A retrospective comparison of three modalities for vestibuloplasty in the posterior mandible: apically positioned flap only vs. free gingival graft vs. collagen matrix.

The effect of apically positioned flap and collagen matrix may be diminished by several factors in posterior mandible, such as low vestibule and high muscle pull. For increasing the dimension of keratinized tissue in posterior mandible, conventional free gingival graft may be more predictable compared to other options.