Ankylosis in teeth occurs when the cementum fuses directly with the alveolar bone, leading to the loss of the periodontal ligament space. This fusion prevents normal tooth movement and eruption, making the tooth immobile and fixed within the socket. The absence of the periodontal ligament disrupts the tooth’s ability to withstand functional forces properly. Clinically, ankylosed teeth often present with infraocclusion and a characteristic metallic sound on percussion. Surgical interventions must recognize the direct bone-to-cementum contact to avoid complications during extraction or orthodontic treatment.

Reference: Oral Pathology, Neville et al., 4th Edition.