Introduction: Escalating use of cone-beam computed tomography contributes to a burgeoning public health issue regarding the amount of ionizing radiation associated with diagnostic imaging delivered to the population, especially children. Methods: Effective doses were calculated and compared from optically stimulated dosimeter measurements and a previously validated protocol using anthropomorphic adult and child phantoms scanned with the Accuitomo 170 (J. Morita, Japan) and MiniCAT (Xoran Technologies, Ann Arbor, MI) CBCT machines. Results: Average child phantom doses (440 and 117 µSv) were 60% and 56% greater than the adult doses from the Accuitomo 170 and MiniCAT units respectively. Thyroid dose, particularly to the child, had a significant contribution to the overall dose. Conclusion: Effective dose for the two units increased as FOV increased. The child dose, especially the thyroid, increased when compared to the adult phantom. Child protocols and the smallest FOV helps reduce the child's effective dose.