Maxillary Permanent Lateral Incisor Overview

Maxillary Permanent Lateral Incisor

• Chronology:

  • Appearance of the dental organ: 5 m.i.u.
  • First evidence of calcification: 1 year
  • Enamel completed: 4-5 years
  • Eruption: 8-9 years
  • Root completed: 11 years

• Type and Function:

  • Function: Incising food and aesthetics.
  • Number of Lobes: Four (three mamelons and cingulum)

• Relation:

  • Contacts the central incisor mesially and the mesial surface of the canine distally.

• No. of Surfaces: Four surfaces and incisal aspect.

• No. of Roots: One root.

• Labial Aspect:

  • Crown Outline: Trapezoid (short side cervically, long side incisally).
  • Outline: Slightly convex mesially, more convex distally, more curved than central incisor, cervical line convex root-wards.
  • Angles: Mesio-incisal angle rounded, disto-incisal angle more rounded

• Surface Anatomy:

  • Surface is more convex than the central incisor.
  • Cervical ridge located at cervical third.

• The Root:

  • Single root, longer than the upper central incisor root.
  • Tapers evenly to apical 1/3, then curves distally with a pointed apex.

• Lingual Aspect: -Same outline as labial aspect -Mesial and distal sides converge lingually, where the lingual surface is narrower than the labial surface. -Convergence accommodates the horseshoe-shaped alveolar process.

• Surface Anatomy Elevations and Depressions:

  • Cingulum (present at cervical 1/3)
  • Marginal ridges (mesial and distal).
  • Incisal ridge.
  • Lingual fossa (lies between previous elevations) -Lingual pit. -Elevations and depressions are more developed than the upper central incisor.

• Mesial Aspect:

  • Outline: Crown is triangular, base cervically, apex incisally; incisal ridge on a line that bisects the root center.
  • Labial outline convex at cervical 1/3 (cervical ridge), then slightly convex to incisal ridge.
  • Lingual outline convex at cervical 1/3 (cingulum), concave at lingual fossa, then slightly convex for incisal ridge.
  • Mesial cervical line convex incisally.
  • Labio-lingual measurement less than the central incisor by approximately 1mm; mesial surface is convex with the maximum convexity at the junction of the incisal and middle 1/3s, (the contact area).
  • Root appears longer than central incisor.
  • Cone shape, blunt apex, developmental depression.

• Distal Aspect:

  • Similar to mesial, but cervical line curvature is less (by 1mm).
  • Contact area located at middle 1/3 (more cervically).
  • Smaller and more convex than mesial.

• Incisal Aspect:

  • May resemble central incisor or a small canine.
  • Labio-lingual dimension is greater compared to the central incisor.
  • Cingulum is centered.

• Pulp Cavity:

  • Mesio-distal Section: Wide, conforming to the crown shape; no three pulp horns (only two).
  • Labio-lingual Section: Chamber pointed incisally, then follows the crown's cervical increase in dimension. -Root canal tapers gradually as it reaches the apex (apical foramen).

• Malformations:

  • Peg-shaped lateral incisor
  • Missing lateral incisor

• Differences between lateral and central incisors: This information is found in a separate question-and-answer section. Four differences are listed and detailed:

  • Size
  • Elevations and depressions
  • Incisal angles
  • Root

Explore the key features and characteristics of the Maxillary Permanent Lateral Incisor, including its chronology of development, function, and surface anatomy. This quiz will test your understanding of its structure and importance in dental anatomy.