Low-dose protocol of the spiral CT in orthodontics: comparative evaluation of entrance skin dose with traditional X-ray techniques

Progress in Orthodontics

Table 1 Absorbed doses (mGy)

X-ray technique	Right eye lens		Left eye lens		Right parotid gland		Left parotid gland		Right thyroid gland		Left thyroid gland
	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD
LC	0.06	0.012	0.09	0.021	0.04	0.0098	0.3	0.052	0.06	0.013	0.07	0.017
PAC	0.28	0.04	0.31	0.056	0.03	0.0087	0.05	0.011	0.07	0.018	0.04	0.009
PR	0.07	0.016	0.08	0.019	0.52	0.14	0.49	0.12	0.08	0.039	0.07	0.0195
LC + PAC + PR	0.41	0.097	0.48	0.101	0.59	0.158	0.84	0.32	0.21	0.097	0.18	0.022
Low-dose CT	0.57	0.11	0.58	0.12	0.78	0.289	0.79	0.30	0.18	0.081	0.17	0.067

For each X-ray technique and organ, the doses have been registered five times. The mean value and the standard deviation (SD) are reported.