A system of nomenclature for deformities of the alveolar process is presented. Descriptive, familiar topographic terms are used (crater, trench, moat, ramp and plane), and specific criteria are given for each term. Two hundred randomly selected osseous deformities in dry skulls were classified by two examiners at independent sessions using the proposed system. One hundred ninety of these defects were given identical descriptions. The nomenclature system is proposed to facilitate communication among practitioners concerning osseous deformities of the alveolar process, as well as to permit comparison of the effectiveness of various therapeutic modalities directed toward bone regeneration in periodontics.