3.history and exam

3. History and Exam3. History and Exam

John Beumer III, DDS, MSJohn Beumer III, DDS, MSandand

Robert Duell, DDSRobert Duell, DDSDivision of Advanced Prosthodontics, Division of Advanced Prosthodontics, Biomaterials and Hospital DentistryBiomaterials and Hospital Dentistry

UCLA School of DentistryUCLA School of Dentistry

This program of instruction is protected by copyright ©. No portion of This program of instruction is protected by copyright ©. No portion of this program of instruction may be reproduced, recorded or transferred this program of instruction may be reproduced, recorded or transferred by any means electronic, digital, photographic, mechanical etc., or by by any means electronic, digital, photographic, mechanical etc., or by any information storage or retrieval system, without prior permission.any information storage or retrieval system, without prior permission.

• Medical and dental historyMedical and dental history• Orofacial examOrofacial exam• Prosthodontic assessmentProsthodontic assessment• PrognosisPrognosis• Preliminary impressionsPreliminary impressions• Tissue conditioningTissue conditioning

History and Clinical ExamHistory and Clinical Exam

Medical HistoryMedical HistoryPotential medical emergenciesEffects on denture supporting

tissuesEffects on oral neuromuscular

control

Effects of SmokingEffects of Smoking

Predisposition to oral cancer

Predisposition to periodontal disease

Success – failure rates of osseointegrated implants

Oral Facial ExamOral Facial Exam::

Oral cancer screening exam

Exam for other pathology

Local

Systemic

Prosthodontic assessment

Intraoral and Extraoral ExamIntraoral and Extraoral Exam

Checking for:Checking for:• ClickingClicking• Popping or crepitusPopping or crepitus

Palpate the temporomandibular joint

Conduct a thorough oral cancer screening Conduct a thorough oral cancer screening examexam

• Lips and cheeksLips and cheeks•Lateral border of the tongueLateral border of the tongue•Floor of the mouthFloor of the mouth•Tonsillar region and the soft palateTonsillar region and the soft palate•Base of the tongue Base of the tongue •OropharynxOropharynx•NeckNeck

Intraoral and Extra Oral ExamIntraoral and Extra Oral Exam

Extraoral ExamExtraoral Exam

LymphaticsLymphaticsThe first sign of oral cancer is often a palpable lymph node The first sign of oral cancer is often a palpable lymph node

Lips and cheekLips and cheek

Examination of the Lips and CheeksExamination of the Lips and Cheeks

Visual inspection Palpation

Bidigital

You are palpating for:• Lumps and bumps, indurations etc.

Examine the denture bearing surfaces, the soft palate, tonsillar region, the vestibules and the buccal mucosa.

Hamular notchHamular notch

Intraoral ExamIntraoral Exam

Examine the lateral Examine the lateral borders of the tongueborders of the tongue

Examine the ventral Examine the ventral surface of the tongue surface of the tongue and the floor of the and the floor of the mouthmouth..

Intraoral ExamIntraoral Exam

Oral Lesions and Disease FactorsOral Lesions and Disease Factors

Diabetes (long term insulin Diabetes (long term insulin dependent)dependent) Epithelium is thinner and Epithelium is thinner and

less keratinized.less keratinized.

Result:Result: Compromised, support Compromised, support and impaired tolerance of and impaired tolerance of complete dentures.complete dentures.

Impact on Complete Dentures

Oral Lichen Planus –Oral Lichen Planus – Erosive lesions and subsequent Erosive lesions and subsequent scarring in the buccal shelf area scarring in the buccal shelf area limit denture extension in this limit denture extension in this region and make it difficult for region and make it difficult for some patients to tolerate their some patients to tolerate their denturesdentures..

Result –Result – Compromised support Compromised support and tolerance of the mandibular and tolerance of the mandibular denturedenture.

Disease FactorsDisease FactorsWickham’s striaeWickham’s striae

PemphigoidPemphigoid –– Chronic Chronic ulceration with subsequent ulceration with subsequent scarring of the oral mucosa.scarring of the oral mucosa.

ResultResult – – Limited denture Limited denture extensions compromising extensions compromising support, stability, retention support, stability, retention and tolerance of completeand tolerance of complete dentures.dentures.

Disease FactorsDisease Factors

Low saliva flow Low saliva flow rates leads to rates leads to increased numbers increased numbers of fungal organisms of fungal organisms leading to a high leading to a high incidence of chronic incidence of chronic CandidiasisCandidiasis..

