basics of complete denture occlusion

how do all dentures move in function and why is it important?

due to contact between opposing occlusal surfaces, so, the prime aim in construction of complete dentures is to ensure that these movements must be controlled

what is centric relation?

defined as the most retruded physiological relation of the mandible to the maxilla, to and from which the individual can make lateral movements. it can exist at various degrees of jaw relation. it is a bone to bone relationship

what is the eccentric jaw relation?

any relationship between the jaws other than centric relation

what is centric occlusion?

the maximum intercuspation between upper and lower teeth (cusp to fossa relation). it is a tooth to tooth relation

how do centric relation and centric occlusion relate to each other in complete dentures?

ideally, CR = CO

what is maximum intercuspation?

the complete intercuspation of the opposing teeth independent of condylar position (related to central occlusion, MI = CO)

what is balanced occlusion?

the bilateral, simultaneous, anterior and posterior occlusal contact of teeth in both centric and eccentric positions (static positions)

what is non balanced occlusion?

the bilateral, simultaneous, anterior and posterior occlusal contact of the teeth in centric position

what is vertical dimension?

the height of the lower third of the face. it is the distance between the upper and lower arches

what are the types of vertical dimensions?

1. vertical dimension of occlusion

2. vertical dimension of rest

3. physiological rest position

what is the vertical dimension of occlusion?

distance between the maxilla and mandible in which the teeth are in maximum intercuspation

what is the vertical dimension of rest?

distance between the maxilla and mandible when in physiological rest position. should be measured at least 3 times

what is the physiological rest position?

it represents the normally relaxed state of the lower jaw. the force of gravity is equal to the neuromuscular tonality of muscle of mastication. it usually hangs open 2-3 mm

what is the freeway space (FWS)?

it is the difference in distance between VDR and VDO

how is freeway space found?

RVD (vertical dimension of rest) - OVD (vertical dimension of occlusion) = FWS

how is VDO found?

VDR - freeway space

how is VDR found?

VDO + freeway space

what is the largest vertical dimension?

VDR is always larger than VDO

what is the measurement of the freeway space?

2-3 mm

what is overbite?

the vertical overlap between upper and lower anterior teeth

what is overjet?

horizontal overlap between upper and lower anterior teeth

what are the compensating curves?

1. curve of spee

2. curve of wilson

3. curve of monson

what is the curve of spee?

refers to anteroposterior curvature of the occlusal surface, beginning at the tip of the lower canine and following buccal cusp tips of bicuspids and molars, continuing to anterior border of the ramus, ending with anterior most portion of mandibular condyle. it is the second compensating curve in complete dentures, unilateral, present anteriorly and posteriorly and present in the mandible

what is the curve of wilson?

the side-to-side (mediolateral) curvature of the occlusal plane. it contacts the lingual cusp tips of the molars on each side of the arch. in the maxillary arch, it results from the outward inclination of the posterior teeth, making the buccal cusps higher than the lingual cusps, producing a convex curve. teeth set on this curve have lateral balance of occlusion. it is the first compensating curve, occurs in the maxilla and bilateral

what is the curve of monson?

a proposed ideal occlusion in which each cusp and incisal edge touches or conforms to a segment of the surface of a sphere 8 inches (20cm) in diameter, with its center in the region of the glabella.

what are the theories of non-balanced occlusion?

1. bonwil theory

2. conical theory

3. spherical theory

how is balanced occlusion achieved?

by curves of compensation, which are:

• curve of wilson

• curve of spee

• curve of monson

what is the spherical theory of occlusion?

proposes that the lower teeth move over the upper teeth along the surface of an imaginary sphere with a diameter of 8 inches (20 cm). The center of this sphere is in the region of the glabella, and its surface passes through the glenoid fossae, following or being concentric with the articulating eminences. it is the same as the curve of monson