correction, labial inclination of upper or lower incisor, SNB angle, ANB angle, FMA, maxillary plane angle, NA-PA, U1-FH, U1-PP changed significantly in both groups (P<0.05), but patients in group A achieved more incisor adduction and less forward moving distance of U6, with significant difference between the two groups (P<0.05). CONCLUSIONS: Most patients with maxillary protrusion have a bad habit of mouth breathing. Muscle function intensifier is used only at night and can relieve the patient's mouth breathing, speed up the movement of teeth, and reduce the loss of anchorage and ultimately, improve the correction efficiency and clinical effect of patients with maxillary protrusion.

[Clinical study of extraction treatment of Class II division I malocclusion with Empower self-ligating brackets].

PURPOSE: To evaluate and compare the treatment efficiency of Empower interactive self-ligating brackets and traditional brackets in Class II division I extraction patients. METHODS: Forty patients with Class II division I malocclusion were randomly divided into 2 groups. Twenty patients received Empower self-ligating technique (group A) and the other 20 patients received MBT technique (group B). Four first premolars were extracted and without any other anchorage devices added in both groups. The duration of treatment, the number of visits and chair-side time were recorded. Cephalometric analysis was performed before and after treatment. The data was analyzed with SPSS 13.0 software package for paired t test. RESULTS: Treatment time and number of visits in group A were more than in group B, but there was no significant difference between the 2 groups. Chair-side time in group A reduced 151.15s on average compared with group B. Significant changes were observed in both groups after treatment. Upper and lower anterior teeth retracted and convex profile improved.U1-SN, U1-NA, L1-MP, L1-NB, UI-PTV, LI-PTV, UL-EP, LL-EP decreased. Significant differences were found in UM-PTV between the 2 groups(P<0.05). CONCLUSIONS: Compared with traditional brackets, Empower self-ligating brackets can save chair-side time, control anterior teeth torque and posterior teeth anchorage effectively, but can not reduce the treatment time or number of visits. Supported by Youth Research Project of Shanghai Municipal Health Bureau(2010Y155).

[The effect of two different methods of rapid maxillary expansion on treatment results of skeletal Class III malocclusion patients with maxillary protraction in early permanent dentition].

PURPOSE: To evaluate and compare the effect of single rapid maxillary expansion and repetitive rapid expansion and constriction with maxillary protraction in treating early permanent skeletal Class III patients. METHODS: Twenty children with skeletal Class III malocclusion were randomly divided into two groups.Ten patients received 1 week of rapid expansion,followed by maxillary protraction(group A) and the other ten patients received 5 weeks of repetitive rapid expansion and constriction followed by maxillary protraction (group B).Cephalometric analysis was performed before and after treatment. The data was analyzed with SPSS 13.0 software package for paired t test. RESULTS: Significant changes in cranio-maxillofacial structures were observed in both groups after 6 months of treatment.Point A moved forward. SNA, ANB, UL-EP, U1-PP, SN-MP, ANS-Me/N-Me, Wit's value increased. L1-MP, LL-EP decreased. Significant differences were found in SNA,ANB,UL-EP between the two groups(P<0.05). CONCLUSIONS: The application of combined repetitive rapid expansion and constriction with maxillary protraction increases the amount of forward movement of the maxilla significantly and presents more favourable profile results in early permanent Class III malocclusion patients.

[Effect of root canal therapy combined pulp mummification in treatment of residual pulpitis after mummification in molars of the gerontal patients].

PURPOSE: To evaluate the effect of root canal therapy combined with pulp mummification in treatment of residual pulpitis after mummification in molars of the gerontal patients. METHODS: One hundred and twenty-two molars with residual pulpitis after mummification were obtained from 108 over 70 years patients. All molars were treated with root canal therapy combined with pulp mummification, and were evaluated after 1 month, 1 year and 2 years. RESULTS: The treatment of all molars was effective within 1 month. The treatment success rate at 1- and 2-year was 86.9% and 76.2%,respectively. CONCLUSION: Root canal therapy combined with pulp mummification is one of the effective methods to treat residual pulpitis after mummification in molars of the gerontal patients over 70 years.

[Clinical stability of immediate load of domestic micro-titanium screws for anchorage in orthodontics].

PURPOSE: To investigate the immediate load stability of domestic micro-titanium screws for anchorage in orthodontics. METHODS: Adult orthodontic patients needing the greatest anchorage were included in the study. Domestic micro-titanium screws were used to be orthodontic anchorage, immediate implantation and loading were conducted. RESULTS: A total of 52 implants of domestic micro-titanium anchorage in 20 patients were used. Forty-seven implants were successful in 20 patients,5 failed. The total loading time was 3-8 months. CONCLUSIONS: Domestic micro-titanium implant screws for anchorage can meet the needs of clinical orthodontics. However, immediate loading results in 10.4% failure rate, especially for the implant with a diameter of 1.2mmx7mm. Supported by Science and Technology Development Foundation of Fengxian District, Shanghai Municipality (Grant No. 090602).