Concepts In Centric And Organization Of Occlusion PDF

CONCEPTS OF OCCLUSION IN CENTRIC POSITION CONCEPTS OF OCCLUSION IN CENTRIC POSITION 1. Point centric. 2. Slide in centric 3. Freedom of centric (long centric)  1- POINT CENTRIC The point centric concept in that in which maximum intercuspation (Centric occlu...

CONCEPTS OF OCCLUSION IN CENTRIC POSITION CONCEPTS OF OCCLUSION IN CENTRIC POSITION 1. Point centric. 2. Slide in centric 3. Freedom of centric (long centric)  1- POINT CENTRIC The point centric concept in that in which maximum intercuspation (Centric occlusion) coincides with centric relation. It occurs in about 10% of natural teeth. Applied in complete denture  CENTRIC RELATION A maxilla to mandible relationship in which the condyles and disks are in the midmost, uppermost position in the glenoid fossae and against the distal slope of the articular eminence MAXIMAL INTERCUSPATION (CENTRIC OCCLUSION) The complete intercuspation of the opposing teeth independent of condylar position, or The best fit of the teeth regardless of the condylar position  2- SLIDE IN CENTRIC Intercuspal position Centric relation About 90% of all individuals with natural dentition centric occlusion and centric relation do not coincide.  SLIDE IN CENTRIC The two or three dimensional sliding movement that the mandible makes as it moves from centric relation to intercuspal position  3. FREEDOM OF CENTRIC (LONG CENTRIC OR BROAD CENTRIC): A relatively flat area is created between centric relation and centric occlusion positions on the occlusal surfaces of the teeth. It is created in the natural teeth by occlusal adjustment. It can be done for complete dentures By using cuspless teeth.  FREEDOM OF CENTRIC Occlusal adjustment to Complete denture cuspless create freedom in centric teeth ORGANIZATION OF THE OCCLUSION ORGANIZATION OF THE OCCLUSION There are three main concepts, which describe the manner in which teeth should and should not contact in the various functional and excursive positions of the mandible. 1. Bilateral balanced occlusion. 2. Unilateral balanced occlusion : (group function} 3. Mutually protected occlusion : 1. BILATERAL BALANCED OCCLUSION. It dictates that a maximum number of teeth should contact in all excursive positions of the mandible. This can be useful in complete denture construction. Bilateral balanced occlusion in natural dentition will subject the natural teeth on the balancing side to destructive obliquely directed forces Maximum contact in centric occlusion Maximum contact in left working side and contact in right non-working side Maximum contact in right working side and contact in left non-working side At least 3 points of contact during protrusion 2. UNILATERAL BALANCED OCCLUSION (GROUP FUNCTION} As cross arch balance is not necessary in natural teeth, unilateral balanced occlusion calls for all teeth on the working side to be in contact during a lateral excursion. On the other hand, teeth on the nonworking side are contoured to be free of any contact.  GROUP FUNCTION Maximum contact in Maximum contact working side and no at centric occlusion contact in non working side 3. MUTUALLY PROTECTED OCCLUSION Mutually protected occlusion is also known as canine protected occlusion, canine rise or organic occlusion. The teeth are arranged so that the overlap of the anterior teeth prevents the posterior teeth from making any contact on either the working or the non-working sides during mandibular excursions. This separation from occlusion is termed disclusion. MUTUALLY PROTECTED OCCLUSION No posterior contact during Maximum contact at protrusion centric occlusion  MUTUALLY PROTECTED OCCLUSION No contact in non-working No contact in working side side  REFERENCES Academy of Prosthodontics (2013): The glossary of prosthodontic terms, J. Prosthet. Dent. 1- Howat A.P, Capp N.J, Parrett N.V.J: A color atlas of occlusion and mal occlusion. Wolf publishing LTD, London, 1991 2- Dawson P. E: Functional occlusion from TMJ to smile design. Mosby Inc., St. Louis, 2007. 4. Ramfjord SP, Ash MM: Occlusion, ed 4, Philadelphia, 1983, WB Saunders. 5- Thomson H.: Occlusion in clinical practice, Bristol, London and Boston, Whright P.S.G. 1981. 6- Simpson G.W.: On Johnson's Modem Practice in Fixed prosthodontics, 4th. Ed, Philadelphia, Toronto, W.B. Saunders Co., 1986.