The Association Between Nasal Skin Thickness and Body Mass Index in Preoperative Rhinoplasty Patients: A Prospective Study

Abstract

Objectives

Skin quality plays a major role in aesthetics, particularly in determining the success of rhinoplasty. Efficient preoperative estimation of nasal skin thickness can improve postoperative results and patient satisfaction. This study aimed to report on the relationship between nasal skin thickness and body mass index (BMI) as a possible tool to measure skin thickness preoperatively among rhinoplasty patients.

Methods

This prospective cross-sectional study targeted patients who visited a rhinoplasty clinic at King Abdul-Aziz University Hospital, Riyadh, Saudi Arabia, between January 2021 and November 2021, and agreed to participate in the study. Data on age, sex, height, weight, and Fitzpatrick skin types were collected. The participant visited the radiology department and underwent ultrasound nasal skin thickness measurement for the five different nasal points.

Results

The study included 43 participants (16 males and 27 females). The average skin thickness of the supratip area and the tip was significantly higher in males than in females (P < 0.05). The average BMI of the participants was 25.8 ± 5.26 Kg/m². Participants with a normal BMI or less represented 50% of the study sample, whereas overweight and obese represented one-quarter (27.9%) and one-fifth (21%), respectively.

Conclusion

BMI was not associated with nasal skin thickness. Differences in nasal skin thickness were found between the sexes.

Keywords

nasal skin thickness weight body mass index rhinoplasty nose

Introduction

The skin is the most obvious organ in the human body, with essential protective and regulatory functions.¹ In addition to its function, skin quality plays a major role in aesthetics, specifically in determining rhinoplasty success. Nasal skin quality consists of dermal thickness and number of pilosebaceous units.² It varies in thickness along the length of the nose. The rhinion area is the thinnest and thickens caudally in the supratip region. The skin covering the cephalic portion of the nose have little subcutaneous fat and sebaceous glands. Conversely, more subcutaneous tissue and sebaceous glands were found at the nasal tip.³ In rhinoplasty, patients with thin nasal skin can be challenging because even the slightest irregularities of the reconstructed osseocartilaginous framework can be visible postoperatively. However, thick skin is rich in sebaceous glands and tends not to show a concrete change in their tip after surgery. Surgeons commonly assess skin quality by visual inspection; as a result, subjective measurement variability without validated tools can produce inaccurate preoperative planning.

Efficient preoperative estimation of nasal skin thickness can improve postoperative results and patient satisfaction. Reportedly, sex, age, ethnicity, and nutritional status affect facial soft tissue thickness.^4,5 Simultaneously, body mass index (BMI) has been found to play a major role in influencing its thickness.^6,7 Various methods have been suggested for measuring nasal and facial soft tissue thickness. For instance, visual examination, palpation, and radiological studies such as ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI).^8-11 Nevertheless, there is no standard measure to evaluate nasal thickness. Preoperative ultrasound has been used by Kosins et al. to measure nasal STE thickness in patients undergoing rhinoplasty.⁸ CT scans have been used in various populations, such as Korean, Caucasian, Saudi, and diverse races.^9-11 Additionally, Ozkul et al. introduced a practical noninvasive method for calculating nasal skin thickness using a Castroviejo Caliper instrument to measure both the nasal dorsum and alar thickness.²

This study aimed to report the relationship between nasal skin thickness and BMI) as a possible tool to measure skin thickness preoperatively among rhinoplasty patients.

