Asymmetries in nostrils and the surrounding tissues of the soft nose--a morphometric study.

Seven measurements and two qualities of the soft nose and nasal bridge were recorded in 156 healthy young adult North American Caucasians. Nostril-type asymmetries and alar base dislocations (31 and 38 of 156, respectively) were associated with other minor nasal disfigurements more often than symmetrical nares or alar base levels. A true alar base dislocation between alae of the same shape was distinguished from pseudodislocation caused by differing alar configurations (two-thirds of cases) or configuration differences along with dislocation (one-third of cases). Columellar deviations, columellar length asymmetry, and alar base dislocations were more frequently to the left, whereas nasal bridge deviations and septal dislocations were more often to the right. On the left side the extent of columellar deviation (5.9 degrees) and degree of alar base dislocation (1.5 mm) were significantly greater than on the right (4.0 degrees, p less than 0.05, and 1.0 mm, p less than 0.01, respectively). Quantitative analysis of the relationship of the minor nasal disfigurements offers valuable data for both surgeons and clinical geneticists.