Citing Authors Flashcards
How much does the jaw normally move in open lat pro and retrusion? WHo studied this?
Posselt
What is the normal range of mandibular movements?
• Opening: 45-55 mm – (Rotation-first 20-25mm)
• Laterally: 10mm
• Protrusion: 9mm
• Retrusion: 1mm
Translation begins at 20 mm between max and mand molars
These limits were described by Posselt in 1952. When the jaw is retruded, the incisors move posteriorly and inferiorly (90% of population)
Discuss Combination Syndrome
- Also called as anterior hyperfunction syndrome
- First described by Kelly (1972) and then by Saunders (1978)
Kelly E. Changes caused by a mandibular removable partial denture vs. a maxillary denture. JPD 1972;27:140-150. • Posterior mandibular ridge resorption • Anterior maxillary ridge resorption • Down growth of maxillary tuberosities • Extrusion of mandibular anterior teeth • Papillary hyperplasia
Saunders. The maxillary complete denture opposing the mandibular bilateral distal extension partial denture: treatment considerations. JPD 1979;41(2):124.
• Loss of vertical dimension
• Occlusal plane discrepancy
- Anterior repositioning of mandible
- Poor prosthesis adaptation
- Epulis fissuratum
- Periodontal changes
Is combination syndrome a syndrome?
• Palmqvist, Carlsson and Owell- challenged it in 2003 refusing to call it a syndrome. JPD 2003 Sep; 90(3): 270-5.
- clear indications and little doubt that the removable denture plays an important causative role in the bone resorption process
- Subjects not wearing dentures had more remaining bone.
- Other than kelly No study on changes in the maxillary mucosa with respect to the mandibular dentition status. papillary hyperplasia - “papillary hyperplasia of the hard palatal mucosa” seem to be rare.
- Other than Kelly No other reports have been found regarding extrusion of mandibular anterior teeth in combination with a complete maxillary denture and a mandibular RPD.
- Enlarged tuberosities are often seen together with supraerupted maxillary molars.
- The supraeruption may create enlarged tuberosities without influence of a denture.
- Dorland’s Illustrated Medical Dictionary defines “syndrome” as “a set of symptoms which occur togeth- er; the sum of signs of any morbid state; a symptom complex.”
no randomized controlled trials (RCTs) on combination syndrome were found.
What is the prevalence of combination syndrome?
Shen K, Gogloff RK: Prevalence of the combination syndrome among denture patients. J Prosthet Dent (1989).
1 in 4 prevalence of combination syndrome in Mx CD and MD anterior natural teeth.
-Examined 150 patients with maxillary CD opposing MD over 5yr. 91/150 completely edentulous Nothing 4/91 no prosth Complete denture (87/91) CD/CD 5% natural teeth(59/150) 24% prevalence!! With Class I RPD 22% Without RPD 25%
Of all 5 changes ..... Mx anterior bone loss Hyper mobile anterior ridge Mx alveolar ridge canting MD posterior bone loss Tuberosity elongation
management of abused oral tissues
Lytle RB. The management of abused oral tissues in complete denture construction. JPD 1957;7(1):27-42.
• If the soft tissues beneath dentures are subjected to excessive stress, they not only become deformed and traumatized, but they also become less resilient and do not readily return to their normal form.
• Eliminate or minimize mechanical factors causing abuse by:
1. Correcting faulty occlusion and other denture defects causing instability
2. Relieve all areas causing excessive pressure and deformation
3. In some extreme cases, placing a temporary relining in the dentures after they have been left out overnight will improve stability and help control soft tissue form
4. Minimizing or eliminating stresses by a soft diet and removal of dentures at night
5. Instructing the patient to stimulate the soft tissues by massage
6. Leaving the dentures out of the mouth 48-72 hours prior to making an impression.
The etiology of inflammatory papillary hyperplasia
Ettinger, R.L. The etiology of inflammatory papillary hyperplasia. J Prosthet Dent 34:254-260, 1975.
incidence of papillary hyperplasia 700 pts Looked at denture factors stability, occlusion relief, stomatitis etc. Painless Incidence 13.9% Men>Women Younger>older *Most common in highest part of palatal vault.
