Arch Design, VDO, Centric Relation Flashcards
The potential space between the lips and cheeks on one side and the tongue on the other; that area or position where the forces between the tongue and cheeks or lips are equal.
Neutral Zone
Where tooth stability is achieved
Neutral Postion
Occluding surfaces fabricated on interim or final denture bases for the purpose of making maxillomandibular relation records and arranging teeth
Contoured to fill neutral zone
Occlusal Rim
What are 3 purposed of occlusal rims?
- Maxillow mandibilar relation records
- Teeth arangement
- Support lips
the bony portion of the maxilla and the mandible in which roots of the teeth are held by fibers of periodontal ligament
denture replaced this
Alveolar Bone
In what direction does the maxilla resorb?
Up & inwad
* Become smaller
In what directon does the mandibular bone resorb?
Out and down
progressivley wider and thinner
This progressive change of the edentulous mandible and maxilla makes many patients appear
Prognathic or pseudoprognathic
Trends in mandibular residual ridge
Anterior?
PM?
Molar?
more resorbtion on
* Anterior= labial
* PM= equal on buccal & lingual
* Molar= lingual
The net morphological result of mandibular ridge resorbtion is ?
Ridge more lingually placed anteriorly, and ridge more buccaly placed on posterior region.
How do you compensate for mandibular ridge resorbtion with occlucal rim?
- Make occlusal rim labial to ridge inthe anterior PM area
- Rim slightly lingual to ridge onmolar area
Tongue size and postion during function affects stabilit of ____ denture
mandibular denture
optimal neutral zone determination is still ____ for speech and esthetic purposes.
manditory for speech and esthetic purposes
Where does maxillary residual ridge resorbtion occur?
Labial and buccal so ridge is usally paletal to original location
This force occurs at the jaw-to-jaw position that is determined by a consistent, repetitive contracted length of the elevator muscles.
* Present throughout tlife
* Erupt until smth stops them
Tooth Eruptive force
Postion where teeth hit together, the tightest or best fit between maxillary and mandibular posterior teeth.
Maximum Intercuspation (MIP)
The complete intercuspation of the opposing teeth ____ of condylar position.
independent
The distance measured between two points when the occluding members are in contact
Verticle demenstion of occlusion VDO
occurs at maximum intercuspation, regardless of condyle position, when teeth are together.
VDO
The determinant of VDO is the _____
Elevato Muscles
VDO is measured from
zygoma to the angle of the mandible (B).
What should the upper and lower heights of the face be?
Approximally equal!
WHat can be a result of collapse of VDO?
Bite collapse! Usually a result of endentulousness
How is VDO established
as part of the process of jaw development and maturation. Changes overtime with resorbtion
What are 3 test that aid in establishing correct VDO by occlusion rims?
- Visual observation (look at space btwn re
- Esthetic facial postion
- Phonetics test (S sound)
The postural position of the mandible when an individual is resting comfortably in an upright position and the associated muscles are in a state of minimal contractual activity
Physiological Rest Postion/ Verticle Dimension at rest VDR
All muscles resting, mandible in this postion >23hrs a day
Space formed when all muscles are at rest, teeth are seperated.
Space between the occlusal surfaces of the Maxillary and Mandibular teeth while the Mandible is in rest position (usually around premolar area)
Freeway space
unclenched
2-4mm of freeway space in what area?
Around canine area
Can change if head postrue changed
Normally, VDO is ____ short from the ____
VDO is 2-4mm short (freeway space) from the VDR
How much freeway space is normally seen?
2-4mm of freway space
How to find exact amount of freeway space steps?
- Mark 2 dots, one on chin one on tip of nose
- Measure dots in occlsuion VDO
- Ask pt to swallow and realx, measure VDR
- Subtract **VDR-VDO= FS **
If FS is >4mm: VDO is?
Overclosed
If FS is < 2mm VDO is?
Too open
What is one method for observing VDR in denture patients?
By using wax rims
How thick do you like wax rims on max and mandible?
- 22mm thick Max
- 18mm thick Mand
A result of what?
- Excessive loading of denture bearing tissues.
- Elevator muscles are unable to return to their normal resting length.
- Continuous muscular activity results in pain.
Reduction of Freeway space, esentially little to no rest
A result of what?
- **Reduction of masticatory ** efficiency. (cant bring teeth together)
- Poor facial appearance and cheek biting.
- Developing symptoms related to TMJ.
Too much freeway space
What is this a result of?
Caused but overclosure of denture,reduced VDO
Failure to provide an adequate ____ results in the anterior lower ridge assuming a more labial relationship to the upper ridge.
Bad VDO= anteiror lower ridge more labial than upp ridge
A result of?
face looks distorted and lips are incompetent.
VDO too open, large
A result of?
VDO is too closed; short!
border appears thin, wrinkles appear around lips, and chin protrudes.
What are some words for the phonetics test of VDO?
Emma, Ohio
overclosure from lloss of vertical dimension, oral skin bacteria and fungi pool in corners of mouth (namely Candida)
Angular cheilitis
A maxillomandibular relationship, independent of tooth contact, in which the condyles articulate in the anterior-superior position against the posterior slopes of the articular eminences
relationship people return too each time they chew and swallow
No affected by presence or absence of teeth, does not change, does not coincined with MIP
Centric Relation
Tongue to roof of mouth gives?
Centric Relation
The occlusion of opposing teeth when the mandible is in centric relation
Centric Occlusion
may or may not be at MIP
Centric occlsuion VS Maximal innercupal postion
Condylar postion?
CO= depened on condylar postion
MIP= indepened of condylar postion
average plane established by the cusp tips and incisal edges of the teeth extended to include the cusp tips of the opposite side
Plane of occlsuion
Curve of?
Curve of Spee
Curve of?
Curve of Wilson
Level & heigh of the occlusal plane is establishe by the?
Occlusal wax rims
In establihsing height of the occlusal plane, the corners of the mouth act as what?
anterior landmarks for the height of the first premolars.
stable posterior landmarks, even in patients with advanced ridge reduction.
Retromolar pads
Where are the mandibular 1st molar level in relation to the retromolar pad?
mandibular first molar is usually at a level corresponding to 2/3rd of the way up the retromolar pad
height of the distal end of the mandibular occlusal rim.
establish the references in the cranium.
E.g.: Face bow record
Oreitnetion relations
establish the amount of jaw separation allowable for use for denture.
E.g.: VD
Verticle Relations
establish front-to-back and side-to-side relations of one jaw to another.
E.g.: Centric relation, centric occlusion
Horizontal relations
