Cutaneous Corpuscular Receptors of the Human Glans Clitoris: Descriptive Characteristics and Comparison with the Glans Penis

Axonal and Glial PIEZO1 and PIEZO2 Immunoreactivity in Human Clitoral Krause's Corpuscles

Krause's corpuscles are typical of cutaneous mucous epithelia, like the lip vermillion or the glans clitoridis, and are associated with rapidly adapting low-threshold mechanoreceptors involved in gentle touch or vibration. PIEZO1 and PIEZO2 are transmembrane mechano-gated proteins that form a part of the cationic ion channels required for mechanosensitivity in mammalian cells. They are involved in somatosensitivity, especially in the different qualities of touch, but also in pain and proprioception. In the present study, immunohistochemistry and immunofluorescence were used to analyze the occurrence and cellular location of PIEZO1 and PIEZO2 in human clitoral Krause's corpuscles. Both PIEZO1 and PIEZO2 were detected in Krause's corpuscles in both the axon and the terminal glial cells. The presence of PIEZOs in the terminal glial cells of Kraus's corpuscles is reported here for the first time. Based on the distribution of PIEZO1 and PIEZO2, it may be assumed they could be involved in mechanical stimuli, sexual behavior, and sexual pleasure.

Krause corpuscles are genital vibrotactile sensors for sexual behaviours

Krause corpuscles, which were discovered in the 1850s, are specialized sensory structures found within the genitalia and other mucocutaneous tissues1-4. The physiological properties and functions of Krause corpuscles have remained unclear since their discovery. Here we report the anatomical and physiological properties of Krause corpuscles of the mouse clitoris and penis and their roles in sexual behaviour. We observed a high density of Krause corpuscles in the clitoris compared with the penis. Using mouse genetic tools, we identified two distinct somatosensory neuron subtypes that innervate Krause corpuscles of both the clitoris and penis and project to a unique sensory terminal region of the spinal cord. In vivo electrophysiology and calcium imaging experiments showed that both Krause corpuscle afferent types are A-fibre rapid-adapting low-threshold mechanoreceptors, optimally tuned to dynamic, light-touch and mechanical vibrations (40-80 Hz) applied to the clitoris or penis. Functionally, selective optogenetic activation of Krause corpuscle afferent terminals evoked penile erection in male mice and vaginal contraction in female mice, while genetic ablation of Krause corpuscles impaired intromission and ejaculation of males and reduced sexual receptivity of females. Thus, Krause corpuscles of the clitoris and penis are highly sensitive mechanical vibration detectors that mediate sexually dimorphic mating behaviours.

Krause corpuscles of the genitalia are vibrotactile sensors required for normal sexual behavior

Krause corpuscles, first discovered in the 1850s, are enigmatic sensory structures with unknown physiological properties and functions found within the genitalia and other mucocutaneous tissues. Here, we identified two distinct somatosensory neuron subtypes that innervate Krause corpuscles of the mouse penis and clitoris and project to a unique sensory terminal region of the spinal cord. Using in vivo electrophysiology and calcium imaging, we found that both Krause corpuscle afferent types are A-fiber rapid-adapting low-threshold mechanoreceptors, optimally tuned to dynamic, light touch and mechanical vibrations (40-80 Hz) applied to the clitoris or penis. Optogenetic activation of male Krause corpuscle afferent terminals evoked penile erection, while genetic ablation of Krause corpuscles impaired intromission and ejaculation of males as well as reduced sexual receptivity of females. Thus, Krause corpuscles, which are particularly dense in the clitoris, are vibrotactile sensors crucial for normal sexual behavior.

How many nerve fibers innervate the human glans clitoris: a histomorphometric evaluation of the dorsal nerve of the clitoris

INTRODUCTION

It is frequently quoted in mainstream media that the clitoris has "8000 nerve endings." However, no study has yet quantified the number of nerve fibers (axons) innervating the human clitoris. The dorsal nerves of the clitoris (DNCs) are the primary source of sensation and somatic clitoral innervation. Therefore, reporting the number of axons in the DNCs is an important step in our understanding of clitoral innervation and sexual response with implications for many fields of medical practice. The purpose of this study is to quantify the mean number of axons in the human DNCs and to report the approximate mean number of nerve fibers that innervate the human glans clitoris.

