Mandibular Central and Lateral Incisors: Differences and Features

General Features

• Position:
  • Mandibular central incisor is the first tooth from the midline.
  • Mandibular lateral incisor is the second tooth from the midline.
• Tooth Numbers: Varies in different tooth numbering systems due to position.
• Eruption Chronology:
  • Central incisor: 6 to 7 years.
  • Lateral incisor: 7 to 8 years.

Measurements

• Crown Length: Same in both incisors.
• Size: Lateral incisor is larger than central incisor in all dimensions except crown length.

Morphological Differences

Labial Aspect

• Crown Shape: Both have a trapezoidal crown shape.
• Incisal Surface:
  • Central incisor: Horizontal, perpendicular to the midline axis.
  • Lateral incisor: Not horizontal, angled due to the distal side tilting cervically.
• Contact Areas:
  • Both incisors have mesial and distal contact areas in the incisal third.
  • Central incisor: Both contact areas are at the same level.
  • Lateral incisor: Distal contact area is slightly cervically placed compared to the mesial.

Lingual Aspect

• Differences mirror those of the labial aspect.

Mesial Aspect

• Morphological Features: No differences between central and lateral incisors.

Distal Aspect

• Morphological Features: No differences between central and lateral incisors.

Incisal Aspect

• Incisal Ridge:
  • Central incisor: Horizontal and perpendicular to the labio-lingual axis.
  • Lateral incisor: Incisal ridge is angled due to a twist in the distal side of the crown toward the lingual direction.