Keywords nasal evaluation - rhinoplasty - outcome measures
Importance of Nasal Evaluation in the Clinical Encounter
Importance of Nasal Evaluation in the Clinical Encounter
The nasal airway has several functions that are essential to a patient's quality of
life including humidifying the air and filtering allergens.[1 ] When there is nasal obstruction, these processes are interrupted and the patient
can become symptomatic. Nasal obstruction can change the normal laminar airflow to
turbulent airflow. These anatomical changes may lead to a symptomatic patient who
will then seek consultation. The timeline and progression of nasal symptoms can provide
valuable information when appropriately elicited. The clinician will obtain a detailed
history of present illness, presence of allergies or sinus disease, past medical and
surgical histories, past and current treatments, and any relevant social history.
A thorough history can guide the physical examination, and when combined will lead
to the proper medical or surgical treatment for the patient.
Understanding the Patient's Goals and whether They Are Reasonable
Understanding the Patient's Goals and whether They Are Reasonable
Assessing the feasibility of achieving the patient's expected goals is paramount to
obtaining optimal surgical results. The patient's functional goals are taken into
account as well as medical comorbidities that may affect the surgical outcome, such
as obstructive sleep apnea, allergies, or comorbidities that may not allow the patient
to tolerate anesthesia. Any aesthetic changes the patient desires to have should be
ascertained, balancing how these aesthetic changes may impact the nasal airway so
as not to sacrifice nasal function in pursuit of aesthetic alterations. It is the
role of the clinician to have a comprehensive understanding of nasal mechanics and
nasal physiology to properly conduct an evaluation prior to determining a surgical
plan. In this article, we aim to provide an overview of the nasal anatomy and nasal
mechanics to better equip the reader with effective tools and techniques in the nasal
evaluation that can be added to their clinical practice.
Anatomy
The functional goals of the patient will often coincide with underlying nasal pathology.
To properly assess the nasal anatomic pathology, one must first reference normal nasal
anatomy and physiology. When evaluating the nose, we recommend that one assess the
external and internal components of collapse separately. The external components of
nasal evaluation can be divided into the upper, middle, and lower vaults. The internal
components can also be divided into thirds for the corresponding points on the external
nose, but these are also subdivided into bony, cartilaginous, and soft-tissue structures.
The bony structures include the frontal bone, nasal bones, the bony septum (perpendicular
plate of the ethmoid and vomer) maxillary crest, anterior nasal spine, and sphenoid
([Fig. 1 ]). The cartilaginous structures include the paired upper lateral cartilages, paired
lower lateral cartilages, quadrangular cartilage, sesamoid cartilages, and accessory
cartilages. The upper lateral cartilages articulate with the nasal bones superiorly,
the septum medially, the lower lateral cartilages caudally, and connective tissue
laterally.[1 ] The lower lateral cartilages can be subdivided into the medial, intermediate, and
lateral crura ([Fig. 2 ]).
Fig. 1 Nasal septum and surrounding structures.
Fig. 2 Profile view of the bony, cartilaginous, and soft-tissue structures of the nose.
There are also several areas of articulation that deserve mention as they have significant
functional contributions. These include the keystone area, Pitanguy's ligament, and
the nasal valves. The keystone area is the attachment of the cartilaginous septum,
perpendicular plate of the ethmoid, and the nasal bone ([Fig. 1 ]). Disarticulation of the septum from these areas can lead to destabilization of
the L-strut and subsequent collapse, and should be carefully managed during surgery.
Pitanguy's ligament is the point of attachment of the skin–soft-tissue envelope (SSTE)
to the intermediate crura of the lower lateral cartilages. This ligament can be sutured
together at the conclusion of the rhinoplasty to eliminate dead space between the
SSTE and the underlying cartilages. The components of the internal and external nasal
valves are shown in [Fig. 3 ].
Fig. 3 (A ) Internal nasal valve borders: septum, upper lateral cartilage, and head of inferior
turbinate. (B ) External nasal valve borders: medial and lateral crus of the lower lateral cartilage,
and the nasal floor.