MildMildCandidiasisCandidiasis

SevereSevereCandidiasisCandidiasis

Angular cheilitisAngular cheilitissecondary to chronicsecondary to chronicCandidiasis.Candidiasis.

Chronic Candidiasis Chronic Candidiasis

Clinical ManifestationsClinical Manifestations

Burning and irritation of the denture Burning and irritation of the denture bearing mucosa, making tolerance of bearing mucosa, making tolerance of complete dentures difficult. In addition complete dentures difficult. In addition the fungus is keratolytic, further the fungus is keratolytic, further compromising support and tolerance.compromising support and tolerance.

TreatmentTreatment

Topical antifungal therapy followed Topical antifungal therapy followed by relining of the dentures (Nystatin by relining of the dentures (Nystatin is the drug of choice. It can be is the drug of choice. It can be dispensed as a cream, a powder or dispensed as a cream, a powder or an oral lozenge).an oral lozenge).

Begins as a traumatic ulcer secondary to an overextended denture flange.Begins as a traumatic ulcer secondary to an overextended denture flange.

Common Oral LesionsCommon Oral Lesions

Inflammatory fibrous hyperplasiaInflammatory fibrous hyperplasia

Continued denture wear and irritation Continued denture wear and irritation leads to inflammatory fibrous hyperplasia leads to inflammatory fibrous hyperplasia (epulis fissuratum).(epulis fissuratum).

Therapy –Therapy – Surgical excision Surgical excision

Common Oral LesionsCommon Oral Lesions

Inflammatory fibrous hyperplasiaInflammatory fibrous hyperplasia

Common oral lesionsCommon oral lesions

Secondary to ill fitting maxillary dentures. Usually complicated by Secondary to ill fitting maxillary dentures. Usually complicated by chronic candidiasis.chronic candidiasis.

Inflammatory papillary hyperplasiaInflammatory papillary hyperplasia

Therapy:Therapy:Antifungal medications applied topically. In extreme Antifungal medications applied topically. In extreme

cases,surgical excision.cases,surgical excision.

Therapeutic Approaches – Palatal Papillary Therapeutic Approaches – Palatal Papillary Hyperplasia**with Associated Candida AlbicansHyperplasia**with Associated Candida Albicans

Antifungal therapy*Antifungal therapy*a)a) Reline or remake dentureReline or remake dentureb)b) Nystatin powder (100,000 units per gram) Apply to undersurface of denture Nystatin powder (100,000 units per gram) Apply to undersurface of denture

three times per day for 3-4 weeksthree times per day for 3-4 weeksc)c) Nystatin cream – Best used for lesions associated with the corners of the Nystatin cream – Best used for lesions associated with the corners of the

mouthmouthd)d) Reline denture with temporary reline materialReline denture with temporary reline material

Surgical excision with electrosurgery (when antifungal therapy has reached an Surgical excision with electrosurgery (when antifungal therapy has reached an end point)end point)

**Nystatin rinse is generally ineffective. Nystatin oral or vaginal Nystatin rinse is generally ineffective. Nystatin oral or vaginal suppositories used as an oral lozenge are reserved for fungal suppositories used as an oral lozenge are reserved for fungal infestations that extend beyond the denture bearing surfacesinfestations that extend beyond the denture bearing surfaces.

**Is this a premalignant lesion? No!!!!

Other Oral Lesions of ImportanceOther Oral Lesions of Importance

Premalignant LesionsPremalignant Lesions

Both these lesions can transform into Squamous Cell CarcinomasBoth these lesions can transform into Squamous Cell CarcinomasLeukoplakiaLeukoplakia ErythroplakiaErythroplakia


Squamous cell carcinomas

Unless detected early most patients with squamous carcinoma have a Unless detected early most patients with squamous carcinoma have a survival of less than 50%. Early detection dramatically improves survival.survival of less than 50%. Early detection dramatically improves survival.

Squamous Cell CarcinomaSquamous Cell Carcinoma•A thorough oral cancer screening exam must be A thorough oral cancer screening exam must be performed on all patientsperformed on all patientsconsidered for complete dentures.considered for complete dentures.

•Early oral cancers (A) are difficult toEarly oral cancers (A) are difficult todetect and may be confused with otherdetect and may be confused with otherphenomenon, but the cure rates are high.phenomenon, but the cure rates are high.

