Denture Placement Denture Placement & Occlusion & Occlusion CorrectionCorrection

Rola M. Shadid, BDS, MScRola M. Shadid, BDS, MSc

Causes of Denture ErrorsCauses of Denture Errors

Clinical errorsClinical errors

Technical errorsTechnical errors

Inherent deficiencies in the material Inherent deficiencies in the material itselfitself

Evaluation ProceduresEvaluation Procedures ProcessingProcessing Polished surfacesPolished surfaces Tissue fit and comfortTissue fit and comfort Retention, stability and supportRetention, stability and support Jaw relationsJaw relations OcclusionOcclusion EstheticsEsthetics SpeechSpeech

Evaluation of Processing *Evaluation of Processing *

Inspect for processing errors, e.g. Inspect for processing errors, e.g. porosityporosity

Inspect for inadequate polishingInspect for inadequate polishing Run your finger along the borders & Run your finger along the borders &

impression surface to check if sharp impression surface to check if sharp edges or acrylic spicules existedges or acrylic spicules exist

Examine frenal notches for sharp edgesExamine frenal notches for sharp edges Examine for adhered plaster or stone Examine for adhered plaster or stone

fragmentsfragments

Patient Education & Preparation Patient Education & Preparation **

• First oral feeling with fullness is normal First oral feeling with fullness is normal & will disappear over time& will disappear over time

• Excessive salivationExcessive salivation

(compulsive spitting or rinsing should be (compulsive spitting or rinsing should be avoided,avoided, instead swallowing encouraged instead swallowing encouraged to remove excess saliva)to remove excess saliva)

Evaluation of Tissue Fit & Evaluation of Tissue Fit & ComfortComfort

Pressure Indicating Paste (PIP)*Pressure Indicating Paste (PIP)*• Every new denture must be checked Every new denture must be checked

with PIP to identify and determine if with PIP to identify and determine if pressure areas exist to reduce them.pressure areas exist to reduce them.

Evaluation of Tissue Fit & Evaluation of Tissue Fit & ComfortComfort

• Never adjust unless you can Never adjust unless you can see exactly where to adjustsee exactly where to adjust

• Use indicator medium Use indicator medium

- (PIP, indelible marker, etc)(PIP, indelible marker, etc)

Place Paste with StreaksPlace Paste with Streaks

How to Read PIP?How to Read PIP?

• Streaks - no Streaks - no contact (N)contact (N)

• No Paste - No Paste - Impingement (I)Impingement (I)

• Paste, no streaks Paste, no streaks - normal contact - normal contact (C)(C)

Evaluation of Tissue Fit & Evaluation of Tissue Fit & ComfortComfort

Severe undercuts Severe undercuts • Cause abrasion and soreness in Cause abrasion and soreness in

seating and removal seating and removal

• ManagementManagement

Relieve with extreme caution with Relieve with extreme caution with aid of PIPaid of PIP

Evaluation of Tissue Fit & Evaluation of Tissue Fit & ComfortComfort

Overextended bordersOverextended borders• Denture appears to rise or has Denture appears to rise or has

inadequate retentioninadequate retention

• ManagementManagement

Identify the offending borders, mark with Identify the offending borders, mark with indelible marker inside the pt mouth and indelible marker inside the pt mouth and carefully reducecarefully reduce

Evaluation of Retention, Evaluation of Retention, Stability & SupportStability & Support

• Test for retentionTest for retention**

• Test for posterior palatal sealTest for posterior palatal seal

Test for RockingTest for Rocking

• Apply alternating finger pressure Apply alternating finger pressure on occlusal surfaces of R & L on occlusal surfaces of R & L sidessides

• Rocking around fulcrum pointRocking around fulcrum point

• Midpalatal raphe is a common Midpalatal raphe is a common fulcrum point if inadequate relief fulcrum point if inadequate relief

has been provided has been provided **

Evaluation of OcclusionEvaluation of Occlusion

• Denture processing Denture processing almost always almost always causes causes changes in occlusion due to dimensional changes in occlusion due to dimensional changes in resinchanges in resin

• These changes are usually manifested as These changes are usually manifested as increase in OVDincrease in OVD

Causes of Occlusal ErrorsCauses of Occlusal Errors• Errors in impressionsErrors in impressions• Ill-fitting trial denture basesIll-fitting trial denture bases• Inaccurate jaw relation recordsInaccurate jaw relation records• Errors during transfer of the records to Errors during transfer of the records to

articulatorarticulator• Incorrect arrangement of posterior teethIncorrect arrangement of posterior teeth• Dimensional changes during curingDimensional changes during curing

• Processing faults……..Processing faults……..**

Why is it difficult to detect Why is it difficult to detect occlusal errors in the occlusal errors in the

mouth? mouth? **

Negative attitude (assume an Negative attitude (assume an error exists and try to find it)error exists and try to find it)

What is the ideal occlusal contact?What is the ideal occlusal contact?

