PeriodonticsIntermediate

Tooth mobility grades

Mobility is measured in grades according to how much the crown moves: from 0 (normal) to 3 (severe).

Diagram drawn by Odonto Fácil

What you need to know

Grade 0: normal (physiological) mobility. All teeth move a tiny bit, about 0.2 mm, thanks to the ligament.
Grade 1: a little more than normal, up to about 1 mm horizontally.
Grade 2: moderate, between 1 and 2 mm horizontally.
Grade 3: severe, more than 2 mm horizontally, or the tooth sinks when pressed (vertical mobility).
Causes: periodontitis and bone loss, bruxism, occlusal trauma, root problems and pulp inflammation.
The exact millimeters vary a little from author to author; what does not change is the order of the grades.

Physiological mobilityThe small, normal movement that the periodontal ligament allows.

Occlusal traumaDamage to the tooth's support from excessive biting forces.

Miller indexThe 0 to 3 scale used to measure mobility.

A tooth moves more than 2 mm and sinks when pressed. What grade is it?

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Grade 3.

Kim GY, et al. Advancements in Methods of Classification and Measurement Used to Assess Tooth Mobility: A Narrative Review. J Clin Med. 2023;13(1):142. View source