Briefly, the lower third of the nose has both major and minor tip supporting mechanisms
([Table 1 ]). These support structures can be manipulated depending on the patient's needs and
will affect the stability of the nose. While manipulating any of the major tip support
mechanism can affect the stability of the nose, such as the medial crural attachment
to the caudal septum, manipulating a minor tip support mechanism may not necessarily
affect the stability of the nose unless several or all of the minor tip support mechanisms
are surgically addressed. Nonetheless, the surgeon should be mindful of all support
mechanisms that are being disrupted during the course of surgery to appropriately
create a stable and aesthetically pleasing nasal structure.
Table 1
Major and minor tip support mechanisms of the nose
Major tip support
Minor tip support
Strength, direction, resiliency of the lower lateral cartilages
Anterior nasal spine
Medial crural footplate attachment to the caudal septum
Membranous septum
Attachment of the upper lateral cartilage and lower lateral cartilage
Cartilaginous septum
Sesamoid cartilages
Interdomal ligament
Skin soft-tissue envelope
Clinical Examination
Evaluation should begin with obtaining a detailed history to understand the timing,
quality, and progression of any nasal symptoms. It is important to note whether the
obstruction is unilateral or bilateral, alternation of laterality, and is there is
nasal drainage, epistaxis, crusting, and seasonal changes. The history should also
include the length of nasal obstruction, prior medications or treatments, history
of allergies, history of trauma, history of nasal or sinus surgeries, and any relevant
past medical history. Nasal pathology can be sectioned into mucosal and structural
disease processes, but a full differential diagnosis should be elicited ([Table 2 ]).
Table 2
Differential diagnosis of chronic nasal obstruction
V: vascular
Hemangioma, juvenile nasopharyngeal angiofibroma, pyogenic granuloma
I: infectious/inflammatory
HIV, vestibulitis, syphilis, rhinosinusitis, nasal polyps, inferior turbinate hypertrophy,
allergic or nonallergic rhinitis
T: trauma
Nasal bone fracture, synechiae, facial nerve paralysis
A: autoimmune
Polyangiitis with granulomatosis, eosinophilic polyangiitis with granulomatosis, sarcoidosis,
lupus
M: metabolic
Cocaine use, rhinitis medicamentosa
I: iatrogenic
Nasal valve collapse, septal perforation, postnasal surgery valve collapse
N: neoplastic
Inverted papilloma, oncocytic papilloma, osteoma, neurofibroma, dermoid, squamous
cell carcinoma, adenocarcinoma, esthesioneuroblastoma, lymphoma, mucosal melanoma,
nasopharyngeal carcinoma, salivary gland neoplasms, lymphoma
C: congenital
Choanal atresia, pyriform stenosis, cleft lip, cystic fibrosis, primary ciliary dyskinesia,
septal deviation
D: degenerative
Atrophic rhinitis
E: endocrine
Pregnancy, hypothyroidism
Mucosal Disease
There are various causes of nasal obstruction due to mucosal disease ([Table 2 ]). It is also important to evaluate for any autoimmune diseases or vasculitides depending
on what was elicited in the history. In this section, we will address the most common
causes of mucosal diseases that contribute to nasal obstruction to include rhinitis,
rhinosinusitis, and inferior turbinate hypertrophy.
Nasal rhinitis can be due to many reasons and can be classified as allergic rhinitis,
nonallergic rhinitis, atrophic rhinitis, rhinitis medicamentosa, vasomotor rhinitis,
or infectious rhinitis. The most common cause of nasal obstruction is rhinitis due
to viral or bacterial causes.[2 ]
Prior treatment with oral allergy medications, nasal steroids, or nasal antihistamine
should be elicited in the history of patients with suspicions for allergic or nonallergic
rhinitis. Chronic use of nasal decongestants suggests that the nasal obstruction may
be due to rhinitis medicamentosa. Nasal congestion and drainage associated with exercise,
eating, or changes in temperature may be due to vasomotor rhinitis.[2 ] It is important to note any of the aforementioned items, especially if the patient
has concurrent structural pathology as these mucosal causes of nasal obstruction will
not resolve with surgery and require preoperative counseling for realistic patient
expectations.
Structural Pathology
The majority of pathologies by which the facial plastic surgeon can surgically repair
are structural in nature. It is precisely for this reason that a comprehensive understanding
of the nasal anatomy is paramount. These structural areas include the internal nasal
valves, external nasal valves, septum, turbinates, and nasal bones.[2 ] The associated pathologies and their clinical significance are discussed further
in the subsequent sections in this article.
