Surgical Flaps: Design and Considerations

Surgical Flaps: Design and Considerations

• Flaps in surgery are tissue sections moved or repositioned, sometimes including bone or other tissues, for better surgical access. They're outlined by incisions, have their own blood supply, allow access, can be repositioned, and are sutured.
• Oral surgeons use bone-and-soft-tissue flaps for jaw reconstruction.
• Soft tissue flaps are a routine part of oral, periodontal, and endodontic procedures to expose tooth and bone structures. Surgeons must know how to plan, execute, and manage them.

Flap Design Parameters

• Flap base must be wider than the free margin to ensure sufficient blood supply and prevent tissue death.
• Flaps need to be a sufficient size to allow clear visualization of the surgical site, insertion of instruments, and support by retractors without tension.
• Long, straight incisions on intact bone heal more quickly than shorter, torn incisions.
• Envelope flaps generally extend two teeth anterior and one posterior to the surgical area; anterior releasing incisions need one tooth anterior and one posterior.

Full-Thickness Flaps

• Full-thickness mucoperiosteal flaps (including mucosa, submucosa, and periosteum) are critical for tooth removal or bone reshaping.
• Periosteum is crucial for bone healing; its replacement speeds up the process. Full-thickness flaps are better than torn tissue in terms of healing.
• Full-thickness flaps result in less bleeding because the plane between bone and periosteum is less vascular.

Incision Considerations

• Incisions must be placed over intact bone to avoid collapse and delayed healing.
• If bone is compromised by a pathology, incisions should be at least 6-8mm away.
• Incisions should also be a safe distance away from any bone that will be removed.

Avoiding Injury to Vital Structures

• Avoid injury to the lingual and mental nerves, especially in the mandible's posterior area.
• Incisions should be kept a safe distance from these nerves, especially in the third molar region (lingual nerve) and mandibular premolar areas (mental nerve).
• Use envelope incisions whenever possible; releasing incisions should be far from nerve exits.
• Maxillary flaps are less likely to damage vital structures, though the greater palatine and nasopalatine nerves and arteries should be considered during palatal flap reflection.

Palatal Flap Considerations

• The greater palatine artery is the main blood supply to palatal soft tissue, emerging from the greater palatine foramen.
• Nasopalatine blood supply to anterior palatal tissue is sourced in the incisive foramen. Incisively neurovascular bundle incisions usually result in minor, manageable bleeding.