Module 1_Basic Surgical Techniques

Question 1

What are the two types of surgery? What is the general outline of both?

Answer 1

Soft tissue
-Incision through skin or mucosa
-Through subcutaneous or submucosal tissue
-Frequently through muscles and around veins and artery
-Then reach object of operation
(an example is treatment of tissue hyperplasia for fitting of dentures)

Hard Tissue

• Pass through skin or mucosa
• Reach bone
• Pass through periosteum
• Pass through until reach object of operation
  (e. g. reaching a buried tooth root)

Question 2

What is done after the object of the operation has been managed?
(e.g. after appendix removed in apendectomy, fracture in bone has been reached and repaired, fat removed in liposuction)

Answer 2

Wound toilet, which involves:

1. Wound debridement
2. Drainage
3. Repair

Question 3

What must access to the object of operation be able to do? Is it generally better to have the access too big or too small and why?

Answer 3

-Access should be planned to cope with all eventualities of the operation in terms of accessing the object of operation and on withdrawing from the site of operation + repair of wound

• Better to have too big as wounds heal at all points rather than at one end, thus 10cm incision will heal at the same rate as 1cm incision provided all factors equal
• Also if 1cm incision involves damage to the edges of the wound then it will heal slower than 10cm (as the wound will now have to replace lost tissue rather than just joining the two ends together, think primary vs secondary intention of healing)

Question 4

How is access done?

Answer 4

1. Making and raising tissue flap
   - Create an incision with a sharp scalpel blade using a pen grip with support from the other hand
   - For control: single cut should be made towards yourself
   - To allow effective healing: cut at right angles to surface
2. Dissection (once through skin or mucosa)
   - Sharp dissection (skin and mucosa, periosteum, bone, object of operation)
   - Blunt dissection (most deep soft tissues), separate rather than cut, most tissues have cleavage planes between them so this is often used

Question 5

What are the principles governing the creation of a flap? Why is a flap generally used for surgical approaches?

Answer 5

Flap used as flap covering layer makes tissue heal better with less chance of breakdown than straight in and out approach

Principles governing flap:

• Adequate access
• Adequate blood supply to flap
• Sharp incision at edges
• Clean dissection (cleavage) of lower edges of flap
• Edges of flap away from deeper operative site (edges of flap not placed over operative site)–> middle of the flap covers site
• Avoid vital structure and parallel muscle forces

Question 6

What is the advantage of blunt dissection over sharp dissection?

Answer 6

Separating tissues mean they heal by simply coming back together

Healing from an incision requires a formal healing process

Question 7

What is a cleavage plane?

Answer 7

Any plane in the body where organs can be readily separated without damaging surrounded tissue, facilitates blunt dissections

Question 8

What is the most common cleavage plane in the oral surgery?

Answer 8

Between mucoperiosteum and bone

• Sharp incision through periosteum down to bone
• Use of periosteal elevator to get beneath periosteum and separate it from the bone

Question 9

What are the issues if the cleavage plane between mucoperiosteum and bone is supraperiosteal?

Answer 9

• Much more bleeding
• Obscures operator vision
• Poorer post op healing

Question 10

What are the general guidelines for dissecting through muscle?

Answer 10

First resort: cleave between muscle groups

If in individual muscle then split the muscle fibres

Cutting perpendicular to muscle fibres causes:

• Difficulty cutting
• Bleeding
• Difficult to repair (need to keep ends together and not under tension, which is very difficult as ends retract upon being cut)
• Poorer function overall

Question 11

Why do bone burs have a larger gap between the blades than dentine burs?

Answer 11

So they don’t clog

Note: bone is also irrigated to help with this and also stops the bone burning

Question 12

What methods are there to remove bone?

Answer 12

Shaving:

• shave off surface of bone with gentle sweeps over whole area
• Effective for small amounts of bone but if need to remove large amounts it is time consuming

Postage stamp method

• Used to remove larger amounts of bone
• Creation of a series of holes through cortex (surface of bone) which are then joined up to form the outline of the planned section, then pass instrument underneath to prise out the block of bone

Chisels

• Bone (especially young) have grain like wood (i.e. parallel fibres)
• Can be split by chisel
• Mandible grain parallel to occlusal surface
• Maxilla no grain but bone thin (thus come away in flakes)
• Bone gets brittle over 40 years (thus less likely to have a predictable grain that can be split)
• Start by cutting at right angles to the grain first (two stop cuts) then parallel to grain to join the two initial cuts (forms a rectangle of bone that can then be removed)
• Very efficient if sharp chisel and experienced operator, but if not careful can fracture entire mandible or large piece of bone with single cut

Question 13

What are two instruments for removing bone? What are some properties?

