Module 5 - Maxillary Incisors

Permanent Anterior Teeth Characteristics & Terms 

• Developmental Depressions

• Triangular

• Contact Area

• CEJ Curvature

• Cingulum & Marginal Ridge

• Fossa

• Grooves & Pits

• Single Rooted

• Esthetic Concerns

General Features of Permanent Maxillary Incisors (Central & Lateral Incisors #7-10)

• Size

  • Maxillary incisors larger than mandibular incisors

  • Maxillary central incisor larger than lateral, however, they resemble each other

  • Wider mesiodistally versus labiolingually

• Shape

  • Labial surfaces are rounded and tapered toward lingual

  • Incisal edge more toward labial when looking at proximal view

• Other Features

  • Lingual surface features more pronounced compared to mandibular incisors

  • Roots are short compared to other maxillary teeth

  • Usually without root concavities

Permanent Maxillary Central Incisors (#8 and #9)

• Erupt between 7-8 years

• Most prominent tooth in the permanent dentition because of their large size and anterior position

Root Features

• Root completely forms at age 10

• Single conical root with blunt apex

• Root length about the same length (or shorter) but wider than lateral

• Pulp cavity mirrors shape of tooth

• 3 horns in pulp chamber

Labial View Features

• Trapezoidal in shape

• Developmental depressions

• Imbrication lines

• Perikymata

• Sharper mesio-incisal angle

• The distal contact is located farther cervically than the mesial contact

Lingual View Features

• Cingulum

• Fossa

• Ridges

Proximal View Features

• The incisal edge is located slightly labial to the long axis of the tooth

• The incisal edge is sloped toward the lingual

• Mesial CEJ curvature greater than any other tooth

• Height of contour at cervical third

Incisal View Features

• The overall shape of the crown from the incisal view is triangular

• Cingulum toward the distal

• Mesial marginal ridge appears longer than distal

• Incisal edge located toward labial side of tooth

Avulsion

• Displacement of tooth from socket

• Maxillary central more at risk due to anterior and labial position

Diastema

• Space between teeth, open contact

• Common between maxillary centrals

Mesiodens

Extra tooth (supernumerary tooth) between #8,9 forms during tooth development

Permanent Maxillary Lateral Incisors (#7 and #10) Crown Features

• Erupt between age 8-9

• Very similar to central, just smaller

• Greatest degree of variation in form of any permanent tooth (except 3rd molars)

Root Features

• Root completion at age 11

• Single conical root that may curve slightly to the distal

• Apex of the root is more sharp, not rounded like maxillary central incisor

• About the same length of root as central (possible longer)

• Thinner than central

• Linguogingival groove may be present on root

• Pulp cavity has single pulp canal and single pulp chamber

Labial View Features

• Labial development depressions and imbrication lines are less common than on the maxillary central incisor

• Crown is smaller and less symmetrical

• Mesial contact is at the incisal third

• Distal contact is at the middle third

• Mesioincisal angle is sharper than the distoincisal angle

• Incisal angles more rounded compared to centrals

Lingual View Features

• More prominent cingulum compared to central incisor

• Deeper lingual fossa compared to central

• Pronounced marginal ridges

• Lingual pit more common on lateral versus central

• Linguogingival groove may be present, more common on lateral compared to central

Proximal View Features

• Crown triangular

• CEJ like central but less curvy

• CEJ more curved on mesial versus the distal

• Incisal edge usually labial to long axis of the tooth

Incisal View Features

• Crown from incisal view is round or oval not triangular like the central

• Mesiodistal measurement is wider than the labiolingual measurement

Developmental Disturbances of Maxillary Lateral Incisors

• Linguogingival groove

• Peg lateral

• Partial anodontia

• Tubercle/Talon cusp