A CBCT will be performed to assess the anatomy of the subnasal area and plan the position, size, shape and thickness of the PEEK Stent. These data will be transferred to a 3D planning software to generate a digital model. Eventually, the PEEK stents will be milled in a milling machine and sterilized in ethylene oxide before the surgery. Local anesthesia will be administered into the vestibular mucosa along the extension of the anterior maxilla. VISTA technique begins with a vestibular access incision in the midline frenum and 2 bilateral incisions at premolar area. A periosteal elevator will be introduced through the incision and inserted between the bone and periosteum to elevate the tissue, creating a subperiosteal tunnel, extending distally based on the dynamic of the smile. The PEEK stent will be in one piece. They will be placed onto the bone and stabilized with 2 bone graft screw for each side. The midline incision and the lateral incisions will be sutured primarily.

Postoperative pain will be evaluated at first and seventh day using numeric rating scale (NRS). Patient will rate his pain on a scale from 0 to 10, with 0 indicating no pain and 10 reflecting the worst possible pain.

• 0 = no pain
• 1-3 = mild pain
• 4-6 = moderate pain
• 7-10 = severe pain

Postoperative edema was measured with a flexible tape measure by calculating the distance between several facial landmarks and comparing them to preoperative values.

Measured according to Landry's Healing Index which records healing on basis of tissue colour, bleeding, ulceration, granulation tissue and epithelisation.

Scores range from 1 (Very poor) to 5 (excellent)

Distance from gingival margin to lower border of upper lip vermilion border will be measured