•Advanced oral cancers (B,) are easy to detect, Advanced oral cancers (B,) are easy to detect, but cure rates are very low.but cure rates are very low.

•Our challenge is to detect oral cancersOur challenge is to detect oral cancerswhen they are small, localized, andwhen they are small, localized, andtreatable.treatable.

AA

BB


Oral ExamOral Exam

Clinical Factors Influencing Clinical Factors Influencing Stability, Retention, and Support of Stability, Retention, and Support of

Complete DenturesComplete Dentures

Definitions – Removable ProsthodonticsDefinitions – Removable Prosthodontics

RetentionRetention – – Resistance to vertical Resistance to vertical displacement of the denture away from the displacement of the denture away from the denture bearing surface during.denture bearing surface during.

StabilityStability – Resistance to lateral displacement – Resistance to lateral displacement of the denture during function.of the denture during function.

Support Support – Resistance to vertical forces of – Resistance to vertical forces of occlusion. Factors of the bearing surface that occlusion. Factors of the bearing surface that resist or absorb occlusal loads during resist or absorb occlusal loads during function.function.

What factors associated with the What factors associated with the denture bearing tissues influence denture bearing tissues influence the quality of the quality of retention, retention, stability, and supportstability, and support provided provided the complete denture?the complete denture?

Quality of Bearing Surface Mucosa Affects SupportQuality of Bearing Surface Mucosa Affects Support ..

The more keratinized attached mucosa available, The more keratinized attached mucosa available, particularly in the mandible, the better the supportparticularly in the mandible, the better the support..

Stratum corneumStratum corneum

Stratum granulosumStratum granulosum

StratumStratumspinosumspinosum

Basal layerBasal layer

Lamina propriaLamina propriaKeratinized Less keratinized

a) Degree of keratinizationa) Amount of attached mucosa vs unattached mucosa

Keratinized Attached mucosa is the Keratinized Attached mucosa is the Remnant of Attached Gingiva.Remnant of Attached Gingiva.

Attached GingivaAttached Gingiva Keratinized attached mucosaKeratinized attached mucosa

Mucogingival junctionMucogingival junction

The more available on the denture bearing surfaces, the better the support.

Maxilla – Maxilla – Abundance of Abundance of keratinized attached mucosa. keratinized attached mucosa. Covers entire palate and alveolar Covers entire palate and alveolar ridgesridges. .

Mandible – Mandible – Narrow zone of Narrow zone of keratinized attached mucosa. keratinized attached mucosa. Confined to the alveolar ridges.Confined to the alveolar ridges.

Note the Note the amalgam tattooamalgam tattoo

Maxilla vs MandibleMaxilla vs Mandible

Loss of Keratinized Attached MucosaLoss of Keratinized Attached Mucosa Result:Result:(a)(a) Reduced support.Reduced support.(b) Reduced tolerance to(b) Reduced tolerance to occlusal load. occlusal load.

Zone of Zone of keratinized keratinized mucosamucosa

What is the impact of bone What is the impact of bone resorption on retention, stability, resorption on retention, stability,

and support?and support?

All three are negatively impactedAll three are negatively impacted..

Ridge ResorptionRidge Resorption

Pattern of Ridge Resorption*Pattern of Ridge Resorption* The rate of resorption is much higher in the mandible than in the

maxilla.

*Talgren, 1964*Talgren, 1964

Resorption patterns in the Resorption patterns in the edentulous patients*edentulous patients*


*From Zarb et al, 1983


Note the sharp mylohyoid ridge (arrow)

Mandible – Prime Support AreasMandible – Prime Support Areas

**Of the above, the alveolar process is most affected by the process of bone resorptionOf the above, the alveolar process is most affected by the process of bone resorption

Retromolar pad Buccal shelf Alveolar process

The The pad contains glandular tissue, loose areolar connective tissue,the lower margin of pad contains glandular tissue, loose areolar connective tissue,the lower margin of the pterygomandibular raphe, fibers of the buccinator, and superior constrictor and fibers the pterygomandibular raphe, fibers of the buccinator, and superior constrictor and fibers of the temporal tendon. The bone beneath of the temporal tendon. The bone beneath does not resorbdoes not resorb secondary to the pressure secondary to the pressure associated with denture use. It is one of the primary support areasassociated with denture use. It is one of the primary support areas.

