Clinical Study Of PAOO Technology In The Retraction Of Mandibular Anterior Teeth Of Skeletal Class ? Malocclusion With Orthodontic Treatment

Objectives:Periodontally accelerated osteogenic orthodontics(PAOO)is applied to moderate skeletal class III malocclusion patients,which used orthodontic camouflage treatment.The aims are to evaluate the clinical effect of accelerating retraction of mandibular anterior teeth,the change of alveolar bone thickness after bone graft,and its effect on root absorption,to provide a reference basis for the clinical application of PAOO technology.Methods:20 patients with moderate skeletal class III malocclusion from the Orthodontics Department of Stomatological Hospital Affiliated to Kunming Medical University were selected,they were planned to use orthodontic camouflage treatment with bilateral maxillary second premolars and bilateral mandibular first premolars extraction,and were treated with fixed straight-wire appliance(Damon self-ligating brackets).All patients had no contraindications to PAOO surgery,randomly divided into experimental group(10 patients,mean age 24.6 ± 5.4 years old)and control group(10 patients,mean age 22.9±5.0 years old).The experimental group received traditional fixed orthodontic treatment,with PAOO surgery in the mandibular anterior teeth labial area,The control group only received traditional orthodontic treatment.To analyze and compare the treatment time of retracting mandibular anterior teeth in the two groups.And respectively,CBCTs were taken before retracting the mandibular anterior teeth and after closing mandibular extraction space.To measure the lengths of the roots before and after the retraction of the mandibular anterior teeth,and the thickness of the dental alveolar bone at different levels(apical region,mid-root region,and crownal-root region)of the central incisors,lateral incisors,and canines.Statistical analysis was performed for the absorption of roots,changes in alveolar bone,and differences between the two groups.Results:1.The retraction time of mandibular anterior teeth in the experimental group was significantly shorter than that in the control group,and the difference was statistically significant(P<0.05);2.CBCT measurements revealed that both the experimental group and the control group had obvious root absorption,but the difference between the two groups was not statistically significant(P>0.05);3.After the retraction of mandibular anterior teeth for orthodontic camouflage treatment in patients with moderate skeletal class ? malocclusion,the thickness of alveolar bone in the mandibular anterior teeth of the control group decreased,and the experimental group increased significantly,and the apical region of the central and lateral incisors as well as the middle-root and crownal-root region of the canines increased relatively more,the difference was statistically significant(P<0.05).Conclusions:1.PAOO technology can shorten the retraction time of mandibular anterior teeth in patients with the moderate skeletal class ? malocclusion.2.During the retraction of mandibular anterior teeth in patients with skeletal class ?malocclusion,there is no difference between the effect of PAOO technology on the root absorption of the mandibular anterior teeth and conventional orthodontic treatment,and won't produce additional effects.3.In the retraction of mandibular anterior teeth,PAOO technology with bone graft can improve or avoid alveolar defects(dehiscence and fenestration)in the mandibular anterior teeth,and maintain good periodontal conditions.