Internal nasal valve collapse may be categorized as static or dynamic (Apaydin 2011; Park 1998). Static internal nasal valve collapse is a narrowing of the middle third of the nose at rest – that is, the angle between the upper lateral cartilage and nasal septum is anatomically small and the resultant area of the valve is similarly reduced. Static collapse is often seen as a result of nasal trauma or previous rhinoplasty in which a weakening of nasal support structures leads to an overly narrowed angle between the upper lateral cartilage and nasal septum (i.e., this may result from simple surgical maneuvers such as skin elevation, mucosal elevation, separation of the upper lateral cartilages from the septum). Static internal valve collapse may also result from scarring of the medial segment of the upper lateral cartilage to the nasal septum following the separation of those structures along with their intervening mucosa. Elevation of the skin-soft tissue envelope, damage to the nasal dilator muscles, and weakening of the mucosal support of the middle third cartilages all contribute to a weakening of nasal valve support.

Middle third narrowing at rest, that is, static internal nasal valve collapse, may be seen upon simple external inspection of the nose in which a pinched middle third may be visible. This often results in a discontinuity along the brow-tip aesthetic line as the middle third is pinched and narrowed, while the upper third, which is supported by bone, remains wide. Classically, the inverted V deformity has been linked to the separation of the upper lateral cartilages from the overlying nasal bones during rhinoplasty, but it is actually seen more commonly either in patients with internal nasal valve collapse who have never undergone previous rhinoplasty or in patients who have had a standard dorsal reduction rhinoplasty without disarticulation of the upper lateral cartilages from the nasal bones (Fig. 22.2). Static internal nasal valve collapse may appear clinically as scar tissue, strictures, or webbing in the valve angle (as might occur after separation of the upper lateral cartilage and mucosa from the septum without sparing the mucosal attachments between the two structures). Congenital or traumatic weakness or absence of the upper lateral cartilages or other deformities (thickening, twisting) of the upper lateral cartilages may result in static narrowing of the middle third of the nose. Additionally, in patients with an overprojected tension-type nasal deformity, overgrowth of the nasal septum causes the angle between the upper lateral cartilage and the nasal septum to be excessively narrowed. Such patients may also frequently be found to have thin and weak upper lateral cartilages, which tend to add a dynamic component to the internal nasal valve collapse.

Dynamic internal nasal valve collapse is an active narrowing of the upper lateral cartilage and middle third of the nose which occurs only with nasal inspiration through a valve which, at rest, appears of normal size (Fig. 22.3a–d). Dynamic nasal valve collapse, in which the middle nasal third appears normal at rest but narrowed upon gentle nasal inspiration, often results from an inherent weakness of the nasal sidewalls (Fig. 22.4). Thin, weak, detached, or absent upper lateral cartilages cannot provide the necessary strength along the nasal sidewall to withstand the negative pressures created by inspiratory nasal airflow – as a result, the sidewalls of the nose fall in as the negative pressure created by nasal inspiration draws them inward. Previous rhinoplasty in which the upper lateral cartilages have been weakened or detached from the nasal septum, congenitally or developmentally thin upper lateral cartilages, and absent upper lateral cartilages may all contribute to such structural weaknesses of the nasal sidewall. In such cases, the patient may not have obvious findings suggestive of nasal valve collapse upon inspection at rest, such as an inverted V deformity or a pinched middle third, but when asked to inspire gently through the nose, there is an active narrowing of the middle third which becomes obvious to the examining physician. In order to appreciate dynamic nasal valve collapse and its effects on nasal breathing, it is often helpful for the examining physician to apply gentle lateral traction on the cheek adjacent to the nose (i.e., Cottle maneuver) to assess for improvements in nasal breathing that might occur with stiffening of the lateral nasal wall by digital traction. Additionally, in order to pinpoint the precise location of the collapse, it is helpful to introduce a cotton tip applicator or ear curette into the suspected area of collapse and observe improvements in nasal obstructive symptoms when the precise site of obstruction is stiffened with the examiner’s help. Application of external nasal dilation devices further helps identify internal nasal valve collapse.