SEMINAR ORTHODONTICS: TWIN BLOCK & FRANKEL APPLIANCE GROUP 5: MASYITAH MUSTAFFA 1090036 SAKINAH MOHD SALEH 1090041 NURMARZURA ABDUL LATIF 1090045 SYAFIQAH NADHIRAH ISKANDAR 1090049
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 appliance • Tooth-borne (active) Twin block • Tooth-borne (passive) Andresen appliance • Myotonic Harvold activator
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.
MODE OF ACTION • works 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.
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.
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 eruption • This 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) case • very 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.
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.
INDICATIONS BASIC USE Class II div I Malocclusion 70% malocclusion Majority have Constricted maxilla Retrognathic mandible N/short lower face height Large OJ Deep OB
INDICATIONS • Class II div I • Class II div 2 • Class I OB • Class I closed bite • Class III • Lateral arch constriction • Anterior/posterior arch length discrepancies • Can also be used in TMJ therapy
INDICATIONS • Permanent dentition and active grower • Uncrowdeddentition with well developed arches • 10mm or less overjet with normal to deep overbite • Improved facial esthetics once the mandible is brought forward to class I • Normal growth direction
INDICATIONS • Note: 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
CONTRAINDICATIONS Tx aim is to relate mandible to maxilla in 3D Transverse, AP and vertically. Requires Maxilla to be in correct position first
CONTRAINDICATIONS • Maxilla must be in proper width • Ensure NO skeletal or facial asymmetry • Maxilla incisors must be torqued correctly • Maxillary incisors should not be too vertical or lingually inclined (as in Class II div 2)
C-TYPE 1 Components • Standard Twin Blocks – Class II Div I (with good arch arch form) • Adams or Delta Clasps, and Anterior Ball Clasps for good retention • Twin Blocks at a 70º angle, to advance mandible • Upper Midline Screw: so upper arch can accomodate • lower arch in advanced position
C-TYPE 2 Components Standard Twin Blocks – Class II Div I (with crowded lower arch) • Adams or Delta Clasps, and Anterior Ball clasps for good retention •Twin Blocks, at a 70º angle, to advance mandible • Upper and lower Midline Screws
C-TYPE 3 Components Stage II – Support Phase Anterior Inclined Plane used to maintain the corrected AP and incisor relationship until buccal segments settle into full occlustion. *Molars must be in contact to begin Stage II
C-TYPE 4 Components Class 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 forward To Open Bite: Reduce upper bite block as ilustrated above
C-TYPE 5 Components Class 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 anteriors To Open Bite: Reduce upper bite block as ilustrated above
C-TYPE 6 Components Twin 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
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’
Also known as functional regulator (FR). • Use during mixed and early permanent dentition stages • Widely used in Class II malocclusion • It produces changes in anteroposterior, transverse, and vertical jaw relationships • Worn full-time basis for 18-24 months. • Then, part-time basis until the fixed appliance are placed to align permanent teeth.
Mode of action • Mandibular 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.
Increase in saggitaland transverse intraoral space. • Increase in vertical space where appliance is kept free from posterior teeth. • Shields loosen up tight muscle and improve muscle tone
References Textbook Orthodontics Principles and Practice, Daljit S. Gill & FarhadB.Naini, 2011 http://www.slideshare.net/shabeelpn/functional-appliances http://www.appliancetherapy.com/global_center/sml/pdf/PBBV5N2.pdf http://wikisites.mcgill.ca/Dentalpedia/index.php/Twin_Block#Indications: http://www.aurumgroup.com/files/removable/C882-Twin_Block_Ortho_4_Eng-web7-2.pdf http://jorthod.maneyjournals.org/content/28/4/271.full?sid=a959ab70-5056-4da6-917f-4cc22a3bfbbd http://www.appliancetherapy.com/global_center/sml/pdf/PBBV5N2.pdf