Occlusal features of Chinese adults in Hong Kong.

The molar relations, overjet and overbite of 201 Hong Kong Chinese adults of mean age 20 years were studied. It was found that 63.7 per cent had Angle Class I, 16.4 per cent had Class II and 19.9 per cent had Class III molar relations. Of the sample studied, 69.7 per cent had normal overjets of two to four mm, 14.9 per cent had increased overjets and 15.4 per cent had reduced or reversed overjets. The most prevalent overbite was zero to one-third of the mandibular central incisor crown length (63.2 per cent of the sample); 31.3 per cent had overbites of one to two thirds of mandibular central incisor crown length; four per cent had overbites of more than two thirds of mandibular incisor crown length; and 1.5 per cent only had open bites.