Tooth 45 (FDI): mandibular right second premolar

The three numbers

About this tooth

Name

Mandibular right second premolar

Set

Adult (permanent)

Position

Lower arch, patient right (lower right, quadrant 4)

Erupts

11 to 12 years

Roots

1

Root canals

1

Crown surfaces

Mesial, distal, buccal, lingual and occlusal.

Also written

#29 (Universal), 4.5 (FDI with a dot), lower right 5, second bicuspid

Read on 23 October 2026. Sources: American Dental Association, Tooth development charts (primary and permanent); Number of roots and canals, from Ingle's Endodontics; 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: 44 (mandibular right first premolar)
• Toward the back: 46 (mandibular right first molar)
• Across the midline: 35 (mandibular left second premolar)
• In the other arch: 15 (maxillary right second premolar)

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