DENTURE WAX TRY IN APPOINTMENT – PHENOMENAL BLUEPRINT

DENTURE WAX TRY IN APPOINTMENT – PHENOMENAL BLUEPRINT

DENTURE WAX TRY IN APPOINTMENT

It is challenging for a dentist to select teeth that fulfill looks and function.

A well-delivered service pays off through active participation of the patient.

It is necessary for a dentist to try waxed dentures in patient’s mouth before finishing them.

 Once the dentures have been processed, it is laborious and difficult and sometimes impossible to effect any alteration, whereas in the wax stage changes can easily be made.

 So the clinical try-in provides the last convenient opportunity to make any alterations in denture.

Your denture wax Try in appointment

You are given with the opportunity to observe and approve the teeth at the try-in appointment of your waxed up denture. The dentures are not going to be completed until your approval.

 You will be provided a mirror with waxed dentures in the mouth and given the opportunity to observe the dentures during normal conversation and facial expression.

You can bring most critical family member or friend to assist in evaluating the appearance of the waxed up trial dentures.

 When you, dentist and staff and your friend are satisfied with the appearance; sign a statement that states:

          “I have been given the opportunity of looking at the final arrangement of the artificial teeth (while positioned in wax). Any necessary changes have been made and I am happy with the general appearance of the dentures”.

Role of family member or friend in denture wax Try in appointment

I insist you to come with someone whose opinion matters to you.

They can observe you both objectively and subjectively.         

The observer is told to look at the overall effect of teeth in relation to the face, hair complexion, when you are relaxed, smiling and talking.


Dentist role


DENTURE WAX TRY IN APPOINTMENT PROCEDURE

Beauty lies in the eye of the beholder.

 Those dentists who concepts of esthetics are pleasing to a great many people are considered outstanding, whereas whose works do not appeal soon suffer from a lack of patients.

 One who possessed beautiful natural teeth but had to lose them is usually exacting about the esthetics of dentures and wants them to look real.

On the other hand, the unfortunate lady who has had not so good teeth all her life wants a change. She may insist on having a change to the other extreme.

Fulfilling the patient’s primary desire is important to the success of new dentures. If the patient’s ideas are completely wrong or just not practical, they should be tactfully explained away early in the procedure. At all times we must be aware of what our patients are thinking.

A bowl of cold water is kept for frequent chilling of the trial dentures.

If the dentures are left in the mouth for more than a few minutes at a time, softening and distortion of the wax may occur.

Checking Retention

An arbitrary test for checking physical retention is attempted by dislodging the denture away from the tissues by exerting a vertical pull on the anterior teeth.

If the retention is good, dislodgement may be extremely difficult or even impossible.

Upper denture usually has good retention.

If the retention of an upper trial denture is not as good, the cause should be identified and, if found to be a fault in the denture, must he corrected.

In the case of the lower denture, retention is often poor because of the relatively small denture bearing area and the difficulty in obtaining an efficient border seal.

Denture Base Extension

Overextension of the denture flanges

Stretching of the sulcus tissues is present in overextension of flanges.

However, in the lingual pouches, visibility is poor, so the dentist will have to make an assessment based on the behavior of the lower denture as the tongue is moved.

Correction of overextension is done by reducing the depth of the offending flange.

The presence of under extension

 When the depth of the sulcus will be seen greater than that of the denture flange during intra-oral examination

Failure to do this will result in reduced physical retention of the finished dentures and inadequate distribution of forces.

Neutral Zone

When the lower denture is inserted, it should remain in place when the mouth is half open and a limited range of tongue movements carried out.

 A useful ‘rule of thumb’ is that the lower, denture will usually be stable if narrow teeth are used and are placed as far buccally, or labially, as possible without displacing the cheek and lip tissues.

By maintaining this, maximum tongue room is provided within the limits dictated by the lips and cheeks.

Verification of jaw relation record

Verifying centric jaw relation record

Mandible is pulled back by the patient as far as it will go and closure is stopped at the first tooth contact.

 The patient is guided into CR by a thumb placed on the anteroinferior portion of the chin and the index fingers bilaterally on the buccal flanges of the lower trial denture.

With the index fingers, the dentist checks that the lower trial denture is seated in an inferoanterior direction.

The patient then pulls his lower jaw back as far as it will go and closes just until the back teeth make a “feather touch.”

 As tooth contact approaches, the dentist’s index fingers should rise off the buccal flanges. Pressure on the buccal flanges, or stretching the lip with the index fingers, will create the risk of posteriorly displacing the lower trial denture. Then the patient closes tightly.

Any error in CR will be apparent when the teeth slide over each other, especially if anatomical teeth are used.

 A second closure made with the same instructions and a stop at first tooth contact will permit visual observation of any error.

 All the teeth that occluded uniformly on the articulator must have equally uniform contacts in the mouth.

