Morphology Form and Function Tooth Parts to Remember

Includes certain cusps, lobes, angles, positions on tooth from different views

Cusp

An elevation or mound on the crown portion of a tooth making up a divisional part of the occlusal surface

Cusps form the bulk of _____ surfaces of ____ teeth

occlusal surfaces of posterior teeth

Premolars have _____ cusps.

Molars have ______ cusps.

Premolars have 2-3 cusps.

Molars have 4 or more cusps.

The incised portion of canine crowns exhibit ___ cusp.

one

_____ DO NOT possess cusps.

Incisors

A smaller elevation on some portion of the crown produced by an extra formation of enamel

tubercle

Common locations for tubercles include ______ and ______.

lingual surfaces of maxillary teeth and lingual surfaces of maxillary molars

Where is the cusp of carabelli located?

maxillary first molars

Lobes are defined as ______.

a primary division of the tooth

The ____ pattern plays a part in the form and function of each individual tooth.

lobe

All anterior teeth are composed of _____ lobes.

Four

What are the lobe names of anterior teeth?

• 3 labial lobes

  • mesiolabial

  • middle labial (labial)

  • distolabial

• 1 lingual lobe (cingulum)

The three labial lobes on permanent anterior teeth are sometimes found on newly erupted incisors, called ______.

mamelons

The permanent anterior teeth have two ______ found on the labial surface.

shallow developmental depressions

The shallow depressions found on labial surface of anterior teeth are ___ & ____

mesiolabial & distolabial developmental depressions

Most permanent premolar teeth exhibit _____ lobes.

four

What are the names of the premolar lobes?

• 3 Buccal

  • mesiobuccal

  • middle buccal

  • distobuccal

• 1 Lingual

The premolar teeth that have 4 lobes

maxillary premolars & mandibular 1st premolar

Developmental depressions can be seen on the _____ surface between lobes.

buccal

What premolar tooth is an exception to the 4 lobe rule and has 5 lobes?

Mandibular 2nd premolar

Lobes on the mandibular 2nd premolar

• 3 Buccal

  • mesiolabial

  • middle buccal

  • distobuccal

• 2 Lingual

  • mesiolingual

  • distoliwngual

Evidence of lobe separation on premolar teeth

• central groove

• lingual groove

• developmental depressions (between 3 buccal lobes)

The permanent maxillary molars are composed of _____ lobes.

four

The 4 lobes of maxillary molars are _____.

• 2 Buccal

  • mesiobuccal

  • distobuccal

• 2 Lingual

  • mesiolingual

  • distolingual

__________ DO NOT exhibit developmental depressions.

Molars

Evidence of lobe separation on maxillary molars include

• central groove

• distolingual groove

• buccal groove (separates 2 buccal lobes)

The _____ are the only molars with 5 lobes.

Mandibular 1st molars

The 5 lobes of mandibular 1st molars are

• 3 Buccal

  • mesiobuccal

  • distobuccal

  • distal (small lobe)

• 2 Lingual

  • mesiolingual

  • distolingual

What lobe separates the distobuccal and distal lobes on mandibular 1st molars?

distobuccal groove

Evidence of lobe separation on mandibular 1st molars

• central groove

• buccal groove

• distobuccal groove

• lingual groove

The other mandibular teeth are composed of _____ lobes.

four

Lobes on permanent mandibular teeth (excluding 1st)

• 2 Buccal

  • mesiobuccal

  • distobuccal

• 2 Lingual

  • mesiolingual

  • distolingual

Evidence of lobe separation on permanent mandibular teeth

• central groove

• buccal groove

• lingual groove

A two dimensional curve of the occlusal plane in the anterior-posterior direction

curve of spee

The Curve of Spee begins at ________ and follows the ________ of the premolars and molars posteriously.

beings at the tip of the canines and follows the buccal cusp tips of the premolars and molars posteriously.

Root inclinations needed to form curve of spee

• maxillary teeth - inclined to mesial

• mandibular teeth inclined to distal

Crowns are in the ____ direction of root inclinations in curve of spee.

Maxillary crowns - inclined to distal

Mandibular crowns - inclined to mesial

A two dimesional curve of the occlusal plane in a medio-lateral direction

curve of Wilson

Root inclinations needed to form curve of Wilson

maxillary - inclined to lingual

mandibular - inclined to buccal

Sphere of monson is also called

compensating occlusal curvature

a three dimensional curvature of the occlusal plane

sphere of monson

The sphere of monson curvature is _____ for the mandibular arch.

Concave

The sphere of monson curvature is _____ for the maxillaryarch.

