tys shen ti rp Flashcards
(14 cards)
what to write when they ask what are the aims of treatment (specific to proviing patient dentures)
- maintenance of good standard of oral health
- with adequate functional efficiency (mastication, speech, deglutition, aesthetics), although it may not be optimal
difficulties in manaement of a fully edentulous patient presenting with a severely resorbed mandibular ridge
and how to treat using conventional techniques
1) poor retention
- physical retention is proportional to surface area
- hence dentures are loose, mobile and can cause hyperplastic folds over time
2) poor support
- minimal SA for support so unable to distribute occlusal stresses
- thus cause further resorption
3) poor stability
- when ridge is flat, lacks resistance to horizontal movement
- stability is also made of retention + support
4) loss of OVD
5) compression of mental nerve
- the foramen is displaced superficially due to resorption
MANAGEMENT TECHNIQUES
go by procedure
1) IMPRESSION
- use functional impression technique because load applied is the same as that in function
- this helps in retention bc maximal coverage is proportional to physical retention
- we need the correct borders to allow for full extension and in order to shape the polished surface such that it allows muscular action to grip onto the surface
- well taken impression also helps in retention because it allows intimate contact between denture base and tissue
- impression helps in support because it helps in the design of a denture with maximal coverage of stress bearing areas to allow for broad distribution of stresses
- well captured impression helps in STABILITY because it allows us to extend to retromolar & distolingual areas to prevent horizontal movement
2) REGISTERING JAW RS
- need to determine correct CR and OVD for STABILITY, and to prevent further destruction of TMJ and alveolar ridge
3) DESIGN OF PROSTHESIS
- ensure balanced occlusion to increase stability and retention
- lower occlusal plane can be given to reduce leverage instability on lower ridge
- teeth placement should be in neutral zone to prevent dislodging forces from tongue, cheek, lips -> confers stability
- use teeth with flatter cuspal inclines and narrower occlusal table so that less stress is transmitted to ridges
what are the possible causes for why an upper denture is loose
intro to essay should always be that we need to understand that denture RETENTION is contributed by BOTH PHYSICAL & MUCOSAL FORCES
1) alveolar ridge resorption
- changes to acuracy of the fit
- if the dentur has been in function very long
- when there is poor fit, there is decreased saliva surface tension, causing air bubbles to extend to border area, breaking border seal
- check by correlating ridge anatomy to fitting surface of denture
2) salivary gland hypofunction
- usually can write this for most complete denture cases bc all elderly
- less saliva means reduced adhesion force
3) lack of PPS
- can be hinted at when they say that the denture gets loose on biting with anterior teeth
3a) or just lack of peripheral seal in general. the peripheral seal is contributed by BORDER SEAL and PPS
- border seal, if underextended, has no vacuum between sulcus and denture
- if overextended, it impinges on muscular and frenal attachments and causes a rebound
4) overexended buccal flange
- suspect when the patient says it gets loose when she opens her mouth too wide
5) occlusal imbalance
- occlusal intereference or early tooth contact on one side causes the denture to tip and break the border seal
- need to adjust occlusion using articulating paper
6) tooth positioning inaccurate
-if anterior tip are set too far from the ridge, during incising, there is an anterior posterior tip
7) polished surface too thick at area buccal to the tuberosities, hence impinges on coronoid during opening, cause denture to drop
during e&d, take a good history. it matters because
- if denture was loose from the start, we suspect poor denture fabrication. but if loose later on, then more likely is degenerative changes
note: apart from denture factors, always make sure to talk about patient factors like
1) poor saliva
- too serous or too mucous
- clinical exam of saliva can be done by chewing on paraffin wax
- if it is stringy or ropey, then the texture is mucous
- can use xerostomia index
2) ridge
- check for undercut that make it impossible for denture base to cover the area
what are the tx options to manage non retentive upper denture
intro: mx is multi fold, encompasses both improving denture features for retention and patient education like addressing other etiological factors
1) denture adhesive
- is less costly than remaking new dentures
- if the disparity is too much eg too much ridge resorption then might be unsuitable as thick layer of adhesive used will give poor adhesive forces
- dependent on patient compliance
2) long term soft liner
- soft liners can engage into undercut areas for better retention
- but requires frequent recalls to change the liner
- and might cause an OH issue because it promotes candida growth
3) tokuyama hard reline
- improves accuracy of the fit
- weaker than denture acrylic slightly
4) fabricate new dentures
- consider this if other factors are also unsatisfactory eg age of denture, already poor aesthetics etc
ofc, can add how we will manage other etiologic factors, like trim unfavourable occlusion that might be leading to the loss of the seal
- give salivary stimulants for hyposalivation, or increase water sipping
why is it impt that the border of upper maxillary complete denture is correctly extended to the Posterior palatal area
PPS is the junction between the hard and soft palate, where pressure applied by the denture can aid in retention, if done within physiological limits
IMPORTANCE OF PPS
1) retention
- ensures continuity of peripheral seal, creating a vacuum between denture and tissue, preventing dislodgement
2) reduce food accumulation
3) reduce patient discomfort
- must be extended properly, not too posterior