Retromolar PadRetromolar PadOne constant, relatively unchanging structure on the mandibular One constant, relatively unchanging structure on the mandibular denture bearing surface is the retromolar pad (dotted line).denture bearing surface is the retromolar pad (dotted line).

Buccal ShelfBuccal Shelf

Boundaries of the buccal Boundaries of the buccal shelf: The external oblique shelf: The external oblique line and the crest of the line and the crest of the alveolar ridge (area within alveolar ridge (area within the dotted linesthe dotted lines).).

The buccal shelf is a The buccal shelf is a prime support areaprime support area because it is because it is parallel to the occlusal parallel to the occlusal planeplane and the bone is very dense. It is relatively resistant to resorption. and the bone is very dense. It is relatively resistant to resorption.

Masseter Masseter groove groove areaarea

Buccinator Buccinator limits the limits the extension in extension in this area this area

Buccal ShelfBuccal Shelf

Buccal shelf area (area within the dotted lines). The greater the access to Buccal shelf area (area within the dotted lines). The greater the access to the buccal shelf the more support there is available for the denture. Access the buccal shelf the more support there is available for the denture. Access is determined by the attachment of the buccinatoris determined by the attachment of the buccinator..

BB

MandibleMandible – – initially buccal lingual dimension of the alveolar initially buccal lingual dimension of the alveolar ridge is narrowed, compromising support (A, B, C).ridge is narrowed, compromising support (A, B, C).

AA

Patterns of Resorption - MandiblePatterns of Resorption - Mandible

CC

But thereafter, the height is affected compromising But thereafter, the height is affected compromising support,stability, and retention (D,E).support,stability, and retention (D,E).

DD


EE

Continued calcification of the Continued calcification of the attachment of the mylohyoid muscle attachment of the mylohyoid muscle leads to the development of a sharp leads to the development of a sharp bony projection on the lingual surface. bony projection on the lingual surface. The mucosa overlying this region is The mucosa overlying this region is poorly keratinized and prone to poorly keratinized and prone to perforation secondary to trauma from perforation secondary to trauma from complete dentures.complete dentures.

Mylohyoid ridgeMylohyoid ridge


Following extraction, Following extraction, resorption is from buccal-resorption is from buccal-labial towards the linguallabial towards the lingual..

Labial plateLabial plate

Result:Result: Some compromise of stability and support Some compromise of stability and support..

Pattern of Resorption - MaxillaPattern of Resorption - Maxilla

Continued resorption leads to loss of vertical height of the alveolus.Continued resorption leads to loss of vertical height of the alveolus.

Result:Result:a. Significant compromise of stability of the denture.a. Significant compromise of stability of the denture.b. Pseudo-class III jaw relation.b. Pseudo-class III jaw relation.c. Secondary affect – compromised retention because ofc. Secondary affect – compromised retention because ofcompromised stability. Peripheral seal of the denture is more easily broken compromised stability. Peripheral seal of the denture is more easily broken because there is because there is little resistance to lateral displacement of the denture little resistance to lateral displacement of the denture during functionduring function..

Patterns of Resorption - MaxillaPatterns of Resorption - Maxilla

Note steep anterior guidance. There are no contacts in working, Note steep anterior guidance. There are no contacts in working, balancing or protrusive when the patient goes through the chewing cyclebalancing or protrusive when the patient goes through the chewing cycle..

As a result, during the chewing cycle , the denture tips anteriorly, As a result, during the chewing cycle , the denture tips anteriorly, compressing the mucoperiosteum of the premaxilla, compressing the mucoperiosteum of the premaxilla, leading to resorption leading to resorption of the bone of the premaxillary area.of the bone of the premaxillary area.

Combination SyndromeCombination Syndrome

It produces a very specific pattern of resorption of the maxilla.It produces a very specific pattern of resorption of the maxilla.

It is caused by edentulous maxilla opposing dentate mandible where It is caused by edentulous maxilla opposing dentate mandible where anterior dentition has been retained and where the denture has not been anterior dentition has been retained and where the denture has not been properly balanced.properly balanced.

Result:Result:(a) Resorption of premaxilla(a) Resorption of premaxilla(b) Hypertrophy (fibrous (b) Hypertrophy (fibrous

hyperplasia)hyperplasia) of maxillary tuberosity.of maxillary tuberosity.(c) Occlusal plane (c) Occlusal plane

problems.problems.