Tx: remove the dentures at night, clean the dentures regularly, massage the tissue, and visit the dentist regularly for maintenance visits
Discuss your technique of obtaining posterior palatal seal
I used the T burnisher to palpate the hamular notch areas, asked the patient to say “ah” and see the movement of the soft palate. I marked the line along this line and connected them to the hamular notches. I then transferred the vibrating the line to the record base.(As advocated by Boucher in his textbook)
Why This technique ?
Simple and physiologically sound
Visually confirmed
Predictable-previously successful to me
Describe various techniques for PPS
- Empirical – Transferring Ah line and Scoring cast (Boucher)
- Physiologic- Valsava Manuever, Iowa Wax (Chen, Laney, Milsap)
- Palpation technique- using a ball burnisher and compress the tissues (Terrell and Swenson)
- Arbitrary (semi functional) – Combination of both techniques
- Functional Impression – Class III; to compensate because there is so much movement
What are the ways to determine the movement of the soft palate?
- Say “ah” and draw a line connecting the hamular notches along the VL. (Boucher)
- Valsava Maneuver (Laney)
- Extent can me made with visual exam w/ a ball burnisher (Terrell and Swenson)
Where is the vibrating line?
Chen found that the vibrating line is never posterior to the fovea palatini.
Usually the PPS extends at least to the vibrating line or 1-2mm beyond it.
I used the T burnisher to palpate the hamular notch areas, asked the patient to say “ah” and see the movement of the soft palate. I marked the line along this line and connected them to the hamular notches. I then transferred the vibrating the line to the record base.(As advocated by Boucher in his textbook)
Discuss relevant literature of PPS
- Chen’s study (25% of people had the FP on the vibrating line and 75% had the FP behind the vibrating line, 0% of people had the FP in front of the vibrating line)
- Avant: PPS is a must; No one type of posterior palatal seal that was tested proved to be superior in all subjects. However, the angle-shaped posterior palatal seal was the most effective of the four designs tested (design C)
- Ettinger and Scandrett (review of 3 types; physiologic is the best)
- Barco (lab data clearly showed that a better fitting denture can be made by relining the heat cured denture with an autopolymerizing resin prior to delivery.)
Nikoukari, In a mouth with a flat palatal vault, the vibrating line is usually farther posteriorly.
Discuss Palatal form
Discuss House’s Palatal form
• Class I: 5-13mm distal (more than 5mm of movable tissue available) Ideal for retention
• Class II: 3-5mm distal (1-5mm of movable tissue available) Good retention –
• Class III: 3-5mm anterior (less than 1mm of movable tissue available) Poor retention
Class III difficulties are in tissue movement, typically present in high vaulted patients, and because of the small area for the posterior palatal seal.
Discuss Lateral Throat Form?
Discuss Neil’s Lateral Throat Form?
A classification used to determine lateral throat form. Patient is told to protrude the tongue ¼ of an inch beyond the edge of the lower lip, pulling the palatoglossus muscle forward.
Originally finger movement when tongue brought forward was used to describe this. A mouth mouth mirror inserted in the retromylohyoid space while patient brings tongue forward is the easiest way to check this.
Class I: No tendency to displace the finger - 8-12mm of extension below the mylohyoid ridge (long, wide flange)
Class II: Intermediate functional position - 4-6mm of extension below the mylohyoid ridge – My patient
Class III: The finger is entirely displaced from this area- 2-3mm of extension below the mylohyoid ridge; RARE
Discuss determination of the incisal edge position:
- Based on F and V sounds (Frush, Pound, Landa)
- Lips in repose (Vig and Brundo, Futalej, Peck and Peck, Burstone)
- Existing incisal edge position
What factors affect denture Retention?
(Jacobsen and Krol)
- Adhesion (physical attraction of unlike molecules)
- Cohesion (physical attraction of like molecules)
- Interfacial Surface tension (resistance to separation of 2 parallel surfaces that is imparted by a film of liquid between them)
- Gravity (for lower)
- Border Seal
- Atmosphere Pressure (for upper)
- Mechanical Undercuts, Parallel walls and rotational insertion paths
- Neuromuscular Control
- Intimate tissue contact
- Orofacial musculature – correct position of denture teeth must be in the neutral zone
