1. Occlusion& try-in
Dr.shanai m.

2. OCCLUSION The static relationship between the incising or masticating surfaces of the maxillary or mandibular teeth or tooth analogues.
Articulation: the static and dynamic contact relationship between the occlusal surfaces of the teeth during function.
Components of occlusion: these are the various element that are involved in occlusion, includes:
Tempro-mandibular joint.
The associated neuromusculature.
The teeth, their contacting surfaces, and associated tissues.
The denture supporting structures.
Centric occlusion: the contact of the opposing teeth (the upper and lower) when the mandible is in the centric relation. this may or may not coincide with maximal intercuspal position
Centric relation: the most retruded relation of the mandible to the maxilla when the condyles are in the most posterior unstrained position in the glenoid fossae from which lateral movement can be made at any given degree of jaw separation.

3. Centric relation is bone to bone relation while centric occlusion is tooth to tooth relation.
Maximal intercuspal position: the complete intercuspation of the opposing teeth independent of condylar position.
In complete denture construction its essential that centric occlusion is in harmony with centric relation , so the dentist is responsible to record centric relation, and maintain this relationship in the laboratory procedure during mounting and arrangement of teeth in centric occlusion.
In centric occlusion, the buccal cusps of the mandibular teeth contacts the central fossa of maxillary teeth, while the lingual cusps of the maxillary teeth fill into the central fossa of the mandibular teeth. This facial overlap prevents cheek biting when the denture are completed. L B

4. Eccentric occlusion: the contacting of teeth or occluding surfaces when the jaws are in any other relation than centric occlusion, these include right and left lateral occlusion, and protrusive occlusion.
Concepts of complete denture occlusion:
Balanced occlusion.
Monoplane occlusion.
Linguilised occlusion.
Balanced occlusion: Bilateral simultaneous contact between anterior & posterior teeth during all centric and eccentric positions
Also the balanced occlusion can be defined as a condition in which there are simultaneous contacts of opposing teeth or tooth analogues (occlusion rims) on both sides of the opposing dental arches during centric or eccentric relation.
Working side : the side toward which the mandible moves in a lateral excursion
Non working (balancing) side : that side of the mandible that moves toward the median line in a lateral excursion (the side opposite the working side).

5. Working when or functional occlusion: the occlusal contacts of teeth on the side to which the mandible is moved, and its occur when the facial or buccal cusps of maxillary teeth meet the facial cusps of the mandibular teeth and the palatal cusps of maxillary teeth meet the lingual cusps of the mandibular teeth. The relationships is not cusp tip to cusp tip, but cusp tip into cusp valley with each maxillary cusp distal to corresponding mandibular cusp.
Working occlusion enable a person to hold and crush food.
Balancing occlusion: occurs simultaneously on the opposite side from working occlusion. Balancing occlusion functions is to maintain the dentures in position during lateral excursive movements.

6. Protrusive occlusion: it’s the relation acquired by the mandible when it moves in protrusive direction from centric position. when condyles travels in this direction, it brings the anterior teeth into a position favorable for incision. Protrusive balancing contact permit the posterior teeth to touch when the anterior teeth are in contact.
In protrusive balance, the distal inclines of the maxillary buccal cusps contact the mesial inclienes of the mandibular buccal cusp
Also protrusive balancing contact may occurs on lingual cusps this help to maintain denture stability.
Natural dentition
Complete denture

7. ADVANTAGES OF BALANCED OCCLUSION
It avoids displacement of denture and help in its stability during functional and non-functional movements
It helps in earlier repositioning of denture, which become displaced during mastication.
It minimize period required for adaptation of patient to the denture due to its stability.
Prevent truma to the supporting tissue since the pressure is equally distributed on the teeth.
Factors influencing balanced occlusion
(1) Inclination of the condylar path (condylar guidance)
(2) Incisal guidance
(3) Orientation of the plane of occlusion
(4) Cuspal angulation
(5) Compensating curve
In lateral position, balancing side

8. Monoplane occlusion
The monoplane occlusion concept utilizing non-anatomic teeth with flat occlusal surfaces set to a flat occlusal plane.
Characterized by occlusal contact of maxillary and mandibular teeth initially in maximum intercuspation. The disocclusion of posterior teeth occurs because of their arrangement in a single plane, and the contact of anterior teeth during movement of the mandible.
Indications of the monoplane occlusion
classII jaw relations.
Class III jaw relations
Handicapped patients
Cross bite.
Doubtful or with out any perfect centric relation recordes
Flat ridge

