Document 381298
Opening Opening Opening Opening Posselt’s Figure Posselt’s Investigations Posselt’s Investigations Posselt’s Figure Posselt’s Figure MP ICP RCP HA MP = Maximal protrusion ICP = Intercuspal position RCP= Retruded Contact position HA = Hinge axis MO = Maximum opening MO Posselt’s Figure – top edge MP ICP IG RCP EE Definitions Articulators – A mechanical representation of the jaws and temporo-mandibular joints Use of articulators Diagnosis • slides and occlusal relationships Treatment planning • Diagnostic wax - up • Occlusal adjustment Fabrication of Splint / Prostheses Articulators Types – Simple Hinge – Average Value – Semi-adjustable – Fully adjustable Articulators Cast Holder Cast Holder Average Value Articulators BONWILL 1854 4” 4” Articulators Average Value 4” 4” Articulators Average Value Articulators Denar II - Arcon Dentatus Non Arcon Denar II Adjustable Condylar Angle, ISS & PSS Articulators Semi-adjustable Can alter; •TMJ to Incisor distance •Bennett Angle •Condylor Guidance Angle •Incisal guidance plate Articulators •Needs Facebow recording •Ideally should be used for complete denture cases Facebow recording For semi adjustable articulator Fully adustable: Denar 5 Posterior wall Superior wall Medial wall Inclination of superior wall Condylar angle Intercondylar (& glenoid fossa) distance ISS Denar 5a Pantographic recording For fully adjustable articulator lots Difficulty of use none Hand Av Held Value S-A Fully Adjustable lots Amount of adjustment none Hand Av Held Value S-A Fully Adjustable lots Cost none Hand Av Held Value S-A Fully Adjustable Articulator use vs time vs cost lots lots Amount of adjustment Difficulty of use Cost none none Hand Av Held Value S-A Fully Adjustable What if patient doesn’t match articulator? Articulator Patient Articulators Articulators Therefore the distance from the condyle to the teeth is crucial We obtain a measurement of this distance with a facebow Facebow Interocclusal record Used to locate the lower model to the upper If lots of good stable occlusal contacts then no IOR needed If need an RCP record, then we need an IOR that is thick and strong enough to obtain a record with the teeth separated and in terminal hinge axis e.g. Moyco Extra Hard Beauty wax For routine ICP records when carrying out multiple crowns / bridgework, Blu-mousse just over the tooth preps is usually sufficient Aids to obtaining THA Bimanual manipulation Cotton wool rolls Anterior “jig” Splint therapy Chin-point guidance Anterior jig Cold-cure acrylic (Duralay/Trim) Greenstick Anterior jig (trimmed) Provides inclined plane Separation of posterior teeth Allows the use of easy flowing occlusal recording media such as Blu-Mousse Anterior Jig From Howatt, Capp & Barrett Clinically useful settings for articulator Condylar angle 25° Immediate side shift 0.3mm Progressive side shift 6° Incisal guidance table Allows shape of palatal to be reproduced Allows length of incisors to be maintained Tooth to be prepped Shape created is the inverse of Posselt’s figure Following tooth prep Tooth form reconstructed Summary The choice of articulator depends upon such factors as; – Intended use – Availability of equipment – Patient's occlusion - Skill of the technician - Expense - Skill of the operator – The more closely the articulator matches the patients anatomy, usually the better the outcome and the less adjustment is required at chairside on fitting prostheses.
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