Test 4 Flashcards
Bifurcation
Bi means two
Mandibular molars are bifurcated
Trifurcation
Tri means three
Maxillary molars ares trifurcation
Cusp
Pointed peak located on the occlusal surface
Identified according to their location(buccal,lingual)
Found on molars, premolars and canines
Cingulum
Single lobe on anterior teeth
Prominence of enamel usually found on the lingual cervical third of anterior teeth
Lobe
Teeth develop in pieces(lobes); become fused to from the crown of the tooth
General rule:facial of incisors ,canines and premolars form from 3 facial lobes… the lingual forms from one lobe to equal 4 lobes
General rule: the molar cusp is a lobe-depends on number of cusps=lobes
Facial surface: 3 lobes
Incisors: 4 lobes
Premolars: 4 lobes
Molars: 4-5 lobes
3rd molars: many lobes
Mamelon
Rounded prominence on the incisal edge/ridge of newly erupted teeth
Formed= fusion of the three facial lobes
Mamelons usually disappear from wear from function
Tubercle
A smaller elevation different from the cusp tip of a molar
Occurs on facial, lingual and occlusal surfaces
DOES NOTrepresent a division of the tooth lobe does
Ridge
Ridge is a convexity(bulge) of enamel on the tooth
Surrounds the all the cusps on posterior teeth or the edge of anterior teeth only on the lingual
Named according to the location of the ridge
Marginal ridge
Rounded elevation of enamel forming the mesial and distal boarder of teeth
The marginal ridge is named according to the location
Anterior teeth marginal ridges are located on the lingual
Triangular ridge
The ridges on teeth and cusps tips are convex
The main triangular ridge runs from the cusp tip to the central part of the occlusal surfaces
Transverse ridge
Transverse ridge is the union of two triangular ridges
Buccal to lingual over the occlusal surface of a posterior tooth
Buccal triangular ridge+lingual triangular ridge =transverse ridge
Oblique ridge
Found only on maxillary molars
It crosses the occlusal surface obliquely(diagonally)
Fossa
Lingual fossa is located between the marginal ridges and incisal ridge to the cingulum
Central fossa
Deep angular valley in the central portion of the occlusal surfaces of molars
Triangular fossa
Shallow pyramid shaped depression on the occlusal surfaces of the posterior teeth (located within the confines the mesial and distal marginal ridges)
Grooves
Developmental
Tooth forms in lobes and fuse= groove demarcation on the occlusal surface
Central developmental groove
Central developmental groove runs mesial and distal
Buccal groove and lingual groove runs off the central groove
Triangular fossa grooves split off the central developmental groove and does not include secondary grooves
Secondary( supplemental) grooves
Not as well defined as developmental grooves
Small, irregular placed grooves on the occlusal surfaces
Are NOT located at major junctions of the lobes
Names by their location
Identify the following grooves
Pits
Central grooves
Supplemental grooves
Mesial marginal groove
Pit
Pinholes
Common are for caries to begin
Named by location( buccal pit/lingual pit)
Fissures
A narrow left (crevice) at the depth of any groove
Caused by fusion of the enamel during tooth development
