Does Size Really Matter? A Review on How to Determine the Optimal Umbilical Size During an Abdominoplasty

In ancient cultures, the navel was more than a cosmetic pleasure point. In Japanese culture, the navel region was referred to as the “Hara”, or a person’s center for life.¹ In Chinese medicine, the umbilicus, or acupuncture point CV8 (Shen Que), is referred to as the spiritual gate.¹ For example, the people of Nanjing, China, regarded the navel region as “the center of heaven, ruled by Earth.”¹ Due to its spiritual importance, both the ancient Japanese and Chinese used the umbilical region for a multitude of medicinal treatments; they believed illnesses involving the spleen, lung, and kidney were cured through the umbilicus given its place overlying the junction of many major vessels of the body.¹ Today, the umbilicus still holds a vital place in modern culture through the practices of yoga, aerobics, and meditation.¹

Beyond its spiritual significance and importance in the practices described above, the navel region has become an important aesthetic component of the abdomen. The introduction of the 2-piece swimsuit in 1946 placed a particular emphasis on the umbilicus region in western culture.² Since then, western fashion has continued to highlight this region and further increased the need for an aesthetically pleasing abdomen. 

Since 2019, the number of abdominoplasties have increased by 49%, with 242,939 performed in 2021, making it the third most performed surgical cosmetic procedure.³ During abdominoplasties, the reconstruction of the umbilicus is a vital component in the patient’s overall satisfaction.^4-6 A visually displeasing umbilicus can ruin an otherwise successful and functional abdominoplasty. The size, shape, and position are the key components that a patient uses to assess the aesthetic outcome.⁷ Although the ideal position and shape have been scrutinized and studied comprehensively, less is known about the optimal size. Therefore, the authors sought to compile a thorough literature review to numerically quantify an aesthetically pleasing umbilicus.

A PubMed search was conducted in July 2022 for studies published with the search terms umbilicus, umbilicoplasty, abdominoplasty, aesthetic umbilicus, and size. These terms were combined to create a unique search string to filter results that focused on the inclusion criteria. The inclusion criteria were English articles that studied the aesthetic or average umbilical size with or without abdominoplasties. Articles were excluded if they did not describe the aesthetic or mean umbilical size or were not relevant to the topic. A final additional manual search among the references of the articles that met the inclusion criteria was conducted to provide a more comprehensive review.  

The literature search generated 21 articles of interest that were read and assessed for eligibility, of which 6 articles were excluded due to topics or discussions irrelevant to the subject matter. Of the 15 remaining articles, 6 met the set inclusion criteria. An additional 10 articles were identified by manually reviewing all the references of the 6 relevant articles from the initial literature search. A total of 16 articles were included in the final review, with the screening process shown in Figure 1. Additionally, the umbilical size, sample population, and study methods for the articles included in the review are described in Table 1. 

Umbilical Size

The literature review analyzed 16 studies focused on aesthetic, average, or surgically constructed umbilical size on both quantitative and qualitative scales. Nine articles reported data measurements in length and width in centimeters.^8-16 In addition, of these 9 articles, 7 focused on both male and female umbilical sizing.^{8-10, 12-15} If a study only reported diameter, an assumption was made that the umbilicus was circular in shape with the diameter equal to both the length and width in centimeters. Two articles reported umbilical size in a vertical:horizontal (V:H) ratio with a value greater than 1 indicating a more vertically shaped navel.^6,17 One article discussed umbilical sizing in percentage terms. Lee et al indicated that the optimal navel size is 5% of a person’s abdominal length, measuring from the xiphoid to the vulva.⁷ Due to the 3 different data measurement metrics, no standardized quantitative approach was used in the 16 articles for evaluating umbilical size. The umbilical sizes reported in the 16 articles ranged from 0.6 to 3.0 cm.

For the qualitative analysis, 4 studies classified the ideal aesthetic navel size as “small.”^18-21 A consensus was reached that a smaller umbilicus is vital for a perceived attractive abdomen. 

Sample Size

The populations examined throughout the 16 studies were only male (n = 1),¹⁷ only female (n = 5),^7,9,12,13,18 or both male and female (n = 6).^{6,8,11,14,16,20} Of the remaining 4 articles, 3 were not applicable due to article topic (focused on abdominoplasty technique)^15,19,21 and 1 did not report on patient gender (n = 20).¹⁰ The total participants were 1263; of the total participants in studies that reported on gender, 63% identified as female (n = 778) and 37% identified as male (n = 465), with 40% of the total male participants originating from 1 study (Gram et al).¹⁷ 

Study Method

The 16 articles used a range of methods to quantify aesthetic or average navel size. Five studies conducted a subjective analysis of umbilical photos of female models where participants rated or ranked the photos for the most aesthetic, naturally looking umbilicus^{7,11,12,18,20} Four studies determined the average navel size by taking linear abdominal measurements of individuals.^8,9,14,16 Two studies evaluated both a subjective analysis of umbilical photos and a quantitative reporting of ideal navel size, including the study by Graham et al that analyzed male models instead of females.^6,17 Three studies reported on the optimal technique, including V-chevron and half-moon methods, for umbilical reconstruction.^10,15,21 Lastly, 2 studies described using an earplug technique to fix abdominal stenosis following abdominoplasty.^13,19 

