| Objective: To study the changes of the craniofacial structure part of bone and soft tissues and teeth when the maxillary canines impacted,and the characteristics of craniofacial structure and clinical correction characteristics of impacted maxillary teeth were discussed.Methods: experiment one: select 20 patients of maxillary impacted canines shooting CBCT of the permanent dentition(group S),17 patients of two canines impacted shooting CBCT of permanent dentition(D group),the control group selected20 case of individual normal occlusion in Shenyang,which collected by Zhao Zhongwan in the Department of Orthodontics in General Hospital of Shenyang military region in 2015.Three-dimensional reconstruction of CBCT using Dolpin software,39 measurement index of reaction craniofacial structure were selected,which included 20 bone and teeth 9,10 soft tissue,measurement data of S group and D group were compared with control group.S group and D group were compared.Independent samples T-teste was taken by SPSS19.0 software pacakage to compare the differences between groups.Experiment two: A female case,12 years old,who is bilateral maxillary impacted canines with incisor root resorption,skeletal Class III,class I,high angle;13and23 highest impacted,were located between 11 and 12,21 and 22,cyst were found around 13 and 23 crowns;11 and 21 root resorption to 1/3 apical,12and22 small teeth androot resorption to 1/3;CBCT revealed moderate amount of bone in the labial and palatine side of 13 and 23,Indications of orthodontic traction for impacted teeth.Therefore,the technique of straight-wire appliance for upper and lower jaw was adopted.Combined surgical fenestration traction 13 and 23 into dentition.Result:Experiment one: maxillary impacted canine bone tissue measurementNA-APo,Wits,ANS-PNS(mm),SNA,ANB,FH-NA decreased significantly(P<0.05),A-B plane angle increased significantly(P<0.05);Tooth measurement project U1-NA increased significantly(P<0.05),L1-MP,L1-NB,L1-APo decreased significantly(P<0.05);which means there was no significant difference between measures of the mandible,soft tissue and facial vertical development and control group.Bilateral maxillary impacted canines bone tissue measurement NA-APo,Wits,ANS-PNS(mm),SNA,ANB,FH-NA,S-N(mm),N-CC(mm)decreased significantly(P<0.05),A-B plane angle increased significantly(P<0.05);tooth measurement of L1-MP,L1-NB,L1-NB(mm),L1-APo decreased significantly(P<0.05);soft tissue measurement A-A(mm)decreased significantly(P<0.05);there was no statistical difference between the measurement items representing the mandibular and facial vertical development and the control group.Bilateral maxillary impacted canines case at U1-NA(mm)with unilateral impacted maxillary canine were small(P<0.05);the values of NA-APo,Wits and ANS-PNS(mm),SNA,ANB,FH-NA,which represented the degree of maxillary process contraction and length development,were significantly higher than those in unilateral canine burying group,but there was no statistical difference.Conclusion:In maxillary impacted canine case,maxillary posterior contraction is relative to craniofacial region,and shorter length.Normal development of mandibular.The trend of skeletal III type,no abnormal in vertical dimension.In unilateral maxillary impacted canine case,the maxillary incisor labial tilted,the mandibular incisor erect,and the soft tissue did not change abnormally.In the bilateral maxillary impacted canines case,the mandibular incisor was upright,the maxillary incisor inclination was normal,and the thickness of the upper lip soft tissue at the upper alveolar seat became thinner.The development of maxillary bone was more limited in bilateral maxillary impacted canines case,but there was no significant difference in bone tissue and soft tissue,and the maxillary incisor was less protruding than that in unilateral incisor,and the maxillary incisor was upright. |
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