Is size in the eye of the beholder? Visual estimation of penis size among transgender and cisgender people and implications for genital gender-affirming surgery and sexual medicine.

BACKGROUND: Transgender men (TM) seeking gender-affirming phalloplasty and transgender women (TW) seeking vaginoplasty and desiring insertive intercourse must consider penis size. Evidence has shown that, at least among cisgender men (CM), penile dimensions tend to be poorly estimated. In transgender patients desiring gender-affirming surgery, inaccuracy in estimation of penis dimensions may lead to unnecessary morbidity: for TW, trauma to the neovagina; for TM with excess girth, an inability to insert. Studies on the accuracy with which transgender and cisgender patients estimate penis size are limited. AIM: To assess the degree of accuracy with which CM and CW, as well as TM and TW, visually estimate the size of the human penis, including length, width, and girth. METHODS: There were 142 participants included (25 TM, 47 TW, 30 CM, and 40 CW; net mean ± SD age, 36.6 ± 11.2 years). Participants were shown these models and asked to estimate length, width, and midshaft girth by visual inspection of 6 realistic models of a penis and scrotum of varying lengths and widths. We evaluated the accuracy of the visual measurements by comparing mean perceived dimensions with the actual dimensions of each model. OUTCOMES: We used a multivariate model of all 3 bias dimensions to test for differences in average bias among gender groups (CM, CW, TM, and TW). RESULTS: TM significantly overestimated length across the longest models. TW significantly overestimated length in the longer 3 models. All groups except for TM significantly underestimated girth in at least 1 model. No groups significantly underestimated width. CM, CW, and TM significantly overestimated width in all 6 models. CLINICAL IMPLICATIONS: When transgender patients use numbers to express penis size (either in neophallus or vaginal depth based on perceived partner size), the result is likely to be larger than expected. Use of realistic penis models as a decision-making tool may help manage patient expectations and surgery decision making preoperatively and improve postoperative patient satisfaction and safety. STRENGTHS AND LIMITATIONS: To our knowledge, this is the first study to assess visual estimation in penis size in TM and CM, as well as TW and CW. The penile models in our study were shown side by side and in the flaccid state despite having dimensions more consistent with an erect penis, which may have influenced estimations across all dimensions. CONCLUSION: Men and women (cisgender and transgender) tend to significantly overestimate penis length and width.

Endocrine, gender dysphoria, and sexual function benefits of gender-affirming bilateral orchiectomy: patient outcomes and surgical technique.

Background: Gender-affirming bilateral orchiectomy (GABO) may be completed as either a standalone procedure (sGABO) or at the same time as gender-affirming vaginoplasty (vGABO). GABO is postulated to decrease gender-affirming hormone therapy (GAHT) dosages and reduce gender dysphoria, but these phenomena are not empirically described in the medical literature. Aim: The primary aim of this study was to describe changes in GAHT dosages after sGABO and vGABO. A secondary aim was to assess sGABO patients' preoperative decision-making priorities and postoperative satisfaction. Methods: A retrospective chart review identified 204 patients who completed GABO as either a standalone procedure (64% of patients) or at the same time as vaginoplasty (36%). Patient demographic data, surgical outcomes, and pre- and postoperative GAHT dosage data were recorded. Patients completed an opinion questionnaire to assessed decision-making priorities, as well as postoperative satisfaction and changes in quality-of-life measures. Outcomes: Primary outcomes included pre- and postoperative dosages of estradiol, progesterone, and spironolactone. Secondary outcomes included sGABO patient priorities, satisfaction with sGABO, changes in quality-of-life measures between sGABO and vGABO patients, and sGABO recommendations to future patients. Results: The sGABO and vGABO patients experienced a statistically significant dosage reduction in all three GAHT assessed: estradiol, progesterone, and spironolactone (P < .05). All patients discontinued spironolactone postoperatively. Zero complications related to GABO were recorded for patients in either group. The patient questionnaire revealed that sGABO patients prioritize decreasing endogenous testosterone and reducing their GAHT as most important in their decision to undergo sGABO prior to vaginoplasty. A majority of sGABO patients reported improvement in all nine quality-of-life indices. None of the sGABO patients would recommend against sGABO to a friend who is waiting for vaginoplasty. Clinical Implications: For patients who are interested in vaginoplasty, sGABO may serve as a more immediate, low-risk, intermediary step that comes with the benefits of GABO, including significant GAHT medication reduction and gender dysphoria relief. Strengths and Limitations: This study offers a comprehensive evaluation of the impact of GABO on patients, combining empirical data with subjective patient feedback. Limitations include the retrospective design and the use of unvalidated survey questions. Conclusion: Prevaginoplasty GABO is a viable option to more immediately alleviate gender dysphoria and reduce GAHT medications for patients who are interested in gender-affirming vaginoplasty.

Neuronal branching is increasingly asymmetric near synapses, potentially enabling plasticity while minimizing energy dissipation and conduction time.

Neurons' primary function is to encode and transmit information in the brain and body. The branching architecture of axons and dendrites must compute, respond and make decisions while obeying the rules of the substrate in which they are enmeshed. Thus, it is important to delineate and understand the principles that govern these branching patterns. Here, we present evidence that asymmetric branching is a key factor in understanding the functional properties of neurons. First, we derive novel predictions for asymmetric scaling exponents that encapsulate branching architecture associated with crucial principles such as conduction time, power minimization and material costs. We compare our predictions with extensive data extracted from images to associate specific principles with specific biophysical functions and cell types. Notably, we find that asymmetric branching models lead to predictions and empirical findings that correspond to different weightings of the importance of maximum, minimum or total path lengths from the soma to the synapses. These different path lengths quantitatively and qualitatively affect energy, time and materials. Moreover, we generally observe that higher degrees of asymmetric branching-potentially arising from extrinsic environmental cues and synaptic plasticity in response to activity-occur closer to the tips than the soma (cell body).

Neuronal Branching is Increasingly Asymmetric Near Synapses, Potentially Enabling Plasticity While Minimizing Energy Dissipation and Conduction Time.

Neurons' primary function is to encode and transmit information in the brain and body. The branching architecture of axons and dendrites must compute, respond, and make decisions while obeying the rules of the substrate in which they are enmeshed. Thus, it is important to delineate and understand the principles that govern these branching patterns. Here, we present evidence that asymmetric branching is a key factor in understanding the functional properties of neurons. First, we derive novel predictions for asymmetric scaling exponents that encapsulate branching architecture associated with crucial principles such as conduction time, power minimization, and material costs. We compare our predictions with extensive data extracted from images to associate specific principles with specific biophysical functions and cell types. Notably, we find that asymmetric branching models lead to predictions and empirical findings that correspond to different weightings of the importance of maximum, minimum, or total path lengths from the soma to the synapses. These different path lengths quantitatively and qualitatively affect energy, time, and materials. Moreover, we generally observe that higher degrees of asymmetric branching- potentially arising from extrinsic environmental cues and synaptic plasticity in response to activity- occur closer to the tips than the soma (cell body).