METHODS

DNC samples were obtained from 7 transmasculine patients undergoing gender-affirming phalloplasty surgery. At the time of nerve coaptation, a small excess of the DNC (5 mm) was collected for analysis at the proximal level of the clitoral body, just distal of the emergence of the DNCs from underneath the pubic symphysis. Samples were placed into 3% glutaraldehyde fixative, postfixed in 1% osmium tetroxide, and serially dehydrated in ethanol and toluene. Samples were then embedded in araldite, sectioned on an ultramicrotome into 1-μm cross sections, and counterstained with 1% toluidine blue. Histomorphometric evaluation was performed at 1000x magnification with a Leitz Laborlux S microscope and image analysis software (Clemex Vision Professional) to obtain an axon counts. Descriptive statistics were performed to yield a mean and standard deviation of the number of axons in the DNCs. Assuming anatomic symmetry between bilateral DNCs, mean total number of somatic nerve fibers innervating the human glans clitoris was obtained by doubling the mean count of the DNCs.

RESULTS

Seven sample DNCs were collected. Of those, 5 were analyzed as 2 did not have sufficient nerve tissue present. The mean number of nerve fibers in the human DNCs was 5140 (SD = 218.4). The mean number of myelinated nerve fibers innervating the human clitoris was 10,281 (SD = 436.8).

CONCLUSION

This study is the first to report the number of axons in the human DNC, at a mean 5140. Given the bilateral nature of clitoral innervation and symmetry of anatomic structures, the approximate mean number of myelinated axons that innervate the human glans clitoris is 10,280. When the uncaptured unmyelinated fibers and contributions from the cavernosal innervation are accounted for, it is clear that far Moree than 8000 axons innervate the human clitoris.

A psychophysical and neuroimaging analysis of genital hedonic sensation in men

Current understanding of human genital-brain interactions relates primarily to neuroendocrine and autonomic control, whereas interactions during sexual stimulation remain largely unexplored. Here we present a systematic approach towards identifying how the human brain encodes sensory genital information. Using a validated affective touch paradigm and functional magnetic resonance imaging, we found that hedonic responses to discriminatory versus affective tactile stimulation were distinctly different for both penile shaft and forearm. This suggests that, as with other body sites, genital skin contains small diameter mechanoreceptive nerve fibres that signal pleasant touch. In the brain, secondary somatosensory cortex (S2) distinguished between affective and discriminative touch for the penile shaft, but not for the forearm. Frenulum stimulation induced the greatest reports of subjective pleasure and led to the greatest deactivation of the default-mode network. This study represents a first pass at investigating, in humans, the relationship between innervation of genital surfaces, hedonic feelings, and brain mechanisms, in a systematic way.

External Genital Revisions after Gender-Affirming Penile Inversion Vaginoplasty: Surgical Assessment, Techniques, and Outcomes

BACKGROUND

Following gender-affirming penile inversion vaginoplasty or vulvoplasty, patients may seek vulvar revision procedures for a variety of common aesthetic and functional concerns. These indications for revision and accompanying techniques are not well-described in the literature.

METHODS

Patients who underwent vulvar revision surgery at the authors' institution were identified, and patient demographics, surgical indications, operative details, and complications were described. Common complaints requiring external genital revision were sorted into four categories: clitoral, labial, introital, and urethral.

RESULTS

Thirty-five patients with a history of vaginoplasty underwent vulvar revision between May of 2017 and December of 2019. The mean age at surgical correction was 38.9 years. Ten patients (28.6 percent) had undergone prior secondary procedures (range, 1 to 3). Mean follow-up after revision surgery was 10.7 ± 8.7 months (range, 0 to 30.6 months). The majority of patients underwent concurrent revisions in multiple "categories". Labial aesthetic concerns were most common (n = 27, 77.1 percent), followed by clitoral (n = 20, 57.1 percent), urologic (n = 17, 48.6 percent), and introital complaints (n = 12, 34.3 percent). Twelve patients (34.3 percent) had canal stenosis requiring concurrent robot-assisted canal revision with peritoneal flaps. Complications included labial abscess (n = 1) and deep vein thrombosis (n = 1). Three patients (8.6 percent) underwent subsequent external genital revisions. Management approaches and surgical techniques for each of these common revision categories are provided.

CONCLUSION

As more individuals seek vaginoplasty and vulvoplasty, surgeons must be prepared to address a range of common aesthetic and functional complaints requiring vulvar revision.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Sensibility, Sensation, and Nerve Regeneration after Reconstructive Genital Surgery: Evolving Concepts in Neurobiology

BACKGROUND

Sensory recovery following phalloplasty and vaginoplasty for gender dysphoria is essential to the overall success of gender-confirming surgery. Anecdotal evidence suggests that superior reinnervation results are seen in genitoplasty compared to other peripheral nerve repair scenarios. Despite these observed differences, the quality of available literature is poor.

