Class II div 1 Malocclusion Class II div 1 Malocclusion Objectives OR What can we do about Goofy? Objectives Describe Class II div 1 Objectives Describe Class II div 1 Describe principles of treatment Objectives Describe Class II div 1 Describe principles of treatment Describe treatment options 1
Objectives Aetiology Aetiology Describe Class II div 1 Describe principles of treatment Describe treatment options Examples of treatment Dento-alveolar Dento-alveolar Skeletal Aetiology Aetiology Dento-alveolar Incisor proclination Aetiology Dento-alveolar Incisor proclination? 82 79 27 125 93 2
Aetiology Dento-alveolar Aetiology Dento-alveolar Aetiology Dento-alveolar Digit sucking? Digit sucking Incisor proclination Lower incisor retroclination 82 79 27 125 87 Aetiology Skeletal Aetiology Skeletal Aetiology Skeletal Mild Mild Moderate 3
Mild Moderate Severe Aetiology Skeletal Mild Moderate Severe Aetiology Skeletal Mild Moderate Severe Aetiology Skeletal High FMPA angle Low FMPA angle Treatment Principles I Ideal Treatment Principles I Treatment Principles I Ideal correct skeletal discrepancy 4
Treatment Principles I Ideal correct skeletal discrepancy Camouflage Treatment Principles I Ideal correct skeletal discrepancy Camouflage hide skeletal discrepancy Treatment Principles I Ideal correct skeletal discrepancy Camouflage hide skeletal discrepancy Depends on patient Treatment Principles I Ideal correct skeletal discrepancy Camouflage hide skeletal discrepancy Depends on patient Growing? Non-growing?? Skeletal discrepancy Growing patient Can we make patients grow????? Skeletal discrepancy Growing patient Can we make patients grow????? Research studies: One patient and it works Series of patients treated and it works Randomised Clinical Trial 5
Skeletal discrepancy Growing patient Can we make patients grow????? Research studies: Randomised Controlled Trails North Carolina study Manchester/UK study Skeletal discrepancy Growing patient North Carolina study shows: Am J Orthod Dentofacial Orthop 1998:113:62-72 Functional appliances produce slightly more mandibular growth Functional reduce the need for orthognathic surgery Headgear reduces maxillary growth Shorter time with fixed, but longer overall treatment time Skeletal discrepancy Growing patient UK study shows: O Brien et al 2004 Functional appliances produce slightly more mandibular growth Early treatment improves self image Twin blocks as effective as Herbst appliances Conclusion Treatment Options Ideal Correct skeletal discrepancy Orthognathic Surgery Functional (if growth occurs) Camouflage Orthodontic treatment results in camouflage of skeletal discrepancies UNLESS patient grows favourably or surgery is used Camouflage Accept skeletal discrepancy Reduce overjet within skeletal limits 6
Treatment principles II Treatment principles II 1. Reduce Overbite Treatment principles II 1. Reduce Overbite Treatment principles II 1. Reduce Overbite 2. Create space (extraction/non extraction)..for Treatment principles II 1. Reduce Overbite 2. Create space (extraction/non extraction)..for 3. Reduction of Overjet +/- relief of Crowding Non extraction Extraction Treatment options 7
Non extraction 1. Space analysis 2. DMUBS (Distal Movement of Upper Buccal Segments) 3. Functional appliances OR Space analysis Assumptions: 1. Aims of treatment is Class I occlusion 2. Skeletal I occlusion 3. Premolar extractions 4. Complaint patient 5. Skilled operator using Fixed Appliances Space analysis Plan lower arch 1. Lower labial segment crowding 2. move canines to align lower incisors 3. Add/subtract any lower centre line shift 4. Add lower buccal segment crowding 5. Total = space requirements Space analysis Plan upper arch Space analysis Plan upper arch 1. Move canines to Class I 2. Add upper buccal segment crowding 3. Total = space requirements Space analysis Which extractions? Space less than 2mm non extraction Space 2-4mm extract 2 nd premolar Space 4-6mm extract 1 st premolar Space greater than 6mm anchorage?? 8
Non extraction DMUBS Mild cases needs co-operative patient Non extraction Functional Growing patient Well aligned arches Extraction Most commonly premolars Space analysis premolar = 7mm Extraction Most commonly premolars Removable appliance Most commonly premolars Removable appliance Fixed appliance Extraction Suitable for removable appliances? 9
Suitable for removable appliances? Indications: 1. proclined incisors 2. Mesial angulation of canines 3. Acceptable lower arch Suitable for removable appliances? Take Cephalogram and undertake a Prognosis tracing Suitable for removable appliances? Trace tip upper incisor about a point ¼ from apex Suitable for removable appliances? Extraction 1. Overbite reduction Removable appliance reduction of overjet. Indications: 1. proclined incisors 2. Mesial angulation of canines 3. Acceptable lower arch Usually a compromised result 10
1. Overbite reduction 1. Overbite reduction Flat Anterior Bite Plane when retracting canines and BEFORE incisor retraction 1. Overbite reduction Flat Anterior Bite Plane - Design Design must include: 1.Height of bite plane required 2. Length of bite plane (ie Overjet) 1. Overbite reduction Flat Anterior Bite Plane - Fitting 1. Overbite reduction Flat Anterior Bite Plane - Fitting 1. Overbite reduction Flat Anterior Bite Plane - USE Molars 2mm apart FABP may need building up/addition 11
2. Overjet reduction Design: Flat Anterior Bite Plane maintains OB reduction Incisor retraction spring e.g. Strap spring e.g.labial Bow 2. Overjet reduction Flat Anterior Bite Plane maintains OB reduction 2. Overjet reduction Flat Anterior Bite Plane adjustment Trim behind incisors to allow retraction 2. Overjet reduction Flat Anterior Bite Plane adjustment To be continued Trim behind incisors to allow retraction 12