Introduction

A rectangular flap was originally used for repair of a cleft lip by Hagedorn. The use of this method is less common for lower lip repair after tumour resection, but with some modifications we have found it to be favourable for reconstruction, especially for the lip to mental region. In particular, we have improved the technique through the use of double opposing rectangular flaps; this is particularly effective for reconstruction of a distinct mentolabial groove and mental protrusion. Flaps on both lateral sides and redundant tissue are used, without the requirement for an extended incision far from the area of surgery or sacrifice of sensation and muscle function. We describe herein the double opposing rectangular rotation flaps technique and show that this approach allows excellent functional and cosmetic restoration of the lower lip.

Surgical procedures

We describe our method in the case of a 77-year-old male patient with squamous cell carcinoma of the lower lip; the size of the induration was 26 mm × 22 mm ( Fig. 1 ). The vertical distance from the mentolabial groove to the vermillion border and the transverse length of the vermilion curved line at the vermilion border were measured preoperatively.

A 77-year-old man with squamous cell carcinoma of the lower lip, occupying the central portion of the lower lip. Incision line for tumour resection and use of a double opposing rectangular rotation flap.

In this patient, the tumour was resected with a safety margin and the transverse length of the defect was estimated to be 70% preoperatively. A superiorly and laterally based rectangular flap A′BCD and the oblique through the incision line X′(Y)Z for creating the medial angle to receive the square flap were outlined along the U-shaped margin, with X′(Y)Z = YW = A′B = BC = CD ( Figs. 1 and 2 ). The length was made equal to the preoperative vertical distance from the mentolabial groove to the vermilion border. Upward rotation of flap A′BCD and downward rotation of angle X′ZY then permitted interdigitation of each component. The location of rectangular flap A′BCD was placed close to the centre, which makes it important to determine points B and X′.

Diagram of the procedures. One side of the square flap is equal to the preoperative distance from the vermilion border to the mentolabial groove.

The additional segment that was excised to tailor the closure inferiorly could be determined in advance by striking equal arcs from Y and D to find point O. In the original report, the resulting redundancy at the inferior angle was corrected like a wedge resection. However, we trimmed the inferior angle to make DO and YO refracted and curved in an attempt to minimize discarded tissue. Finally the two opposing flaps, ZYWO and A′BCD, were interdigitated to give a protrusion of the mentum using the abundant redundant tissue ( Figs. 2 and 3 ). For a vermilion defect, a bilateral vermilion advancement flap with extended incision into the oral cavity was used and provided sufficient volume ( Fig. 3 ).

Just after the operation. The rectangular flap is interdigitated to the opposite side, forming the protrusion of the mental protuberance. The bilateral vermilion advancement flaps are united and provide sufficient volume.

Photographs just after the operation and at 18 months postoperatively are shown in Figs. 3 and 4 , respectively. The contour and symmetry of the lower lip to the mentum showed a favourable outcome. The suture line was placed in the centre of the mentum, but the scar was barely visible after 18 months ( Fig. 4 ). The contour line of the reconstructed lower lip and the hollow just below and the reconstructed mental protuberance are particularly noteworthy. The functional results were also good. Thus, satisfactory results were obtained both aesthetically and functionally.

Eighteen months after the operation. The scar is barely visible. A good contour of the lower lip to the mentum is present, with reconstruction of a distinct mentolabial groove (arrowhead) and protrusion of the mental protuberance.