Ankylosis
Pronunciation: an-kih-LOH-sis
Abnormal fusion of a tooth to the surrounding alveolar bone, eliminating the normal periodontal ligament space.
Full Definition
Dental ankylosis occurs when cementum or dentine fuses directly with the alveolar bone, obliterating the periodontal ligament. It most frequently affects primary molars and can result in infraocclusion, where the ankylosed tooth appears to 'submerge' below the occlusal plane as the alveolus continues to grow. Radiographically, loss of the normal periodontal ligament space is the hallmark finding. Editors working on pediatric dentistry or orthodontic manuscripts should note that 'ankylosis' in the dental context differs from 'temporomandibular joint ankylosis,' which refers to fusion within the joint itself. The adjective form is 'ankylosed.'
Usage
Usage note: In dental copy, always specify 'dental ankylosis' or 'TMJ ankylosis' to avoid ambiguity, as the term is also used in general medicine for joint fusion.
In Context
- "Ankylosis of the lower left second primary molar was confirmed by the absence of a periodontal ligament space on the periapical radiograph." — Pediatric dentistry case note
- "The author uses 'ankylosis' and 'infraocclusion' interchangeably, but these are distinct findings requiring separate descriptions." — Manuscript editing comment