[Median inter-incisor line. Clinical symptomatology].

Since unilateral mastication causes asymmetry of mouth and face, a child's interincisal midline can reveal the first signs of alteration of masticatory function. Early detection of the functional pathology, preferably before it has established itself as such, allows the clinician to correct it by means that are relatively unburdensome for the patient, thereby forestalling severe organic alteration and favouring proper, balanced occlusal development. Centering the mandible in stable centric occlusion, together with simple treatment promoting alternating bilateral mastication, allows the correct development of the growing patient's stomatognathic system.