Patients and Methods

The study was a prospective cross-sectional study that targeted patients who visited a rhinoplasty clinic seeking rhinoplasty at King Abdul-Aziz University Hospital (KAUH) Riyadh, Saudi Arabia, between January 2021 and November 2021. KAUH is a teaching and referral hospital for all otolaryngology subspecialties, including facial plastic surgery in Riyadh, and provides health services to Saudi citizens and residents. This research was approved by the Institutional Review Board of the research committee of at college of medicine at king Saud University program with IRB registration number: E-21-6530. Informed consent was obtained from the patients involved in this study. Patients with previous rhinoplasty surgery, other sinonasal surgeries, or congenital nasal deformities were excluded from the study. Age, sex, and Fitzpatrick skin type were collected from the patient history and physical examination. Height was measured using a metric stadiometer and weight was measured using standardized medical measurements. BMI was calculated using the following formula: BMI = body mass divided by the square of body height and is expressed in units of kg/m². A data collection sheet was used to measure different variables. The participants underwent ultrasound nasal skin thickness measurement by a specialized radiologist for five different nasal points using a GE LOGIQ E9 US machine, superficial probe, frequency 9–15 Mhz (Figure 1). The 5 points are: nasion, nasal dorsum, rhinion, supratip area, and tip defining point. The nasion point defined as the most anterior point of the frontonasal suture that joins the nasal part of the frontal bone and the nasal bones. Dorsum is the midline anterior bony prominence of the nose. Rhinion is a point at the lower end of the median suture joining the nasal bones. Supra tip point is the nasal region where the inferior region of the nasal dorsum meets the tip of the nose. Tip defining point is located at the apex of the tip lobule and formed by the junction of the medial and lateral crura of each lower lateral cartilage. The measurement of the nasal tip was done by calculating the depth from the superficial skin to the dome of the lower lateral cartilage for each side then dividing by two. The data were transferred to an Excel spreadsheet with all the required variables. Data were input from the Excel spreadsheet and analyzed using R v.3.6.3. Counts and percentages were used to summarize categorical variables, and mean ± standard deviation (SD) was used for continuous variables. Linear regression analysis was used to assess the factors associated with nasal skin thickness. The models were adjusted for age and sex. Hypothesis testing was performed at the 5% significance level.

Figure 1.

Correlation between nasal skin thickness and BMI.

Results

The study sample included 43 participants (16 males and 27 females). The average skin thickness of the supratip area was significantly higher in males than females (6.31 vs. 5.45, respectively, P < 0.05). The average skin thickness of the tip was significantly higher in males than in females (3.58 vs. 2.93, respectively, P < 0.05). The average BMI of the included participants was 25.8 ± 5.26 Kg/m². Respondents with a normal BMI or less represented 50% of the study sample, while overweight and obese respondents represented one-quarter and one-fifth (27.9% and 21%, respectively), as shown in Table 1. Table 1 also shows the association between BMI and nasal mucosal thickening, which revealed that BMI was not associated with any of the included measurements Table 2.

Table 1.

Descriptive Statistics for the Study Sample.

	Total	Female	Male	P value
	N = 43	N = 27	N = 16	P value
Age	27.9 (8.84)	30.4 (8.87)	23.6 (7.18)	0.009
Nationality				0.282
Non-Saudi	3 (6.98%)	3 (11.1%)	0 (0.00%)
Saudi	40 (93.0%)	24 (88.9%)	16 (100%)
BMI	25.8 (5.26)	26.6 (5.26)	24.6 (5.19)	0.249
US nasion in mm	4.04 (1.01)	3.91 (0.98)	4.27 (1.04)	0.274
US Mid dorsum in mm	2.43 (0.90)	2.33 (0.82)	2.61 (1.04)	0.364
US Rhinion in mm	1.81 (0.70)	1.66 (0.55)	2.06 (0.86)	0.106
US supratip area in mm	5.77 (1.17)	5.45 (1.02)	6.31 (1.24)	0.026
US tip in mm	3.17 (0.71)	2.93 (0.66)	3.58 (0.61)	0.002
Fitzpatrick skin type	3.00 (0.31)	3.00 (0.39)	3.00 (0.00)	1.000
BMI category				0.094
Underweight	3 (6.98%)	0 (0.00%)	3 (18.8%)
Normal	19 (44.2%)	14 (51.9%)	5 (31.2%)
Overweight	12 (27.9%)	6 (22.2%)	6 (37.5%)
Obesity class I	6 (14.0%)	5 (18.5%)	1 (6.25%)
Obesity class II	3 (6.98%)	2 (7.41%)	1 (6.25%)

Categorical data is summarized using counts and percentages.