Occlusal planeOcclusal plane

Hypertrophic Hypertrophic maxillary maxillary tuberositiestuberosities

Resorbed Resorbed premaxillapremaxilla

Combination Combination SyndromeSyndrome

Mandible – Similar Phenomenon ObservedMandible – Similar Phenomenon Observed

Resorption can be so severe as to require augmentation with bone grafts Resorption can be so severe as to require augmentation with bone grafts in order to prevent pathologic fracture of the mandiblein order to prevent pathologic fracture of the mandible.

Measures to Prevent or Slow ResorptionMeasures to Prevent or Slow Resorption..1. 1. Well adapted and properly extended dentures with Well adapted and properly extended dentures with properly designed and executed occlusion. properly designed and executed occlusion.2. Retention of residual tooth roots in key locations2. Retention of residual tooth roots in key locations ..

3. Use of osseointegrated implants3. Use of osseointegrated implants

Retained roots and osseointegrated implants are useful because they Retained roots and osseointegrated implants are useful because they absorb much of the occlusal load locally, thereby preventing absorb much of the occlusal load locally, thereby preventing compression of the periosteum and in turn preventing resorption of the compression of the periosteum and in turn preventing resorption of the adjacent bone.adjacent bone.

Retained root tips (A) andRetained root tips (A) andOsseointegrated implants Osseointegrated implants (B, C)(B, C)

AA

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CC

The denture rests on the The denture rests on the implants or root tips. implants or root tips. Compression of the Compression of the mucoperiosteum is minimized, mucoperiosteum is minimized, preventing resorption of the preventing resorption of the underlying bone.underlying bone.

Preventive MeasuresPreventive Measures

Note tissue bar connected to the implantsNote tissue bar connected to the implants

Bar facilitates retention, stability and Bar facilitates retention, stability and provides support in the anterior regionprovides support in the anterior region..

Preventive MeasuresPreventive Measures

Frenum – Folds of mucus membrane containing fibrous Frenum – Folds of mucus membrane containing fibrous connective tissue (A) (arrows).connective tissue (A) (arrows).

AA

Frenum are of little consequence. However, they may limit Frenum are of little consequence. However, they may limit denture extensions (B) (arrows) or make seal difficult to denture extensions (B) (arrows) or make seal difficult to maintain, and occasionally affect the retention of the maxillary maintain, and occasionally affect the retention of the maxillary denture.denture.

BB

Other Factors – Frenum AttachmentsOther Factors – Frenum Attachments

Other factors – Frenum attachmentsOther factors – Frenum attachmentsMandibular frenum. Mandibular frenum.

If they are prominent If they are prominent they may affect denture they may affect denture extensions, particularly extensions, particularly the lingual frenumthe lingual frenum

Buccal frenumBuccal frenum

Lingual frenumLingual frenum

Floor of mouth posture and Floor of mouth posture and tongue position (depth of tongue position (depth of retromylohyoid space) affect retromylohyoid space) affect stability and retention.stability and retention.

Favorable anatomy as seen Favorable anatomy as seen here (A, B,) permits here (A, B,) permits development of a longer development of a longer lingual flange.lingual flange.

AA

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Result: Improved stability and Result: Improved stability and retention of the mandibular dentureretention of the mandibular denture

Floor of Mouth Posture and Tongue PositionFloor of Mouth Posture and Tongue Position

Impressions and dentures made for patients with Impressions and dentures made for patients with favorable floor of mouth posture and favorable favorable floor of mouth posture and favorable (anterior) tongue position. Note length of lingual (anterior) tongue position. Note length of lingual flange. Stability and retention are enhanced.flange. Stability and retention are enhanced.

Favorable Floor of Mouth PostureFavorable Floor of Mouth Posture

Patients with unfavorable floor of mouth posture and tongue Patients with unfavorable floor of mouth posture and tongue position (A, B). The tip of the tongue has lost its definition position (A, B). The tip of the tongue has lost its definition and is retruded and the floor of the mouth is elevated.and is retruded and the floor of the mouth is elevated.

Result:Result: Length of lingual flange of the denture will be limited, compromising Length of lingual flange of the denture will be limited, compromising stability, retention and the ability of the patient to control the lower denture.stability, retention and the ability of the patient to control the lower denture.