Patient-Reported Outcome Measures
Patient-Reported Outcome Measures
It can be helpful to use a validated nasal survey to further assess symptoms. Commonly
used surveys include the Nasal Obstruction Symptom Evaluation (NOSE), and the Standardized
Cosmesis and Health Nasal Outcomes Survey (SCHNOS). The NOSE instrument consists of
five functional nasal questions that are rated by the patient from 0 to 5. The raw
score can then be multiplied by 5, with a maximum score of 100.[3 ] The SCHNOS survey was more recently developed and is useful when there is a cosmetic
component that the patient wants to be addressed.[4 ] The SCHNOS consists of 10 questions, also rated from 0 to 5, that incorporates both
functional questions of the nose and cosmetically related questions. The cosmetic-focused
questions address how the patient feels about the shape of their nose, their self-esteem,
and, overall, how they feel the nose fits their face. The NOSE and SCHNOS surveys
have four questions each that overlap in terms of nasal functionality. The SCHNOS
and the NOSE surveys have a strong correlation in scores when assessing the functional
components.[4 ] Rhinoplasty surgeons should strongly consider utilizing patient-reported outcome
measures (PROMs) in the pre- and postoperative assessment of their patients.
Other non-nasal specific PROMs include the EuroQol 5-Dimension (EQ-5D), 10-Item version
of the Functional Outcomes of Sleep Questionnaire (FOSQ-10), and the FACE-Q. The EQ-5D
has five different domains consisting of mobility, self-care, usual activity, pain/discomfort,
and anxiety/depression and is graded on a Likert scale.[5 ] Improvement in the EQ-5D tends to correlate with improvement in the NOSE score.[5 ] The quality-of-life improvement patients experience based on the EQ-5D after septorhinoplasty
due to improvement in nasal obstruction is significant when measured as a health utility
value.[6 ]
[7 ]
The FOSQ-10 consists of five domains: general productivity, activity level, vigilance,
social outcomes, and intimate and sexual relationships. Each domain has between one
and three questions, with a total score ranging from 5 to 20.[8 ] The FACE-Q is directed more toward cosmetic procedures. This questionnaire has three
different components: satisfaction with appearance, quality of life, and adverse effects.[9 ] The satisfaction with appearance section only needs the nasal-related questions
answered. The raw score can be tabulated and then converted to a scale score.[9 ]
These surveys can be administered during the initial consultation and also after a
period of recovery postsurgery to objectively assess the PROMs. The PROMs can provide
meaningful information on a patient's subjective improvement in symptoms, as the changes
and improvement in nasal structure do not always correlate with the patient's subjective
experience.
Physical Examination
After a thorough history has been obtained, an equally thorough physical examination
should be performed. Understanding the nasal anatomy is fundamental to being able
to perform the physical examination and subsequently develop an appropriate surgical
plan.
The status of the septum should be noted, with the presence of septal deviation, and
the position of the dorsal and caudal septum. Any abnormalities in the septal mucosa
should be noted with special attention to friability of the mucosa, septal perforations,
prominent vasculature, or abnormal crusting. Any of these could indicate a vasculitis,
inflammation, previous surgery, and/or autoimmune disorders. Use of endoscopy can
be helpful in evaluating the posterior aspect of the nose if anterior rhinoscopy does
not allow full examination, or to rule out other nasal pathologies such as inflammatory
nasal disease.[10 ]
Turbinate hypertrophy should be noted as well as any obvious concha bullosa of the
inferior or middle turbinates. The nasal valves should be evaluated and the presence
of narrowing of the internal and/or external nasal valves, and/or lateral wall insufficiency
(nasal valve collapse) should be noted. Dynamic valve collapse can be assessed by
having the patient deeply inhale through the nose. Stabilization of the valve collapse
can be performed with Cottle's maneuver, which pulls the cheek skin laterally to open
the nasal valve, or with modified Cottle's maneuver in which the examiner places a
small-caliber instrument in the area of the internal nasal valve as the patient inspires.
Tip support and the position of the lower lateral cartilages should be noted to develop
an appropriate plan for addressing any lateral wall insufficiency while factoring
in resultant changes to the nasal tip.
It is imperative to note any asymmetries, deviations, or curvatures present externally.
