Oral Anatomy [LEC] - Surfaces & Landmarks of Teeth

Marginal Ridge
Triangular Ridge
Transverse Ridge
Oblique Ridge
Labial Ridge
Buccal Ridge
Lingual Ridge
Cervical Ridge

Marginal Ridge
Triangular Ridge
Transverse Ridge
Oblique Ridge
Labial Ridge
Buccal Ridge
Lingual Ridge
Cervical Ridge

Types of Ridges

Triangular Ridge

Descends/ inclines from the tip of the cusp towards the center or part of the occlusal surface.

Present only on premolars and molars.

Named according to the cusp and its location

Transverse Ridge

Present particularly on the occlusal surface of premolars and mandibular molars

Oblique Ridge

Present only on the occlusal surface of maxillary deciduous 2nd molar and all the permanent maxillary molars

Inclined Planes

The sloping are found between two cups ridges.

Valley

Fossa

An irregular depression or concavity on surface of tooth

Central Pit

Center of occlusal fossa where development grooves join

Lingual Fossa

Found on lingual surface of incisors and cuspids

Central Fossa

Depressions on center of occlusal surface of maxillary and mandibular molars

Sulcus

A long depression on the surface of a tooth between ridges and cusps the inclines of which meet at an angle

Groove

A shallow linear depression on the surface of a tooth

Developmental Groove

It usually separate lobes or major part of the tooth

Tubercle

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

Canine Eminence

Prominent on the labial surface of the root surface of the permanent maxillary surface

Developmental Depression

Long narrow linear depression on the long axis of the mesial and distal surfaces of the root of the tooth

Found during the development of the tooth

Facial Surface
Lingual Surface
Proximal Surface
Incisal or Occlusal Surface

Crowns of all teeth have 5 surfaces, namely...

Facial Surface

May be labial or buccal surface

Labial Surface

Surfaces of incisors and canines that are towards the lip

Buccal Surface

Surfaces of premolars and molars that are toward the face cheek

Lingual Surface (Palatal Surface)

Surfaces facing the tongue

Mesial Surface & Distal Surface

Two types of Proximal Surfaces

Mesial Surface

Surface towards the midline

Distal Surface

Surface away the midline

Incisal Edge
Occlusal Edge

Two types of Incisal or Occlusal Surface

Incisal Edge

The surface of incisors and canines that come in contact with those in the opposite jaws during the act of closure are called _____

Occlusal Surface

The surface of the premolars and molars that come in contact with those in opposite jaws during act of closure are called _____

Occlusal Table

Come in contact during mastication. Also known as Occlusal Surface.

Cusp

A pointed or rounded elevation or mound on the crown of a tooth.

Can be found on molars, premolars, cuspid, and bicuspid

Cusp

Peak

Present in occlusal

Chewing grinding

Mesial and Distal Cusp Slope

Inclined surfaces that from an angle at the tip of the two cusps

Mesial and Distal Cusp Slope

2 cusp slopes / cusp ridge slopes

Cingulum

Is the lingual lobe of an anterior tooth and makes up the bulk of the cervical third of the lingual surface.

Maxillary anterior & Permanent dentition

Cingulum is prominent to ______ teeth

Girdle or Belt

Other name of Cingulum in Latin

Lobe

Is one of the primary sections of formation in development of crown of a tooth

Cusps & Mamelons

Representative of lobes

Mamelons

Are three rounded protuberances found on incisal ridges of newly erupted incisor teeth

Mamelons

Small rounded protuberance/ projections

Prominent on edges of newly erupted permanent
incisors maxillary and mandibular

3 Facial / Labial
1 Palatal / Lingual

4 Lobes of anterior teeth

Mesial Lobe
Middle Lobe
Distal Lobe
Cingulum / Palatal Lobe

Name the 4 lobes of anterior teeth

Mesial Lobe

Largest lobe

Middle Lobe

Smallest lobe

Grooves

Separates the lobes in mamelons

In posterior teeth, the number of lobes is to the number of cusps

Ridge

A linear elevation on the surface of a tooth and is named according to its location and or form.

