Class lll malocclusion treated with Insignia® System
Abstract
A 19-year-old woman sought treatment for her protrusive lower chin. The diagnostic evaluation revealed bilateral maxillary second molar buccal crossbite, and a severe skeletal Class lll malocclusion (DI=60). The patient preferred a non-surgical correction and extraction treatment of four second molars was selected to correct bilateral buccal crossbite and create spaces for whole arch retraction. Furthermore, two infrazygomatic crest(IZC) screws and two buccal shelf(BS) screws were installed to retract upper and lower dentitions and close extraction spaces. The digitally set up, customized self-ligating Insignia® brackets and archwires were selected and significantly enhanced treatment efficiency. This difficult case (DI=60) was corrected in 18 appointments over 25 months, and the patient was satisfied with the final results.
The ideal treatment results were attributed to a correct treatment plan and the customized appliances(Insignia®). One key decision of this treatment was to extract 4 second molars to solve buccal crossbite and create space for retraction while substituting them with impacted third molars to avoided further complicated surgical removal. This resulted in reduction in treatment time and complexity.
摘要
本案例是一位主訴下顎突出的19歲女性，診斷評估為嚴重骨性第三類異常咬合，兩側第二大臼齒頰側錯咬 (buccal crossbite)。術前評估(DI=60)難度為60分。患者選擇非手術的治療方式，於是決定拔除四顆第二大臼齒來解決後牙錯咬及創造出後退空間。此外，上下頷分別各植入兩顆IZC screws 和BS screws以往後牽引上下齒列以及關閉拔牙空間。在確立治療計劃後，使用3D數位設定，客製的自鎖式矯正器及序列性矯正線。這個困難的案例 (DI=60) 以極高的效率，在經過18次診療，歷時25個月完成。病人相當滿意最終的治療結果。
這個案例的成功歸功於正確的治療計劃及客製化的矯正裝置系統 Insignia®。其中一個關鍵要素在於選擇拔除四顆第二大臼齒以解決後牙錯咬及創造出後退的空間，再來利用智齒取代拔除的第二大臼齒，可免於日後拔除埋伏齒的複雜手術。如此一來可以減少治療時間，並簡化治療難度。