Answer 13

Chisel:

• Single Bevelled tip
• Therefore point on one end
• Hence when connect tend to skid

Osteotome:

• Double bevelled tip
• Thus Point at the centre of the tip
• Thus when connect tend to continue in straight line

Hand instruments:
Rongeurs (pro ronjurs)
-Cut bone like pliers
-End and side cutting 
-Used for removing pointed edges of bone (such as interseptal bone following removal of teeth)
Bone files
-Smooth off edges of bone
-Mainly to finish off, but can be used to smooth over protrusions like mandibular tori

High speed bone cutting via burs

• Dental burs will drive air into the wound (can cause emphysema/air in tissues)
• Dental burs can also drive lubricating oil into wound (foreign body reaction)
• Dental hand drills can also not be properly sterilised (incorporation of bacteria into area of the wound)
• If use dental drill to drill bone to remove tooth will likely end up with large swelling that will become infected and can compromise airway in mandibular 3rd molar region
• However can use dental drill to section tooth if flap has not yet been open

Question 14

What are the goals of retraction? Who’s role is it to retract the tissues?

Answer 14

• Provide access
• Protect tissues from instruments (such as drills)
• Assistants (this means undergrad students)–> poor retraction will slow an operation and increase risk of post-op complications–>also pay attention unless you want your glove sutured to the wound

Question 15

What are the goals of haemostasis?

Answer 15

• Access and vision

- Minimise post op complications (e.g. by prevention of haematoma formation)

Question 16

What methods of haemostasis tend to be most effective?

Answer 16

Those that involve pressure

Question 17

What does the debridement stage of the wound toilet involve?

Answer 17

• Management of solids*
• French for Removal of debris
• Continously remove debris as much as possible during operation as it is produced
• At end of operation check no remaining pieces
• As necessary irrigate wound with saline
• Remove any sharp bone edges
• Remove all pathologic and damaged tissue (minimise healing time period)

Question 18

What does the drainage stage of the wound toilet involve?

Answer 18

• Manaement of fluids*
• Fluids such as pus need to have access to and be drained to the outside so won’t remain in the wound
• Obliterate dead space so won’t fill with fluid and require later drainage

Question 19

What two things can happen to a haematoma and when do they normally occurs?

Answer 19

Revascularised and removed by the body

• Usually occurs if less than 1cm wide
• Progresses from outside in

Necrosis

• Breakdown of haemotoma
• Progresses from the inside out
• Results in abnormal healing

Question 20

If there is a defect in the buccinator muscle resulting in a dead space, what can be done to obliterate it?

Answer 20

Bring ends of the muscle together to close off the dead space (however as muscle shortened this will make the cheeks tight)

Squeeze the skin and oral mucosa on either side together to close the space (however this will result in a dimple)

Question 21

What is involved in the “repair” stage of the wound toilet?

Answer 21

-Before closing wound, re-check operative field and ensure all swabs and instruments accounted for (this is a major role of the scrub nurse: count everything and advise surgeon that site is clear and all instruments accounted for)

• Main method of repair is suturing
• Holds tissues together (requires several days) + haemostasis (requires several hours)
• Flap design essential (if flaps sit comfortably then will not require much repair; whereas if wound gapes or is under tension then more difficult to suture)
• Sutures apply pressure at end of capillaries and thus control bleeding

Question 22

What instruments are used for suturing?

Answer 22

Needle holders
-Several types, must be long enough to reach depth of wound

Needles
-Round or triangular cross section

Resorbable or non resorbable sutures

• Non-resorbable commonly used (silk or nylon)
• However resorbable often used when buried in tissue or removal difficult (gut or polyglycolic)

Question 23

What are the different types of sutures (technique/placement wise)

Answer 23

Single interrupted
(most common)

Mattress

Continuous

Question 24

What 3 categories can instruments generally be classified into?

Answer 24

• Access
• Objective
• Toilet