denture esthetics -a forgotten artshankariyerdds.com/AAID_Maxicourse_Asia/course_materials_Module_… · • VLC Resin – Triad Thursday, March 19, 2009. Thursday, March 19, 2009

denture esthetics-a forgotten art

K Jayadevan DDS, Shankar Iyer DDS

Thursday, March 19, 2009

dentures – the resistance

• not lucrative• time consuming• failures • not sexy• unappreciated• implants as alternatives


dentures - Issues

• prevention - fewer dentures being made• decreasing emphasis on the curriculum• failures of implants • diagnostic wax-ups and stents • affording population• availability of time and compliance


dentures – impact on esthetics

agenda: examination diagnosis treatment plan

techniques procedures results


denture esthetics – the exam• meet the patient before meeting the mouth


denture esthetics – the exam

• refer out for cosmetic improvements


denture esthetics – the exam• establish rapport – communicate


goals and desires• review of medical history


goals and desires

• examine current dentures – how may sets?


goals and desires• what is the chief complaint?


goals and desires• “don’t try to be the genius to fix the patient’s

problems right away”


when to jump in• verify fit, comfort, retention, stability, bite, “Patients most often may like existing

esthetics and only want increased fit”


achieving esthetics -the first step

• esthetics starts with impressioning• examine the ridges and relate them to the face• combination syndrome


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Impression Concepts

• Healthy Tissues• Extension to include basal seat• Harmony - anatomical and physical

limitations• Removal without damage to tissues• Correct positioning of tray• Dimensionally stable tray and impression

material


IMPRESSION OBJECTIVES

Support RetentionStabilityMaintain the health of oral tissuesFoundation for improved appearance


Support


Stability


Retention• Resistance to removal in a direction

opposite that of insertion


Factors involved in retention of dentures

1-Interfacial force : resistance to separation of two parallel surfaces that are imparted by a film of liquid between them

1- interfacial surface tension 2- interfacial viscous tension

2- Adhesion3- Cohesion4- Atmospheric pressure

5- Oral and facial musculature6- Undercut- Rotational path- Parallel walls7- Gravity


Custom Tray

• 2 – 3mm thick• Stepped handle in the anterior region• Border 2mm short of depth of sulcus• Cover the hamular notches• 2mm posterior to vibrating line• VLC Resin – Triad










Border Molding

• Modelling compound sticks• Added to tray in sections• Must be adequately softened• Preshaped to proper contour with fingers• Must be tempered in a water bath• Chilled after removal from mouth• Rounded contours



Maxillary Border Molding

Anterior Region Lip - elevated & extended out, downward & inward

Buccal Frenum Region Cheek – elevated, pulled downward & inward, moved backward and forward


Maxillary Border Molding

Posterior region Cheek – outward, downward and inward

Patient opens wide and moves mandible form side to side











Mandibular Border Molding

Anterior Labial Region Lip – lifted outward, upward & inward

Buccal Frenum Region Cheek – lifted outward, upward & inward moved backward and forward


Mandibular Border Molding

Posterior Buccal region Cheek – outward, upward and inward

Patient exerts a closing force while downward pressure exerted by dentist to activate masseter muscle


Mandibular Border MoldingAnterior Lingual Region Tongue protruded - determines length of

lingual flange Tongue pushed against front part of palate –

determines thickness

Mid Lingual Region Tongue protruded – determines length and slope

of lingual flange Tongue touches cheek on both sides


Mandibular Border MoldingPosterior Lingual Region Tongue protruded – activates the superior

constrictor muscle

Retromolar Pad Patient opens wide – determines length of

posteromedial border


Impression Materials

Mucostatic e.g. Zinc Oxide eugenol paste More Fluid Minimal displacement of tissues

Mucodisplacive e.g. polyvinylsiloxane, polysulphide, More Viscous More displacement of tissues



Tray Preparation

• Excess modeling compound removed

• Hole places in rugae area of maxillary tray

• Adhesive applied to tray


Tray Preparation

• Excess modeling compound removed

• Hole places in rugae area of maxillary tray

• Adhesive applied to tray



Impression Material

• Mixed according to manufacturer’s instructions

• Evenly distributed within tray

• Cover all borders








Reasons for remaking impressions

• Incorrect positioning of the tray• Large voids or discrepancies• Incorrect consistency of impression

material• Movement of the tray before final set• Incorrect border molding procedures• Using too much or too little impression

material







Boxing Impressions

• Preserves functional width of sulcus• Preserves functional depth of sulcus• Boxing wax strip attached 2-3mm below

border• Vertical wall extends 10-15mm above

impression• Seal wax with hot spatula






POSTERIOR

PALATAL

SEAL


Posterior Palatal Seal

• Pterygomaxillary (hamular) notches

• Vibrating Line – Junction of Moveable & non-moveable tissue

• Fovea Palatinae





















achieving esthetics -the first step

• special techniques for flabby ridges• dual impression techniques• the sulcus esthetics


