What describes Class 3 mobility?

Class 3 mobility is characterized by significant displacement of the tooth, specifically greater than 2 mm, or movement that indicates bouncing in its socket. This level of mobility usually signifies severe compromise of the supporting structures, such as the periodontal ligament and alveolar bone, often associated with advanced periodontal disease. The presence of such pronounced movement indicates that the tooth is not stable and is at a high risk for loss, necessitating clinical intervention. The other descriptors provided do not meet the criteria for Class 3 mobility, which is specifically defined by this degree of movement and instability.