FIGURE 1.

Human primary failure of eruption (PFE) molars are associated with tooth root anomalies including truncation and dilacerations. (a,b) 3D surface model overlays: mandibular superimposition of registered right and left hemisections (original and mirrored) within the same patient. Composite 3D computed tomography (CT) images of the mandible, views from the lingual side. (a) Registration was done using the cranial base. Familial PFE patient with unilateral posterior abnormality, PTH1R, c.356 C > T, p.P119L missense mutation. (b) Regional registration was done using the body of the mandible as reference. Sporadic PFE patient with bilateral posterior abnormality, PTH1R, c.395 C > T, p.P132L, missense mutation. Light green and red: teeth and jaw on the affected/severe mandibular hemisection, respectively. Beige and green: teeth and jaw on the contralateral/mild side, respectively. Yellow arrows: asymmetry of the mandibular body, yellow arrowheads: first molars associated with pronounced PFE phenotypes and tooth root anomalies. (c-f) Composite 3D surface model overlay of the mandibular first molars, views from the buccal side (c,e) and the mesial side (d, f). Bilateral first molars were superimposed on the crown. Light green: teeth on the affected/severe side, beige: teeth on the contralateral/mild side. Blue arrowheads: dilacerations (curved roots), green arrowheads: truncation (short roots) associated with dilacerations