Convex

The axial position is the angulation of the teeth with respect to the _________.

alveolar bone

For the axial position of maxillary anterior teeth, the root inclines toward the _____.

lingual (palate)

For the axial position of maxillary anterior teeth, the incisors’ root inclines _____ in the mesial/distal direction

nearly straight in mesial/distal direction

Maxillary canine roots of incline toward the _____

distal

For the axial position of maxillary premolar teeth, the root inclines toward the _____ & ______.

lingual (palate) & distal

For the axial position of maxillary molars the root inclines toward the _____ & ______ .

lingual (palate) and distal

For the axial position of mandibular anterior teeth, the root inclines toward the _____.

lingual

For the axial position of mandibular anterior teeth, the incisor root inclines toward the _____.

nearly straight in mesial/distal direction

For the axial position of mandibular anterior teeth, the canine root inclines toward the _____.

distal

For the axial position of mandibular premolar teeth, the root inclines toward the _____.

distal

For the axial position of mandibular premolar teeth, the 1st premolar root inclines slightly toward the _____.

lingual

For the axial position of mandibular premolar teeth, the 2nd premolar root inclines slightly toward the _____.

buccal

For the axial position of mandibular molar teeth, the roots incline toward the _____ & ______.

buccal and distal

Rule #1 of root shape: Roots are normally widest toward the _____ area and taper toward the _____.

widest toward the cervical area and taper toward the apex

Rule #2 of root shape: _____ teeth and _____ normally have single roots. (except maxillary 1st premolar)

Anterior teeth & premolars

Rule #3 of root shape: __________ normally possess three root branches (one lingual, two buccal)

Maxillary molars

Rule #4 of root shape: ______ molars normally have two root branches (one mesial, one distal).

Mandibular

Which premolar has 2 root branches?

maxillary first

Which teeth are a single root?

anterior teeth and premolars (except maxillary first premolar)

Which teeth have two roots?

maxillary first premolar

• one palatal and one buccal

mandibular molars

• one mesial and one distal

Which teeth have three roots?

maxillary molars

• one mesiobuccal, one distobuccal, one palatal

________________ are aligned into one continuous valley in each quadrant.

The continuity of central grooves

Continuity of central grooves allows for a trough ____________ through the centers of the occlusal surfaces of the posterior teeth

antero-posteriorly

The continuity of central grooves allows for

more efficient food flow pattern during mastication

The height of ____________ ofadjacenteeth in the same arch should be at the same level.

marginal ridges

Adjacent marginal ridges are normally shaped so that they create a small _________ between posterior teeth or ________ between anterior teeth.

occlusal embrasure between posterior teeth

he between anterior teeth

The amount of ______________ seems to be related to the width and lengths of the crown, as well as the location of the contact areas.

cervical line curvature

Rule for cervical line curvature:

1. The cervical line is normally curved toward the _______ on facial and lingual surfaces.

apical

Rule for cervical line curvature:

2. The cervical line is normally curved toward the ________ on the mesial and distal surfaces

incisal (occlusal)

Rule for cervical line curvature:

3. The depth of the cervical line curvature on any individual tooth is normally greater on the ______, compared to the _____ surface.

greater on mesial; compared to the distal

Rule for cervical line curvature:

4. Cervical lines on adjacent proximal surfaces of adjacent teeth have approximately the same _________.

depth of curvature

Rule for cervical line curvature:

5. The depth of the curvature on all surfaces is greater on _________ and decreases posteriorly.

central incisors

Mesial cervical line curvatures range from _____ to _____.

3.5 mm to 1 mm

Distal cervical line curvatures range from _____ to _____.

2.5 mm to 0 mm.

1. The height of contour on the facial surfaces of all anterior and posterior teeth is located in the _______ third.

cervical

2. On anterior lingual surfaces, the lingual height of contour is located in the ______ third.

cervical

3. On posterior lingual surfaces, the lingual HOC is located in the ____ third.

middle or occlusal

How great is the contour in maxillary dentition?

½ mm or less

How great is the contour in mandibular dentition?

½ mm or less, ¾ mm (facial surface of 2nd premolar), 1mm (facial surface of 1st molar and 2nd molar)

The ____ are the termination of the embrasure.

line angles

There should be symmetry in the location of line angles of ____ teeth.

adjacent

Line angles are more noticeable when viewed from the _____ aspect.

incisal (occlusal)

The open space between the proximal surfaces of two adjacent teeth in the same arch, where they diverge facially or lingually, and incisally or cervically from the contact area.

Embrasures

Embrasures provide _______

a passage through which food escapes from the occlusal surfaces during mastication; also service as integral part of self-cleaning process

1. Incisal (occlusal) embrasures increase in relative size from the ______ to ______.

anterior to posterior

2. Cervical (gingival) embrasures decrease in relative size from _____ to _____.

anterior to posterior

3. The labial and lingual embrasures are nearly ____ in size in anterior teeth

equal

4. The lingual embrasure is normally _____ than the buccal embrasure in posterior teeth.

larger

5. When one side of an embrasure has a certain contour, the other side of the embrasure will

normally have a similar contour

The triangular shaped area (inter proximal space) between adjacent teeth in same arch is formed by what?

• the alveolar bone at its base

• proximal surfaces of addict teeth on its sides

• contact area of the adjacent teeth at its apex

Normally the contact areas ____ in size with age, due to abrasion between proximal surfaces

increase

Proper location of contact areas aids in ____ and prevents ____.

stabilization of dental arch and prevents food from slipping between teeth

1. contact areas become more _____ located from anterior to posterior

cervically

2. On an individual tooth, distal contact is _____ than mesial contact.

more cervical

3. Contact area - Size _____ from anterior to posterior

increases

4. Anterior teeth contact areas are normally centered _____

labiolingually