At first contact, even maximum At first contact, even maximum intercuspation at CR without denture intercuspation at CR without denture shifting or instability & without pain shifting or instability & without pain **

Types of Occlusal ErrorsTypes of Occlusal Errors

• CO not coincide with CRCO not coincide with CR

• Premature contact (high point) in one or Premature contact (high point) in one or both sidesboth sides

• Uneven distribution of occlusal contactsUneven distribution of occlusal contacts

• Eccentric movement prematurities Eccentric movement prematurities (protrusive & lateral)(protrusive & lateral)

What are the Methods of What are the Methods of Detecting Occlusal Errors?Detecting Occlusal Errors?

Touch & slide method Touch & slide method (Refer to lecture 9)(Refer to lecture 9)

Denture dislodges or shifts when pt Denture dislodges or shifts when pt occludesoccludes

Pt complains of pain beneath Pt complains of pain beneath denture basesdenture bases

Correction of Occlusal Correction of Occlusal ErrorsErrors

1.1. Laboratory remountingLaboratory remounting

2.2. Clinical remountingClinical remounting

3.3. Direct intraoral correctionDirect intraoral correction

Laboratory Remounting *Laboratory Remounting *

DisadvantagesDisadvantages

Cannot correct errors made while Cannot correct errors made while recording jaw relationsrecording jaw relations

Cannot correct errors made while Cannot correct errors made while mounting the casts on the articulatormounting the casts on the articulator

Does not compensate changes caused by Does not compensate changes caused by settling of the denture basessettling of the denture bases

Clinical Remounting with New Clinical Remounting with New Interocclusal RecordsInterocclusal Records * *

AdvantagesAdvantages Correct errors made during recording of jaw Correct errors made during recording of jaw

relations, or while mounting cast on relations, or while mounting cast on articulatorarticulator

Less chair side time Less chair side time Corrections away from the patient’s viewCorrections away from the patient’s view No saliva which makes detection by No saliva which makes detection by

articulating paper difficultarticulating paper difficult No shifting of dentures or incorrect closure by No shifting of dentures or incorrect closure by

ptpt

The Aim of Clinical Remounting The Aim of Clinical Remounting

The prematurities are ground The prematurities are ground until multiple, uniformly until multiple, uniformly distributed and even contacts distributed and even contacts are obtained bilaterallyare obtained bilaterally

Clinical remounting is currently Clinical remounting is currently the most commonly preferred the most commonly preferred method of occlusal correctionmethod of occlusal correction

Clinical Remounting Clinical Remounting ProcedureProcedure

• Ask patient to bite on Ask patient to bite on cotton rolls for 10 min.cotton rolls for 10 min.

• Guide mandible into Guide mandible into CR several times.CR several times.

• Bite registration Bite registration material is placed on material is placed on the post. teeth of the the post. teeth of the mandibular denturemandibular denture

Clinical Remounting Clinical Remounting ProcedureProcedure

• Guide mandible into Guide mandible into CRCR

• Obtain interocclusal Obtain interocclusal record of CR.record of CR.

Clinical Remounting Clinical Remounting ProcedureProcedure

• Mount upper denture Mount upper denture using remounting jigusing remounting jig

• Mount lower dentureMount lower denture

Clinical Remounting Clinical Remounting ProcedureProcedure

Selective Spot Grinding * Selective Spot Grinding *

The art of reducing premature contacting surfaces, so that an equal pressure exists at all points with interference at no point.

How to Recognize How to Recognize Premature Contacts?Premature Contacts?

• A dark ring with a light A dark ring with a light center usually denotes a center usually denotes a premature contactpremature contact

• You should distinguish You should distinguish betw. marks made by betw. marks made by normal occlusal contacts normal occlusal contacts and those of premature and those of premature contactscontacts

• Articulating paper should Articulating paper should not be reused many times not be reused many times and should be changed and should be changed often.often.

Selective Spot GrindingSelective Spot GrindingSelective Spot GrindingSelective Spot Grinding

Make grinding until Make grinding until even (same intensity), even (same intensity), stable, and multiple stable, and multiple marks spread over marks spread over wide area in both sideswide area in both sides

Make grinding until Make grinding until even (same intensity), even (same intensity), stable, and multiple stable, and multiple marks spread over marks spread over wide area in both sideswide area in both sides

Eliminating Occlusal ErrorsEliminating Occlusal Errors

• Re-establishment of CO.Re-establishment of CO.

• Correction of protrusive relation.Correction of protrusive relation.

• Correction of working side occlusal errors.Correction of working side occlusal errors.

• Correction of balancing side errors.Correction of balancing side errors.

Initially, centric occlusion errors are Initially, centric occlusion errors are corrected, followed by protrusive, R & L corrected, followed by protrusive, R & L lateral interferences.lateral interferences.

Basic Tooth PositionsBasic Tooth Positions

Balancing Contacts Centric Occlusion Working Contacts

Selective Grinding Rules to Selective Grinding Rules to Obtain COObtain CO

After the first few taps on the articulating paper only a After the first few taps on the articulating paper only a few high contacts appear.few high contacts appear.

The marking process and the grinding are repeated until The marking process and the grinding are repeated until all except the anterior teeth contact in CO.all except the anterior teeth contact in CO.

Ideally all holding cusps Ideally all holding cusps ** of the maxillary and of the maxillary and mandibular posterior teeth will make simultaneous mandibular posterior teeth will make simultaneous contacts.contacts.

