Penile frenulum

The frenulum of the penis, often known simply as the frenulum (from frēnulum) or frenum, is a thin elastic strip of tissue on the underside of the glans and the neck of the human penis. In men who are not circumcised, it also connects the foreskin to the glans and the ventral mucosa. In adults, the frenulum is typically supple enough to allow manual movement of the foreskin over the glans and help retract the foreskin during erection. In flaccid state, it tightens to narrow the foreskin opening.

The penile frenulum is homologous to the clitoral frenulum in the female. It is similar to the lingual frenulum between the tongue's lower surface and the lower jaw, or the frenulum between the upper lip and the outside of the upper gum.

In some men, the frenulum may appear shorter than normal, a phenomenon known as frenulum breve. Treatment of frenulum breve may be non-surgical, or in other cases, especially with penile chordee, it may include frenulectomy or frenulum lengthening.

Structure
The frenulum is a highly vascularized strip of mucosal tissue on the ventral side of the glans and the neck of the penis. It forms the interface between the outer and inner foreskin layers. During gestation, it forms as the lateral edges of the preputial lamina approach in the ventral midline. The two sides of the lamina do not fuse in the midline but remain separated by a thin septum of mesenchyme that will create the preputial frenulum. As part of the glans penis, the frenulum is innervated by divisions of the pudendal nerve; the dorsal nerve of the penis and a branch of the perineal nerve. Blood supply to the frenulum is provided by branches of the dorsal artery of the penis that curve around each side of the neck to enter the frenulum and the glans from its ventral surface. It is uncertain whether the frenular artery is single or paired. Veinous drainage is thought to occur around the neck of the penis from smaller paired venules. The frenulum occurs on the ventral midline of the glans, where the two glans wings merge forming the septum glandis.

Research
The role of the frenulum in penile erection has been studied in cases of men with short frenula and premature ejaculation. Short frenulum may sometimes be associated with unsatisfied intercourse. Treatment with lengthening or reconstruction of the frenulum in uncircumcised and circumcised men was reported to have positive results in satisfied intercourse, prolonged erection and time of ejaculation.

For individuals with spinal cord injuries preventing sensations from reaching the brain, the frenulum just below the glans can be stimulated to produce orgasm and peri-ejaculatory response. It is often a way for those with spinal cord injuries to engage in sexual activities and subsequently feel pleasure.

Clinical significance
Frenulum breve is a condition in which the frenulum is short and restricts the movement of the foreskin, which may or may not interfere with normal sexual activity. Frenulum breve may also contribute to frenular chordee, where the glans is pulled toward the ventral body of the penis. The condition can be treated with surgical and non surgical treatment. Non surgical treatment includes stretching exercises and steroid creams. Surgical treatment includes frenuloplasty (frenulum lengthening or reconstruction), frenectomy, or circumcision. There are a variety of different circumcision techniques in which the frenulum can be spared and left completely intact.

It is possible for the frenulum to tear during sexual activities. This type of injury usually heals by itself. In more severe cases, the frenular artery may be injured causing bleeding.

The frenulum may be entirely missing in cases of first degree hypospadias.

Frenectomy and frenuloplasty
As a treatment for frenulum breve or frenular chordee, a frenectomy or frenulectomy can be performed to excise the frenulum from the penis. This is a form of genital frenectomy. This procedure results in a smooth surface. A less invasive treatment which often retains the natural appearance and function of the frenulum to some degree is a frenuloplasty or frenulum lengthening. This procedure involves a (partial) incision of the frenulum and realigning the edges to gain more length. This makes the frenulum longer, effectively relieving pain and discomfort.