The authors suggest a taxonomy and a specific terminology from Greek etymology for vertical maxillo/mandibular excess dysmorphies, "long face" or "high face" (hypsoprosopia) to be more exact, so as to make their diagnosis and their therapeutic approach easier. They distinguish three anomalies which may, separate or in association, cause an increased vertical dimension of the face: hypsomaxillia, hypsogenia and inter incisal anterior vertical gap or hyposostomy, which may itself be differentiated into 3 aetiological sites (vertical posterior maxillary dento-alveolar excess, vertical anterior mandibular dento-alveolar deficiency, excessive gonial angle opening or amblygonia). They submit a clinical and teleradiographic table specific for each anomaly, relying on patients having achieved their full dento-osseous growth. When confronted with associated cases, they can therefore more systematically apply the various osteotomies, partial or total, maxillary or mandibular, or even combined operations.