Surgical-orthodontic Treatment Of The Labially Impacted Maxillary Canines With Non-conventional Extraction

Objective: To evaluate effects of surgical-orthodontic treatment in labiallyimpacted maxillary canines using non-conventional extraction.Methods: A case with classⅠmalocclusion was selected from the OrthodonticDivision of The First Affiliated Hospital of Dalian Medical University in2010, who was14.3years old and both of the labially maxillary canines transposition. Jaw normal, overjet and over biteⅠ°, the molar relationship of both was neutral.14and44were crossbite. The maxillary dental midline deviated0.5mm to the left relative to the facialmidline. Crowed of upper arch and lower arch, the crowding of Maxillary arch is13mm,the crowding of mandibular is8.5mm. Spee curve was4mm. The maxillary canines areretained deciduous teeth. By analysis of patients with type surface fault analysis,projection measurement analysis and CT3D reconstruction analysis, the patient waslabially and bilateral impacted maxillary canines then was treated by extraction of thedeciduous maxillary canines and the right maxillary lateral incisor and the other threefirst bicuspids with surgical-orthodontic treatment. Orthodontic treatment technologyusing Straight Arch Wire Technique, smoothed the denture, closed the teeth clearance,obtained the positive over jet and over bite at the end of this phase. Analysis of pre andpost-treatment lateral radiographs was done in a week.36typical measurements wereselected from Downs and Steiner and Wylie analysis, so as to observeing and measuringthe upper and lower jaw and lip inclination of the upper and lower incisors and the sideface of the soft tissue changes; shooting X-ray radiograph to observe the change of13and23crowns mobile position and the situation of13and23root resorption.Results: The course of orthodontic treatment was25months. Comparing thechanges between pre-treatment and post-treatment: the labially impacted maxillarycanines were moved to their original position. The Extraction treatment to providesufficient space for13and23moving into the column and make the upper and lowerdentition aligned, and being the center line and maintain a class I molar relationship and keep the side of the face. Because the patient’s oral health was not good, the23labialgingival mild redness in traction13and23enqueue later. Improved after peridontaltreatment, gingival inflammation was brought under control, morphology gums back tonormal. Roots resorption of maxillary canines and lateral incisors did not be seen.Periodontal state of maxillary dentition was good. SNA did not be changed, SNBincreased0.5°, ANB decreased0.5°, NP-FH increased3°and FMA decreased2°,U1-NA decreased9°, L1-NB decreased3°. These changes indicated that the mandibletured to anticlockwise. The flank was not changed obviously. The patient and her familywere satisfied with the result after orthodontic treatment.Conclusion: For this patient, who was labially impacted maxillary canines, we canget a good therapeutic eddect by using surgical-orthodontic treatment withnon-conventional extraction. At the same time, we also can get the lower the risk oftreatment and shorten the treatment time.