Marginal Ridges

Linear round borders of the enamel that form the mesial and distal margins of the occlusal surfaces of the posterior teeth or the lingual surfaces of the anterior teeth.

Can only be seen on the margins of the teeth

Transverse Ridge

Formed by the union of the buccal and lingual triangular ridges that crosses the surface of the posterior teeth in transverse direction

90

Transverse Ridge: about __ degrees to both the buccal and lingual surfaces

Oblique Ridge

Is formed by the union of triangular ridges of the mesio-lingual and distal ridge of distobuccal cusp in oblique direction

Oblique Ridge

Is a ridge crossing obliquely the occlusal surfaces of maxillary molars and formed by the union of the triangular ridge of the distobuccal cusp and the distal cusp ridge of the mesio-lingual cusp.

Labial Ridge

On the labial surface of the tooth that runs cervico-incisally almost at the center of the labial s.

Labial Ridge

Prominent labial ridge running from cusp tip to the cervical area

Buccal Ridge

Runs cervico-occlusally approximately at the center of the buccal surface

Lingual Ridge

Found on center of lingual surface of tooth which extends from cingulum to the cusp tip in the permanent canine and posterior teeth

Cervical Ridge, Neck of the teeth

Runs mesio-distally at the cervical third of the labial surface of the crown that is present particularly on the deciduous teeth and only on the permanent molars also known as ____

Mesial Cusp Ridge
Distal Cusp Ridge
Triangular Ridge
Buccal Ridge

Cusp ridge is made up of?

4

Cusp Ridge: Each cusp has ____ cusp ridge extending in different directions from its tip

Pit

A sharp pinpoint depression on the surface of enamel

Small Defect

Pit is sometimes called a ____ _____ on the enamel crown of tooth.

Buccal Pit
Central Pit
Lingual Pit

Examples of Pit

Buccal Pit

Terminal part of buccal developmental groove

Major Fossa

Central Fossa is considered as?

Minor Fossa

Triangular Fossa is considered as?

Triangular Fossa

Situated next to the distal and mesial marginal ridges (mesial triangular fossa and distal triangular fossa)

Developmental Groove

Is a short, shallow groove or line between the primary parts of the crown or root.

Supplemental Groove

Is less distinct and does not mark the junction of primary parts

Developmental Depression

Long and narrow linear depression on the long axis of the tooth found on the mesial and distal surfaces of the root of the tooth during the development of teeth.

Accidental Grooves

Grooves that are not supposedly there

Groove & Inclines

Can be seen in sulcus

Sulcus

Valley or long depression

Fissures

Sometimes can cause cavity

U
V
I
IK
Inverted Y

Types of Fissures

Fissures

Long narrow channel or cleft located at the depth formed during the development of the tooth

Eminence

Prominence or projection of a bone or enamel on a tooth surface

Part of the root that is very bulgy

Line

Two surfaces meet

Point

Three surfaces meet

6

Number of line angles of anterior teeth

8

Number of line angles of posterior teeth

4

Number of point angles of anterior and posterior teeth

Cervical third

Middle third

Incisal/occlusal third

Division of thirds occluso-gingiually

Medial third, middle third, distal third

Division of thirds mesio-distally (crown)

Labial third, middle third, lingual third

Division in thirds facio-lingually (crown)

Cervical third, middle third, apical third

Division in roots

Inclined plane

Sloping area found between two cusp ridges, each cusp exhibits four of these

Cusp ridge

Extending in a different direction from the cusp tip

Central groove

Also known as Lewis offset

Crest of curvature

Greatest convexity or bulge

Contact area

More broader and applicable on the posterior teeth

Contact point

Applicable on the anterior teeth

Diastema

An open space between two adjacent teeth

Interproximal space

The area between the teeth

Interdental papilla

A triangular fold of gingival tissue

Embrasure

Part of the interproximal space not occupied is called?

Central axis of tooth

Where the highest convexity can be found

Embrasure

Means " spillways “ / potential v-shaped space that surrounds the contactarea

Palatal / lingual embrasures

Largest among other embrasures because of the teeth is being designed or curved