The umbilicus has long been a focal point of the abdomen for ancient medicine, religion, and aesthetic purposes, with the latter being exemplified in fashion, advertisement, and entertainment industries. The appearance of the umbilicus is directly related to patient satisfaction in those undergoing abdominoplasties. In current practice, the optimal umbilicus is reported to be small, vertically oriented, T- or oval-shaped, and with a superior hood.^{6,11,12,18,20} Age, weight gain, pregnancy, and hernias can cause deviations from the optimal umbilical size by creating a large umbilicus, horizontal or disoriented shape, and projection that may be considered aesthetically displeasing.^6,11,18 Although extensive literature has been conducted on orientation, shape, and hooding, less is known about the optimal size. While many studies report that the most aesthetic umbilicus is small, an exceedingly small umbilicus is considered unattractive and can result in umbilical stenosis after abdominoplasties.¹⁶ This review summarizes the current literature to attempt to quantify an optimal umbilical size that is considered aesthetically and naturally pleasing. 

This review analyzed a total of 16 articles for optimal umbilical size. Five studies reported on the aesthetic size of the umbilicus,^{7,11,17,18,20} 3 studies discussed the most natural-looking umbilicus,^8,9,14 4 studies integrated knowledge on optimal size in umbilicoplasties,^12,15,16,19 2 studies discussed techniques for fixing abdominal stenosis,^13,19 and 2 studies evaluated a combination of these metrics.^12,16 

Ample attention was brought to the characteristics of an aesthetically pleasing umbilicus by Craig et al in 2000, who initially discussed the parameters of the ideal female umbilicus.¹⁸ Twenty-one examiners, of whom 6 were female and 15 were male, ranked the umbilicus of 147 women’s photographs by using a scale of 1 (unappealing) to 10 (appealing) and found that the optimal belly button is small.¹⁸ In 2008, Cavale et al expanded on this study and recruited a larger sample size of 251 examiners (167 female and 84 male). Examiners ranked 5 photos of the female umbilicus with variations in shape, and results were similar to those of Craig et al.²⁰ Two additional studies reported that the optimal umbilical size is small.^19,21 However, these studies failed to assign a numerical value to their observation that a smaller umbilicus is more aesthetically pleasing. 

In a 2013 study by Lee et al based on the assumption that models have ideal aesthetics, computerized image analysis was used to quantify the most aesthetic umbilicus of 37 female Playboy Playmates. The optimal navel was found to be oval-shaped with a diameter of 5% ± 1% of the abdominal length (xiphoid to vulva).⁷ Furthermore, Visconti et al analyzed navel parameters in 81 of the top 2013 bikini models to find the average V:H ratio of the navel. Their findings resulted in a V:H ratio of 1.4 ± 0.46, suggesting the optimal umbilicus has a shorter transverse diameter.² 

In contrast, Graham et al analyzed 81 of the top male underwear models in 2012 and found the optimal V:H ratio of the navel was 0.88 ± 0.34. This suggests that the optimal navel size in men includes longer transverse diameters, rather than the shorter measurements previously suggested.¹⁷ Further studies have reported that there are significant differences in umbilicus parameters between men and women (P = .0014).^20,22 Before Graham et al, most studies only assessed aesthetic navel metrics in women, not accounting for potential gender differences. Therefore, current navel metrics in abdominoplasties for men might not be reflective of the most aesthetic outcome. However, the high standard deviation in these results suggest there is variability in the optimal navel size, and further studies are needed to quantify the ideal umbilical size for men and women.

Deviating from aesthetics, 3 studies evaluated the most natural-looking navel by determining the mean umbilical size in a sample population.^9,11,14 In 2010, Pallua et al evaluated 137 individuals, aged 19 to 70 years, to find an average navel width of 0.66 cm and height of 1.05 cm in women and a navel width of 0.92 cm and height of 1.12 cm in men.¹¹ In 2019, Yu et al analyzed 80 young individuals, 43 female and 37 male, for navel measurements to find a mean navel height of 2.1 ± 0.6 cm and mean navel width of 2.3 ± 0.7 cm.¹⁴ 

Understanding the mean umbilical size in the general population is important for achieving a natural result in tummy tucks. These results suggest that umbilical size differs with gender, which also leads to differences in the natural appearance of the navel. Further, these studies report variability in navel size, as Pallua et al reported a smaller average navel size than that reported in Yu et al. More studies are needed to quantify mean navel metrics. These studies bring focus to the vital question as to whether there is a difference between the most aesthetic and the most natural umbilicus.