METHODS

The authors reviewed the body of English language literature regarding sensory outcomes following genitoplasty for gender confirmation.

RESULTS

The available body of literature discussing the basic science and clinical science aspects of sensory recovery following gender-confirming genitoplasty is small. Available data show that sensory recovery following vaginoplasty produces high rates of reported orgasmic ability, largely through the neoclitoris, and a neovagina with vibratory and pressure sensation similar to that of the native vagina. Phalloplasty sensory outcomes are variable, with the largest series reporting return of sensation in the neophallus that is slightly less than what is measured in control men. Erogenous sensation, including the ability to orgasm, is present in nearly all patients after several months.

CONCLUSIONS

Existing series indicate that genitoplasty patients experience faster and more complete recovery than any other peripheral nerve regeneration scenarios. However, there are many potential confounding factors in assessment and reporting, and more consistent and reproducible measure endpoints measures are needed. Further research is needed to better understand both the basic science and clinical science of peripheral nerve regeneration in genitoplasty, which may change fundamental aspects of current paradigms of peripheral nerve regeneration.

Glans clitoris innervation: PIEZO2 and sexual mechanosensitivity

The clitoris is a leading player in female sexual arousal, if not the main protagonist. Despite this role, studies performed on this structure with specific neuroanatomical techniques are few. This study focuses on glans clitoris innervation, with special emphasis on sensory corpuscles and the presence of the mechanotransducer protein PIEZO2 in these structures. Six glans clitoris samples were obtained at autopsy covering an age spectrum between 52 and 83 years old. Several types of nerve terminations including free nerve endings, genital endbulbs as well as Meissner-like corpuscles and Pacinian corpuscles, but not Ruffini corpuscles, were found. Although corpuscular morphology in the glans clitoris was subtly different from the cutaneous digital counterparts, their basic composition was comparable for both Pacinian and Meissner-like corpuscles. Genital endbulbs showed heterogeneous morphology, and the axons usually exhibited a typical "wool ball" or "yarn ball" aspect. Some of them were lobulated and variably encapsulated by endoneurial elements (65%); from the capsule originate septa that divides the genital endbulbs, suggesting that they are found in clusters rather than as single corpuscles. In addition, most corpuscles in the glans clitoris showed axonal PIEZO2 immunoreactivity, thus, suggesting a mechanical role and molecular mechanisms of mechanosensibility similar to those of digital Meissner's corpuscles. Our results demonstrate that sensory corpuscles of the glans clitoris are similar to those of other glabrous skin zones, as most genital organs are characterized by clusters of corpuscles and the occurrence of the mechanoprotein PIEZO2 in the axons. These findings strongly suggest that PIEZO2 participates in erotic and sexual mechanical sensing.

Overview on metoidioplasty: variants of the technique

Number of gender dysphoric people increased over the last few decades with positive social acceptance of transpopulation. Genital gender affirming surgeries are of utmost importance in order to adjust body to the mind of these individuals. Creation of the phallus is usually the last step in transmen transition, which remains demanding and challenging for surgeons, with different options for phalloplasty available. The ideal phallus is esthetically appealing, with preserved tactile and erogenous sensation, enables standing micturition and sexual function with minimal donor-site morbidity. Metoidioplasty, as a variant of phalloplasty, uses the hormonally hypertrophied clitoris to create the neophallus. Metoidioplasty can be considered as a method of choice for thin-built individuals looking for male genitalia with preserved erogeneity, in one-stage genital gender affirming surgery. It can be combined together with removal of reproductive organs and vaginectomy. Preoperative consultation with patients and postoperative follow-up as well as multidisciplinary approach are essential for successful treatment.This literature review aims to assess and discuss different metoidioplasty approaches with a special reference to authors' current metoidioplasty technique.

