Contacts, Embrasures, COC's, Etc. Flashcards
Line/angle created by junction of facial and proximal surfaces
Facial line angles
When viewed from the facial and lingual aspect, how do incisal/occlusal embrasures change from anterior to posterior?
Incisal/occlusal embrasures get bigger from anterior to posterior when viewed from lingual and facial
Over time, how do teeth move due to interproximal attrition?
Teeth move mesially - arch shortens
Distance of crest of convexity from cervical line on facial and lingual surfaces of mandibular anterior teeth
< .5 mm
Distance of crest of convexity from cervical line of lingual surface of mandibular second premolars
¾ mm
Line around tooth where enamel and cementum meet
Separates anatomical crown and root
Cervical line
Where are mesial/distal contacts of a single tooth in relation to one another?
Distal contacts are more cervical than mesial contacts
EXCEPT mx 1st premolar
Functions of proximal contacts
Stabilizes tooth in alveolus and dental arch
Prevent food impaction
Protects interdental papillae by deflecting away food
Features of epithelial attachment
Seals soft tissue to tooth
Variable in location
Tendency to migrate apically during life moving from enamel to cementum
Normal attachment follows curvature of CEJ
Which tooth is the longest and strongest in both arches
Canine
How does the depth of the curvature of the cervical line change from anterior to posterior?
The depth of the curvature of the cervical line on ALL surfaces decreases from anterior to posterior
Where is the buccal crest of convexity on posterior teeth?
Cervical third
All teeth have distal contacts located more cervically than the mesial contacts EXCEPT
Maxillary 1st premolar
How do facial and lingual line angles compare?
Facial line angles are normally more prominent than lingual line angles
Generally, where are the facial/lingual crests of convexity in relation to the cervical line?
Less than 1 mm beyond cervical line
How does arch change over time?
Becomes shorter because of interproximal attrition
Teeth move mesially
Pyrimidal/triangular shaped space between surfaces of adjacent teeth cervical to contact
Interproximal space
The mesial and distal terminations of the occlusal surfaces of posterior teeth, and lingual surfaces of anterior teeth
Marginal ridges
When viewed from the facial and lingual aspect, how do cervical embrasures (interproximal spaces) change from anterior to posterior?
Cervical embrasures get smaller from anterior to posterior when viewed from facial and lingual
How do proximal contacts change with age?
Get bigger
Start out as contact points
Abrading action of teeth over long period of time
Attachment of hard tissue (bone) to the tooth’s root structure
Periodontal ligament
What are the boundaries of the interproximal space
Interproximal contact - apex
Proximal surfaces - sides
Alveolar crest - base
How many roots do anterior teeth normally have?
1
How are the central developmental grooves of posterior teeth arranged?
Normally aligned in a continuous groove from tooth to tooth
Provide for trough anterior to posterior through centers of occlusal surface of posterior teeth
Provide for a more efficient food flow pattern during mastication
Functions of embrasures
Spillway for food during mastication, reducing forces on teeth
Part of self cleansing process of tooth
Stimulation of periodontium
Anterior embrasure important in esthetics
Prevents food impaction through contact areas
Attachment of the soft tissue of the mouth to the tooth
Epithelial attachment
Greatest areas of contour incisio (occluso)-cervically on the facial and lingual surfaces
Facial and lingual heights of contour (crests of convexity)
How do the lingual and buccal crests of convexity compare in posterior teeth?
Lingual crest of convexity is more occlusal than buccal crest of convexity (cervical third)
Where is the lingual crest of convexity on anterior teeth?
Cervical third
Distance of crest of convexity from cervical line of lingual surface of mandibular molars
1 mm
COC in middle third
Features of marginal ridges
Height of marginal ridges of adjacent teeth should be at same level
Shaped to creat a small occlusal (posterior) or lingual (anterior) embrasure
Opening between the adjacent surfaces of the teeth that widens from the contact points towards the facial, lingual, incisal, occlusal, and cervical surfaces
Embrasure
Gingival tissue that fills interproximal space
Gingival papilla (interdental papillae)
Imaginary line which marks the level of termination of the soft tissue surrounding the tooth
Separates clinical crown and root
Variable
Gingival line/crest/margin
How many roots do premolars normally have?
1
Touching of two surfaces of adjacent teeth
Proximal contact
Distance of crest of convexity from the cervical line on the facial and lingual surfaces of all maxillary teeth and the facial surfaces of mandibular posterior teeth
.5 mm
Which teeth do not have wider lingual embrasures than facial embrasures? Why?
Maxillary 1st molars
Only tooth that is wider mesio-distally on lingual than facial
NO LINGUAL TAPER - HAS FACIAL TAPER
Another name for interproximal space
Cervical embrasure
How do the size of the proximal contacts change from anterior to posterior?
Size of contact areas increase from anterior to posterior
Function of crests of convexity
Provide protection and stimulation of gingival tissue
Deflect food away from tissue
Describe proximal contacts of posterior teeth
Located slightly facial facio-lingually
Describe proximal contacts of anterior teeth
Centered facio-lingually
The depth of the curvature of the cervical line is normally greater on which proximal surface?
Mesial
How do the cervical line curvatures of adjacent teeth compare?
The cervical line depth of curvature is the same on adjacent proximal surfaces of adjacent teeth
Why are lingual embrasures wider than facial embrasures (when viewed from incisal/occlusal) EXCEPT maxillary 1st molars?
Lingual taper
Where is the facial crest of convexity on anterior teeth?
Cervical third
How many roots do mandibular molars normally have? Where?
2
1 mesial, 1 distal
When viewed from the incisal/occlusal aspect, how do the lingual and facial embrasures relate to one another (EXCEPT for maxillary 1st molar)?
Lingual embrasures are wider than facial embrasures
The crests of convexity on the proximal surfaces are the same as…
The contact areas
How do proximal contacts change from anterior to posterior?
Become more cervically located
How many roots do maxillary molars normally have? Where are they?
Three
1 lingual, 2 buccal