Correction of the centric relation
Technique 1

The posterior teeth are removed from the lower occlusion rim, and both occlusion rims are placed in the mouth.

 Impression plaster (bite registration paste), is mixed, and placed on both sides of the lower occlusal rim in the molar and premolar regions.

Then the patient is instructed to pull the lower jaw back and close slowly until requested to stop and hold that position.

 The closure is stopped when the anterior teeth have the same vertical overlap as they had before the posterior teeth were removed.

When the plaster or registration paste is set, the new record is removed with the two occlusion rims, and the lower cast is remounted on the articulator.

Technique 2

In an alternate technique, beeswax occlusal rim is used to replace the removed posterior teeth. The patient is guided into the most retruded position till the upper posterior teeth will indent the softened opposing wax rims.

The lower cast is remounted on the articulator, and the lower posterior teeth are reset in centric occlusion.

Eccentric jaw relation records

The ideal amount of protrusion for making the record is the amount of protrusion necessary to bring the anterior teeth edge to edge.

 However, the mechanical limitations of most articulators require a protrusive movement of at least 6 mm so that condylar guidance can be adjusted.

Methods of registering the condylar path may be classified as

–          Intraoral  

–          Extraoral

Extraoral methods are generally exemplified by the Gysi and McCollum techniques.

The intraoral methods

–          Plaster and carborundum grind-in,

–          Chew-in by teeth opposing wax,

–          Chew-in modified by a central bearing point,

–          Needles’s styluses cutting a compound rim,

–          Needles’s technique modified by a Messennan tracer,

–          Protrusive registration in softened compound,

–          Protrusive registration in plaster, and

–          Protrusive registration in softened wax.

Plaster interocclusal record is made for CR.

The patient is instructed to protrude the jaw farther when the protrusive record is made.

 The minimum amount of protrusion for condylar guidance adjustment is 6 mm.

Lateral interocclusal records can be made to set the condylar inclination and the mandibular lateral translation on the articulator.

Moreover, most semi-adjustable articulators are not able to accept many lateral eccentric records.

Eccentric interocclusal records may be made with extraoral tracings.

While the tracing device is still attached to the rims, the amount of protrusive movement is determined by observation of the distance between the apex of the tracing and the needle point. The amount and direction of the lateral movement can be determined by observing the distance of the needle point from the apex of the tracing while the needle is on one of the arcs of the tracing. When the needle point is 6 mm from the apex, the mandible in the first molar region will be approximately 3 mm lateral to its position in CR.

The molar tooth will have moved laterally 3 mm because it is approximately midway between the tracing and the working-side condyle.

Freeway Space

The lower denture is inserted and the vertical dimension at rest is measured.

Then, the upper denture is inserted and the occlusal vertical dimension at occlusal is measured by asking the patient to occlude and free way space is calculated

Finally, the patient should be asked to speak while wearing the trial dentures.

The teeth do not normally contact during speech but approach most closely when the ‘S’ sound is made. The separation is known as the closest speaking space and is usually about 1 mm.

If the occlusal vertical dimension of the trial dentures is excessive, space may be absent; correspondingly, it will be increased if the occlusal vertical dimension is too small.

 This assessment can be made by asking the patient to count out loud from ‘sixty’ to ‘seventy’.

If the freeway space is too large, it is corrected by adding the appropriate thickness of wax to the occlusal surfaces of the posterior teeth on one of the dentures, and then recording the jaw relationship in the retruded contact position.

If the freeway space is too small, or absent altogether, teeth will have to be removed from one of the dentures and replaced with a wax rim before the new recording can be made.

 Esthetics

FRONTAL
SAGGITAL
HORIZONTAL

Summary

The dentist at the try in appointment should check for:

  1. The bases for fit and extension.
  2. Thin labial flange at frenum area.
  3. Posterior palatal seal and length of maxillary denture.
  4. Posterior tooth position for height of plane, relation of plane to ala-tragus line, tongue room, and ridge relation.
  5. Anterior tooth position for lip support, length, and relation to lower lip.
  6. Entire setup for vertical dimension of the face. Test balance and simultaneous tooth contacts in all desired positions. If discrepancies exist between the articulator and the mouth, make new jaw relation records.
  7. Check palatal contour and incisor positions in speaking. Use “F” and “V” sounds to test the maxillary incisors, and sibilant sounds for vertical dimension and lower-to-upper incisal relationships.
  8. Wax-up for support and proper external form. If tori exist on the maxilla or mandible, be sure there is sufficient thickness to allow relief later on.
  9. Be sure to repeat and continue instruction of the patient in understanding and handling of the new dentures.

REFRENCES

  • Zarb-Bolender; Prosthodontic treatment for edentulous patients; 12th edition
  • Sheldon winkler; Essential of complete denture prosthodontics; 2nd edition
  • R.M. Bhasker and J.C. Davenport; Prosthetic treatment for edentulous patients; 3rd edition


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