AA BB

Unfavorable Floor of Mouth Posture and Unfavorable Floor of Mouth Posture and Retruded Tongue Retruded Tongue PositionPosition

Carefully examine the retromylohyoid space to determine the floor of mouth posture. After placing the mirror in the RMH space, instruct the patient to move the tongue to opposite side.The less your mirror is displaced the more favorable the floor of mouth posture and the longer the distal lingual flange will be.

Determining Floor of Mouth PostureDetermining Floor of Mouth Posture

Result:Result:a. Improved retention. Note denture snaps onto retention bar.a. Improved retention. Note denture snaps onto retention bar.b. Improved stability (from the implants and the tissue bar).b. Improved stability (from the implants and the tissue bar).c. Improved support (anteriorly).c. Improved support (anteriorly).d. Better control of the bolus (tongue no longer must position denture and control d. Better control of the bolus (tongue no longer must position denture and control the bolus simultaneously).the bolus simultaneously).

Solutions - Retruded Tongue Position and Solutions - Retruded Tongue Position and Unfavorable Floor of Mouth Contour.Unfavorable Floor of Mouth Contour.

1. Dentures retained with osseointegrated implantsDentures retained with osseointegrated implants

This surgical procedure This surgical procedure has been used to has been used to overcome problems overcome problems caused by a retruded caused by a retruded tongue position, tongue position, unfavorable floor of mouth unfavorable floor of mouth posture and a narrow posture and a narrow residual zone of residual zone of keratinized attached keratinized attached tissue. tissue.

Muscle attachments in the floor of the mouth are lowered and the zone of attached Muscle attachments in the floor of the mouth are lowered and the zone of attached keratinized tissue is widened with the skin graft.keratinized tissue is widened with the skin graft.

a.Resulta.Result:: Improved stability and retention of the denture because the lingual Improved stability and retention of the denture because the lingual flange is lengthened.flange is lengthened.

b.Resultb.Result:: Improved support, because the zone of attached keratinized tissue Improved support, because the zone of attached keratinized tissue is is dramatically widened.dramatically widened.

2. Skin graft vestibuloplasty2. Skin graft vestibuloplasty

Skin grafted areasSkin grafted areas

Solutions - Retruded Tongue Position and Solutions - Retruded Tongue Position and Unfavorable Floor of Mouth ContourUnfavorable Floor of Mouth Contour..

Residual Residual keratinizedkeratinizedattached mucosaattached mucosa

Impact of Saliva and Salivary GlandsImpact of Saliva and Salivary Glands

Palatal glandsPalatal glands

Glandular tissueGlandular tissue

Posterior palatal Posterior palatal seal areaseal area

The presence of these The presence of these glands permit compression glands permit compression of the tissues helping to of the tissues helping to overcome poor adaptation of overcome poor adaptation of the denture in this area the denture in this area secondary to shrinkage of secondary to shrinkage of the acrylic resin during the acrylic resin during processing. Peripheral seal processing. Peripheral seal of the denture is thereby of the denture is thereby maintained.maintained.

Posterior Palatine Salivary GlandsPosterior Palatine Salivary Glands

When making impressions this area of tissue is compressed, allowing us to When making impressions this area of tissue is compressed, allowing us to compensate for shrinkage of the acrylic resin during polymerization and compensate for shrinkage of the acrylic resin during polymerization and movement of the denture base during function.movement of the denture base during function.

Result:Result: Tissue adaptation of the denture is maintained and therefore peripheral Tissue adaptation of the denture is maintained and therefore peripheral seal and retention of the maxillary complete denture is maintained.seal and retention of the maxillary complete denture is maintained.

When these glands atrophy, the tissue become less compressible When these glands atrophy, the tissue become less compressible making it more difficult to obtain and maintain peripheral seal.making it more difficult to obtain and maintain peripheral seal.

Posterior Palatine Salivary GlandsPosterior Palatine Salivary Glands

Shrinkage of acrylic resin is also accounted for by Shrinkage of acrylic resin is also accounted for by scoring the cast in the postdam area (arrowscoring the cast in the postdam area (arrow).).

Posterior Palatal Seal AreaPosterior Palatal Seal Area

Salivary Flow and RetentionSalivary Flow and Retention

Low flow ratesLow flow rates• Difficult to achieve and maintain Difficult to achieve and maintain peripheral seal of the maxillary peripheral seal of the maxillary denturedenture• Compromised adhesion and Compromised adhesion and cohesioncohesion.