Individualized Surgical Treatment of Different Types of Labia Minora Hypertrophy

Objective To explore an optimal surgical approach for different types of labia minora hypertrophy and to design a better personalized surgical treatment plan for patients. Methods Forty-five patients with labia minora treated in our department from January 2014 to January 2019 were the study participants. Depending upon the appearance of the labia minora, they were divided into length labia minora hypertrophy, width labia minora hypertrophy, overall labia minora hypertrophy, and labia hypertrophy combined with clitoris foreskin. By combining the characteristics of the patient's labia minora hypertrophy and the aesthetic requirements for postoperative appearance, we designed a personalized treatment plan for each group of patients. The surgical approaches include upper pedicle flap wedge resection, upper and lower pedicle flap similar to wedge resection, lower pedicle flap pedicle wedge resection, and labia minora combined with clitoris foreskin surgery. We followed up the postoperative results, recovery, and complication rates for a period of 3 months. Results All patients who underwent surgery had good wound healing. The labia minora had good bilateral symmetry, moderate size, and desired appearance. The scar of the surgical incision was also not obvious. The postoperative labia minora felt normal without any serious complications. Overall, the treatment effect was satisfactory. Conclusion There are many surgical methods for the reduction in the labia minora. Our findings suggest that in order to achieve better results, a personalized surgical plan should be designed considering the patient's unique type of hypertrophy and the individual aesthetic requirements. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Penile pacinian neurofibroma

Pacinian neurofibroma (PNF) is a lobulated benign neural tumor with prominent structures resembling pacinian bodies. These tumors most commonly occur in areas where normal pacinian bodies are found, such as the hands and feet. Although pacinian bodies are common in the penis, no cases of penile PNF have been reported to date. We present a case of PNF on the dorsal glans penis of a 47-year-old man. The lesion presented as a single flesh-colored papule and the biopsy showed a dermal neurofibroma consisting of bland spindle cells with wavy nuclei, without mitoses or atypia, and some nodular structures with a concentric arrangement and a pacinian appearance. Immunohistochemistry demonstrated positivity for CD34 and Vimetin and negativity for Epithelial Membrane Antigen (EMA). S100 was highly positive in the most central areas of the pacinian-like nodules, while the periphery and non-nodular parts of the neurofibroma were less intensively expressed.

Body Movement Is Associated With Orgasm During Vaginal Intercourse in Women

Very few studies have investigated the relationship between women's ability to experience an orgasm during vaginal intercourse and specific stimulation techniques. We examined two common techniques during vaginal intercourse both with and without simultaneous external clitoral stimulation: (1) body movement, in particular back-and-forth swinging movements of the pelvis and trunk; and (2) precise rubbing of the clitoris with an immobilized body. Structural equation modeling was used to compare the effects of the two stimulation techniques on women's orgasm frequency (N = 1,239). As hypothesized, the frequency of orgasm during vaginal intercourse with simultaneous clitoral stimulation was positively associated with a preference for body movement during arousal. Body movement, as opposed to body immobilization, was also associated with a higher frequency of orgasm during vaginal intercourse without simultaneous clitoral stimulation. We conclude that body movement is associated with more orgasms during vaginal intercourse, whereas precise rubbing of the clitoris with an immobilized body is not associated with more orgasms. Teaching women to move their pelvis and trunk in a swinging back-and-forth movement during vaginal intercourse might therefore facilitate reaching an orgasm, whereas encouraging them to self-stimulate the clitoris might be less helpful if done with an immobilized body.

Clitoral Epidermal Inclusion Cyst Resection With Intraoperative Sensory Nerve Mapping Technique

BACKGROUND

Despite the ever increasing popularity of labial and clitoral surgeries, the best practices and long-term effects of reconstructive procedures in these regions remain unknown. This is particularly noteworthy because the presentation of nerve-related symptoms may be delayed up to a year. Despite the convention that these surgical procedures are low risk, little is known about the best practices that may reduce the postoperative complications as a result of these reconstructive surgeries. We describe a preoperative sensory mapping technique in the context of a symptomatic inclusion cyst in the clitoral region. This technique delineates anatomical and functional regions innervated by the dorsal clitoral nerve while minimizing the vascular watershed area in the midline.

CASE

A prototypical case of a patient with a clitoral mass is discussed with clinical history and surgical approach. Prior to surgical excision, the dorsal clitoral nerve distribution was mapped in order to avoid a surgical incision in this sensual zone.

