[Labial incompetence and maxillodental dysmorphosis]. / Incompétence labiale et dysmorphose maxillo-dentaire.

A definition of labial incompetence is given and emptrasis placed on the fact that this is a symptom of maxillodental dysmorphism (MDD) and not of nasal dyspermeability. Pathogenic features are discussed, the relevant clinical and paraclinical diagnostic features of MDD outlined, and the different alveolodental and/or bony (maxillary or mandibular) dysmorphias responsible for labial incompetence described. Principles of orthodontic and surgical treatment are centered on re-establishment of a correct articulation and therefore labial competence.