Introduction

The nose represents the central feature of the face with an aesthetically profound effect on the overall balance of the other facial features. Accordingly, enhancing a flat, poorly defined nose can give definition to the face and refine its overall appearance. For this reason, augmentation rhinoplasty has long been practiced as a well-established procedure among Asians, who have relatively smaller noses than Caucasians. Significantly, the ability to conveniently reshape the nose without undergoing surgery is a key benefit of filler rhinoplasty, which has made it one of the most popular filler procedures among Asian patients.

While some drawbacks of filler rhinoplasty versus conventional surgery are the need for repeat treatments when using temporary fillers and the unsuitability for reduction rhinoplasty (e.g. sharpening a bulbous nose, reducing the size of a large hump, or narrowing a wide nasal base), the countervailing advantages are numerous and compelling: it ensures minimum social downtime since there is no significant bruising or swelling even immediately after the procedure compared with surgery; in terms of its safety profile, filler rhinoplasty does not entail any of the potential risks arising from surgery, such as unnatural contractural pull and distortion; furthermore, filler rhinoplasty is capable of making the shape appear more natural by allowing the creation of arches extending from the medial brows to the dorsum of nose.

This chapter aims to provide an overview of the concept, techniques, useful tips, and precautions involved in performing filler rhinoplasty.

The attractively proportioned nose and face

There is no set standard for an ideal nose that works for every face, since aesthetic standards tend to vary among different ethnicities, between the sexes, as well as evolving over time. Just as importantly, facial beauty is a function of the balance among various facial features, including the nose, which together produce an aesthetically pleasing result. Thus, efforts have been directed at identifying the ideal facial and nasal proportions, and effecting changes that afford better proportionality and harmony to the overall face. This notion of facial proportion also assists the field of filler rhinoplasty in the planning of the treatment strategy for a given patient.

The nose is divided into several subportions including the dorsum, sidewall, nasal tip, ala nasi, and columella. Such regional subdivision helps with surgical planning and descriptions of the cosmetic procedures. In addition, there are certain topographic landmarks of the nose used for describing the cosmetic and reconstructive procedures. Recognized topographical facial landmarks are shown in Figure 17.1. Of such landmarks, the nasion, sellion (radix), rhinion, and pronasale are worthy of mention with respect to filler rhinoplasty. Although the term ‘nasion’ is sometimes confusingly used to refer to the deepest point of the nasal root, it in fact represents the median anterior tip of the nasofrontal suture. Rather, the sellion represents the deepest point of the nasal bone or the nasofrontal angle. Since the sellion is also the bony landmark, corresponding to surface anatomy, the term ‘radix’ is used for the deepest point of the nasal root or the nasofrontal angle. Rhinion refers to the osteocartilaginous junction, while pronasale is the most prominent point of the nasal tip and the subnasale represents the junction between the columella and philtrum.

Figure 17.1 Topographical facial landmarks and ideal facial proportion.

On the frontal view, a balanced face should divide into equal vertical thirds and equal horizontal fifths, as shown in Figure 17.1. The ideal length of the nose in proportion to the face is three-quarters the length of the lower one-third of the face, from the subnasale to mentum. Meanwhile, the ideal nasal width at the alar base is believed to correspond to the intercanthal distance, which equals one-fifth of the facial width. The width of the body of the nose should be 80% of the width of the nose at the alar bases. The narrowest point of the nasal dorsum is at the radix, where the width at the radix approximates the height of the palpebral fissure. A gentle curve emanating from the medial brow courses along the lateral border of the nasal dorsum to end at the ipsilateral tip-defining point. Any irregularities of this line will be easily noticeable as deviations from the contralateral line, thereby contributing to asymmetry and unsightly appearance.

On the lateral view, there are certain facial angles related to the nose that deserve special mention in evaluating filler rhinoplasty patients (Fig. 17.2). The glabella-to-radix line intersecting with the radix-to-tip line forms the nasofrontal angle. Ideally, this angle should be within 115–130°. Meanwhile, the nasofacial angle is the angle formed by the line tangent to the nasal dorsum intersecting with the vertical facial plane, which is a two-dimensional coronal section connecting the glabella-to-pogonion line. The aesthetic ideal for the nasofacial angle is 35–40°. The nasolabial angle is defined by the line from the subnasale to the superior vermilion border of the upper lip intersecting with the line tangent to the columella from the subnasale. The ideal aesthetic range should be between 90° and 110° depending on the ethnicity and sex.