It is not uncommon for one or two functional cusps not to It is not uncommon for one or two functional cusps not to make contact after establishing the final CO.make contact after establishing the final CO.

It is not necessary to continue adjusting until these cusps It is not necessary to continue adjusting until these cusps make contacts because aggressive adjustment will make contacts because aggressive adjustment will sacrifice the established OVDsacrifice the established OVD

Selective Grinding Rules to Selective Grinding Rules to Obtain COObtain CO

As far as possible, avoid grinding cusp tips As far as possible, avoid grinding cusp tips especially centric holding cusps, instead especially centric holding cusps, instead grind the opposing fossae or marginal grind the opposing fossae or marginal ridges where the centric holding cusps ridges where the centric holding cusps occludeocclude

If the high contact is on the centric If the high contact is on the centric holding cusp inclines, the cuspal inclines holding cusp inclines, the cuspal inclines can be reduced, thereby gradually moving can be reduced, thereby gradually moving the contact more toward the bearing cusp the contact more toward the bearing cusp tip. tip.

A centric holding cusp may be reduced A centric holding cusp may be reduced when it interferes with another centric when it interferes with another centric holding cusp or when makes interferences holding cusp or when makes interferences in centric and eccentric positionsin centric and eccentric positions

Re-establishment of CORe-establishment of CO

Problem: Teeth too longSolution: Deepen the fossae

Re-establishment of CORe-establishment of CO

Problem: Teeth too nearly end to endSolution: Grind Inclines

Re-establishment of CORe-establishment of CO

Problem: Too much horizontal overlapSolution: Broaden central fossae

After the CO re-establishment….After the CO re-establishment….

• DO NOT:DO NOT:

- Reduce maxillary lingual cusps.Reduce maxillary lingual cusps.

- Reduce mandibular buccal cusps.Reduce mandibular buccal cusps.

- Deepen the fossae.Deepen the fossae.

Correction of Protrusive Correction of Protrusive RelationRelation

• The teeth are brought The teeth are brought edge to edgeedge to edge

• Any interferences to Any interferences to smooth anterior gliding smooth anterior gliding of dentures are of dentures are eliminated by grindingeliminated by grinding

• Elimination of Elimination of protrusive interferences protrusive interferences along a path of 3 to 5 along a path of 3 to 5 mm is sufficientmm is sufficient

Correction of Working Side Correction of Working Side Occlusal ErrorsOcclusal Errors

BULL rule BULL rule

buccal upper-lingual lowerbuccal upper-lingual lower

Correction of Working Side Occlusal Correction of Working Side Occlusal ErrorsErrors

• Reduce lingual inclines of buccal cusps of Reduce lingual inclines of buccal cusps of upper teeth.upper teeth.

• Reduce buccal inclines of lingual cusps of Reduce buccal inclines of lingual cusps of lower teeth.lower teeth.

ON WORKING SIDE ONLY!!!ON WORKING SIDE ONLY!!!

Correction of Working Side Correction of Working Side Occlusal ErrorsOcclusal Errors

Problem: Buccal and lingual cusps too long.Solution: Change inclines of balancing cusps.

Correction of Working Side Correction of Working Side Occlusal ErrorsOcclusal Errors

Problem: Buccal cusps are too longSolution: Change lingual incline of maxillary buccal cusp

Correction of Working Side Occlusal Correction of Working Side Occlusal ErrorsErrors

Problem: Lingual cusp too long.Solution: Change buccal incline of lingual cusp of mandibular tooth.

On the balancing side, the cusps usually On the balancing side, the cusps usually involved are the functional cusps and involved are the functional cusps and therefore grinding becomes more therefore grinding becomes more confusingconfusing

Correction of Balancing Side Errors

Correction of Balancing Side Errors

Correction of Balancing Side Correction of Balancing Side ErrorsErrors

• Decide which supporting cusp maintains Decide which supporting cusp maintains CO and reduce its opponent.CO and reduce its opponent.

Correction of Balancing Side Correction of Balancing Side ErrorsErrors

Grind the lingual Grind the lingual incline of the incline of the mandibular mandibular buccal cusp.buccal cusp.

Direct Intraoral CorrectionDirect Intraoral Correction

DisadvantagesDisadvantages Requires a lot of pt cooperationRequires a lot of pt cooperation Pt should have good neuromuscular controlPt should have good neuromuscular control SalivaSaliva Inaccurate closure by ptInaccurate closure by pt Misleading due to resiliency of tissues and Misleading due to resiliency of tissues and

shifting of denture basesshifting of denture bases

ReferencesReferences

1.1. Boucher's Prosthodontics Treatment for Boucher's Prosthodontics Treatment for Edentulous Patients. Twelfth Edentulous Patients. Twelfth Edition.Chapter 20.Edition.Chapter 20.

2.2. Dalhousie continual educationDalhousie continual education

3.3. Complete Denture Prosthodontics, 1Complete Denture Prosthodontics, 1stst Edition, Edition, 2006 by John Joy Manappallil, Chapter 192006 by John Joy Manappallil, Chapter 19