Corrección de mordida cruzada posterior vestibular en dentición primaria. Reporte de dos casos clínico

Posterior vestibular cross bite buccal cross or scissors bite occurs when the lingual cusps of the upper molars occlude buccally to the central pits of the lower molars or when the palatal surfaces of the maxillary teeth are in contact with the buccal surfaces of the lower teeth. They may be functional, caused by a lingual inclination of the lower molars or asymmetries in the mandible. The early treatment is recommended for normalize transversal relations and promote correct development of occlusion. Two cases of vestibular unilateral posterior cross bite in primary and early mixed dentition are presented. Case 1: male patient age 5, presented extensive carious lesions, normocclusion, vestibular unilateral posterior cross bite right side was treated with Bi Helix appliance, bands cemented to the second primary molars. Case 2: male patient age 5, presented extensive carious lesions, normocclusion and vestibular unilateral posterior cross bite left side was treated with direct composite tracks. In both cases was achieved satisfactory transverse relationship by correcting the vestibular cross bite. Conclusion: The posterior vestibular cross bite can occur due to occlusal interferences that produce mandibular deviation and inappropriate inclinations of primary molars. When this is the etiology, using direct composite tracks, elimination of premature contacts and lower expander type bi Helix is a successful treatment.