Osteoradionecrosis of the mandible: a case series at a single institution

Table 3 ORN severity in relation to radiation modality, dose and time to diagnosis

	Stage 1	Stage 2	Stage 3	p value
Radiation modality ^∞	IMRT 4/4	IMRT 3/3	IMRT 1/5	p = 0.03*
Radiation modality ^∞	IMRT 4/4	IMRT 3/3	Conventional 4/5	p = 0.03*
Radiation dose (Gy), mean ± SD ^§	52.5 ± 5	60 ± 0	59 ± 9.86	p = 0.312^¶
Average time from radiation to diagnosis in months (range)	6.47 (3.0–12.0)	9.83 (6.0–11.9)	52.35 (9.0–129.6)	p = 0.056^¶

^∞ Modality information is missing on 1 patient with Grade 1 and 1 patient with Grade 3 disease.
^§ Dose information missing in 2 patients with Grade 3 and 1 patient with Grade 1 disease.
* Freeman-Halton extension of the Fisher exact probability test.
^¶ One-way Analysis of Variance (ANOVA).
IMRT intensity modulated radiation therapy.
SD standard deviation.

ISSN: 1916-0216