Etiology and treatment of tooth ankylosis

Abstract

1. 1. Tooth ankylosis, the fusion of bone and cementum, is a progressive anomaly of tooth eruption which usually has a profound effect on the occlusion. 2. 2. Deciduous teeth become ankylosed far more frequently than do permanent teeth, the ratio being better than 10 to 1, and lower teeth are ankylosed more than twice as often as upper teeth. 3. 3. Tooth ankylosis exhibits selectivity as to site (nearly all ankylosed teeth are molars, deciduous or permanent) and selectivity as to physiologic time (nearly all ankyloses occur in the deciduous or mixed dentitions). 4. 4. Tooth ankylosis is not likely to be of random or accidental origin; nor is excessive or traumatic pressure a probable cause, although the latter enjoys wide acceptance as a possible explanation. Tooth ankylosis may be due to a disturbed metabolism. 5. 5. Treatment depends upon whether the ankylosed tooth is deciduous or permanent, the time of onset, the time of diagnosis, and the location of the affected tooth. There are six possible situations: 5.1. A. If the ankylosed tooth is deciduous and has a successor, the general rule is to extract immediately and, if necessary, to insert an appropriate space maintainer. 5.2. B. If the tooth is deciduous and without a successor and the onset is early so that “submergence” is threatened, treatment involves extraction and space maintenance. 5.3. C. If the tooth is deciduous and without a successor and the onset is late, proximal and occlusal contacts may be built up at maturity. 5.4. D. If the ankylosed tooth is permanent and the onset is early, the tooth should be luxated. If repeated luxation proves ineffective, the tooth should be extracted. It should not be permitted to “submerge.” 5.5. E. If the onset of ankylosis is late, the permanent tooth should be luxated. If the attempt is unsuccessful and the tooth does not “submerge,” it may be built up at maturity. 5.6. F. A deeply “submerged” ankylosed tooth, deciduous or permanent, should be left undisturbed unless it is infected or constitutes an immediate or potential threat to the occlusion.