Continuous variables are summarized using mean (SD).

Continuous variables are compared using unpaired t-test, and categorical data are compared using the Chi-square test of independence.

BMI, body mass index; US, United States.

Table 2.

Association Between Body Mass Index and Nasal Mucosal Thickening.

	Total	Normal or underweight	Overweight	Obese	P value
	N = 43	N = 22	N = 12	N = 9	P value
US nasion in mm	4.04 (1.01)	3.84 (0.92)	4.17 (1.07)	4.38 (1.12)	0.156
US mid dorsum in mm	2.43 (0.90)	2.13 (0.61)	2.83 (1.01)	2.63 (1.18)	0.070
US rhinion in mm	1.81 (0.70)	1.70 (0.62)	1.89 (0.76)	1.98 (0.82)	0.274
US supratip area in mm	5.77 (1.17)	5.69 (1.17)	5.87 (0.97)	5.84 (1.50)	0.694
US tip in mm	3.17 (0.71)	3.04 (0.73)	3.40 (0.62)	3.20 (0.78)	0.389
Fitzpatrick skin type	3.00 (0.31)	3.00 (0.31)	3.00 (0.43)	3.00 (0.00)	1.000

Statistical analysis is performed using one-way ANOVA.

Data are summarized using mean (SD).

BMI was used as a continuous variable analysis (Figure 1), which showed that BMI was not associated with nasal skin thickness in any of the measured regions. The skin thickness of the mid dorsum was positively associated with the skin thickness of the supratip area (r = 0.482, P < 0.01) and the skin thickness of the rhinoin (r = 0.48, P < 0.01). The highest correlation was observed between the skin thickness of the mid dorsum and rhinoin skin thickness (r = 0.854, P < 0.001). Linear regression analysis results for the mid dorsum and rhinoin areas showed that only sex was significantly associated with rhinoin thickness (B = 0.52, P < 0.05) as shown in Table 3. In addition, only sex was significantly associated with supratip thickness (B = 0.93, P < 0.05) and tip area (B = 0.67, P < 0.05) as shown in Table 4.

Table 3.

Linear Regression Analysis for Middorsum and Rhinoin Areas.

	US mid dorsum in mm			US rhinion in mm
Predictors	Estimates	CI	P value	Estimates	CI	P value
(Intercept)	1.15	−0.17–2.47	0.087	0.96	−0.05–1.98	0.063
Age	0.02	−0.02–0.05	0.332	0.01	−0.01–0.04	0.365
Gender: Male vs. Female	0.47	−0.15–1.08	0.131	0.52	0.05–0.99	0.031
BMI (1 category increase)	0.24	−0.03–0.51	0.076	0.12	−0.08–0.33	0.241
R²/ R²adjusted	0.119/0.051			0.129/0.062

BMI is included as a polynomial term.

BMI, body mass index; CI, confidence interval.

Table 4.

Linear Regression Analysis for Nasion, Supratip, and Tip Areas.

	US nasion in mm			US supratip area in mm			US tip in mm
Predictors	Estimates	CI	P value	Estimates	CI	P value	Estimates	CI	P value
(Intercept)	3.45	1.96–4.94	<0.001	4.83	3.17–6.49	<0.001	2.68	1.71–3.65	<0.001
Age	−0.01	−0.05–0.03	0.686	0.00	−0.04–0.04	0.985	−0.00	−0.03–0.02	0.757
Gender Male vs. Female	0.38	−0.31–1.07	0.268	0.93	0.16–1.70	0.019	0.67	0.22–1.12	0.005
BMI (1 category increase)	0.25	−0.06–0.55	0.107	0.22	−0.12–0.55	0.201	0.13	−0.07–0.33	0.193
R²/R²adjusted	0.098/0.028			0.166/0.102			0.237/0.178

BMI was included as a polynomial term.

BMI, body mass index; CI, confidence interval.

