The Orthodontic Treatment Of Adult Angle's Class ? Division 1 Malocclusion With Mini-implant Using For Upper Anterior Teeth Intrusion

Objective:To discuss the Clinical Orthodontic effect of the Intrusion of mini-implant implanted between upper central incisors in adult Angle's class ? division 1malocclusion.Method:An adult patient was selected from Dalian Doctor Clinic in 2014.The patient was a 20-year-old re-correcting female and was diagnosed with Angle's class ?division 1 malocclusion,skeletal class ?,maxillary protrusion compared with mandible,anterior dental arch protrusion,upper incisors flared,convex profile.The degree of crowding in upper arch was 3mm and 5mm in lower arch.The degree of Curve of spee was 3mm deep.Large overbite of 5mm and overjet of 4mm was measured.1mm shifted mandible midline to the left.Plan of treatment was drawn according to analysis result: weak anchorage,extract 15,25,35,45.Straight Arch Wire Technique was applied.In the course of treatment,implant a mini-implant between upper central incisors on the mucogingival junction to control the vertical direction of the front teeth.Use 50 g strength to depress the upper incisors.To close the extraction space class I and ? elastic traction were used.At the same time molar relationship were adjusted.After the treatment,Improved Harley maintainers were used to prevent recurrence in Maxilla and mandible.The first cephalometric superimposition tracings were measured and compared with the last.Result: It lasted 22 months during the course of the treatment.After the treatment,On maxillary and mandibular arch,dentition was aligned in coordinational relationship.Extraction space was closed.Tooth inclination and inclination axis coordinate.In addition to the canine root slightly distal tipping,there was no inappropriate rotation.Molar relationship turns to class I from class ? and class ? canine relationship remains.TMJ are well.The last Orthopantomograph showed good periodontal membrane and no obvious teeth root resorption.Compared pre-treatment cephalometric tracing with post-treatment indicates: SNA decreased 1°,SNB remained,ANB decreased 1°.Wits changed from 3 mm to 2 mm,skeletal class ? malocclusion improved than before.Mandibular plane Angle from 38°reduced to 36°,FMA changed from 27° to 25°,vertical height remained well,mandible turns to spin counterclockwise.U1-NA °decreased 3°,U1-NA decreased 3mm,NA/PA changed from 12°to 10°.Overjet changed from 4 mm down to 3 mm.Indicated that protrusion upper arch and flared incisors got obvious improvement.Maxillary anterior teeth depression was 2mm.IMPA reduced 2°,mandibular incisors got retrusion and upright.Z Angle from 69°increases to 75°,ULEP reduced to 0 mm from 3 mm,LLEP reduced from 3 mm to 1 mm,lower lip exhibited obvious retrusion,mentolabial sulcus depth increases from 5 mm to 4 mm.mandibular incisors got retrusion and upright.Z Angle from 69°increases to 75°,ULEP reduced to 0 mm from 3 mm,LLEP reduced from 3mm to 1 mm,lower lip exhibited obvious retrusion,mentolabial sulcus depth increases from 5 mm to 4 mm.Protrusion of the chin and lips got more natural.Profile got obvious improvement.Facial proportions got more coordinated.Conclusion: This patient was Angle's Class ? Division 1,skeletal class ?malocclusion.Extracting four second premolar,using the straight wire technology,with micro-implant(1.5mm*8mm)between upper central incisors,used to depress upper anterior teeth.As anchorage micro-implant can depress maxillary anterior teeth effectively,reduce the patient's deep overbite,improve the profile.