Morsels to Chew

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Morsels to Chew –
Occlusion Comparison Chart

Occlusion. One of the most passionately preached yet incompletely digested dental subjects. As a freshman dental student, I recall one particularlynebulous study session. My frustration subsided only after I stopped “swallowing” jargon and I began “savoring” concepts.

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A Comparison Chart of Occlusal Relationships:
Natural Teeth Versus Denture Teeth

Natural Teeth in “Normal-Ideal”
Occlusion
Denture Teeth in “Balanced”
Occlusion
Every effort should be made to avoid producing undesirable contacts during reconstruction of the natural dentition.In natural teeth, the disclusion of teeth during excursions can be critical. Every effort should be made to produce as many balanced contacts during the arrangement of the denture teeth.In denture teeth, maximum tooth contacts during excursions, helps to distribute forces & prevent tipping of the denture.

Static Relationships

Natural Teeth in “Normal-Ideal”
Occlusion
Denture Teeth in “Balanced”
Occlusion
Maximum interdigitation of
natural teeth.Condyles in CO position as dictated by the patient’s teeth.
Maxmium interdigitation of denture teeth.Condyles in CR position as manipulated by dentist & recorded in jaw relation record.
CO=CR or
CO is not equal CR
CO=CR
Condyles in midmost, uppermost, rear most, unstrained position in the fossa.When CO is not equal to CR, a “slide in centric” occurs.
When CO = CR = “freedom in centric”
Condyles in midmost, uppermost, rear most, unstrained position in the fossa.When CO is not equal to CR, then jaw relation records and/or occlusal relationships are incorrect.

Functional Relationships

Natural Teeth in “Normal-Ideal”
Occlusion
Denture Teeth in “Balanced”
Occlusion
When anterior teeth slide into protrusion, – posterior teeth
disclude.Posterior contacts are undesirableduring protrusive movements.This posterior separation of the teeth is due to the patient’s condylar inclination and anterior guidance. This is termed the:
“Christenson’s Phenomenon”
When anterior denture teeth slide into protrusion, – posterior denture teethcontact.Balanced posterior contacts are desirable during protrusive movements.Balanced denture occlusal schemes override the “Christenson’s Phenomenon” by the arrangement of the posterior teeth with a:
“Compensating “Curve”
Group Function or Canine Guidedposterior contacts.Accurate working side contacts prevent deflective contacts on the balancing side. Cross tooth contacts are incorporated on all posterior teeth.Accurate working side contacts should NOT prevent contacts on the balancing side.
No posterior balancing contacts.Contacts on the balancing side are termed interferences.
The balancing side may also be referred to as the non-working ornonfunctional side.
Multiple Balanced posterior contacts.Buccal inclines of the maxillary lingual cusps are in even contact with the lingual inclines of the mandibular buccal cusps.The balancing side in dentures should NEVER be referred to as the non-working or nonfunctional side.