Discussion

Our study aimed to determine the relationship between nasal skin thickness by measuring skin thickness preoperatively among rhinoplasty patients using ultrasound technique measurements and BMI. Nasal skin thickness was reported to be an important factor for rhinoplasty, interfering with intraoperative difficulty, the final result of rhinoplasty surgery, and overall satisfaction.^2,4 Patients involved in the study were categorized according to their BMI into normal, overweight, and obese groups. Skin thickness measurements were performed using the US scan technique to determine the association between obesity and skin thickness. There is no standardized method for nasal skin thickness measurements. Different modalities have been used in the literature, and most rhinoplasty surgeons utilize visual inspection to assess skin thickness;¹² however, many authors have utilized CT scans in many populations.^9-11 Okzul et al.² used the Castroviejo Caliper instrument, and showed that only sex was significantly associated with the thickness of the rhinion, supratip, and tip areas, which is consistent with the findings of Simpson and Kim et al.^4,5 In addition, Jacob et al. found that the nasal soft tissue envelope was thicker in individuals with a higher BMI.¹² Similarly, facial soft tissue was thicker in the Chinese population in those with a higher BMI.¹³ In addition to these findings, Alharethy et al. showed that BMI did not influence the nasal shape.¹⁴ In our study, BMI was found to have an insignificant association with nasal skin thickness areas, including the nasion, mid dorsum, rhinion, supratip, and tip areas.

Obesity often increases subcutaneous fat. A study by Boza et al. compared the skin manifestations in obese patients with a control group of normal-weight patients. The study showed that a large number of dermatological diseases are associated with a greater extent in obese populations such as striae, pseudoacanthosis nigricans, and bacterial infections.¹⁵ Numerous studies have detailed the effects of obesity on craniofacial measurements.^6,7,16,17 Similarly, Moghadam et al. revealed a significant association between soft tissue thickness, MRI measurements, and BMI.¹⁸

Nonetheless, few studies have been conducted to understand the relationship between BMI and nasal skin thickness and whether it can be used as a predictor of skin quality.

Alharethy et al. illustrated the CT measurements of the skin thickness at the nasion and the rhinion region of 100 patients. The study found no correlation between nasal thickness and BMI in all nasal regions.¹⁹ However, Dey et al. described the correlation between BMI, other facial features, and nasal STE thickness in a sample size of 190 patients. They found that thick skin is more prevalent in patients with rich sebaceous skin, telangiectasias, higher Fitzpatrick skin type, male sex, and higher BMI. In contrast, thin skin is associated with increased visibility of nasal tip cartilages, freckles, lower Fitzpatrick skin type, female sex, and lower BMI.¹² Ming et al have used US technique to measure dermal and epidermal facial thickness and have found that gender had a significant impact on the thicknesses of facial dermis and epidermis of normal adults while BMI had no correlation with epidermal and dermal thicknesses which is consistent with findings of our study.²⁰

Small sample size is considered one of the limitations of this study and because of this to better represent the population more studies with larger sample size are needed in the future.

In conclusion, BMI was not associated with nasal skin thickness. Differences in nasal skin thickness were found between the sexes.

Footnotes

Acknowledgments

We would like to thank Editage () for their English language editing for this research.

Author confirmations

Hassan Assiri: Literature review, Data collection, manuscript writing.

Waleed Abdelkader: Literature review, Imaging interpretation, manuscript writing.

Rayan Alfallaj: Literature review, result analysis, manuscript writing, submission.

Yasser Alarimah: Literature review, Data collection, manuscript writing.

Hadeel AlMajed: Literature review, Data collection, manuscript writing.

Ahmed Alarfaj: Research Idea, Literature review, manuscript writing, review.

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Data availability

All research data can be accessed through an excel files for review.

Ethical Approval

This research was approved by the Institutional Review Board of the research committee of at college of medicine at king Saud University program with IRB registration number: E-21-6530.

Correction (August 2023):

Hassan Assiri and Yasser Alarimah affiliation has been updated in the article.

ORCID iDs

Hassan Assiri

Rayan Alfallaj

References

Richardson

. Understanding the structure and function of the skin. Nurs Times. 2003;99(31):46-48.