CONCLUSIONS

In our practice, preoperative sensory mapping is a clinically useful planning tool that requires minimal instrumentation and no additional operating time. Sensory mapping allows identification of the functional zone innervated by the dorsal clitoral nerve, which can aid in minimizing damage to the area.

fMRI Localization of Spinal Cord Processing Underlying Female Sexual Arousal

Using functional magnetic resonance imaging, the authors aimed to determine the roles of the human spinal cord in mediating sexual responses in women. Functional magnetic resonance imaging of the entire lower thoracic, lumbar, and sacral spinal cord was performed using a sexual stimulation paradigm designed to elicit psychological and physical components of sexual arousal. Responses were measured in 9 healthy adult women during 3 consecutive conditions: (a) erotic audiovisual, (b) manual clitoral, and (c) audiovisual plus manual stimulation. Functional magnetic resonance imaging results in healthy subjects demonstrate that this method is sensitive for mapping sexual function in the spinal cord, and identify several key regions involved in human sexual response, including the intermediolateral cell column, the dorsal commissural nucleus, and the sacral parasympathetic nucleus. Using spinal functional magnetic resonance imaging, this study identified many of the spinal cord regions involved in female sexual responses. Results from audiovisual and manual clitoral stimulation correspond with previous data regarding lumbar and sacral neurologic changes during sexual arousal. This study provides the first characterization of neural activity in the human spinal cord underlying healthy female sexual responses and sets a foundation for future studies aimed at mapping changes that result from sexual dysfunction, spinal cord trauma or disease.

Histological Correlates of Penile Sexual Sensation: Does Circumcision Make a Difference?

INTRODUCTION

The question of whether removal of sensory receptors in the prepuce by circumcision affects sensitivity and/or sexual pleasure is often debated.

AIMS

To examine histological correlates relevant to penile sensitivity and sexual pleasure.

METHODS

Systematic review of the scientific literature on penile structures that might affect sensitivity and sexual sensation. Articles were included if they contained original data on human male penile histology or anatomy. Individual articles, including reference lists, were evaluated. They were then considered in relation to physiological data from articles retrieved by a previous systematic review.

RESULTS

We retrieved 41 publications on penile structure. Considered in the light of 12 reporting physiological measurements, our evaluation finds that sexual response is unlikely to involve Meissner's corpuscles, whose density in the prepuce diminishes at the time of life when male sexual activity is increasing. Free nerve endings also show no correlation with sexual response. Because tactile sensitivity of the glans decreases with sexual arousal, it is unrelated to sexual sensation. Thermal sensitivity seems part of the reward mechanism of intercourse. Vibrational sensitivity is not related to circumcision status. Observations that penile sexual sensation is higher post circumcision are consistent with greater access of genital corpuscles to sexual stimuli after removal of the prepuce. This is based on the distribution of these corpuscles (which are located in the glans) and, in uncircumcised men, the position of the retracted prepuce during intercourse, rather than any change in the number of genital corpuscles. The scientific literature suggests that any sexual effect of circumcised men may depend solely on exposure of the glans and not on the absence of the prepuce.

CONCLUSION

Based on histological findings and correlates of sexual function, loss of the prepuce by circumcision would appear to have no adverse effect on sexual pleasure. Our evaluation supports overall findings from physiological measurements and survey data.

Anatomy of the clitoris and its impact on neophalloplasty (metoidioplasty) in female transgenders

The current management of female to male transgender surgery is based on the advances in neophalloplasty, perioperative care and the knowledge of the female genital anatomy, as well as the changes that occur to this anatomy with preoperative hormonal changes in transgender population. Since the clitoris plays the main role in female sexual satisfaction, its impact on the outcome in female to male transgender surgery is predictable. Although female genital anatomy was poorly described in majority of anatomical textbooks, recent studies have provided a better insight in important details such as neurovascular supply, ligaments, body configuration, and relationship with urethral/vaginal complex. This article aims to review current state of knowledge of the clitoral anatomy as well its impact on clitoral reconstruction in female to male sex reassignment surgery.

The gentle touch receptors of mammalian skin

The skin is our largest sensory organ, transmitting pain, temperature, itch, and touch information to the central nervous system. Touch sensations are conveyed by distinct combinations of mechanosensory end organs and the low-threshold mechanoreceptors (LTMRs) that innervate them. Here we explore the various structures underlying the diverse functions of cutaneous LTMR end organs. Beyond anchoring of LTMRs to the surrounding dermis and epidermis, recent evidence suggests that the non-neuronal components of end organs play an active role in signaling to LTMRs and may physically gate force-sensitive channels in these receptors. Combined with LTMR intrinsic properties, the balance of these factors comprises the response properties of mechanosensory neurons and, thus, the neural encoding of touch.

The assessment of sensory detection thresholds on the perineum and breast compared with control body sites

INTRODUCTION

Few studies explored multiple sensory detection thresholds on the perineum and breast, but these normative data may provide standards for clinical conditions such as aging, genital and breast surgeries, pathological conditions affecting the genitals, and sexual function.

