Concrescence diagnosis using Cone Beam CT. A case report

Abstract

Background: Dental concrescence (DC) is an anomaly of dental development where the roots of two or more adjacent teeth are joint by root cement^1,2. It has a prevalence of 0.2 - 3.7% in primary dentition and 0.8% in permanent dentition^1-6. It is usually diagnosed during tooth extraction or as a radiographic finding^3,7. This anomaly can affect the planning and outcome of endodontic, periodontal, prosthodontic, orthodontic, and extractions treatments^4,6. 

Clinical Presentation: Male patient, 18 years old, shows up at the dental office for orthodontic evaluation. The d.D.S requested a panoramic radiography, in which semi-included 2.7 was observed with a projected root in the distal root zone of 2.6. After radiographic finding, a CBCT of 2.6-2.7 area was requested with a FOV of 4x4 cm and a voxel size of 125 μ to evaluate possible impaction of said molars. Individual axes of each root were corrected, and a multiplanar evaluation of the area under study was performed, showing tooth 2.6 with great bone defect and distal furcation involvement, with long and divergent roots. Partially erupted tooth 2.7 with mesiobuccal root (MB) with hypercementosis and mesial profile fused with the distal surface of the distobuccal root (DB) of tooth 2.6 in its apical third. Images were compatible with DC amid teeth 2.6-2.7. 

Clinical Relevance: DC occurs exclusively in the posterior maxillary area, mainly among the maxillary second and third molars^3,4,9,10. In the present case, teeth involved were in the posterior maxillary region but corresponded to a first and second molar.

DC is usually diagnosed during tooth extraction or as a radiographic finding since its clinical detection is practically impossible^3,4,6,7,9. Given the limitations inherent to two-dimensional radiographic images, such as distortion and superposition of structures, the use of CBCT is extremely useful, since it eliminates these limitations and allows a three-dimensional examination, thus improving diagnostic precision^{3,5,6,8 -10}. 

Conclusion: Given the suspicion caused by a two-dimensional image, the indication of CBCT provides relevant information for the correct and precise diagnosis of DC, and its subsequent treatment-planning, minimizing risks associated.