Ozkul

Kocagöz

Balıkcı

Verim

Yaşar

. A practical method for assessing nasal skin quality. Eur Arch Otorhinolaryngol. 2013;270(6):1839-1842.

Whitaker

Johnson

. Skin and subcutaneous tissue in rhinoplasty. Aesthet Plast Surg. 2002;26:S1-S19.

Simpson

Henneberg

. Variation in soft-tissue thicknesses on the human face and their relation to craniometric dimensions. Am J Phys Anthropol. 2002;118(2):121-133.

Kim

Ruprecht

Wang

Lee

Dawson

Vannier

. Accuracy of facial soft tissue thickness measurements in personal computer-based multiplanar reconstructed computed tomographic images. Forensic Sci Int. 2005;155(1):28-34.

Starbuck

Ward

. The affect of tissue depth variation on craniofacial reconstructions. Forensic Sci Int. 2007;172(2-3):130-136.

Ferrario

Dellavia

Tartaglia

Turci

Sforza

. Soft tissue facial morphology in obese adolescents: A three-dimensional noninvasive assessment. Angle Orthod. 2004;74(1):37-42.

Kosins

Obagi

. Managing the difficult soft tissue envelope in facial and rhinoplasty surgery. Aesthet Surg J. 2017;37(2):143-157.

Cho

Kim

Yeo

Kim

Jang

. Nasal skin thickness measured using computed tomography and its effect on tip surgery outcomes. Otolaryngol Head Neck Surg. 2011;144(4):522-527.

10.

Jomah

Elsafi

Ali

KSAE

Abdullah

Gelidan

. Nasal skin thickness measurements using computed tomography in an adult saudi population. Plast Reconstr Surg Glob Open. 2019;7(9):e2450.

11.

Eggerstedt

Rhee

Buranosky

Batra

Tajudeen

Smith

Revenaugh

. Nasal skin and soft tissue thickness variation among differing races and ethnicities: An objective radiographic analysis. Facial Plast Surg Aesthet Med. 2020;22(3):188-194.

12.

Dey

Recker

Olson

Bowen

Hamilton

. Predicting nasal soft tissue envelope thickness for rhinoplasty: A model based on visual examination of the nose. Ann Otol Rhinol Laryngol. 2020;130(1):60-66.

13.

Dong

Huang

Feng

Bai

Zhao

. Influence of sex and body mass index on facial soft tissue thickness measurements of the northern Chinese adult population. Forensic Sci Int. 2012;222(1-3):e1-e7.

14.

Alharethy

Mousa

Alharbi

Aldrees

AlQaryan

Ju Jang

. Does skin thickness affect satisfaction post rhinoplasty? Middle eastern population as an example. Saudi Med J. 2018;39(12):1238-1241.

15.

Boza

Trindade

Peruzzo

Sachett

Rech

Cestari

. Skin manifestations of obesity: A comparative study. J Eur Acad Dermatol Venereol. 2012;26(10):1220-1223.

16.

Öhrn

Al-Kahlili

Huggare

Forsberg

Marcus

Dahllöf

. Craniofacial morphology in obese adolescents. Acta Odontol Scand. 2002;60(4):193-197.

17.

Nádaždyová

Štefánková

Samohýl

. The impact of body mass index on craniofacial parameters. Kontakt. 2016;18(4):e253-e257.

18.

Eftekhari-Moghadam

Latifi

Nazifi

Rezaian

. Influence of sex and body mass index on facial soft tissue thickness measurements in an adult population of southwest of Iran. Surg Radiol Anat. 2020;42(5):627-633.

19.

Alharethy

Alohali

Alquniabut

Jang

. Bone and soft tissue nasal angles discrepancies and overlying skin thickness: A computed tomography study. Aesthetic Plast Surg. 2018;42(4):1085-1089.

20.

Meng

Feng

Shan

Yuan

Jin

. Application of high frequency ultrasound to assess facial skin thickness with gender, age and BMI in healthy adults. BMC Med Imaging. 2022;22(1):113. doi:10.21203/rs.3.rs-1387962/v1.