Preputial anatomy and frenar band
In classical description of prepuce, it is divided into outer and inner (mucosal) layer. The outer layer is a continuation of the shaft skin, up to the rim of junction with the mucosa at the opening of the prepuce at rest. The mucosa or inner preputial skin from the junctional or transitional zone to the sulcus where it continues as the mucosal covering of the glans [1]. Just inside the junctional rim of prepuce at the dorsal aspect is a transverse band of ridges 10–15 mm wide. Except the area of this band rest of the mucosa is smooth. The ridged band is continuous with the frenulum, being a radial band over 60% of the penile diameter-the dorsal and lateral aspects-then turning distally to form a V-shape on the ventral aspect whilst reducing its width to merge with the frenulum [1]. Dorsal penile frenulum is a rare developmental abnormality; only one such case is available in literature [2]. We report another case of dorsal penile frenulum with normal penile anatomy, normal ventral frenulum but a dorsal frenulum present since birth.

A 24-year-old male presented with complaint of dyspareunia. There was no history of balanoposthitis in childhood. On examination, the size of penis, scrotum and testis was found to be normal. The external urinary meatus was at its normal position. On retracting the prepuce, there was a band connecting dorsum of glans to prepuce, V-shaped and double layered. A normal ventral frenulum was present. Frenuloplasty of the dorsal penile frenulum was done which led to retraction of normal prepuce. In postoperative period, patient remained asymptomatic.

The embryological development of penile frenulum is related to the development of prepuce. The prepuce is formed by reduplication of the ectoderm covering the distal part of the phallus in third month of fetal life. The prepuce separates from the glans to form preputial sac and residual adhesion of ectoderm to the glans penis on the ventral aspect persists and is called frenulum [3]. The preputial and urethral folds fuse on the ventrum of the glans as the frenulum. Failure of fusion of the urethral folds blocks development of prepuce ventrally especially the frenulum [4]. Penile torsion is a rotation of the shaft of penis, usually to the left (counterclockwise) direction. It results in the urethral meatus being placed in oblique position, such that median raphe makes a spiral curve from the base of the penis to the meatus [5]. Singla et al. Postulated that probably during the embryological development of preputial sac, the latter separated from the glans on all sides except on the dorsal side and residual adhesions on dorsal side formed the dorsal frenulum [2].

I agree with this theory of adhesion during embryological life because

1. Frenulum thus formed was two layered
2. It was adherent to the dorsum of glans at one point only

Simple division of dorsal frenulum led to restoration of normal prepuce.

1. Mcgrath K. The Frenular Delta. In: Denniston GC, Hodges FM, Milos MF eds. Understanding Circumcision: A Multi-Disciplinary Approach to a Multi-Dimensional Problem. New York: Kluwer Academic/Plenum Publishers; 2001.    
2. Singla SL, Garg P, Bishnoi PK, Singh B. Dorsal penile frenulum. Urol Int 1997;59(1):55–6.   [CrossRef]   [Pubmed]    
3. Williams PL, Warwick R, Dyson M, Bannister LH. Gray's anatomy. 37ed. Edinburgh: Churchill Livingstone; 1989. p. 733–4.    
4. Max M. Normal and Anomalous Development of the Urinary Tract. In: Walsh PC eds. Campbell's Urology. 7ed. London: WB Saunders; 1998. p. 1582–3.    
5. Shaeer O. Torsion of the penis in adults: prevalence and surgical correction. J Sex Med 2008 Mar;5(3):735–9.   [CrossRef]   [Pubmed]