Abnormal dental physiology Dental hypermobility Dental hypermobility is the loosening or excessive movement of a tooth within its socket beyond its normal physiological limits. 2026-08-02T09:51:37Z The Miller classification of dental hypermobility defines grade 1 as the first distinguishable sign of movement greater than normal; grade 2 as a movement of a tooth that allows its crown to move one millimeter from its normal position in any direction; and grade 3 as movement of more than one millimeter. Teeth that may be rotated or depressed in their alveoli are classified as grade 3.