Figure 17.2 Facial angles.

Ethnic differences

The typical features of a Caucasian nose, leptorrhine (tall and thin) have been described above. The African platyrrhine (broad and flat) nose is characterized by a low radix, short concave dorsum, widened alae base, a bulbous and an underprojected tip, flared alae with round nostril, and extremely thick skin. The Asian mesorrhine (intermediate) nose is characterized as a blend of the above two; it is typically characterized by a low broad dorsum, short nasal bones, a round underprojected and underrotated tip, columellar recession, somewhat rounded nostrils, and moderately thick skin. The nasal tip is unilobular instead of definite nasal tip definition. Understanding these ethnic differences is useful for tailoring filler rhinoplasty to the needs and characteristics of the different ethnic groups. One must also take note, however, of the increased intermingling among different racial groups, and the difference among races even within the same ethnic group. Moreover, as the standard of beauty becomes increasingly universal, applying a strict ethnic classification would be less meaningful.

Vascular patterns of the nose (Fig. 17.3)

The blood supply to the external nose is largely divided into the ophthalmic artery, a branch of the internal carotid system, and the facial artery, a branch of the external carotid system. The dorsum of the nose is principally supplied by the lateral nasal artery, a branch of the angular artery branching out from facial artery, with a contribution over the upper part of the dorsum of the nose by the dorsal nasal artery. The dorsal nasal artery is a branch of the ophthalmic artery originating from the internal carotid artery. As a result, the potential for inadvertent intra-arterial injection and embolization leading to blindness exists. The columellar is supplied by the septal branch (columellar branch) of the superior labial artery, which branches off from the facial artery. The blood supply to the nasal tip originates primarily from the lateral nasal artery or the dorsal nasal artery and to some extent from the septal branch (columellar branch) of the superior labial artery. If the filler material is injected intra-arterially into the dorsal nasal artery or lateral nasal artery during the procedure of filler rhinoplasty, then some ischemic symptoms such as purpura, edema, pustules in the nose, and even skin necrosis of the nasal tip may happen.

Figure 17.3 Vascular patterns of the nose.

Types of filler

In order to retain the enhanced nasal shape, it is advisable to use fillers high in viscoelasticity. Good examples include Restylane^® SubQ or Juvéderm^® Voluma in the case of hyaluronic acid (HA) fillers, and Radiesse^®, a filler agent made of calcium hydroxylapatite. For making fine corrections, use of HA fillers such as Restylane^® is recommended. Beginners performing filler rhinoplasty are advised to apply HA fillers, since any unsatisfactory results are readily reversible by using hyaluronidase, which can dissolve the HA filler within 1 day.

Anesthesia

When using the 30-gauge needle, topical anesthetic cream applied 20–30 minutes in advance is sufficient for reducing the pain and bleeding during the procedure. If a cannula is used, prior injection of local anesthetic is advised to help minimize the potential discomfort caused by the large size of the cannula as well as the pain caused by the filler preparation itself. Where augmentation is confined to the nasal dorsum, the anesthetic is to be injected subcutaneously at three different points, including the sellion, the rhinion, and the nasal tip (infratip lobule). When lifting of the nasal tip is also required, local anesthetic must be injected additionally into the columella and the nasolabial junction. In order to minimize incidental volume change effected by the injected anesthetic itself, the amount of local anesthetic placed in each of these sites should be limited to no more than 0.1 mL per point.

Injection technique (Fig. 17.4)

Whereas some practitioners only use the needle for filler rhinoplasty, others prefer the cannula; it is a matter of personal preference. As a general rule, however, when augmentation is performed on the entire nasal dorsum or whole nose including the columella, using a cannula has some benefits over using a needle because it can prevent risks of unwanted bruising as well as embolization, which is the most significant adverse effect in filler rhinoplasty. Regarding the size of cannula, 21 gauge is required for Restylane^®