The changes seen externally are a direct reflection of the status of the internal
structure of the nose. For example, convexities or concavities in the upper third
can indicate nasal bone deviation; a pinched mid-vault could indicate lack of support
of the upper lateral cartilage, and a bulbous nasal tip can indicate a domelike shape
to the lower lateral cartilages. These will be described in further detail.
Physiologic Measurements
There are several ways to objectively measure the nasal airway. These include acoustic
rhinometry, rhinomanometry, and nasal peak inspiratory flow. These methods provide
objective data regarding the patient's nasal obstruction in terms of airflow, airway
resistance, and cross-sectional area of the nasal airway.[11 ]
[12 ]
[13 ] Computed tomography (CT) scans are obtained by some surgeons, particularly in the
cases with a history of complex or uncertain surgeries, or possible implant placement,
even though the authors of this study do not routinely obtain CT scans and rely instead
on the physical examination findings.
Acoustic Rhinometry
The cross-sectional area and volume of the nasal airway can be measured with acoustic
rhinometry.[11 ] Sound waves are transmitted through the nasal cavity and measured as the sound waves
return.[11 ] The time between administering the sound wave and the reflection correlates with
the nasal passage length.[11 ] The amplitude of the reflected sound wave and the distance the sound waves traveled
through the nose can be used to calculate the approximate cross-sectional area of
the nose.[11 ]
Rhinomanometry
Rhinomanometry measures airflow and airway resistance by recording the transnasal
pressure.[1 ]
[11 ] There are both active and passive versions of this tool. In the active version,
the patient is breathing through a single nasal cavity and the pressure is measured
on the contralateral nasal cavity. In the passive method, a face mask is placed over
the patient's nose and air is delivered.[1 ]
[11 ] This allows the clinician to assess the airflow and airway resistance. While this
may not be necessary to assess surgical candidacy, it can be useful as a comparison
postoperatively to calculate the amount of improvement of both of these measures.
Peak Nasal Inspiratory Flow
Peak Nasal Inspiratory Flow
Peak nasal inspiratory flow (PNIF) measures the maximum airflow during a forced inspiration.[11 ] There are different meters that can be used to measure the PNIF; the result is read
in liters per minute (L/min). The patient is asked to inspire maximally through the
device while keeping their mouth closed. The highest of three maximal attempts is
utilized.[12 ] A normal PNIF is around 138.4 L/min.[11 ] The changes can be assessed preoperatively and postoperatively to objectively measure
the individual patient's improvement in nasal obstruction after surgery. Although
it can be used on the individual patient, one should keep in mind that PNIF correlates
only weakly with the NOSE scores, so its utility as a diagnostic tool is limited.[12 ]
Computational Fluid Dynamics Modeling
Computational Fluid Dynamics Modeling
Computational fluid dynamic measures simulate the fluid patterns of liquids and gases
within a defined space and the interaction of these fluids and gases with the boundaries
of the defined space.[14 ] It can be applied to the nose using a three-dimensional recreated nasal geometry
using CT or magnetic resonance imaging that allows for measurement of nasal airflow.[14 ] Specific software (Lexma Technology) can be used with the lattice Boltzmann method
to determine the nasal airflow.[14 ] In patients with bilateral static nasal obstruction, there is a positive correlation
between the airflow measurement and the NOSE survey.[14 ]
Nasal Analysis
Photography
It is imperative to take preoperative photographs for a more detailed analysis of
the nasal structures. The following views should be taken: frontal, bilateral obliques,
bilateral profiles, bird's-eye view, and basal view. Camera settings should be adjusted
to avoid excess or inadequate exposure. Typical focal length will be between 90 and
105 mm.[15 ] The shutter speed should be between 1/1,000th and 1/60th of a second.[16 ] Finally, the aperture size is measured via f-stops. The f-stop is the ratio of the
focal length to the aperture diameter. A larger f-stop correlates to a smaller aperture
size.[16 ]
The nose should be fully in focus, and the lighting must be adequate to obtain high-quality
photographs. The depth of field is the distance range where all aspects of a photograph
are in focus. The depth of field can be altered by changing the focal distance, changing
the distance of the photographer to the patient, or changing the aperture size. Aperture
size tends to be the easiest to change.[16 ] It is important to keep in mind that if the aperture size is decreased, then there
is risk of having an underexposed photograph, which can be controlled by decreasing
the shutter speed to allow more time for light to pass through.[16 ]
Once the photographs are taken, a nasal analysis can be performed using the photographs.
