The most common medical procedure in the US is infant male circumcision. The long-term-health impact of neo-natal circumcision has received little study while the consequences of circumcision on sexual function in the adult male have received even less attention.
A recent study by M. Sorrels and colleagues from the National Organization of Circumcision Information Resource Center and Michigan State University mapped the fine-touch pressure thresholds of the adult male penis in circumcised and uncircumcised men and compared the two populations. The study is published in the April 2007 issue of BJU Int.
Adult male volunteers were evaluated with a 19 point Semmes-Weinstein monofilament touch-test to map fine-touch pressure thresholds of the penis. Circumcised and uncircumcised men were compared using mixed models for repeated data, controlling for age, type of underwear worn, time since test ejaculation, ethnicity, country of birth, and level of education.
Analysis of results showed the glans of the uncircumcised men had significantly lower thresholds than that of circumcised men (P = 0.040). There were also significant differences in pressure thresholds by location on the penis (p < 0.0001). The most sensitive location on the circumcised penis was the circumcision scar on the ventral surface. It was remarkable that five locations on the uncircumcised penis that are routinely removed at circumcision had lower pressure thresholds that the ventral scar of the circumcised penis.
This study suggests that the transitional region from the external to the internal prepuce is the most sensitive region of the uncircumcised penis and more sensitive than the most sensitive region of the circumcised penis. It appears that circumcision ablates the most sensitive parts of the penis.