Occlusion 1 Flashcards
what is the SIMPLE definition of occlusion?
the contacting of occlusal and incising surfaces of opposing maxillary and mandibular teeth
what is the GPT 8th ed definition of occlusion?
the static relationship between the incising or masticating surfaces of the maxillary or mandibular teeth or tooth analogues
what is the REALISTIC definition of occlusion?
The dynamic morphological and physiologic relationships among all components of the masticatory system including the neuro-musculature, TMJs and teeth
what is the importance of occlusion?
- Essential to both general and dental health
- Mastication
- Ability to speak
- Enjoy food
- Aesthetics
what is the history of occlusion?
- Since the 1800’s occlusal concepts/theories have come and gone.
- Most occlusal concepts are based in part on theory, and all of these theories borrow in part from the past
what is maximum intercuspal position (MIP)?
The complete intercuspation of the opposing teeth independent of condylar position
what is centric occlusion?
The occlusion of opposing teeth when the mandible is in centric relation; this may or may not coincide with the maximal intercuspal position
what is centric relation?
a physiologic position of the condyle-disc
assemblies that occurs naturally when the masticatory musculature functions in a coordinated manner
how does centric relations relate to prosthodontics?
until the position and condition of the temporomandibular joints are precisely determined, an accurate maxillomandibular relationship cannot be verified
what is the current definition of centric relation in the CPT 9?
is 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
what is the most important thing to understand about centric relation?
it should be a posterior position that is unstrained and repeatable. We can help guide a patient but should never force the mandible in a posterior direction.
With loss and/or wear of teeth the mandible tends to take a protrusive posture.
what is overload and when may it happen?
When teeth interfere with centric relation and/or maximal intercuspation they may then be subject to overload
Occlusal trauma may result, with excessive wear, mobility, sensitivity or pain, and fractured cusps. Additionally, there will be an increase in nociceptor and proprioceptor signals that effect neuromusculature control, which may attempt to “reroute” mandibular closure
which arch is usually larger and what shape are arch forms generally ?
maxillary is slightly larger
arches may be square, ovoid and tapering
what roles do arch configuration, tooth size and shape play?
- esthetics
- phonetics
- mastication/deglutition
- para-functional bruxism
The ________ posterior teeth have a horizontal overlap on the buccal aspect, while the _______ posterior teeth have a horizontal overlap on the lingual aspect. Adequate horizontal overlap of each reduces the potential for _______ and _______
maxillary, mandibular, cheek, tongue biting
The occlusal plane is generally elevated _______ relative to the natural horizontal plane (when the patient is standing) by approximately 8 to 10 degree
antero-posteriorly
Typically, the maxillary incisal edges show from ______ mm at the resting lip length with the free gingival margin showing at a high smile
0 to 2
The incisors are generally aligned with the patient’s________, although variations are common due to tooth loss, tooth size-arch length discrepancies, mesial drift, tooth agenesis and tooth wear/altered eruption patterns
facial midline
what is the definition of plane of occlusion?
refers to an imaginary surface that theoretically touches the incisal edges of the incisors and the tips of the occluding surface es of the posterior teeth
what is the significance of plane of occlusion?
a flat occlusal plane will not allow simultaneous contact in more than one area of the dental arch. That is why the occlusal plane is usually curved.
what is the definition of Vertical Dimension of Occlusion (VDO or OVD)
The distance between two selected anatomic or marked points (usually one on the tip of the nose and the other on the chin) when in maximal intercuspal position
what is the definition of Rest Vertical Dimension (RVD)
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
what is interocclusal distance?
The distance between the occluding surfaces of the maxillary and mandibular teeth when the mandible is in a specified position
what is interocclusal rest difference?
the difference between the rest vertical dimension and the occlusal vertical dimension. (was called Freeway Space)
RVD – OVD = IRD