Principles of Flap Design and Suturing

Question 1

What is a surgical flap? What is the purpose of a surgical flap?

Answer 1

Soft tissue flap used to:

Facilitate surgical extractions

Treat pathology (eg apical surgery and periodontal surgery)

To create access for soft tissue and bone augmentation procedures (eg implant surgery)

Question 2

How does flap design and incorrect technique affect the outcome of treatment?

Answer 2

Correct flap design facilitates adequate exposure and promotes healing

Periosteum plays a vital role in bone healing

Torn and macerated flap heals more slowly

Less bleeding when full thickness flap is elevated

Question 3

What is full-thickness surgical flaps?

Answer 3

Full-thickness muco-periosteal flaps reflected off bone

Question 4

How is a mucoperiosteal flap created?

Answer 4

Incision in the gingival sulcus with one smooth continuous stroke, keeping knife blade in contact with bone throughout.

Reflection of flap begins at the papilla with a periosteal elevator pushing mucoperiosteum away from bone with firm continuous pressure.

Retract the mucoperiosteal flap by pressing firmly against bone not against soft tissue

Question 5

What are the important principles of flap design to consider?

Answer 5

Surgical incision

Blood supply

Access to underlying tissues

Replace in the original position

Maintain with sutures

Question 6

How should a surgical incision be made if the patient is edentulous?

Answer 6

Incision is made along the crest of the ridge.

Question 7

What can accidentally be damaged in edentulous patients with extremely resorbed mandibles?

Answer 7

Mental foramen may rest near the top of the residual alveolar ridge so risk of damage to the mental nerve.

Question 8

How is the mucoperiosteal flap completed?

Answer 8

Incision in the gingival sulcus with one smooth
continuous stroke, keeping knife blade in contact with bone throughout

Reflection of flap begins at a papilla with a periosteal elevator, pushing mucoperiosteum away from bone with firm continuous pressure

Retract mucoperiosteal flap by pressing firmly
against bone, not against soft tissue

Question 9

How does the incision affect healing post surgery?

Answer 9

Wound heals across the incision. Sharp incision heals more rapidly along the line than torn mucosa.

Question 10

What locations is an incision good to make?

Answer 10

Make incision over intact
bone. Incision unsupported
by sound bone results in
wound dehiscence and
delayed healing

If bucco-cortical plate
eroded or surgery removes
bone over tooth, incision at
least 6-8mm away in area
of intact bone

Avoid anatomical structures eg lingual nerve

 Use envelope incision
or relieving incisions
well anterior or
posterior to mental
foramen

Question 11

What is the purpose of an oblique vertical relieving incision?

Answer 11

Allows broad base flap to preserve adequate blood supply.

Question 12

How should vertical relieving incision be carried out?

Answer 12

Should not cross the canine prominence to reduce the tension in suture line and risk of wound dehiscence.

Vertical relieving incision should not be directly on the facial aspect of tooth nor in the papilla as this may result in a soft tissue defect

Question 13

Why is the base of the flap broader than the free gingival margin?

Answer 13

To preserve blood supply

Question 14

What is the major blood supply to palatal soft tissue?

Answer 14

Greater palatine artery anterior and middle palate

Lesser palatine artery posterior palate.

Question 15

How can the flap be made to facilitate access to underlying tissues most optimally?

Answer 15

Adequate sized flap used to facilitate visualisation of area and for insertion of instruments to perform surgery.

Flap held out of surgical field without tension and by retractor resting on intact bone.

Question 16

What kind of flap is used to access a palatally impacted canine?

Answer 16

An envelope flap

Question 17

How should flap be positioned at the end of surgery?

Answer 17

Should be positioned back into place and stitched to hold it

Wound healing across the incision

Wound closure should be tension free

Question 18

What are the types of mucoperiosteal flaps?

Answer 18

Envelope flap

Four-cornered flap (Trapezoid)

Three-cornered flap (triangular)

Semi-lunar incision

Question 19

What does a four-cornered flap look like?

Answer 19

2 relieving incisions with a broader base than gingival margin.

Envelope incision with 2 relieving incisions.

Question 20

What does a three-cornered flap look like?

Answer 20

Sulcular incision with a vertical relieving incision

Question 21

What does a semi-lunar incision looks like?

Answer 21

Avoids marginal attached gingiva.

Flap is moon shaped and doesn’t involve the sulcus.

Question 22

What is the purpose of suturing?

Answer 22

To hold the flap in position and speed wound healing.

Aids in haemostasis

Holds mucoperiosteal flap over bone.

Can aid in maintaining clot in alveolar bone

Question 23

Which needles are most commonly used in oral surgery?

Answer 23

3/8 circle and 1/2 circle needles.

Question 24

What are the types of needle bodies used for suturing?

Answer 24

Round-bodied needles

Conventional cutting needles

Reverse cutting needles (Ideal for tough tissues like skin, tendon sheath or oral mucosa)

Question 25

Which sutures should be used for oral surgery?

Answer 25

Depends on the type of tissue being repaired

There are absorbable and non-absorbable sutures. Monofilament or braided.

Question 26

What are the features of the ideal suture?

Answer 26

Ideal suture is the smallest possible suture:

that also provides high uniform tensile strength.

Ability to hold wound securely during healing phase

Can rapidly resorb

Uniform diameter, sterility, pliability, knot security, least amount of tissue reactivity, and predictability.

Question 27

What are the types of absorbable sutures?

Answer 27

Braided = Vicryl and vicryl rapide

Monofilament = Monocryl, fast absorbing gut, and chromic gut.

Question 28

What are the types of non-absorbable sutures?

Answer 28

Braided = Ethibond, silk

Monofilament = Ethilon

Question 29

How are sutures usually placed?

Answer 29

Sutures are usually first placed distal to the last tooth in each interproximal space.

Single interrupted suture can be placed across both papillae of tooth socket.

First insert sutures through the more mobile tissue flap.

When space is restricted use a 3/8 or 1/2 circle needle.

Question 30

How should the suture be held?

Answer 30

Only needle holders should be used to grasp suture needles.

Suture needle should be inserted and pulled through the tissue in line with the curve of the needle.

Grab the suture needle in center of the needle. Never at its tip or near where the thread is swage to the needle

Question 31

How should suturing be done? (Technique)

Answer 31

Needle should enter tissue at right angles to tissue.

Do not place sutures closer than 2 - 3mm from flap edges to prevent tearing through the flap during suturing.

When suturing, flaps should be approximated. Pull the suture just tight enough to secure the flap in place