AIMS

The aim of this study was to provide normative data on sensory detection thresholds of three sensory modalities on the perineum and breast.

METHODS

Thirty healthy women aged between 18 and 35 years were assessed on the perineum (clitoris, labia minora, vaginal, and anal margin), breast (lateral, areola, nipple), and control body locations (neck, forearm, abdomen) for three sensory modalities (light touch, pressure, vibration).

MAIN OUTCOME MEASURES

Average detection thresholds for each body location and sensory modality and statistical comparisons between the primary genital, secondary sexual, and neutral zones were the main outcome measures.

RESULTS

Average detection thresholds for light touch suggest that the neck, forearm, and vaginal margin are most sensitive, and areola least sensitive. No statistical difference is found between the primary and secondary sexual zones, but the secondary sexual zone is significantly more sensitive than the neutral zone. Average detection thresholds for pressure suggest that the clitoris and nipple are most sensitive, and the lateral breast and abdomen least sensitive. No statistical difference is found between the primary and secondary sexual zone, but they are both significantly more sensitive than the neutral zone. Average detection thresholds for vibration suggest that the clitoris and nipple are most sensitive. The secondary sexual zone is significantly more sensitive than the primary and neutral zone, but the latter two show no difference.

CONCLUSION

The current normative data from sensory detection threshold are discussed in terms of providing standard values for research and clinical conditions. Additional analysis from breast volume, body mass index, hormonal contraception, menstrual cycle, and sexual orientation do not seem to influence the results. Sexual abstinence and body piercing may have some impact.

The role of clitoral anatomy in female to male sex reassignment surgery

Introduction. Controversies on clitoral anatomy and its role in female sexual function still make clitoral reconstructive surgery very challenging. We evaluated the role of clitoral anatomic features in female to male sex reassignment surgery. Material and Methods. The study included 97 female transsexuals, aged from 18 to 41 years, who underwent single stage metoidioplasty between March 2008 and January 2013. The operative technique involved vaginectomy, the release of clitoral ligaments and urethral plate, urethroplasty by combining buccal mucosa graft and genital flaps, and scrotoplasty with insertion of testicle prostheses. Postoperative questionnaire was used to evaluate aesthetic, functional, and sexual outcome. Results. The mean followup was 30 months. The mean length of the neophallus was 7 cm, compared to mean preoperative length of the hypertrophied clitoris of 3.3 cm. Complications occurred in 27.84% of all patients, related mostly to urethroplasty. Voiding while standing was achieved in all cases. None of the patients had problems in sexual arousal, masturbation, or orgasms. Conclusion. Accurate knowledge of the clitoral anatomy, physiology, and neurovascular supply is crucial for a successful outcome of female to male sex reassignment surgery. Our approach appears to ensure overall satisfaction and high quality of sexual life.

Erect penile length and circumference dimensions of 1,661 sexually active men in the United States

INTRODUCTION

Penile size continues to receive popular and empirical attention. Little is known about the process of self-measurement and whether the behaviors a man engages in to become erect for self-measurement are associated with his erect penile dimensions.

AIMS

The article aims to assess men's erect penile dimensions in a study in which the men would presumably be motivated to report accurate information about their penis size; and to explore associations between men's erect penile dimensions, their method of measurement, and their demographics.

METHODS

Data are from an Internet-based baseline phase of a large prospective daily diary study that compared men's use of a standard-sized condom to men's use of a condom sized to fit their erect penis.

MAIN OUTCOME MEASURES

The main outcomes are participant characteristics, activities engaged in during self-measurement process, and self-reported erect penile length and circumference.

RESULTS

For this sample of 1,661 men, the mean erect penile length was 14.15 cm (SD = 2.66; range = 4 to 26 cm), and the mean erect penile circumference was 12.23 cm (SD = 2.23; range = 3 to 19). Participant characteristics were not associated with measured length or circumference. Most men measured their penis while alone, using hand stimulation to become erect.

CONCLUSIONS

In this sample of men who measured their erect penile length and circumference for the purposes of receiving a condom sized to fit their erect penis, we found a mean erect penile length of 14.15 cm and a mean erect penile circumference of 12.23 cm. The self-reported erect penile dimensions in this study are consistent with other penile dimension research. Also, findings suggest that mode of getting an erection may influence erect penile dimensions. Additionally, how a man becomes erect for self-measurement may be associated with his erect penile length and/or circumference.