Chris' Top 11 Cases: 5.Crowded CII Division 2 Malocclusion｜【Chris Chang Ortho】CC457

Crowded Class II Division 2 Malocclusion with Class I
Molars Due to Blocked In Lower Second Premolars

Abstract
An 18y2mo female presented a Class II Division 2 malocclusion associated with typical dental alignment problems: retroclined upper central incisors, labially flared maxillary lateral incisors, deep overbite, and severe crowding. Skeletally the malocclusion was complicated by a retrognathic mandible (ANB of 9°) steep mandibular plane angle (MPA 34°) and severe facial convexity (24°). Despite the Class II/2 pattern, the molars were Class I due to ectopic eruption and mesial migration of the mandibular first molars, which resulted in the second premolars being blocked out. The Discrepancy Index (DI) was 37. Treatment mechanics were passive self-ligating brackets, early light short elastics (ELSE), anterior bite turbos, and extra-alveolar (E-A) miniscrews in the infrazygomatic crests to retract the entire maxillary arch. Nonextraction treatment for 32 months resulted in an acceptable skeletal compromises (4° increase in the MPA and lower incisor to mandibular plane angle of 109°), but dental alignment was excellent, as documented with Cast-Radiograph (CRE) score of 22 and a Pink and White (P&W) dental esthetics score of 3. (Int I Ortho Implantol 2014;35:64-78 )