Abstract Oriented lateral cephalometric roentgenograms proved to be satisfactory in the evaluation of the results of a new vestibular extension procedure used on 6 subjects. The surgical procedure involved repositioning of the mentalis and incisive muscles with fixation in the new position by sutures and a splint. This procedure obtained primary healing with little or no scar in the depth of the vestibule. Results after 6 months, with the lip in a relaxed position, showed an increased vestibular depth ranging from 4.5 to 12.1 mm., with a mean gain of 7.0 mm. The results with the lip in a functional position showed an increased depth ranging from 5.6 to 9.4 mm., with a mean gain of 7.1 mm. Thus, there was a significant increase in vestibular depth as a result of operation which was maintained over a 6-month period.