Relationship between oro and nasopharynx permeability and the direction of facial growth

Most scientific literature relates vertical growth to individuals with decreased upper airway permeability. However, we often find subjects with a long face and a normal breathing pattern, most likely caused by other aetiological factors. And, frequently, we also find decreased upper airway permeability with horizontal growth. The aim of the study was to compare the cephalometric measurements of the oro and nasopharynx permeability with the facial growth direction and to identify the most common facial growth direction in individuals with decreased upper airway permeability.

Cephalometric analysis was carried out in 158 pre-adolescent patients at the Orthodontic appointment, using facial profile teleradiographs. Parameters used were Jabarak's ratio and measurement of oro-nasopharynx space. Data collected were submitted to statistical treatment.

This study points to the presence of an intermediate growth in individuals with diminished oro and nasopharynx permeability, either simultaneous or separate. The number of individuals with diminished permeability and vertical growth is close to the number of individuals with horizontal growth.

The individuals with diminished permeability of the upper airway present an intermediate growth direction, representing the most frequent type. In the less common growth directions, there is a slight tendency to horizontal facial growth verified in individuals with diminished nasopharynx permeability. Also, a light tendency to vertical facial growth is present when oropharynx permeability is reduced.