There are many flap designs recommended for the removal of impacted third molars. Western Surgical and Sedation’s STOW will discuss four different flap designs: envelope, triangle, modified triangle, and “S” flap. The most commonly recommended flaps are the envelope and triangle. No flap is perfect for all situations.
The initial incision for a mandibular envelope starts 1-1.5 cm distal to the second molar and ends near the central groove of the second molar. The incision starts on the buccal near the external oblique ridge and can be extended as needed for access. DO NOT place incisions directly distal to the second molar. Never place incisions or use instruments on the lingual of the surgical site. You may cause lingual nerve paresthesia.
Maxillary envelope flap incisions start in the hamular notch distal to the tuberosity and end between the central groove and distal buccal cusp of the second molar. Mandibular and maxillary envelope flaps should end distal to the second premolar. The papilla between the first molar and second premolar is included in the flap. One suture distal to the second molar is usually sufficient for closure.