Incisions and Flaps PDF

Incisions and flaps 1 Flap is simply defined as a section of soft tissue that is outlined by surgical incisions, carries its own blood supply, allows surgical access to underlying tissues, can be replaced as required on its original position, maintained with sutures and is expected to heal. Most...

Incisions and flaps 1 Flap is simply defined as a section of soft tissue that is outlined by surgical incisions, carries its own blood supply, allows surgical access to underlying tissues, can be replaced as required on its original position, maintained with sutures and is expected to heal. Most of the oral surgical procedures require the reflection of a full mucoperiostial flap incorporating mucosa, submucosa and periosteum to gain access to the area that is the object of surgery 2 Incision It is simply defined as a cut or wound made by cutting with a sharp instrument. The basic principles of incisions in oral surgery include: • A blade number 15 is suitable for most oral surgical procedures. Sometimes a blade number 12 is used • A new and sterile blade should be used for each patient and it should be replaced with a new one intraoperatively if its cutting edge becomes blunted when necessary. • The scalpel blade is mounted on the scalpel-handle with the help of a needle holder, or hemostat, with which it slides into the slotted receiver with the beveled end parallel to that of the handle. • The scalpel is grasped in a pen grasp for maximum control and tactile sensitivity. • The incision should be made at right angle to the underlying bone. • Incision is made with a firm, continuous stroke to cut through not only the mucosal surface but also the periosteum overlying the bone 3 Principles of flap design • Avoid injuring anatomical structures. • The base of the flap should be wider than its apex (free gingival margin). • The flap should be of adequate size for good visualization and accessibility of the operative field • Incision should not cross underlying bony defect that existed prior to surgery, or is produced by surgery. so that the flap margins, when sutured, should rest on intact and healthy bone to prevent wound dehiscence and poor healing. • Vertical releasing incisions should start at the buccal vestibule and end at the line angle of the tooth, not the labial surface. the interdental papilla which should either be excluded or included in the flap. Do not extend the vertical incision beyond the depth of the muco-buccal fold Vertical incisions are made in the concavities between bony eminences. 4 Cont…vertical releasing incision Vertical releasing incision are contraindicated in certain sites in the oral cavity: Transverse incisions in the palate: to avoid injury to the greater palatine artery.  Lingual surface of the mandible: to avoid injury to the lingual nerve. Canine eminence: because it increases the tension on the suture line which lead to wound dehiscence. In the area of mental foramen, between mandibular first and second premolars: to avoid injury to the mental nerve. 5 6 7 8 Flap reflection and retraction • The mucoperiosteal flap is reflected from the underlying bone using periosteal elevators. like Howarth, Ash, the no.9 Molt, Seldin, or Freer types. • The elevators should be firmly pushed at approximately 30-45° to the surface of the bone such that the periosteum is stripped from it. It is important to try to raise both mucosa and periosteum in one layer. • Reflection of the flap begins at the papilla; the periosteal elevator is pushed underneath the papilla and is turned laterally to pry the papilla away from the underlying bone. • If it is difficult to elevate the tissue at any one spot, the incision is probably incomplete, and that area should be re-incised. • A dry, sterile swab can be interposed between the periosteal elevator and the bone. • The elevator may also be used for holding the flap after reflecting, facilitating manipulations during the surgical procedure. • The retractor must rest on the bone and the flap must not be squeezed or crushed between the retractor and bone. • Delicate flap handling and manipulation using toothed tissue forceps. • Avoid desiccation of the flap 9 CONSIDERATIONS IN FLAP DESIGN 1. Number of teeth involved 2. Length and shape of roots involved 3. Presence or absence of periradicular pathosis 4. Extent of periradicular lesion 5. Sulcular depth 6. Location and size of frenum and muscle attachments 7. Approximating anatomic structures. 8. Access needed. 9. Types of restorations in surgical area. 10. Width of attached gingiva. 