Flap extension attained by vertical and periosteal-releasing incisions: A prospective cohort study

Objectives: To evaluate the effect of vertical and periosteal-releasing incisions (PRI) on the extension of the buccal flap in a trapezoidal flap design. Material and methods: Thirty patients scheduled for implant surgery accompanied by bone augmentation were recruited. The amount of flap extension pulled with a minimal tension of 5g using a dynamometer was measured before and after the first and the second vertical incisions (VI) and PRI. The results were compared based on gender, surgical site and operator's experience. Results: The first VI extended flap length by 1.1 ± 0.6mm, 113.4% more compared with the original flap length. The second VI increased flap length by 1.9 ± 1mm (124.2%), and the PRI significantly extended flap length by 5.5 ± 1.5mm (171.3%) (P<0.001). The length of the first and the second VI and the amount of flap extension by each incision were compared, and there were no statistically significant differences between gender, surgical site (maxilla vs. mandible) and operator's experience (faculty vs. residents). Conclusion: Vertical and PRI in a trapezoidal flap design can be successfully utilized to attain tension-free primary closure during implant or periodontal surgeries. However, the PRI appears to be the only determinant key factor that can significantly extend the length of the flaps, while host- and operator-related factors might not have any significant effect on such flap extension.