Comprehensive Management of Skeletal Class II Division 1 Malocclusion with Bilateral Crossbite using Haas Expander and ForsusTM FRD: A Case Report

Abstract

Skeletal Class II malocclusion is a jaw discrepancy where the mandible is retruded relative to the maxilla, leading to a convex profile, increased overjet, and potential deep bite. It may result from mandibular deficiency, maxillary excess, or both. This case report details the comprehensive management of a 19-year-old male patient with a Class II Division 1 malocclusion, characterised by an orthognathic maxilla, retrognathic mandible, increased overjet and overbite, and a convex facial profile. The treatment involved fixed orthodontic therapy using the McLaughlin-Bennett-Trevisi (MBT) 0.022” prescription for comprehensive tooth alignment and leveling. Maxillary expansion was achieved using a Haas expander, a tooth- and tissue-borne appliance designed to widen the upper arch. Class-II correction was carried out with the ForsusTM Fatigue Resistant Device (FRD), a Fixed Functional Appliance (FFA) that applies continuous force to advance the mandible and correct the sagittal jaw discrepancy. Following two years of active treatment, the patient achieved a well-aligned dentition, a Class I molar and canine relationship, and an improved facial profile. This case highlights the efficacy of FFAs in the non-extraction management of Class II malocclusion, demonstrating favourable dentoalveolar and soft-tissue changes.