Many unidentified dead bodies are discovered every day, not just from acts of terrorism and natural disasters, and this is becoming a major problem worldwide . In Japan, with a population of 120 million, approximately 1000 people are discovered annually as unidentified cadavers, and the police are required to investigate these cases.
In their initial investigations of unidentified corpses, the police seek to identify them using factors, such as age and gender, as well as by their belongings. These dead bodies are often thought to be skeletons or highly decayed. However, in fact, most of them are recently deceased.
Gender is relatively easy to determine by assessing the genitals or DNA examination. However, it is very difficult to estimate age based on cadaver appearance.
Recently, some researchers reported the utility of computed tomography (CT) images for age estimation, especially for the living or nonskeletonized corpses [2, 3]. However, a body must be transported to obtain CT images, which requires time and effort and incurs costs.
We previously reported that postmortem serum prostate-specific antigen (PSA) level and prostate volume correlate with age and discussed the use of PSA in an objective age estimation .
The age-related increase in serum PSA levels has been attributed mainly to prostate enlargement due to prolonged exposure to serum testosterone during aging [5,6,7]. Testosterone is also related to the growth of the penis in newborn infants .
Therefore, we also investigated whether the size of the male genitalia similarly exposed to serum testosterone during aging could change with age in our previous report. We found that penile length almost stopped increasing during adolescence, remained unchanged in middle age, and decreased slightly in older males . The saying “Big nose, big hose” suggests that nose size indicates penile length. However, scientific reports that prove this statement are not available to date.
In this report, to confirm the truth of this statement, we analyzed the relationships between stretched penile length (SPL) and nose size as well as the weight of male genital organs in middle-aged people.