A hairbrush 10 has rounded outer surfaces 23, 25 of hinged heads 22, 24 that, when the brush is closed, achieve a closed form that is generally round or spherical in cross-sectional shape. Another aspect of the present invention includes inner head surfaces 26, 28 that support bristles and that are complementarily shaped concave and convex, respectively, to hold a tuft of hair in a curved position as the tuft is pulled through the closed heads.