The photographs can be shown to the patient so that they understand the external issues
that are related to their symptoms. This should be performed in a systematic fashion,
so that all components of the nose are addressed every time. The external components
can be described in detail with the photographs and taken into consideration with
the intranasal findings.
Location of Pathology
Septum
Evaluation of the septum can be split into the caudal septum, dorsal septum, and remaining
intermediate portion of the septum. One should describe the position of the caudal
septum, the status of the posterior septum, and the presence of any bony spurs or
deviations. There can be prominence of a swell body, which can also narrow the nasal
airway, particularly at the internal nasal valve.
A weakened dorsal septum could lead to saddling. This would need correcting with spreader
grafts and possible dorsal augmentation grafting. A weakened caudal septum could result
from a variety of etiologies to include poor cartilage quality, trauma resulting in
septal fracture, or over-resection from prior surgery. The result could present as
poor tip support and/or tip ptosis.
The location of the deviation can help guide what type of surgical approach can be
used. For example, a caudal septal deviation or a high septal deflection could make
a successful endonasal approach more difficult to achieve due to the access available
and the different maneuvers needed to correct the abnormalities of the septum.
Turbinates
Any hypertrophy should be noted, along with any evidence of concha bullosa. If hypertrophy
is noted during the examination, testing the mucosa for response to a topical nasal
decongestant, such as oxymetazoline, can give insight into the effects of performing
submucosal turbinoplasty. If there is a poor response to the nasal decongestant, but
there continues to be turbinate hypertrophy present, the problem is likely excess
or osteitic conchal bone.
Nasal Valves
Static Collapse
The external nasal valve and the internal nasal valve should be evaluated for any
static narrowing. The external nasal valve can be narrowed by a displaced caudal septum,
splaying of the medial crural footplates, recurvature of the lower lateral cartilages,
concavities of the lower lateral cartilages, congenital weakness of the lower lateral
cartilage, cephalic malpositioning of the lower lateral cartilages, loss of vestibular
skin, a ptotic tip, postsurgical vestibular stenosis, deviation of the anterior nasal
spine, or even facial paralysis.[2 ]
The internal nasal valve is the narrowest section in the nose, and contributes significantly
to nasal airway resistance.[2 ] It can be narrowed by a deviated nasal septum, particularly if there is a dorsal
septal deviation, enlarged turbinates, medialized upper lateral cartilages, medialization
and depression of the nasal bone, and/or prominence of the swell body. Short nasal
bones with long upper cartilages may increase suspicion for some level of internal
valve collapse due to lack of rigid support for the cartilage.
Dynamic Collapse
Dynamic valve collapse can be elicited by having the patient inspire deeply through
their nose. Poor cartilaginous support can cause collapse to occur at both the internal
and external nasal valve. Supporting the valves in clinic and gauging the relative
benefit to the patient is a useful way to determine whether there is utility in placing
support grafts. When this is observed, one can anticipate needing to enhance the support
in these regions surgically through cartilaginous grafts, suturing techniques, tensioning
of the nose, or a combination of these.
External Nose
Upper Third
The position of the nasal bones and any asymmetry should be noted. The height, length,
and width of the nasal bones should also be assessed. The shape of the nasal bones
should be assessed, particularly if there is any convexity or concavity present. This
becomes especially important with a history of nasal trauma, as these convexities
and concavities can help guide the need for medial or lateral osteotomies to straighten
the nose and open the nasal airway.
Any step-offs between the nasal bone articulation and the upper lateral cartilage
should be palpated. The presence of a step-off deformity at this junction often reflects
as an inverted-V deformity. This deformity is caused by disruption of the upper lateral
cartilage attachment to the dorsal septum, which in turn causes a medialization and
depression of the upper lateral cartilage in relation to the nasal bone and the septum,
thus giving the appearance of an inverted-V. Any rhinion horns, which are bony prominences
on the nasal bones at the rhinion, should be noted, as well as the presence of a bony
hump.