Understanding and quantifying the most aesthetic and natural size of the navel is important because plastic surgeons use this to determine best practices in umbilical reconstruction. For example, 4 studies in this review used set umbilical length in their reconstructions.^10,12,15,21 Hespe et al measured a navel diameter of 1.5 cm when performing their half-moon technique in umbilicoplasty.¹⁵ Rozen et al described their technique for umbilical transposition in abdominoplasties in which navel is constructed with a maximum length of 2.5 cm and maximum width of 1.5 cm.¹⁰ Visconti et al designed navels ranging from 1.3 to 2.1 cm in diameter in 23 patients who underwent a deep inferior epigastric perforator free flap breast reconstruction.¹² All these studies reported patient and surgeon results as subjectively positive. These techniques construct navels ranging from 1.3 cm to 2.5 cm, close to the average size of the small finger (~1 cm) to the thumb (~1.9-2.2 cm). 

Most articles in this review concluded that the smaller the umbilicus, the more aesthetically pleasing. Following this principle, the most aesthetically pleasing umbilicus would be an umbilical size of 1 cm or less. However, maintaining navel hygiene is an important component in achieving a positive surgical result that must be also be considered, as 10% to 20% of patients deal with complications following abdominoplasties.²³ Furthermore, a bacterial infection of the skin, especially in skin folds, is the second most common complication of abdominoplasties that can lead to inflammation, tenderness, edema, and elevated local temperature.²³ The umbilicus is at an increased risk to develop an infection after abdominoplasties because it is considered a skin fold, contains unique bacteria, and has no direct blood supply. While most studies report the optimal umbilical size is small, the umbilicus needs to be large enough to fit a finger to clean and prevent infection.²⁴ 

Additionally, the concern for constructing an umbilicus closer to 1 cm or less is that there is an increased risk for umbilical stenosis. However, Kachare et al and Dini et al each posed a potential solution to this problem by using a firm ear plug technique to combat abdominal stenosis.^13,19 In 2006, Dini et al first attempted this technique, taking advantage of the small size of the ear plug (~1 cm), and was successfully able to fix abdominal stenosis while maintaining a small diameter. Building off of this technique, Kachare et al placed firm ear plugs, the size of the external auditory ear canal and the small finger, in 21 female patients who underwent abdominoplasties; the plugs were placed 2 weeks postoperatively and left in place for 4 to 6 weeks.¹³ In both studies, patients achieved an appropriately sized belly button and were highly satisfied with the results.^13,19 The earplug placement technique after abdominoplasties allows for patients to clinically achieve the optimal small umbilicus size range from the small finger to the thumb (~1-2 cm) while maintaining proper hygiene.

There is a consensus among the authors reviewed that the ideal umbilical size is small, ranging in size from 0.6 to 3.0 cm. These sizes allow for a small enough umbilicus to be considered aesthetically pleasing while maintaining accessibility to the navel for proper hygiene practice. 

The senior author of this review shares a similar opinion. He has evolved his technique over the past 10 years, with 173 abdominoplasty cases performed from 2012 to 2022, to create an umbilicus with subjectively high surgeon and patient satisfaction. In the past, he constructed a vertically oriented, superior hooded umbilicus with a length of 1.2 cm and a width of 2.0 cm. Currently, he constructs the umbilicus with a length of 1 cm and a width of 0.5 cm. This was found to be the smallest umbilical size that achieved aesthetic satisfaction while maintaining proper hygiene. To this end, he determined that marking should be done on stretched skin. If marked on unstretched skin, there is a risk of improper sizing with a larger navel that could lead to patient dissatisfaction. 

Despite the consensus among authors, there are several limitations to this review. There are a limited number of studies, ever-changing beauty standards, cultural and ethnic differences in beauty preferences, a disproportionate study of women, primarily qualitative observations, and high variation in quantitative data on umbilical size. This suggests further studies are needed to better elucidate the importance of size for umbilical reconstruction in abdominoplasties.

This literature review summarizes prior author studies on the relationship between umbilical size and individual perceived satisfaction. Despite a “smaller” size being the standard, the lack of uniform quantifiability of umbilical size leads to different definitions of small among physicians and the diverse patient population. These discrepancies can also lead to umbilical stenosis, improper navel hygiene, and patient dissatisfaction. Patient consultation and size are important variables that need to be considered by physicians when constructing the ideal umbilicus. 

A literature review was conducted to determine the ideal umbilical size. The consensus was to construct a navel that is “smaller,” without a defined measurement, to maintain the most aesthetically pleasing umbilicus and achieving high patient satisfaction. The lack of definite proportions and defined sizing can create difficulty in constructing the ideal umbilicus in abdominoplasties. More studies are needed to quantify the optimal umbilical size and account for potential gender, cultural, ethnic, and age differences.

Affiliations: ¹University of Louisville School of Medicine, Louisville, Kentucky; ²Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Louisville, Louisville, Kentucky

Correspondence: Milind D Kachare, MD; Milind.Kachare@gmail.com

Funding: This study received no means of outside funding. 

Disclosures: The authors report no known or perceived conflicts of interest regarding the material presented in this manuscript.