9. Linguilised occlusion
This is described as the occlusal contacts of maxillary palatal cusps of the posterior teeth initially with the occlusal surfaces and marginal ridges of the mandibular teeth in maximum intercuspation, and continuous contact of the palatal cusps with the mandibular teeth during various movement of the mandible that permit light contact of the anterior teeth as the pass over one another.
The maxillary platal cusps are the main functional occlusal elements. These may oppose mandibular 0˚ or shallow cusp teeth in balanced or non-balanced patterns depending on the needs of patient.
advantages
The presence of a cusped tooth in the maxillary premolar and first molar regions looks more natural when compared to zero˚ tooth.
The use of maxillary lingual cusps could be expected to centralize the occlusal forces and reduce the frictional resistance of flat teeth sliding over one another.
Additional stability can be gained during parafunctional movements.

10. Try-in appointment
In try-in appointment (clinical-stage) the teeth are tried in before processing them in acrylic resin to
Verify the maxillomandibular records that were made without teeth (tentative record)(occlusal relationship).
Test for the acceptance of the established vertical dimension of occlusion.
Determine if the positions of the teeth and the contours of the denture base are compatible with the surrounding oral environment.
Evaluate the arrangement for esthetic requirements.
Make additional inter-occlusal maxillo-mandibular records if needed for further adjustment of articulator for excursive movements after the try-in like protrusive

11. Various aspects of try in
A-Extraoral examination of the trial dentures.
The trial denture bases
Check the following:
The trial denture bases must be stable.
The borders of the trial denture base should be smooth, round, and have no sharp edges.
Also the border should be shaped to conform to the depth and width of the sulcus.
The mounted cast on articulator is checked for:
A) Maintaining of the vertical dimension of occlusion
Top of the incisal pin is level with the upper member of the articulator.
The incisal pin is in contact with the incisal table.
The teeth
It is the dentist responsibility to select the proper shade, and size of the teeth and to determine that the teeth are set correctly.
Elimination of the excess wax is done to avoid the camouflages of the teeth relationships to overlook the occlusion.

12. B-Intraoral Examination Of The Trial Dentures
To reduce the risk of cross- contamination, the trial denture should be sprayed with suitable antiseptic solution and washed in running water, before inserted in patient mouth.
1) Checking the trial dentures separately:
Trying- in the upper denture.
Trying- in the lower denture.
2) Checking the upper and lower dentures together.
Denture base extension: .
Posterior extension
The posterior border of the upper trial denture base should extended from the one hamular notch to the other along the vibrating line of the soft palate, and correctly placed on the master cast.
Retention
It is noted that the retention of the trial denture is less than that of completed denture, due to Absence of a posterior palatal seal.
Poor adaptation of the trial denture base to the tissues.
The trial denture should stay in position when the mouth is opened.
Stability
It is tested by applying pressure in a tissue ward direction with the index finger in the premolar and molar regions on each side alternately.
This pressure must be directed at right angles to the occlusal surface where displacement does occur.
Maxillary trial denture

13. Lower denture trial Denture base extension:
The lower trial denture extension should be tested with the patient mouth is opened no more than half opened position to allow the surrounding musculature is in an acceptable state of relaxation
Usually the lower denture retention is poor when compared to the upper denture due to:
1) Small denture bearing area
2) The difficulty in obtaining an efficient border seal.
Tongue space
Natural teeth occupy a position in the mouth where the inward pressure of the lips and the cheeks is neutralized by an equal and opposite outward pressure of the tongue, and it is in this zone of neutral pressure that the artificial teeth must be set (neutral zone).

14. Checking the upper and lower dentures together
The patient should be seated in an upright position.
The patient head is not supported by the headrest (the headrest may effect the physiologic rest position of the mandible so, it effect the amount of interocclusal distance).
Verifying the Vertical dimension
Evaluation of Vertical dimension at rest & at occlusion
phonetics & esthetics
facial dimension & facial expressions
lip length in relation to teeth
Verifying Centric Relation
Pt. is guided into CR by a thumb placed on the antero-inferior portion of the chin & index finger bilaterally on the buccal flanges of the lower denture.
Any Error in CR will be apparent when teeth slide over each other.

15. intraoral correction method
posterior teeth are removed from lower occlusal rim
Impression plaster is mixed & placed on the rim.
Pt. is instructed to close the mouth slowly until the anterior teeth have same vertical overlap as they had before the posterior teeth were removed.
After the plaster is set, rims are removed & this corrected new record is mounted on a articulator.