Vertical maxillary asymmetry: a prevalent lateral roll in spatial orientation.

Vertical maxillary asymmetry (VMA) is a condition characterized by distinct morphologic features: dentoalveolar asymmetry, canted nasal floor and occlusal plane, and asymmetric lip elevation. An extensive literature search failed to produce depictions of differential vertical asymmetry in conditions other than specific congenital or pathologic symptoms, the most prominent of which are presented in this report for comparison with VMA. The records of nine patients illustrate the localized nasal/maxillary/occlusal vertical asymmetry, which does not affect the orbits or the mandible. Although a prevalent rotational roll in spatial orientation is observed with VMA, many patients exhibit deviations in the other rotational planes of space (pitch and yaw). Potential etiology includes dentoalveolar compensation to localized skeletal or dental disturbances and possibly neuromuscular origins. Treatment approaches, prevention, and research avenues are discussed. Regardless of future confirmation of VMA as an independent entity encompassing hard and soft tissue components, its establishment as a phenotype associated with malocclusion warrants its inclusion in orthodontic diagnosis, with a possible impact on treatment planning and conduct. Moreover, its introduction as a diagnostic feature of malocclusion justifies the incorporation of the posteroanterior cephalograph as a key pretreatment record in orthodontics.