‘It's all in the pinch’: A description of a novel method for assessing nasal soft tissue pliability for nonsurgical rhinoplasty with hyaluronic acid filler

To the Editor, Nonsurgical rhinoplasty (NSR) with injectable hyaluronic acid fillers is gaining popularity.1 However, as with any aesthetic procedure, NSR requires assessment and planning to determine who may be an appropriate candidate for treatment. We describe a technique for assessing the pliability of the skin in the nose and present a new Nose Pliability Assessment Scale (NPAS), which may be a useful method of summarizing skin flexibility and behavior before nonsurgical treatment. When utilizing the NPAS, the overall firmness, thickness and mobility of the soft tissues are evaluated. The pliability of the soft tissue envelope is assessed using a ‘pinch test’, performed between the thumb and index, using the hyponychium of each digit. The skin is pinched caudal– cranial at the tip and bilateral to midline (from lateral to medial) at the radix and bridge. This maneuver allows the clinician to isolate the mobile soft tissues and slide them over the immobile osseocartilaginous skeleton. At the tip, the cartilage can be soft and flexible, and it is easy to pinch a composite of soft tissue and cartilage ‘en bloc’. This is incorrect, and one must be deliberate about the tissues being clasped. This can be challenging in noses with thick or sebaceous skin, or in previously operated noses where scar tissue may have obliterated natural soft tissue planes, making it more difficult to discern. However, with practice, clinicians will soon develop the technique and tactile sense. The pinch test is a useful method of assessing the potential space between the soft tissue layers and the periosteum/perichondrium, where the dermal filler gel is injected.2,3 The pinch test is applied to the radix, dorsum and nasal tip and each region is graded separately. The NPAS consists of a grading system, ranging from 1 to 5 (see Table 1 for details). When considering nonsurgical rhinoplasty, the ideal nose is adequately flexible with a thin soft tissue envelope. Patients with tissues that are graded as 3 or 4 on the NPAS are ideal for nonsurgical correction as they allow for accurate soft tissue assessment and manipulation, as well as easy filler gel injection. Postsurgical rhinoplasty patients may have a very tight skin pinch test, graded as 1 or 2 on the NPAS, due to extensive scarring from surgery and disruption of the natural anatomical planes. A tip that is overly tight with very little or no mobility on the skin pinch portends higher risk for vascular and cosmetic complications. Grade 5 tissues are characterized as being excessively soft and flexible, with a tip that feels as if it is ‘empty’. This renders patients with Grade 5 noses poor candidates for nonsurgical correction. The skin envelope that is lacking structure and native volume and contains a thin and weak cartilaginous foundation. The skin laxity can lead to injection of higher volumes of filler in an attempt to restore tension and structure, resulting in a bulbous and overfilled nose that lacks definition or projection. There is a higher likelihood of filler migration due to the lack of intrinsic soft tissue tension that would normally hold its shape and help to maintain filler within the area of injection. Figures 1– 3 depicts the examination findings of patients with various ratings on the NPAS. See Videos S1– S3 for examples of


