Concrescence of Teeth

Concrescence can be developmental or acquired. Loss of inter-dental bone and lack of periodontal functional stimulation can allow layers of cementum to unite between tooth roots.

The union involves cementum rather than enamel or dentine. It occurs almost always in the upper molar region and may involve an upper second and third molar.

Concrescence is most important when removal, orthodontic movement, or root-canal access is being considered. Joined roots can make these procedures more difficult and alter the surgical plan.

Two-dimensional images may not show the anomaly clearly. Panoramic radiography and cone-beam CT can show an unclear boundary between roots and help plan treatment before extraction.

If separation is biologically possible, one tooth may be sectioned and removed or moved away orthodontically; simply separating adjacent roots without changing their proximity can allow concrescence to recur. Extraction may be used when the union impairs appearance, hygiene, or causes disease.

Imaging, surgical complexity, and whether teeth are separated, moved orthodontically, or extracted can all shape the amount of clinical work needed. Cone-beam CT may be used for diagnosis and planning.

Removing concrescent upper teeth can fracture the maxillary tuberosity or the floor of the maxillary sinus. Sectioning before extraction may reduce this risk in suitable cases.

A developmental union cannot be prevented. Before extraction, thorough assessment and cone-beam CT in justified cases can identify joined roots and help avoid serious complications.