A group of 31 patients whose mandibles had been augmented surgically with various methods using hydroxylapatite granules between 1984 and 1987, were followed-up to rate their subjective and objective masticatory function. The subjective assessment of the treatment result is comparable to the opinion given about vestibulo- and floor of the mouth-plasty. Masticatory function determined according to the method of fractionated sieving of the chewed food did not show any significant differences from the function measured in complete denture patients with strong alveolar bones. The need for regular follow-up is emphasized.