Geometry of the Nose Part III: The External Nose
Before Dr. Slupchynskyj conducts any Rhinoplasty Surgery, he takes specific measurements of the patient’s nose and surrounding areas. In the first part of this series, we examined the “landmarks” of the nose as starting points for these measurements. In the second part, we looked at the measurements and angles that Dr. Slupchynskyj uses to determine the proportions of the nose. In this discussion, we will explore the regions of the external nose and how they relate to the nose as a whole.
The nasal root is literally where the nose starts to grow. The root’s boundaries can be found between the orbital sockets of the eyes. Compared to the rest of the nose, the nasal root forms a depression between the eyes. The indentation forms at the junction point where the frontal bone of the skull meets the nasal bones. A thin line of bone, known as the anterior nasal spine, stands as the foundation of the nasal root. The anterior nasal spine holds the cartilage of the upper nose in place.
Measurement: Nasal Root Depth-Width Index
The Nasal Root Depth-Width Index measures the ratio between the depth of the nasal root and its width. Dr. Slupchynskyj measures the distance between the sellion (s) (deepest point of the nasofrontal angle) and the endocanthion level (the point at which the inner ends of the upper and lower eyelid meet). The width of the nasal root is measured by the distance between the maxillofrontale (mf) – the point where the nasal protrusion starts.
The index is the ratio between these two measurements (root depth/root width), multiplied by 100. In the faces of the “above average” women in the study mentioned in the previous article, the mean index was 78.5, with a standard deviation of 11.1.
The nasal bridge forms the midsection of the nose. The bridge is also the section of the nose about which most patients have concerns. Their concerns often revolve around the angle of inclination, the straightness or crookedness of the bridge, and the appearance of any bumps or irregularities in the line leading down to the tip.
Measurements: Nasal Bridge Index
One of the measurements that concerns plastic surgeons is the length of the nasal bridge. The length of the nasal bridge is measured from the nasion (n) (the depression just below the brow ridges) and the tip of the nose. The Nasal Bridge Index is the ratio between the bridge length and the nose height (measured from the nasion (n) to the subnasale (sn)). In the faces of the “above average” women in the study mentioned in the previous article, the mean Nasal Bridge Index was 87.8, with a standard deviation of only 3.1.
The lower third of the nose is known as the “soft nose”. These lower areas include the nasal tip (pronasale (prn)), the “wings” of the outer nose (alare (al)) and the cartilage that runs from the tip to the upper lip between the nostrils (columella).
Measurement: Nasal Tip Protrusion-Width Index
Another important measurement relates the extent of the nose’s protrusion from the face relative to the width of the nose at its widest point. The ratio of the length of the columella to the width of the nose at the alare gives surgeons important data on the proportions of the soft nose. In the faces of the “above average” women in the study mentioned in the previous article, the mean Nasal Tip Protrusion-Width Index was 62.2, with a standard deviation of only 5.5.
In the final part of this series, we will examine the differences in these measurements among men and women of different races and ethnicities. We will also look at the different techniques for Rhinoplasty procedures for men and women of different ethnic backgrounds.