Concrescence is mostly seen in the maxilla, but it can be observed in the mandible. Although it is a rare condition, concrescence may be seen between a third molar and supernumerary fourth molar.

Schematic showing how loss of PTH1R signaling disrupts Smad3 and Wnt pathways, driving abnormal cementum growth and pathological tooth-bone fusion. Teeth remain securely attached to the jaw through a ...