- also need to rmb that smooth continuity of denture and tissue reduces perception of presence of denture
4) compensate dimensional warpage within denture base
how to ensure good extension of PPs
anterior vibrating line
posterior vibrating line
discuss the physical and physiological factors that are responsible for the retention of the complete maxillary denture
and explain their influences on your prosthetic clinical technique
PHYSICAL
- accuracy of fit
- peripheral seal: need to have functional border moulding
- mucosal coverage
- path of insertion” surveying should be done to utilize undercuts and create an oblique patho of insertion/ withdrawal which aligns with the undercut
PHYSIOLOGICAL
- polished surface meant to be supported/ gripped by buccinators
- placement of teeth in neutral zone between lips, cheeks
- salivary forces also ensure good accuracy of fit
how would you approach a patient with maxillary flabby ridge and lower ridge which is flat and severely resorbed in terms of impression taking
problem is the differential support ability between firm and posterior ridge and anterior flabby ridge (anterior ride is more displaced in function)
impression technique is the 2 stag
- close fitting tray with window for anterior ridge
- border moulding with green stick wax, open mouth techqniue
- impression of firm ridge with ZOE and functional moulding
- slight mucocompressive technique, apply some pressure to the mucosa
- impress anterior ridge with impression plaster
for severely resorbed loewr ridge:
- consider closed mouth technique which is preferred because when patient bites down in CR, natrual pressure is applied to the mucosa which simulates actual functional conditions
- because mech retention in a flat resorbed ridge is minimal. so closed mouth functional impressions utilize peripheral muscular support to grip denture
- since patient is closing into centric relation, it also allows for simultaneous recording of vertical dimension and occlusal plane
- whereas open mouth technique records tissues at rest
so for closed mouth method, need to use either existing denture or acrylic resin tray with occlusal rim adjusted to correct ovd. then material is SOFT IMPRESSION ACRYLIC RESIN like a tissue condition like viscogel, kerrfit
method: get px to move and occlude for 5-10 minutes to simulate functional movements and occlusal loading
“the use of CR Position increases the usccess rate of managing CD patients” discuss the rationale of this statement
first must say that success is defined by function in mastication, speech, deglutition and providing adequate aesthetics, plus preserve health of masticatory apparatus
should be achieved by RETENTION SUPPORT AND STABILITY (always go back to first principles)
then define CR position as the position where condyle articulates with the thinnest avascular portion of their respective discs with the complex in the anterior superior position against the articular eminences. this is independent of tooth contact.
why need CR IN CD?
- in edentulous patient, mandible is capable of a wide range of circumductory movements limited by ligament of joint
- since there are no teeth or natura occlusion to guide mandibular movements
- thus cr establish guidelines to develop occlusion in harmony with various structures of the masticatory apparatus, including TMJ
- CR also maintains physiologic and anatomical health of tissues
- when MI = CR, it provides stability to the prosthesis and hence preserves the health of tissues by even distribution of stresses
problems patient experiences with increased and decreased ovd
OVD split into function, appearance and health
INCREASED OVD
function
1) clicking on speech and eating
2) speech difficulties with s,p, b sounds
3) difficulty in mastication
4) swallowing difficulties
appearance
1) strained
2) excessive show of teeth
health of mucosa
1) pain in tmj/mom
2) destruction of alveolar ridge, which will resorb to attain FWS
DECREASED OVD
1) fnction- inefficient mastication
2) appearance - collapsed
3) health - angular cheilitis
random ways that can be used to dtermine ovd (excluding the ones we use to check ovd normaly)
normally we use phonetics
- p,b,m sounds: lips should be able to touch
- s sound for speaking space
- c, s sound to see anterior teeth come together
OTHERS (for theory purposes)
1) swallowing threshold: wax rim should touch at the beginning of swallowing cycle
2) closing forces::
- maximum closing force should be able to be exerted at OVD
- by right technique should be to attach force meter to upper and lower base plates
3) tactile sense and patient perceived comfort
- use timmer screw device with a screw attached to maxillary occlusal rim and plate attached to mandibular occlusal rim
- adjust till overextended and reduce until patient is comfy
4) check with facial dimensions
- OVD is said to be similar to:
- vertical height of ear
- vertical distance between glabella and ala of nose
- vertical distance from outer canthus/ pupil to corner of mouth
5) check using patients old dentures
what are the methods of obtaining and recording CR
OBTAINING:
1) place tip of tongue on posterior part of the palate and close
2) guide mandible backward without applying too much pressure on chin
3) patient to swallow and close with back teeth
RECORDING:
1) wax wafer
2) pin technique
- after obtaining cr at desired ovd, place 6 staples to attach upper and lower rim
- seal lingually with hot wax
- idk what this is lah, chatgpt says to provide consistent ref point to guide closure
3) gothic arch technique
- maxillary block is attached with pointer, mandibular block attached with plate
- to adjust till ovd obtained
- from retruded position, range of anterior, posterior and lateral movements are made
problems associated with distal extensions
COMBINATION SYNDROME
1) flabby maxillary anterior ridge (got bone loss)
2) papillary hyperplasia of hard palate (takes time, not always present)
3) overgrowth of maxillary tuberosity
4) marked residual ridge resorption of lower bilateral FES
5) SUPRA ERUPTION OF LOWER ANTERIOR TEETH
