Nasal Analysis




Introduction


Nasal analysis in the setting of the preoperative consultation is undoubtedly one of the most critical elements of the rhinoplasty process. This is the time in which the patient and surgeon communicate expectations, build rapport, and mutually decide whether to proceed with surgery. In addition, it provides an opportunity for the surgeon to analyze the patient’s anatomy and personal aesthetics, thereby developing a surgical plan leading to the most sought-after result: a satisfied patient. A well-executed surgery and beautiful result from the surgeon’s perspective will be frustrating for both parties if the patient’s desires are not considered. This chapter will examine the various components of nasal analysis, including patient history, nasal proportions, the tripod concept, nasal subunits, physical examination, photography, and imaging.




Patient History


A proper preoperative history must begin with the patient’s demographic data, comorbidities, previous surgery (particularly any prior nasal surgery or other cosmetic surgeries), medications, prior hospitalizations, medication allergies, and family/social history and a thorough review of systems. The patient should complete a list of medications, including over-the-counter medications, herbal supplements, and vitamins. The use of nasal steroid sprays, antihistamines, and decongestant sprays such as oxymetazoline (Afrin) and phenylephrine (Neo-Synephrine) should be documented. A history of tobacco, alcohol, and drug use should be obtained. Components of the social history, such as profession and marital status, can provide a more complete picture of the patient as a whole and offer some clues regarding the patient’s expectations of surgery and support system. The age of the patient is also important, as a 55-year-old patient is less likely to tolerate a dramatic change in appearance than is a 16-year-old. It is important in teenagers to ascertain just where they are along their growth curve so as to render a result that ultimately balances with the other facial features. In teenage females, our rule is to wait at least until 2 years following menarche before performing elective rhinoplasty—typically sixteen years old. In teenage males, we typically wait until the age of 17.


After reviewing the general history, we begin the assessment of the nose by asking the open-ended question, “What is it that you don’t like about your nose?” This allows the patient to describe, in his or her own words, the specific aspects of the nose that are most bothersome to them. It is helpful to note the order in which patients mention these features, as this typically reflects the degree to which they are bothered by each aspect. This exercise is also very useful in getting a preliminary sense of the patient’s own aesthetic sense and expectations, as well as his or her attention to detail. Such information can help determine at this early stage the chance for a successful outcome.


This is followed by the question, “How long have you been bothered by your nose?” At this stage, any history of nasal trauma or prior nasal surgery is elicited and discussed in more detail. The desire for a rhinoplasty should generally be one that has been present for some time, and persons who have recently decided to have the operation, on a whim, should be counseled and asked to return several months later once they have given it further thought. The motivation for seeking nasal surgery is revealed at this time. Patients are spurred to consider a rhinoplasty for a variety of reasons and the specific factors may impact the surgical plan. For example, a patient seeking a rhinoplasty to erase physical signs resulting from past domestic abuse may benefit from a more profound change than would a 55-year-old attorney who has recently noted that her nasal tip is drooping with age. The surgeon must also carefully assess whether the patient exhibits signs of body dysmorphic disorder. Patients who fixate on their nose in an unhealthy manner or who have unreasonable expectations regarding the impact that the nose will have on their life (e.g., promotion at work) are likely to be persistently unhappy after rhinoplasty.


Functional issues such as nasal obstruction, allergic rhinitis, or chronic rhinosinusitis are extremely pertinent in rhinoplasty. The surgeon should ascertain if one side of the nose is more difficult to breathe through than the other and assess the severity of the breathing difficulty. Sleep habits such as snoring, the use of nasal breathing strips, and sleeping on one side must be documented. It is also worth documenting whether the symptoms are seasonal, positional, or related to certain foods. Patients should be asked about symptoms such as recurrent epistaxis as well. Computed tomography (CT) scan of the sinuses is often useful for patients with functional concerns.


Any prior history of nasal surgery, including previous rhinoplasty, septoplasty, or functional endoscopic sinus surgery, should be discussed. Prior operative reports can be quite useful in formulating a surgical plan, although it is important to recognize that these notes are not always accurate. The timing of the most recent rhinoplasty is important to consider because the nose will continue to change over 12 or more months as postoperative edema resolves and wound contracture takes place. The surgeon must also question the patient about previous breast surgery when considering harvest of costal cartilage. Similarly, prior otoplasty or ear surgery is pertinent when auricular cartilage may be needed.


The patient’s ethnic background can provide insight into their particular cultural aesthetic. A patient from South America, for example, will likely have a different idea of what constitutes an attractive nose than a similarly aged patient of Middle Eastern descent. This sort of consideration is essential for delivering a surgical result that the patient desires, even if it varies from the surgeon’s own inclination. Additionally, appreciation for cultural differences helps with the process of preoperative imaging and facilitates development of a sense of trust with the patient.




