Methods and anatomical methods of orienting the occlusal plane?
(6 anatomical methods and 3 other methods)
1) Parallel to the interpupillary line
2) parallel to the ala-tragus line (campers line)
3) Mx anterior should be seen 1-2mm below the upper lip line and the max posterior should be at the height of stensens duct
4) Md anterior should be at the height of the lower lip line and the Md posterior should be level with the top 1/2 of the retromolar pad
5) Orient labio-lingually over the crest of the lower residual ridge
6) Inclination should be at the height of the residual ridge
- Cephalometrics
- pre-extraction records
- comparison to existing denture
What are 3 requirements for a good CR record?
- Ensure mandible is in the most retruded position.
- Keep record in an undistorted state until the mounting is complete.
- Apply equal vertical pressure to the tissues when making the record
Why is it important to know the dental history for an edentulous patient when treatment options are severely limited??
To assess patients ability to use a denture? (Neuromuscular control)
Tissues that make up the residual ridge?
Mucosa: epithelium and connective tissue
Submucosa and periosteum
Residual alveolar bone
5 key factors of the selective pressure technique?
- Custom tray is most important factor. needs to be perfect size
- Borders of tray are reduced to allow space for border molding material but still support impression material
- Space must be provided using wax spacer and/or relief holes to relieve pressure and allow material to escape
- Proper placement and alignment of tray on arch
- Minimal operator pressure while holding tray during impression
List the clinical steps in fabricating a complete denture (8 steps)
- Patient history and examination
- Diagnosis, treatment plan, prognosis
- edentulous impressions, diagnostic, and final impression
- maxillomandibular relationship records (VDO, facebow, CR)
- Selection and arrangement of artificial teeth
- waxing and processing of trial dentures
- denture insertion procedures
- patient education and maintenance procedures
What significant factors are affected by gingival contour? (5 points)
- improved esthetics for patients with high smile line
- provides for appropriate support and contour of the lip and cheek
- improved tolerance and comfort
- facilitates stability and control
- prevents chronic biting of the lip and cheek
What is the purpose of a remount jig?
Purpose is to reposition the teeth of an upper denture into their original position and to preserve the facebow mounting record
Purpose and steps for a patient remount?
Purpose for a patient remount is that adjusted denture bases seat more accurately than record bases and to accommodate for errors made during the making of CR records.
The steps are to take a new centric relation record, verify, the mandibular denture is remounted and verified. Then, the occlusion is adjusted until the occlusion on the articulator is the same as the patients occlusion.
Why do we take a protrusive record?
So take a protrusive record so that we can adjust the condylar elements and inclination of the inclination of incisal guidance
What is the purpose of the facebow? (3 points)
- Allows for some alteration in the VDO once dentures are mounted on the articulator without causing errors in the occlusion
- Maintains the relationship of the maxillary cast to the upper member of the articulator during mounting of the cast
- Permits the semi-adjustable articulator to be used to the full extent of its capabilities
What is the effect of incisal guidance on occlusal scheme?
Incisal guidance discludes posterior teeth, the greater the incisal guidance, the more the posteriors disclude
3 types of articulators?
- fully adjustable
- non-adjustable
- semi-adjustable
List the key benefits for lingualized occlusion (6 points)
- good esthetics
- freedom of non-anatomic teeth
- potential for bilateral balance
- centralizes vertical forces
- minimizes tipping forces
- facilitates bolus penetration
What are the advantages of monoplane occlusion? (6 points)
- reduces horizontal forces
- CR can be developed as an area rather than a point
- freedom of movement
- can develop solid occlusion despite arch alignment discrepancy
- easily adaptable to situations prone to denture base shifting
- easy to set and adjust teeth
Patient complains about lower denture lifting off from mandibular ridge, what are possible problems? (3 points)
- poor neuromuscular control
- anterior contacts in centric
- poor balanced occlusion in excursion and protrusion
What effect does steep cusps have on protrusion and excursive movements? (2 points)
- steeper cusps allow for balanced occlusion to be maintained during excursive movements
- allow anterior disclusion in lateral excursion
Why dont you want anterior contact in denture occlusion?
Anterior contact dislodges dentures posteriorly. With continued ridge resorption there is settling of the dentures in an upward and forward movement. This increases the potential for traumatic anterior contact and increased anterior maxillary ridge resorption.
Fill in the Theilman formula ( 5 marks)
C=condylar inclinationIncisal guidance/Occlusal planecuspal inclination*compcurve
What is the purpose of making diagnostic impressions (2 marks)?
- To make final impression tray
2. To aid in diagnosis and treatment planning
What is Christensen’s phenomenon (1 mark)
When mandible is protruded in natural dentition and dentures, there is a naturally occurring gap that is present between the posterior teeth. In dentures, this may cause reduced stability of the dentures therefore, compensating curves must be introduced into the dentures in order to counteract this.
What is the name of the polymer used for the denture base?
TruTriad VLC
Your patient has severe maxillary and mandibular ridge resorption. What problems might you encounter when planning a complete denture?? (4 points)
- reduced retention, support, and stability
- Resorption on the mandible can result in trauma and perforation of the tissue overlying the mylohyoid due to poor keratinization of the mucosa
- Resorption of the alveolus will result in a poor peripheral seal of the denture because of little resistance to lateral displacement of the denture during function
- Denture placement could impinge the inferior alveolar nerve on the mandible which can cause pain
Your patient has lingual tori. What do you have to do when planning a denture for this patient? (2marks)
- shorter lingual flanges to avoid occlusal loading on the tori
- monoplane teeth should be selected to provide a balanced occlusion and to distribute occlusal forces on a larger area