Middle Third
Deviation of the mid-vault should be noted. This is often a reflection of a deviated
nasal septum, but it can also be due to asymmetry of the upper lateral cartilages,
or even abnormal or asymmetric scarring from prior trauma or nasal surgery. The nasal
valve should be assessed for any static or dynamic narrowing. The height of the middle
vault should be assessed for the presence of a dorsal hump that is likely cartilaginous
in nature or for evidence of a saddle nose deformity. A narrow or pinched middle third
is often an external finding of internal nasal valve narrowing.
Supratip
Fullness of asymmetry should be assessed. Bulbous or boxy lower lateral cartilages
can give the appearance of a full supratip region, which can extend into the middle
third of the nose. Pollybeak deformity can also be assessed in this region. Pollybeak
deformity can result from many etiologies including over-resection of the bony dorsum
along with under-resection of the dorsal septum, over-resection of the caudal septum,
over-resection of the alar cartilages, and excessively thick skin or excessive scarring
in the supratip. Pollybeak deformity is a visual diagnosis, but the surgeon must be
prepared to address any number of etiologies as a part of surgical planning when attempting
repair.
Tip
The nasal tip should overall be assessed for asymmetry, deviation, projection, and
rotation. Tip support can be examined by applying pressure to the tip and evaluating
the degree of collapse posteriorly with this maneuver. Poor tip support can be the
reflection of weak lower lateral cartilages, weak attachment of the medial crural
footplates to the caudal septum, and/or compromise of the scroll region. Collectively,
interruption of multiple minor tip support mechanisms can also lead to decreased tip
support.
Tip projection and tip rotation should also be measured. There are various ways to
measure tip projection. Commonly included measures for assessing tip projection include
Simon's method, a one-to-one ratio of the upper lip length to the tip length, and
Goode's method, according to which the ratio of the tip length to the dorsal length
should be 0.66.[15 ] Nasal tip projection can also be measured by drawing a line in profile view from
the anterior border of the lip superiorly along the nose. Tip projection is thought
to be appropriate if the amount of nasal tip anterior to this line is 50 to 60% of
the of the total tip length from the tip defining point to the alar facial groove.[17 ] In males, the tip rotation should be between 90 and 95 degrees. In females, the
tip rotation should be between 95 and 110 degrees.
Alar Base
The width of the alar base should be noted, as well as the symmetry from the midline
of the columellar labial junction. The width of the alar base in a Caucasian nose
should lie between the medial canthi.[15 ] In African American noses, the alar base should be roughly between the caruncles.
A wider-than-ideal alar base could benefit from alarplasty.
Bulbosity or Boxiness
A bulbous or boxy tip may be caused by splaying of the interdomal ligaments, wide
domes of the lower lateral cartilages, and convex orientation of the lateral crura,
giving an overall domelike shape to the lower lateral cartilages. This shape to the
lower lateral cartilages can extend beyond the nasal tip region and cause fullness
of the supratip region and even the middle third of the nose. A domelike configuration
of the lower lateral cartilages results in a trapezoidal shape of the tip.
Columella
The position of the columella relative to the midline of the columellar labial junction
and to the tip should be documented. The height of the columella should also be measured.
The columellar base, columella, and nasal tip should each be about one-third in height.
The base of the columella should be assessed for excessive width, which can be caused
by splaying of the medial crura or medial crural footplates, excess scar, cartilage
grafts, a wide anterior nasal spine, and/or caudal septal deviation.
Columellar show should be documented with a normal columella between 2 and 4 mm from
the inferior border of the columellar to the alar margin. A line can be drawn bisecting
the apices of the nostrils. Above that line to the alar margin would be the alar height
and below that line to the inferior border of the columella would be the columellar
hang. Alar retraction or a congenitally high arch is present when the alar height
is greater than 2 mm. In prior nasal surgery or trauma, this alar retraction can be
most commonly due to soft-tissue loss, cartilage loss, or aggressive cephalic trims.
Conclusion
The nose is a very complex structure, largely due to its functional role in breathing
and its essential aesthetic role in providing facial harmony. It requires mastery
of the nasal mechanics and nasal physiology to formulate a surgical plan and effectively
change the shape of the nose. Clinical evaluation is paramount in ultimately developing
an appropriate surgical plan tailored to the patient. Assessing the nose in a systematic
fashion and using objective measures can help quantify the patient's degree of nasal
obstruction. Additionally, use of PROMs can allow for quantification of patient-perceived
concerns and their subjective outcomes.