L E T T E R T O T H E E D I T O R 'It's all in the pinch': A description of a novel method for assessing nasal soft tissue pliability for nonsurgical rhinoplasty with hyaluronic acid filler
To the Editor, Nonsurgical rhinoplasty (NSR) with injectable hyaluronic acid fillers is gaining popularity. 1 However, as with any aesthetic procedure, NSR requires assessment and planning to determine who may be an appropriate candidate for treatment.We describe a technique for assessing the pliability of the skin in the nose and present a new Nose Pliability Assessment Scale (NPAS), which may be a useful method of summarizing skin flexibility and behavior before nonsurgical treatment.
When utilizing the NPAS, the overall firmness, thickness and mobility of the soft tissues are evaluated.The pliability of the soft tissue envelope is assessed using a 'pinch test', performed between the thumb and index, using the hyponychium of each digit.The skin is pinched caudal-cranial at the tip and bilateral to midline (from lateral to medial) at the radix and bridge.This maneuver allows the clinician to isolate the mobile soft tissues and slide them over the immobile osseocartilaginous skeleton.At the tip, the cartilage can be soft and flexible, and it is easy to pinch a composite of soft tissue and cartilage 'en bloc'.This is incorrect, and one must be deliberate about the tissues being clasped.
This can be challenging in noses with thick or sebaceous skin, or in previously operated noses where scar tissue may have obliterated natural soft tissue planes, making it more difficult to discern.However, with practice, clinicians will soon develop the technique and tactile sense.
The pinch test is a useful method of assessing the potential space between the soft tissue layers and the periosteum/perichondrium, where the dermal filler gel is injected. 2,3The pinch test is applied to the radix, dorsum and nasal tip and each region is graded separately.
The NPAS consists of a grading system, ranging from 1 to 5 (see Table 1 for details).When considering nonsurgical rhinoplasty, the ideal nose is adequately flexible with a thin soft tissue envelope.Patients with tissues that are graded as 3 or 4 on the NPAS are ideal for nonsurgical correction as they allow for accurate soft tissue assessment and manipulation, as well as easy filler gel injection.Post-surgical rhinoplasty patients may have a very tight skin pinch test, graded as 1 or 2 on the NPAS, due to extensive scarring from surgery and disruption of the natural anatomical planes.A tip that is overly tight with very little or no mobility on the skin pinch portends higher risk for vascular and cosmetic complications.
Grade 5 tissues are characterized as being excessively soft and flexible, with a tip that feels as if it is 'empty'.This renders patients with Grade 5 noses poor candidates for nonsurgical correction.The skin envelope that is lacking structure and native volume and contains a thin and weak cartilaginous foundation.The skin laxity can lead to injection of higher volumes of filler in an attempt to restore tension and structure, resulting in a bulbous and overfilled nose that lacks definition or projection.There is a higher likelihood of filler migration due to the lack of intrinsic soft tissue tension that would normally hold its shape and help to maintain filler within the area of injection.There is minimal mobility in the skin and the nose remains stiff and non-compliant.There is less than 2 mm of skin pinch possible Grade 3 There is moderate mobility in the skin and tissue planes are discernible.The soft tissue envelope remains moderately tight with 2-5 mm of pliability on skin pinch Grade 4 There is good mobility in the skin and tissue planes can be easily discerned and lifted.The soft tissue envelope can be comfortably manipulated, and skin pinch is 6-10 mm Grade 5 The soft tissue envelope is loose, and the nose feels soft.There is a rolling mobility in the skin and >10-mm skin pinch tactile assessment of three patients exhibiting various NPAS grades of the nasal radix, bridge and tip.
In addition, we assessed the inter-rater reliability of the NPAs with a group of 24 practitioners who were asked to independently evaluate six patients using the NPAS.These practitioners received a brief description of the NPAS prior to using the scale.With NSR treatments on the rise, we feel the NPAS is useful for assessing patient candidacy and provides a summary measure for nasal soft tissue pliability.We hope to continue to refine and validate this tool so that it may be used more widely in clinical and research contexts.

AUTH O R CO NTR I B UTI O N S
All authors listed have contributed to the creation of this manuscript.
Dr. Ayad Harb has developed the tool and contributed to the writing of this manuscript.Dr. Amane Abdul-Razzak has contributed to the writing of this manuscript and the statistical analysis.Dr. Shahd Twijiri has contributed to the writing of this manuscript and data collection.

CO N FLI C T O F I NTER E S T S TATEM ENT
Ayad Harb, Amane Abdul-Razzak and Shahd Twijiri have no conflicts of interest to declare.

DATA AVA I L A B I L I T Y S TAT E M E N T
The data that support the findings of this study are available from the corresponding author upon reasonable request.

E TH I C S S TATEM ENT
This study was conducted in accordance with the principles outlined in the Declaration of Helsinki.

CO N S E NT
Verbal and written consent was obtained for the use of any images in this manuscript.

Figures 1 -
Figures 1-3 depicts the examination findings of patients with various ratings on the NPAS.See Videos S1-S3 for examples of This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.© 2023 The Authors.Journal of Cosmetic Dermatology published by Wiley Periodicals LLC.
The intraclass correlation coefficient (ICC) was measured using IBM® SPSS Statistics version 29.0 as an indicator of the inter-rater reliability of the NPAS.A two-way random effects ICC model was used with absolute agreement analysis.The ICC was 0.92 (95% CI 0.80-0.99),indicating excellent agreement amongst practitioners after minimal training and no experience.

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I G U R E 1 A 44-year-old female presenting prior to nonsurgical rhinoplasty treatment.Presents with desire to straighten bridge and elevate tip of nose.Pinch test demonstrates Grade 3 pliability of nasal tip.F I G U R E 2 A 39-year-old female presenting for assessment prior to nonsurgical rhinoplasty treatment.Pinch test demonstrates Grade 1 pliability on NPAS at nasal tip.Presents with desire to refine nasal bridge and elevate tip.

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I G U R E 3 A 26-year-old female presenting for clinical assessment prior to nonsurgical rhinoplasty treatment.Pinch test demonstrates Grade 5 pliability on NPAS at radix.Presents with desire to conceal dorsal bump and elevate nasal tip.