Nasal Anatomy


An understanding of the anatomy of the nose is obviously quite crucial for the rhinoplasty surgeon. The underlying structural framework of the nose consists of the paired nasal bones superiorly and the five major nasal cartilages caudally. The nasal bones are attached to the frontal bone superiorly, the lacrimal bones superolaterally, and the ascending processes of the maxilla inferolaterally.


The bony septum is composed of the perpendicular plate of the ethmoid posterosuperiorly and the vomer posteroinferiorly. The quadrangular cartilage, which can vary dramatically in size among different ethnic groups, provides the structure for the anterior portion of the septum. This cartilage is the predominant support of the dorsal and caudal portions of the lower two-thirds of the nose.


The upper portion of the quadrangular cartilage flares along its dorsal edge and is fused between the upper lateral cartilages. This is particularly relevant in the setting of profile reduction, as this flared segment is the excised portion. This can lead to narrowing and collapse of the middle vault if not properly supported. The internal nasal valve is comprised of the angle formed by the septum, the upper lateral cartilage, and the head of the inferior turbinate. The paired lower lateral cartilages sit caudal to the upper lateral cartilages. The lower lateral cartilages are divided into three segments—the medial, intermediate, and lateral crura. The medial crura overlap the caudal edge of the septum. The region between the lower lateral and upper lateral cartilages is called the scroll, which is the recurvature of the upper lateral cartilages. This scroll can be prominent in some individuals.


The skin and soft tissue envelope overlying the bony-cartilaginous framework of the nose must also be understood. The skin of the nose varies in thickness significantly. The upper third is moderately thick but tapers into a thinner region over the rhinion or mid-dorsum. The skin over the lower third of the nose is more sebaceous and thick and tends to hypertrophy with age. Below the skin lies the nasal superficial musculoaponeurotic system, or nasal SMAS. There are four major groups of nasal muscles: dilators, compressors, elevators, and depressors. The dilators are the dilator naris anterior and dilator naris posterior. The sole compressor is the transverse nasalis. Elevators include the procerus and levator labii superioris alaeque nasi while the depressors are the depressor septi nasi and alar nasalis.




Nasal Proportions


A thorough discussion of the rhinoplasty consultation must first begin with a consideration of nasal proportions. The nasofrontal angle is defined as the angle between a line tangent to the nasal dorsum and a line tangent to the glabella through the nasion. This should measure between 115 and 135 degrees ( Figure 3-1 ). An obtuse nasofrontal angle gives the illusion of a very long nose on frontal view, as the patient lacks a well-defined nasal starting point ( Figure 3-2 ).




Figure 3-1


The nasofrontal angle should measure between 115 and 135 degrees.



Figure 3-2


A shallow nasofrontal angle of nearly 180 degrees ( A ). On AP view, this obtuse angle causes the nose to appear excessively long ( B ).


The nasolabial angle is composed of the angle formed by a line from the subnasale to the most anterior point of the columella and a line connecting the labrale superius to the subnasale. This angle should ideally measure 90 to 95 degrees in men and 95 to 110 degrees in women ( Figure 3-3 ). As a general rule, individuals with shorter stature can tolerate a more obtuse nasolabial angle as there will be less visible nostril when viewed from the front by average-statured individuals.




Figure 3-3


Nasolabial angle. Normal range is 95 to 110 degrees for females and 90 to 95 degrees for men.


Less frequently discussed angles include the nasofacial angle and nasomental angle. The nasofacial angle represents the angle formed by a vertical line from the glabella to the pogonion, as it intersects with a line from the nasion to the nasal tip. This angle can vary from 30 to 40 degrees ( Figure 3-4 ). The nasomental angle describes the angle between the nasion-tip line and the line from the tip to the pogonion. The range of this angle is from 120 to 132 degrees ( Figure 3-5 ).




Figure 3-4


Nasofacial angle, ideally 30 to 40 degrees.



Figure 3-5


Nasomental angle, 120 to 132 degrees.


A significant relationship exists between the nose and chin and the two must be considered in conjunction with one another. The chin should ideally reach a vertical line drawn from the nasion, perpendicular to the Frankfort horizontal plane. The Frankfort horizontal plane represents the line drawn from the superior edge of the tragus to the infraorbital rim, which should be parallel to the ground in standard photographs ( Figure 3-6 ). An underprojected chin must be discussed with the patient, as this can give the illusion of an overprojected nose. The option of chin augmentation should be offered in these situations.




Figure 3-6


The Frankfort horizontal plane: a line drawn between the superior edge of the tragus and the infraorbital rim should parallel the floor.


The ideal projection of the nose has been described by Crumley as a 3 : 4 : 5 right triangle. The shorter side of the triangle represents the tip projection, the distance from the alar crease to the tip. The ratio between this measurement and the distance between the nasion and tip-defining point should be 0.6. This tip projection ratio was previously described by Goode, with the ideal ratio between 0.55 and 0.6 ( Figure 3-7 ).


Mar 23, 2019 | Posted by in OTOLARYNGOLOGY | Comments Off on Nasal Analysis

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