1) Coalescence 2) Developmental tooth pathology 
Concrescence is a condition of teeth where the cementum overlying the roots of at least two teeth join together. The cause can sometimes be attributed to trauma or crowding of teeth. Surgical separation of the teeth may be necessary if one is to be extracted. ...
• (n.) Coalescence of particles; growth; increase by the addition of particles.
Synonym: coalescence. ... 2. In dentistry, the union of the roots of two adjacent teeth by cementum. ... Origin: see concrement ... (05 Mar 2000) ... 
(kәn-kres´әns) a growing together of parts originally separate, such as of the roots of teeth. in embryology, the flowing together and piling up of cells.
Con·cres'cence noun [ Latin concrescentia .] Coalescence of particles; growth; increase by the addition of particles. [ R.] Sir W. Raleigh. 
Type: Term Pronunciation: kon-kres′ens Definitions: 1. In dentistry, the union of the roots of two adjacent teeth by cementum. Synonyms: coalescence
a growing together, as of tissue or embryonic parts; coalescence.