Saliva as a LubricantSaliva as a Lubricant

Low flow ratesLow flow rates• Primarily affects the mandibular denture Primarily affects the mandibular denture

bearing surfaces.bearing surfaces.• Results in more friction at the mucosa-Results in more friction at the mucosa-

denture interface as the mandibular denture interface as the mandibular denture slips and slides over the denture denture slips and slides over the denture bearing surface duringbearing surface during functionfunction..

Neuromuscular ControlNeuromuscular Control

• Some patients have the ability to manipulate Some patients have the ability to manipulate their lower denture and control the bolus their lower denture and control the bolus simultaneously, regardless of the quality of the simultaneously, regardless of the quality of the design and construction of the denture.design and construction of the denture. • Many patients with good neuromuscular control Many patients with good neuromuscular control can overcome unfavorable bearing surface can overcome unfavorable bearing surface contours and anatomy and chew efficiently with contours and anatomy and chew efficiently with their complete dentures and the converse is also their complete dentures and the converse is also true.true.

Tissue Factors Affecting SupportTissue Factors Affecting Support

Mandible:Mandible:• Retromolar padRetromolar pad• Alveolar ridge contoursAlveolar ridge contours (the (the

broader the more support)broader the more support)• Amount of attached Amount of attached keratinized mucosakeratinized mucosa (the (the

more present the better more present the better the support)the support)

• Buccal shelf areaBuccal shelf area (the more (the more access and the greater access and the greater the surface area the the surface area the better the supportbetter the support

Maxilla:Maxilla:• Amount of keratinized Amount of keratinized

mucosamucosa• Alveolar ridge contoursAlveolar ridge contours• Palatal shelf area and Palatal shelf area and contourcontour

Tissue Factors Affecting StabilityTissue Factors Affecting Stability

Mandible:Mandible:• Alveolar ridge heightAlveolar ridge height• Floor of mouth contourFloor of mouth contour (favorable vs. unfavorable)(favorable vs. unfavorable)• Tongue positionTongue position (anterior vs. retruded)(anterior vs. retruded)• Neuromuscular controlNeuromuscular control• Presence of flabby, Presence of flabby, moveable denture moveable denture bearing bearing surface surface tissuestissues..

Maxilla:Maxilla:

• Alveolar ridge heightAlveolar ridge height• Presence of well formed Presence of well formed

maxillary, moveable maxillary, moveable denture bearing denture bearing

surface tissues surface tissues tuberositiestuberosities• Presence of flabbyPresence of flabby

Tissue Factors Affecting RetentionTissue Factors Affecting Retention

MandibleMandible::

Primary FactorsPrimary Factors::• Tongue positionTongue position• Floor of mouth postureFloor of mouth posture• Neuromuscular controlNeuromuscular control

Secondary FactorsSecondary Factors• Peripheral sealPeripheral seal• AdhesionAdhesion• CohesionCohesion

Maxilla:Maxilla:• Shape of the palatal vault (peripheral Shape of the palatal vault (peripheral seal)seal)• Drape of the soft palate - House Drape of the soft palate - House classification (peripheral seal)classification (peripheral seal)• Quality and quantity of saliva Quality and quantity of saliva (peripheral (peripheral

seal)seal)• Compressibility of posterior palatal seal Compressibility of posterior palatal seal

area (peripheral seal)area (peripheral seal)• Presence of well shaped tuberositiesPresence of well shaped tuberosities• Height of alveolar ridge (resistance to Height of alveolar ridge (resistance to

lateral displacement)lateral displacement)

Clinical exam - Prosthodontic AssessmentClinical exam - Prosthodontic Assessment

Assessment of existing dentures• Retention• Stability• Vertical dimension of occlusion• Centric relation• Esthetics

Prosthodontic AssessmentProsthodontic Assessment

Posterior teeth• Tooth forms• Materials• Wear


Retention - Maxilla

Apply a tipping force to the incisors in an attempt to break seal


Stability - Maxilla


Stability and Retention - Mandible

Prognosis based upon:Prognosis based upon:

• Bearing surface anatomy, tongue Bearing surface anatomy, tongue position and floor of mouth postureposition and floor of mouth posture

• Neuromuscular controlNeuromuscular control

• Denture historyDenture history

• Psychological classificationPsychological classification

3.history and exam

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