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achieving esthetics -the rim factors• facial support


achieving esthetics -the rim factors

• fox planes and arbitrary esthetic planes• campers line


achieving esthetics -the rim factors• the true smile line

• the denture look vs. smile line dentures


denture esthetics jr - vertical relationship• if it looks good it must be good


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denture esthetics jr at cr• are we opening or restoring vertical?• always register CR• verify with fricatives and smiles


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denture esthetics -selection of teeth

• facial form and tooth form• selection of mold, size and shape• color of teeth – shade guides• denture base colors – the Mehary guides


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denture esthetics• selection of articulators • balanced vs anterior guidance• types of arrangement

• do not correct skeletal discrepancies with teeth arrangement


Development of Denture


The Evolution

Teeth Forms

•1909 – Dentists Supply Company– 33 degree cusp (Gysi)


The Evolution

Teeth Forms

•1932 – Pilkington and Turner (shallower 30 degree teeth– Tetrahedral forms


The Evolution

Tooth Forms Anatomic forms:1927 – Gysi - modified “crossbite” posterior -maxillary lingual cusp only

against mandibular anatomic form - origin of ligualized occlusal

scheme?


The Evolution

Tooth Forms Modified Anatomic forms:1922 – 1927 Victor Sears - “channel” tooth - mesiodistal channel in maxillary

posteriors against mandibular central ridge

- origin of controversy – “to balance or to reduce thrust?”


The Evolution

Tooth Forms Modified Anatomic forms: 1930 – Avery brothers: - “scissor-bite technique” - opposite of Sears - not marketed commercially


The Evolution

Tooth Forms Modified Anatomic forms: 1935 – French (similar to Sears) 1936 – McGrane “curved cusp” 1937 – Max Pleasure (Anti-Monson,

Flat and Monson) 1942 – John Vincent (resin with metal

vs. porcelain teeth)


The Evolution

Tooth Forms Modified Anatomic forms: 1941 – S.H. Payne “lingualized occlusal

concept” - popularized by Pound and Murrell 1973 – Mehringer - FGP with metal inserts 1977 – Levin (functionally generated

occlusal forms(modification of Sosin 1961) – cast in gold


The Evolution

Tooth Forms Nonanatomic or 0 degree cuspless forms: 1929 – Hall “inverted cusp tooth” 1929 - Myerson “True Kusp” FLX – freedom in lateral excursion - complete free gliding contact 1939 – Swenson “non-lock” 1946 – Hardy’s VO (Vitallium Occlusal) 1951 – Myerson “Shear-cusp” first cross-linked

teeth Sears –Myerson combination – Porcelain vs.

acrylic 1952 – Cook – “Coe masticators – Stainless steel

holes vs. porcelain teeth


The Quest

Improved masticatory efficiency with control of vertical and horizontal

forces to minimize trauma to supporting tissues


Balanced Occlusion

•Bilateral, simultaneous, anterior and posterior occlusal contact of teeth in centric and eccentric positions


Factors Affecting Balanced Occlusion

•Condylar Guidance:Controversies:

– no definite condylar path. The Condyle can adjust to any occlusal scheme

– how closely does the condylar path have to match with that of patient’s?

– how much variance is tolerable?Kurth, Payne, Weinberg


Factors Affecting Balanced Occlusion• Incisal Guidance- Esthetics- Phonetics- Arch Form- Ridge relationship


Factors Affecting Balanced Occlusion

• The Plane of Occlusion– ½ - 2/3rds height of retromolar pad– Parallel to ala tragus line– Commissure of the mouth


Factors Affecting Balanced

• The compensating curve– Christiansen’s phenomenon– Link between IG and CG


Factors Affecting Balanced

• Cuspal angulation


The balance beam

IG CG

CA

POCC


- trial of the esthetics

• verify contours, phonetics, support, smile line • verify jr• get the patients approval• retry with old set – mix and match


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esthetics of interim immediates• the failing FPD• one step impression and master casts• the acrylic template and denture base• tryin and reline


esthetics of immediates

• the decoronation procedure vs extraction• impressions• – the one day dentures – decoronation• - the one day dentures – extractions• - the one day smile make over


denture esthetics

• transformations


Documents

denture esthetics -a forgotten artshankariyerdds.com/AAID_Maxicourse_Asia/course_materials_Module_… · • VLC Resin – Triad Thursday, March 19, 2009. Thursday, March 19, 2009