Download - 13.natural vs. complete centure occlusion
13. 13. Natural vs. Complete Natural vs. Complete Denture OcclusionDenture Occlusion
Michael Hamada DDSMichael Hamada DDSDivision ofDivision of Advanced Prosthodontics, 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.
Natural Dentition:Organic OcclusionNatural Dentition:Organic Occlusion
Organic occlusions present in a variety of individual tooth size, Organic occlusions present in a variety of individual tooth size, shape, form and alignment, but ideally exhibit certain shape, form and alignment, but ideally exhibit certain characteristic features.characteristic features.
Natural Dentition:Organic OcclusionNatural Dentition:Organic Occlusion
Bilateral Posterior Centric Bilateral Posterior Centric ContactContactAnterior GuidanceAnterior GuidanceMutually Protective Mutually Protective Scheme of OcclusionScheme of Occlusion
Complete Denture OcclusionComplete Denture Occlusion
Likewise, complete denture occlusions present in a Likewise, complete denture occlusions present in a variety of forms, but also exhibit certain common variety of forms, but also exhibit certain common characteristicscharacteristics
Complete Denture OcclusionComplete Denture Occlusion
Bilateral Posterior Centric Bilateral Posterior Centric ContactContactCentralized ForcesCentralized Forces““Balance” to minimize Balance” to minimize tippingtipping
Differences between Natural and Differences between Natural and Complete Denture OcclusionComplete Denture Occlusion
Differences between Natural and Differences between Natural and Complete Denture OcclusionComplete Denture Occlusion
Arise from fundamental differences in– Sensory Feedback Mechanism– Derivation of :
RetentionStabilitySupport
– Reaction of Supporting Structures to Masticatory Forces
Differences between Natural and Differences between Natural and Complete Denture OcclusionComplete Denture Occlusion
Neuromuscular and Sensory Feedback
Precision of feedback may be somewhat compromised following loss of teeth and associated structures
Differences between Natural and Differences between Natural and Complete Denture OcclusionComplete Denture Occlusion
Derivation of Retention, Stability and Support
Fundamental differences between how they derive retention, stability and support dictate differences in occlusion design between natural and CD occlusion
Retention, Stability and SupportRetention, Stability and Support
Denture Bearing Surface
RetentionRetention
– Resistance to dislodgment forces in a vertical direction away from the bearing surface
Retention, Stability and SupportRetention, Stability and Support
Denture Bearing Surface
StabilityStability
– Resistance to laterally oriented dislodgment forces
Retention, Stability and SupportRetention, Stability and Support
Denture Bearing Surface
SupportSupport
– Factors of the Bearing Surface which resist forces in a vertical direction towards the bearing surface
Differences between Natural and Differences between Natural and Complete Denture OcclusionComplete Denture Occlusion
For natural dentition, derived through the periodontium, providing:Sensory Feedback MechanismDifference in reaction of Supporting Structures to Masticatory Forces– Differences in load transfer mechanism and physiology
Derivation of Retention, Stability and Support
Differences between Natural and Differences between Natural and Complete Denture OcclusionComplete Denture Occlusion
Residual Ridge Resorption (RRR)– Non-physiologic compression (as may occur
under denture bases) results in further resorption, as compared to . . .
– Physiologic levels of tension results in apposition (such as that transmitted by loading the PDL through natural dentition)
Mobile bases on mucosaTeeth move as an unitMalocclusion affects entire base immediatelyNon-vertical forces affect all teeth and is traumaticIncising affects all teeth attached to baseBilateral balance is often desired for base stabilityDecreased tactile sense
Retained in PDL
Units move independently
Malocclusion effects not immediate
Non-vertical forces affect only teeth involved and usually well tolerated
Incising doesn’t affect posteriors
Bilateral balance is rare
Tactile sensitivity
Natural Dentition Denture “Dentition”
Differences between Natural and Complete Differences between Natural and Complete Denture OcclusionDenture Occlusion
Because of compromises inherent in restoring the edentulous arch, CD tooth forms and arrangements (i.e. occlusion), should be designed to provide function and aesthetics while MINIMIZING DENTURE BASE TIPPING (LATERAL) FORCES
Denture “Dentition”
Complete Denture OcclusionComplete Denture Occlusion
SummarySummary
Goal of complete denture occlusion is preservation of structure and restoration of function and esthetics
Consequences of tooth loss create anatomic changes which result in differences in derivation of retention, stability and support between natural and complete denture teeth
SummarySummary
The differences in the design of natural and complete denture occlusion are the consequence of differences in the derivation of retention, stability and support
Complete denture form and tooth placement is biomechanical in nature