Table 1.

Characteristics of the study and control groups.

Characteristic	PTC Group (n = 43)	Control Group (n = 17)	p
Mean age	11.8 years	11.4 years	p = 0.34
Sex (male/female)	20/23	7/10	p = 0.45
Opening pressure (cm H2O)	40	24	p ˂ 0.001