# Class II Malocclusion > Class II malocclusion in BDS Orthodontics: division 1 and 2 features, subdivision, skeletal basis, functional appliances, headgear and extraction choices. - Canonical URL: https://prepelephant.com/topics/bds/orthodontics/class-ii-malocclusion-bds - Exam / course: BDS · Subject: Orthodontics - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-02 - Last updated: 2026-10-02 - How to cite: "Class II Malocclusion", PrepElephant, https://prepelephant.com/topics/bds/orthodontics/class-ii-malocclusion-bds ## Direct answer In a Class II malocclusion the mandibular first permanent molar occludes distal to the maxillary first molar — Angle's distocclusion — with the incisor pattern separating division 1 (proclined upper incisors, increased overjet, incompetent lips, lip trap) from division 2 (retroclined upper central incisors with a deep overbite, typically strong musculature and a good chin). A subdivision marks unilateral involvement named by the affected side. The skeletal basis is mandibular retrognathism in most division 1 cases, with maxillary excess in a minority, which is why growth modification — functional appliances to advance or redirect the mandible, extraoral traction to restrain the maxilla — works only while the child is growing. After growth, the options narrow to camouflage with premolar extraction and retraction, or orthognathic surgery for severe skeletal discrepancies. ## What you must remember - **Division 1 features:** proclined upper incisors, increased overjet, V-shaped tapering maxillary arch, convex profile, lip trap with the lower lip cushioned behind the uppers, hyperactive mentalis, often a mouth-breathing or thumb-sucking aetiology. - **Division 2 features:** retroclined upper central incisors (lateral incisors frequently proclined or mesially angled), deep overbite with typically normal or reduced overjet, deep palate, strong masseteric activity, well-developed chin — the trap for anyone who equates Class II with big overjet. - **Skeletal diagnosis first:** mandibular retrognathism is the commonest basis for division 1; treat the jaw discrepancy, not just the overjet, or relapse follows. - **Functional appliances** (activator, bionator, Twin Block) posture the mandible forward to stimulate condylar growth and remodel the glenoid fossa — ideally in the pubertal growth spurt or just before it; expect dentoalveolar as well as skeletal effects. - **Cervical or combined-pull headgear** restrains a prognathic maxilla and distalises molars — the tool for maxillary-excess Class II, worn commonly 12-14 hours daily with orthopaedic force (about 400-600 g per side as classically taught). - **Camouflage in adults:** first premolar extraction with maxillary incisor retraction, keeping the ANB compromise in mind; Class II elastics help dental correction. - **Division 2 treatment extras:** torque the retroclined centrals forward, correct the deep bite (often with an anterior bite plane or intrusion mechanics) and watch for relapse driven by the strong musculature. ## Planning one growing Class II division 1 case An 11-year-old girl with a 9 mm overjet, convex profile, retrognathic mandible, Class II molars bilaterally and a persistent lip trap sits squarely in the growth-modification window. The sequence: confirm skeletal maturity (hand-wrist film or cervical vertebral maturation — aim to start functional treatment around CS3), correct any habit and nasal airway issue first, then a Twin Block full-time for 6-9 months to posture the mandible forward, converting the molars toward Class I. Follow with a short fixed-appliance phase for detailing and incisor torque, and retain with attention to the lip trap — an anterior inclined plane or lip exercise regime — because the soft tissue that created the overjet will rebuild it if the lips never become competent. Contrast the plan for a division 2 boy of the same age: the deep bite and retroclined centrals come first (torque and bite-opening mechanics within a fixed appliance), the molar relation often needs less change than the incisor relation, and extraction decisions are more conservative. Same class, almost opposite mechanics — which is why the division, not the class, drives the plan. ## How examiners and Indian college teaching frame it The long-question bank is predictable: "Classify Class II malocclusion; discuss the aetiology and management of Class II division 1" — and the marking scheme expects division features, the skeletal versus dental distinction, and a named functional appliance with its construction bite. Viva tables often place a division 2 model in front of you and ask why the overjet is normal yet the case is Class II — answer with the retroclined centrals and deep overbite. A favourite MCQ pair: the commonest skeletal cause of division 1 (mandibular retrognathism) and the appliance of choice in a growing patient. Indian clinical conventions also expect you to time treatment around the pubertal spurt and to say so explicitly in case discussions — examiners reward the phrase "growth modification is possible because the patient is in the ascending limb of the growth spurt". ## Frequently asked questions ### How does Class II division 2 differ from division 1? Division 2 has retroclined upper central incisors with a deep overbite and usually normal or reduced overjet, while division 1 has proclined upper incisors with increased overjet and a convex profile. ### What is the most common skeletal basis of Class II division 1? Mandibular retrognathism — a deficient or posteriorly positioned mandible — with maxillary prognathism accounting for only a minority of cases. ### Which appliance suits a growing child with mandibular deficiency? A functional appliance such as a Twin Block, activator or bionator, ideally started just before or during the pubertal growth spurt. ### How is deep overbite managed in Class II division 2? By torquing the retroclined incisors forward, levelling the curve of Spee and using bite-opening mechanics — anterior bite planes in growers or true incisor intrusion with light forces (about 10-20 g per tooth) where indicated. ### What is a Class II subdivision? A Class II molar relation confined to one side, named for the side in deviation — subdivision right means the right side is Class II.