Exam 1 Flashcards
Occlusion
Contact relationship between between maxillary and Mandibular teeth when jaw is fully closed and relationship between teeth in the same arch
When dentition is in occulusion the maxillary arch _____ the Mandibular arch ______&______
Overhangs
Horizontally
Vertically
Over jet
Horizontal overhang
Overbite
Vertical overhang or overlap between the 2 arches
Rest position of occlusal surfaces
Also “Interocclusal clearance” “freeway space”
Lips closed and jaw in nonfunctional position (occlusal surfaces not touching)
2-3mm of space
When is the only time teeth should touch?
Functional situations
Parafunctional habit
When teeth touch in nonfunctional situations
Ex: bruxism (grinding), clenching, finger sucking
Parafuncational habits are _____. Pt is usually ____, not ____ ______,etc.
as a clinician you should
Unconscientious
Anxious
Not paying attention
Make pt aware of habit
5 phases of Arch/dentition development
Phase 1- eruption of permanent 1st molars, man to max
Phase 2-eruption of permanent anterior teeth, c to l
Phase 3-eruption of permanent premolars (primary molars gone)
Important phase bc of leeway space
Phase 4-eruption of permanent canines and 2nd molars
*canine is final tooth to stabilize arch (completes arch/dentition)
*max. Canine last to be replaced @ 12 years old.
*Before arrival of canine, position transient (short time)
Phase 5-eruption of third molars
Chronological order of teeth coming in very important
Space maintainer recommended for prematurely extracted teeth
Permanent replacement can then find right space and erupt properly
Otherwise neighboring teeth will tilt to occupy the space and opposing teeth with super erupt
Mesial drift
Teeth have natural tendency to move mesially
What happens if tooth is extracted and not immediately replaced?
2 teeth around the space (anterior and posterior) will tilt to occupy this space
The opposing tooth will super erupt to try to occupy space
Disharmony for whole dentition
When examining pts mandible and natural functions, what are you observing?
Protrusion
Retrustion
(Forward and backward)
Lateral movements
Lateral occlusion
&
Working side v non working/balancing
Ask patient to move mandible to right and left
Only canines should touch cusp tip to cusp tip (contralaterly)
Side to which jaw has been moved
Opposite side of working
Protrusive occulusion
All 8 incisors touch at once
Centric relation
Position of mandible relative to maxilla
Mandible in most retruded position (not teeth to teeth)
Determined by maximum contraction of muscles of jaw —> during swallowing
Centric occlusion
Maximum contact between occluding surfaces of max and mand teeth
Forces on teeth that stabilize teeth in final position
Muscles surrounding teeth (both around and weak affect)
-facial expression, buccal, labial, tongue
Chronological order of teeth coming in and out
Primate spaces
-result of growth of bone between teeth
-mesial to maxillary canines and distal to Mandibular canines
Leeway space
-difference in size mesiodistally between primary molars and perm premolars
Lengthening of arch
Occlusion of permanent teeth is affected by
Occlusion of primary teeth
3 types of occlusion in primary teeth
Best to worst
Compares distal surfaces of second molars (maxillary and Mandibular)
- Mesial step
- Flush terminal plane
- Distal step
Mesial step
Distal surface of Primary Mandibular second molar MESIAL to maxillary second molar distal surface
Predicts permanent occlusion will be good
Flush terminal plane
Distal surfaces of both maxillary and Mandibular second molars are in an end to end relationship
50/50 probability that permanent occlusion will be good depending on other factors
(Primate space, leeway space, lining of jaw, restorations, extractions)
Distal step
Worst
Primary Mandibular second molar distal surface DISTAL to maxillary Second molar
Predicts permanent occlusion will be bad
Dentition
Natural teeth in jaw bone (primary and permanent)