Table 3. Mean Radiation dose (D_mean) to oral cavity and its subunits.

Primary		Oral cavity	p-value	Oral Tongue	p-value	Lips	p-value
Tonsil (n = 8)	IMRT-N	39.3 ± 5.6 Gy		42.5 ± 5.3 Gy		15.8 ± 4.2 Gy
	IMRT-S	35.9 ± 6.2 Gy	< 0.001	37.6 ± 6.2 Gy	< 0.001	13.2 ± 4.5 Gy	< 0.001
Larynx (n = 5)	IMRT-N	27.9 ± 6.2 Gy		30.9 ± 5.4 Gy		16.8 ± 0.3 Gy
	IMRT-S	24.2 ± 7.3 Gy	< 0.001	25.2 ± 6.2 Gy	< 0.001	14.5 ± 1.6 Gy	0.1282
Total (n = 13)	IMRT-N	34.9 ± 8.0 Gy		38.1 ± 7.9 Gy		16.0 ± 3.7 Gy
	IMRT-S	31.4 ± 8.7 Gy	< 0.001	32.8 ± 8.8 Gy	< 0.001	13.5 ± 4.0 Gy	< 0.001

IMRT-N: Intensity Modulated Radiation Therapy with Neutral tongue position; IMRT-S: Intensity Modulated Radiation Therapy with “stick-out” tongue position; Primary: Primary site of caner; Gy: gray; p-value using t-test, Data are presented as mean ± standard deviation.