1 SEMINAR ORTHODONTICS: TWIN BLOCK & FRANKEL APPLIANCE GROUP 5:MASYITAH MUSTAFFASAKINAH MOHD SALEHNURMARZURA ABDUL LATIFSYAFIQAH NADHIRAH ISKANDAR
2 Introduction Functional appliance: “removable or fixed orthodontic appliances that aim to utilise, eliminate or guide forces arising from muscle function, tooth eruption and growth in order to alter skeletal an dental relationships”.Types:Tissue-borne Frankel applianceTooth-borne (active) Twin blockTooth-borne (passive) Andresen applianceMyotonic Harvold activator
3 TWIN BLOCK removable functional appliance. made up of two components, an upper and lower plate, which works together to posture the lower jaw forward.frees up the “locked-in” lower jaw and encourages it to grow to its fullest potential.the upper (and sometimes lower) plate may also have an expansion screw to widen the arch.treatment with a Twin Block appliance typically takes 12 to 18 months.
6 MODE OF ACTIONworks on the philosophy of occlusal inclined planes and use of masticatory force throughout the day.If the mandibular inclined planes are in a distal relation to that of maxilla then the force acting on the mandibular teeth will have a distal force vector leading to a Class II growth tendency.
8 The aim of the inclined planes of the bite blocks in twin block is to modify these inclined planes and cause more favorable growth pattern.Hence the unfavorable cuspal contacts of the distal occlusion are replaced by favorable proprioceptive contacts on the inclined planes to correct the malocclusion and free the mandible from its locked distal position.
9 Adjustment of the occlusal plane: deep overbite case the upper block should be slightly trimmed occluso-distally to leave the lower molars 1 mm clear of the occlusion to allow for eruptionThis is usually done at the first visit, with subsequent reductions performed, as needed, until the proper vertical relationship is established.reduced overbite (or open bites) casevery important that NO trimming is done on the blocks.all posterior teeth must remain in contact with the blocks to PREVENT eruption of the posterior teeth.
11 Appointment Scheduling: First Appointment: Delivery of the appliance and patient instruction. Adjustment of the occlusal planes. One Week Later: Adjust the bite blocks if the lower molars have erupted into contact. For arch development, have the patient begin expansion screw activation at one turn per week. One months Interval:check adjustment. Watch for proper vertical, lateral and AP development.
12 Class II div I Malocclusion INDICATIONSBASIC USEClass II div I Malocclusion70% malocclusion Majority have Constricted maxilla Retrognathic mandible N/short lower face height Large OJ Deep OB
14 INDICATIONS Class II div I Class II div 2 Class I OB Class I closed biteClass IIILateral arch constrictionAnterior/posterior arch length discrepanciesCan also be used in TMJ therapy
15 INDICATIONS Permanent dentition and active grower Uncrowded dentition with well developed arches10mm or less overjet with normal to deep overbiteImproved facial esthetics once the mandible is brought forward to class INormal growth direction
16 INDICATIONSNote: if patient is Class II div 2 with limited overjet or Class II div 1 with crowded and irregular incisors, you must align the upper incisors with a fixed or removable appliance before starting a twin bloc. It is recommended to hold the incisors in place for several months before delivering the appliance
17 CONTRAINDICATIONSTx aim is to relate mandible to maxilla in 3D Transverse, AP and vertically. Requires Maxilla to be in correct position first
18 CONTRAINDICATIONS Maxilla must be in proper width Ensure NO skeletal or facial asymmetryMaxilla incisors must be torqued correctlyMaxillary incisors should not be too vertical or lingually inclined (as in Class II div 2)
19 Standard Twin Blocks – Class II Div I (with good arch arch form) ComponentsC-TYPE 1Standard Twin Blocks – Class II Div I (with good arch arch form)Adams or Delta Clasps, and Anterior Ball Clasps for good retentionTwin Blocks at a 70º angle, to advance mandibleUpper Midline Screw: so upper arch can accomodatelower arch in advanced position
20 Standard Twin Blocks – Class II Div I (with crowded lower arch) ComponentsC-TYPE 2Standard Twin Blocks – Class II Div I (with crowded lower arch)• Adams or Delta Clasps, and Anterior Ball clasps forgood retention•Twin Blocks, at a 70º angle, to advance mandible• Upper and lower Midline Screws
21 Stage II – Support Phase ComponentsC-TYPE 3Stage II – Support PhaseAnterior Inclined Plane used to maintain the correctedAP and incisor relationship until buccal segments settleinto full occlustion.*Molars must be in contact to begin Stage II
22 Class II Div II Twin Block ComponentsC-TYPE 4Class II Div II Twin Block• Adams or Delta Clasps•Twin Blocks, at a 70º angle, to advance mandible• Upper and lower Midline Screws• Lingual Springs to move anterior forwardTo Open Bite: Reduce upper bite block as ilustrated above
23 Class II Div II Twin Block “Saggital” ComponentsC-TYPE 5Class II Div II Twin Block “Saggital”• Adams or Delta Clasps, and Ball clasps• Standard 70º Twin Blocks• Adjust screws ¼ turn per week to advance anteriorsTo Open Bite: Reduce upper bite block as ilustrated above
24 Twin Block to close the Bite ComponentsC-TYPE 6Twin Block to close the Bite• Adams or Delta Clasps• Standard 70º Twin Blocks• Tongue guard to prevent tongue thrust and act as Inclined plane to support the corrected incisor relationship• Lower Acryclic extended to 6’s with indicated clasps• Acrylic relieved lingual to anteriors to encourage reduction of open bite
25 FRANKEL APPLIANCE‘ It is a tissue-borne type removable functional appliance developed by Rolf Frankel that aims to remove muscle forces in labial and buccal areas that restricts the skeletal growth’
27 Also known as functional regulator (FR). Use during mixed and early permanent dentition stagesWidely used in Class II malocclusionIt produces changes in anteroposterior, transverse, and vertical jaw relationshipsWorn full-time basis for months.Then, part-time basis until the fixed appliance are placed to align permanent teeth.
28 Indications Frankel’s regulator 1 FR-I a FR-I b FR-I c To treat class I and class II division malocclusionto treat Angle’s class I malocclusion with deep biteTo treat Angle’s class II division I malocclusion, OJ not exceed 5mmto treat Angle’s class II division I malocclusion, OJ more than 7 mmFR-IIto treat Angle’s class II malocclusion division I and class II malocclusionFR-IIIto treat Angle’s class III malocclusionFR-IVTo treat bimaxillary protrusion and open biteFR-VUsed with headgear
34 Mode of actionMandibular protraction mandibular repositioning is provided by inferior border of vestibular shield, lower labial pad and lingual shield.Muscle function adaptation: pads and shields massage the blood vessels increase circulation.Lateral expansion Max;4-6mm. Mand;2-4mm. Due to vestibular shield inhibits cheek muscle from acting against occlusion. Thus allow the tongue to determine the lateral positioning of the teeth.
35 Increase in saggital and transverse intraoral space. Increase in vertical space where appliance is kept free from posterior teeth.Shields loosen up tight muscle and improve muscle tone
36 ReferencesTextbook Orthodontics Principles and Practice, Daljit S. Gill & Farhad B.Naini, 2011Twin_Block_Ortho_4_Eng-web7-2.pdfda6-917f-4cc22a3bfbbd