[Clinical analysis of two-phase treatment of 35 cases with Angle Class II division 1 malocclusion].

PURPOSE: To evaluate the clinical value of the two-phase treatment of Angle Class II division 1 malocclusion. METHODS: Thirty five cases with Class II division 1 malocclusion were treated with two-phase treatment(Twin-block functional appliance and fixed appliance).Lateral cephalograms were taken before and after treatment for each patient. The results were analyzed with paired t test using SPSS11.0 software package. RESULTS: After treatment ,the bite relation of molars ,the overbite and overjet and soft tissue profile were improved. ANB angle,U1-SN,OB,OJ,UL-E,ULP were decreased respectively(P<0.01). SNB, C(o)-G(o),G(o)-G(n),C(o)-G(n) were increased respectively(P<0.01). L1-Mp and FH-MP were increased, too(P<0.05). CONCLUSIONS: Twin-block functional appliance possesses the orthopedic effects on Angle Class II division 1 malocclusion.It limits the maxillary growth forward and promotes the mandibular growth by repositioning the mandible forward.These may contribute to a harmonious relationship of upper and lower jaws and a better profile.

[Effect of post space preparation on the sealability of root canal filled with 3 filling methods].

PURPOSE: To evaluate the effect of post space preparation on the sealability of canals filled with 3 filling methods. METHODS: The crowns of 24 human anterior teeth extracted for periodontal disease were removed and the working length of canal was unified to be 16 mm. The teeth were divided into 3 groups at random: group A (normal temperature flow gutta-percha single-corn technique with GuttaFlow), group B (lateral compaction technique with AH Plus) and group C (warm vertical condensation technique with AH Plus+ BeeFill thermoplastics system). The root canals were prepared and filled according to different system. Microleakage of root canals of pre-post space preparation was measured with a fluid transport study one week after filling. Then the post space was prepared using 1#- 6# G drill step by step, by leaving 4 mm of root canal filling material apically. Microleakage of root canals of post-dowel space preparation was measured again. SPSS13.0 software package was used for statistical analysis. RESULTS: No difference was found between pre-post space preparation and post-dowel space preparation in each experimental group (P>0.05). In pre-post space preparation, significant difference was found between group A and group B, group B and group C (P<0.05). In post-dowel space preparation, difference was found between group A and group B.Group A had the lowest microleakage (4.328+/-2.020)x10(-3)microl x kPa(-1) x min(-1). CONCLUSIONS: The post space preparation do not effect the sealability of three root canal sealers. The sealability of canals filled with AH Plus are different when filled with different filling methods. Normal temperature flow gutta-percha single-corn technique with GuttaFlow gains the best sealability.