Tooth 71 (FDI): mandibular left primary central incisor

The three numbers

About this tooth

Name

Mandibular left primary central incisor

Set

Baby (primary)

Position

Lower arch, patient left (lower left, quadrant 7)

Erupts

6 to 10 months

Sheds

6 to 7 years

Crown surfaces

Mesial, distal, labial (facial), lingual and incisal.

Also written

Letter O (Universal), 7.1 (FDI with a dot), lower left A

Read on 23 October 2026. Sources: American Dental Association, Tooth development charts (primary and permanent); Dental anatomy, citing Ash and Nelson, Wheeler's Dental Anatomy, Physiology and Occlusion. Ages and counts are usual figures, and teeth vary from person to person.

On the chart

Teeth next to it

• Toward the middle: 81 (mandibular right primary central incisor)
• Toward the back: 72 (mandibular left primary lateral incisor)
• Across the midline: 81 (mandibular right primary central incisor)
• In the other arch: 61 (maxillary left primary central incisor)

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