TOOTH TERMINOLOGY
TOOTH TERMINOLOGY
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Clinical crown
Ø
Part that is
visible in oral cavity – occlusal to the gingival margins
v
Anatomic crown
Ø
Part that is
covered by enamel – coronal to
the cervical line
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A V-shaped incipient enamel extension
coronoradicularly on a crown may be found in bifurcated areas of any multirooted
teeth and commonly on Eskimo teeth
Ø
May be
smaller or larger than clinical crown
§
Larger than
clinical crown in gingivitis
§
Smaller (shorter) than clinical crown in
gingival recession
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Occlusal surface
Ø
Chewing surface
of posterior teeth
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Incisal edge
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Cutting of
anterior
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Point Angles (4)
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3 come together
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Line Angles
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Anterior (6)
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Not mesioincisal or distoincisal (because they are
rounded)
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Posterior (8)
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Ridge
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Any linear
elevation on the surface of a tooth
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Oblique – Mx M1s (& primary Mx M2s) – examples of tth with oblique ridges.
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Labial – Canines –
only…this is called Buccal ridge on PMs.
§
Buccal – PMs
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Cervical –
Primary teeth
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Marginal – All teeth
·
The ridge that extends from the
distoincisal angle to the cingulum is the distal marginal ridge
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Triangular – Posterior
teeth
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Transverse – Union of a L triangular ridge of a B cusp & a B triangular
ridge of a L cusp
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Marginal ridges
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Marginal ridges
on adjacent teeth are usually at the same height
§
Occlusocervically, the height of the mesial
marginal ridge of a perm Mn M1 is the same as the height of the distal marginal
ridge of a Mn PM2
§
NOT at the same height on the Distal of Mn PM1 and
Mesial of Mx PM2
Ø
When restoring the marginal ridges of
posterior teeth, their shape should be
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Rounded to help
form occlusal embrasures and improve food flow (decreases food impaction)
§
Wide enough for strength and to provide an
occlusal platform when there are opposing cusps
Ø
The following
marginal ridges have little or no contact in centric & eccentric
relationships:
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Mesial of Mx canine(I think Distal of Mx Canine is not getting
a contact from the Mn PM1)
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Mesial of Mn PM1
§
Distal of Mn PM2?????
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Developmental
grooves (Primary)
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Sharply defined,
shallow, linear depressions
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Separate lobes or cusps
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Buccal/lingual grooves
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Separate cusp ridges from marginal ridges – see Brand book,
p.174, for an illustration
Ø
Pits are at the
junction
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Supplemental
grooves (Secondary)
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Small, less
distinct, irregularly placed grooves
Ø
Do not demarcate
major divisional parts of a tooth
§
The groove that extends from the mesial pit
of Mx PMs towards the the MB line angle is the MB secondary groove
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Cusp
Ø
Elevation of
mound of enamel
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Mamelons (Sean –
thanks a lot)
Ø
Small, rounded projections on incisors
Ø
Indicative of malocclusion in teenagers & adults
Ø
Anterior open bite is likely in a 10-year-old pt
Ø
Usually 3
mamelons
Ø
Not found on
primary teeth
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Tubercle
Ø
Extra formation
of enamel
Ø
Cusp of Carabelli (it is NOT formed by a lobe, but
it is a tubercle)
Ø
What is the thing called between 2 cusp ridges on a
cusp?? à Tubercle? Only answer making any sense
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Cingulum
Ø
Bulbous elevation
of enamel, from a lingual lobe on anterior
Ø 12 cingula in a complete dentition – 1 for each anterior
tooth.
Ø Lingual cusp of Mn
PM1 similar to growth of Cingulum of a canineà both done by
lobes
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Sulcus
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Long depression or a V-shaped valley on
occlusal surface of a posterior tooth between ridges and cusps
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Fossa
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Irregular
depression or concavity
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Lingual
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Central
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Triangular
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Pits
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Jxn of developmental grooves
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Fissure
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Narrow channel or
crevice
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Sometimes deep
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Depth of developmental
groove
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Embrasures (4 per
contact)
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Generally
speaking:
§
Contacting surfaces have Bigger embrasure
·
Mx ant – L > F
·
Mn ant – F > L – the oddball
§
Posteriors – L >
F (except for between Mx M1 and M2 molars)
Ø
Where is the smallest embrasure??? à Incisal embrasure of Mn
centrals, than Incisal of Mx centrals
Ø
Buccal/Facial
§
Rounding of the mesiofacial &
distofacial line angles contributes to the formation of facial embrasures
§
The
deflective function of mesiofacial & distofacial line
angles protects the facial part of the interdental papilla
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Is the biggest embrasure of the PM1 and
the canine is on the F or L – I think????
Ø
Lingual
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Posterior embrasures are generally larger
on the L than on the F w/ the contact w/ in the facial moiety, except between
Mx M1 & M2
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Occlusal/Incisal
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The
widest is found between Mx canine & PM1 (1979b)
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The largest is found between Mx lateral
& canine (with Mx canine & PM1 as an option…hmm…) (1996)
Ø
Cervical
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This is the
interproximal space
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The apex of the triangular-shaped boundary
of the IP space is the contact area of the adjacent teeth
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Fxns
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Spillways
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Self-cleansing
§
Protect
§
Stimulate
tissue
Ø
The largest
incisal embrasure is between Mx lateral & canine (because
canine-PM1 embrasure is not an ‘incisal’ embrasure)
Ø
Posterior embrasures are generally larger
on the lingual than on the facial, with the contact area within the facial
moiety, EXCEPT between maxillary M1 & M2
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Arch stability
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Cusps, root forms, contact areas, &
periodontal fibers all contribute to arch stability
§
NOT Embrasures
Ø
Other contributors: Facial & occlusal
embrasure, and horizontal & vertical overlap
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Lobes:
Ø
One of the
primary sections of formation in the development of the crown of a tooth
Ø
Represented by a
cusp in posterior and mamelons and cingula in anteriors
Ø
Separated
by developmental grooves or developmental depressions in anteriors
Ø
The minimum
number of lobes any tooth can develop from is 4
§
Anteriors
·
3 labial, 1
lingual
·
The perm Mx central incisor has 3 mamelons
& 4 developmental lobes
§
Premolars
·
3 Buccal, 1
lingual
¨
The lingual cusp of a Mx PM1 is formed
entirely by the lingual lobe
·
Except for Mand 2nd
PM (3 Buccal, 2 lingual)
§
1st
Molars (Mn) –
·
5 lobes (by each
cusp)
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2nd
Molars (Mx M1)
·
4 lobes (cusp)
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3rd
Molars
·
At least 4 lobes
(variations exist)
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