Principles of Surgery and flap designing

Principles of Surgery

Principle 1 

- Use a Sharp Blade 

- Standard blade = #15 for oral surgery (#11 and #12 are specialized options as well) 

- Sharp blades allow clean incisions w/o damage from making multiple strokes 

- The rate a blade dulls depends on resistance of tissues and contact with bone -->  Blades need frequent changing 

Principle 2 

- Use Firm continuous strokes 

- ↑ tissue damage occurs from repeated tentative strokes. 

Principle 3 

- Avoid Cutting Vital Structures 

- Cut deep enough to define the next major layer when making incisions close to vessels, ducts and nerves 

- Vessels can be divided, and nerves freed from adjacent tissues away from area to be incised 

Principle 4 

- Make incisions perpendicular to epithelial surface when planning to reapproximate 

- A 90 degree squared edge incision is easier to re-orient properly during suturing and is less 

susceptible to necrosis from ischemia  

Principle 5 

- Ensure properly placed incisions 

- When possible make incisions through ATTACHED gingiva and over healthy bone 

- Keep a margin of a few mm away from damaged bone -> suture margins should be over healthy bone 

- Incisions made around teeth to be extracted are done in the sulcus if possible 

Principles of Flap Design :

Flaps help to ↑ the access to the surgical area 

- Maintaining design principles work to ↓ Necrosis, Dehiscence and tearing 

Prevent Necrosis

 - Apex of flap NEVER wider than base 

- Sides should run either parallel or converge to the apex (top) of the flap 

- Length should be NO MORE than 2x the width of the base. Width should be > length 

- Axial blood supply should be included in the base 

- Don’t twist, stretch or grab flap w/ anything that could damage the vessels 

Prevent Dehiscence 

- Approximate edges of flap over healthy bone 

- Handle the edges gently 

- Don’t suture flap under tension 

*Dehiscence exposes underlying bone = pain, bone loss, ↑ scarring* 

Prevent flap tearing 

- Larger incisions heal just as quickly as short ones -> Go bigger to prevent tearing from imparting too much force on tissue 

- Add releasing incisions to ↓ the tension placed on the tissues