| Objective: The aim of this research was to explore the malocclusion orthodontictreatment which because of multiple maxillary teeth missing lead to Bolton indexdiscrepancy and to analysis the clinical characteristics, diagnosis, design and treatmenteffects of this malocclusion.Methods: The patient was13-year-old Chinese female, Han nationality, withabsent three maxillary permanent incisors because of trauma. Mandibular and maxillarywere essentially normal. The molar relations were Angle Class I bilaterally. In addition,a unilateral canine crossbite on the left side and premolars of maxillary locked occlusionon the right were observed. The right mandibular second deciduous molar was retained.She had a Concave type. Treatment planning was based on analysis the model, X-raycephalometric and Bolton index which was to extract the left mandibular lateral incisorsand retain deciduous tooth. Upper and lower teeth were used SWA technology. Thetreatment result of this patient was effective, and it contained of straightening teeth,removing crowding, removing crossbite with posterior bite plate and lingual spring andcorrecting the locked teeth in premolar area. It also expanded missing teeth place withNiTi open coil springs. Finally, bilateral canine and first permanent molars reachedneutral relationship. Cephalometric films were taken to measure the upper and lowerjaw and shaft angle of the upper and lower incisors and the side face of the soft tissuechanges before and after treatment. Panoramic radiograph were made to observe the change of teeth mobile position and the situation of root sorption.Results: The course of orthodontic treatment lasted20months. On the end oftreatment which provided the following outcomes: Class I molar and caninerelationships on both sides, adequate overbite and overjet, no mandibular anteriorcrowding and no crossbite and locked occlusion. Maxillary deficiency tooth areaclearance had been effectively expanded. There was a good occlusal relationship. Andthe patient and her parents were satisfied with the results.(1) Treatment planning wasextraction the left mandibular lateral incisors and retained deciduous tooth which wasbased on the model analysis, X-ray cephalometric and Bolton index analysis. The resultwere: relieving lower crowding, flatting spee curve and adductor mandibular anteriorteeth. And the left mandibular canine moved to mesial in order to let the canine andmolar relationship to neutral, then all teeth occlusal relative to cusp fossa relationship.(2)Posterior bite plate and lingual spring both solved the occlusal interference and movedthe left maxillary canines and right maxillary lateral incisor to buccal mobile. Then, itcould lift the crossbite and increased the width of anterior teeth.(3) The patient was15years old at the end of treatment and couldn’t implant or prosthetic treatment in anterior.So we increased resin teeth in the retainer for aesthetic repair until the edentulous repairor planting after the age of18.Conclusion: In this case, treatment planning was based on the model analysis andCephalometric radiography to extract the left mandibular lateral incisors. This is anon conventional extraction scheme. Although the mandibular midline didn’t exist, itcould lift of the lower anterior crowding. The treatment changed canine to Class I,adequate overbite and overjet and also provided canines and first molars to bite cuspfossa relationship relative. Lateral mandibular incisor Extraction made a better effectfor this patient than other treatment. |
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