10 11 12 Two-sided Flap (Triangular Flap) • This flap is the made with a horizontal incision along the gingival sulcus or alveolar ridge mucosa and a vertical releasing incision. The vertical incision begins approximately at the vestibular fold and extends to the interdental papilla of the gingiva. This flap is performed labially or buccally on both jaws indicated in the surgical removal of root tips, impacted teeth, small cysts, and apicectomies. • Advantages are; it ensures an adequate blood supply, satisfactory visualization and accessibility, good re-approximation; it can be easily modified to a three-sided flap, or even lengthening of the horizontal incision. • Disadvantages are; limited access, tension when flap is retracted and it may result in defect of attached gingiva. 13 14 Three-sided Flap (Trapezoidal, Rectangular Flap) • This flap consists of a horizontal incision along the gingival or alveolar ridge mucosa and 2 vertical releasing incisions. • indicated when an extensive surgical field exposure is required especially when two-sided flap is inadequate. Especially indicated for large lesions, multiple teeth and long roots. • The main advantages include; • very good accessibility and visualization of the surgical field with minimal tension on the tissue, and good reapproximation of tissue to the original position. • The disadvantages are the possibility of producing an attached gingival defect. • This flap cannot be lengthened or modified once reflected. 15 16 • Semilunar Flap • This flap is the result of a curved incision, which begins just beneath the vestibular fold and has a bow shaped course with the convex part towards the attached gingiva. The lowest point of the incision must be at least 0.5 cm from the gingival margin, so that the blood supply is not compromised. Each end of the incision must extend at least one tooth over on each side of the area of bone removal. • Indications: The semilunar flap is used in apicoectomies and removal of small cysts and root tips. • Advantages of this flap are small incision, easy reflection, no attached gingival defect especially around prosthetic appliances (crowns and bridges) and easy oral hygiene. 17 Disadvantages of this flap are limited accessibility and visualization of the surgical field, re-approximation may be difficult due to the absence of reference points, tendency to tear due to excessive tension on reflection and the possibility that the flap may made over defective bone as a result of inadequate planning or underestimation of the size of the bony defect so that the margins of the flap will not rest on intact bone leading to collapse of the flap and wound dehiscence. 18 4. Submarginal (Ochsenbein-Luebke) ➢Formed by scalloped horizontal incision in attached gingiva and two vertical releasing incisions. ➢Scalloped incision corresponds to the contour of the marginal gingiva. ➢ ➢There must be an adequate band of attached gingiva present (45mm). ➢ ➢This requires a very careful analysis of attachment level along the entire length of the horizontal incision. 19 4. Submarginal (Ochsenbein-Luebke) Advantages - Does not involve marginal or interdental gingiva. - Does not expose crestal bone - Minimizes gingival recession where crowns are in place and esthetics is a concern. - Minimizes crestal bone loss. - Easy to reapproximate flap. 20 4. Submarginal (Ochsenbein-Luebke) Disadvantages 1) -Unable to extend flap, if needed 2) - Disruption of blood supply to marginal gingival tissues, must rely on collateral circulation (which may not exist resulting in sloughing of marginal gingiva) 3) - Limited use in mandibular surgery 4) - Possible delayed healing- Possible scarring-Possible flap shrinkage 5) - Full root and crestal bone are not exposed, so periodontal defects and root fractures are difficult to visualize and treat 21 A flap with a Y-shaped incision. This flap used in surgical procedures of the palate, mainly for removal of exostoses (torus palatinus). The first flap consists of an incision along the midline of the palate with 2 anterolateral incisions made anterior to the canines, additional posterolateral incisions can be added to improve accessibility indicated in large tori, but care should be taken not to sever the greater palatine vessels. The major disadvantage of these flaps is that they can easily tear as the mucosa overlying palatine tori can be fairly thin. 22 Flaps that are used for closure of oroantral fistula or communication include; Buccal Advancement Flap which is in essence a three-sided flap that after reflection the periosteum is transversely incised so that the flap remains pedicled only by the mucosa allowing it to be advanced and sutured to the palatal tissues. The other flap is the Palatal Transpositional Flap that incorporates the greater palatine vessel, it is rotated and sutured to the buccal tissues. 23