Objective To objectively evaluate the intrusion effects on the maxillary incisors of implants versus conventional method(J-hook headgear ,utility arch) .Methods Such online databases as Cochrane library ,PubMed ,EMbase ,VIP ,Wanfang and CNKI were searched by randomized control test and prospective case controlled study about implants vs conventional anchorage for the maxillary incisor intrusion .After study selection ,assessment and data extraction conducted ,meta-analyses were performed by u-sing the RevMan 5 .1 software .Results Totally 11 studies were included ,6 studies involving 154 patients were included in the J-hook headgear group ,5 studies involving 127 patients were included in the utility arch group .The results of meta-analyses showed that :(1)Compared with the J-hook headgear ,implants had more decrement in the distance of upper center incisior cutting to palatal plane(P<0 .001) ,more decrement in overbite(P=0 .001) ,shorter treatment time (P<0 .001) ,less increase in SN-OP angle(P=0 .004) ,less decrement in distance of maxillary molar cusp to palatal plane (P=0 .020);There was no statistically significant differ-ence in overjet ,root resorption(P>0 .05) .(2)Compared with the utility arch ,implants had more decrement in the distance of the center of resistance of the upper incisor to palatal plane (P=0 .010) ,less increase in U6-PP angle (P<0 .001);There was no statis-tically significant difference in the distance of upper center incisior cutting to palatal plane ,U1-PP angle ,the distance of upper first Molar cutting to palatal plane ,sagittal position of the mesial tip of the upper first Molar ,overbite ,overjet ,course of treatment ,root resorption(P>0 .05) .Conclusion The implants anchorage intruded the maxillary incisor was better than conventional method (J-hook headgear ,utility arch) ,it has more incisor intrusion ,shorter treatment time and more comfortable for the patients ,there was no difference in root resorption between the two groups .

OBJECTIVE: To establish the Chinese Han national criteria for the thickness of upper lip in Chongqing and to investigate the effect of lip thickness on lip retraction in orthodontic treatment.
 METHODS: A total of 240 adult patients (male=120, female=120) of Chinese Han nationality aged 18-35 years in Chongqing were treated with cephalograms and measured the thickness of upper lip. We established the Chinese Han national criteria for the thickness of upper lip in Chongqing according to the results. Sixty-eight female patients with Angle II 1 from Department of Orthodontics Stomatological Hospital of Chongqing Medical University were treated with maxillary premolars extraction, and pre- and post-treated with lateral cephalograms, then divided into 3 groups according to our criteria: a thin lips group, a normal lips group and a thick lips group. The ratio of the incisors retraction and the upper lip retraction were measured and calculated. The correlation between incisors retraction and the upper lip retraction was analyzed by the Pearson correlation method.
 RESULTS: There was statistical significance in the thickness of upper lip between males and females (P<0.01). The ratio of maxillary inscior retraction to the upper lip soft tissue retraction was 1.6:1, 2.2:1 and 2.9:1 in the thin lips group, the normal lips group and the thick lips group, respectively.
 CONCLUSION Gender differences exist in the thickness of upper lip. Upper lip retraction with the incisors was negatively correlated with the soft tissue thickness of the upper lip in females with Angle II 1.
Adolescent ; Adult ; Bicuspid ; Cephalometry ; Female ; Humans ; Incisor ; Lip ; anatomy & histology ; Male ; Tooth Extraction ; Young Adult