PRINCIPLES OF SURGERY

Definition of oral surgery Developing a surgical diagnosis or pre surgical evaluation Basic necessities for surgery or pre surgical preparation Asepsis Preparation of Patient and Surgeon Techniques of sterilization Maintainence of sterility Surgical staff preparation Incisions Principles of flap designing and different types of flaps Tissue handling Hemostasis Suture and suturing techniques Decontamination and debridement Edema control Conclusion Bibliography

CONTENTS

Oral and maxillofacial surgery is the specialty of dentistry which includes the diagnosis, surgical and adjunctive treatment of diseases, injuries and defects involving both the functional and esthetic aspects of the hard and soft tissues of the oral and maxillofacial region

1. DEFINITION (according to american dental association and adapted in 1990)

The aim of preoperative evaluation is not to screen broadly for undiagnosed disease but rather to identify and quantify any comorbidity that may have an impact on the operative outcome

The context in which preoperative preparation is conducted ranges from an outpatient office visit to hospital inpatient consultation to emergency department evaluation of a patient.

PRESURGICALEVALUATION

Know your patientExamine your patient and gather patient and

scientific data including the use of consultants. Look at the data and analyze for hypothesis

testingConsider the alternativesIs picking up a knife the best thing to do?To practice evidence based treatment.

Before subjecting a patient to anesthesia we should.........have a surgical diagnosis

It depends on:->Adequate access>Adequate light>Clean surgical field

BASIC NECESSITIES FOR SURGERY

Sepsis- Breakdown of tissue by action of microbes and is usually accompanied by inflammation

Antiseptic- Substance that can prevent multiplication of organism capable of causing infection. Anstiseptics are applied on living tissues while Disinfectant are applied on inanimate object.

Sterility- freedom from viable forms of micro organisms

Sanitization –reduction of number of viable organisms

ASEPSIS

To minimise wound contamintaion by pathogens because during a surgery, dentist violates the epithelial surface which is the most important barrier against an infection

During oral surgical procedures dentist, assistant and equipment become comtaminated with patients blood and saliva

ASEPSIS

TECHNIQUES OF INSTRUMENT STERLIZATION

By using disposable materials:-Surgical field maintaenance

MAINTAINENCE OF STERILITY

1. Hand and arm preparation Done by antiseptics with low toxicity like iodoform, chlorhexidine, and hexachlorophene

Two techniques are used forA. Clean technique- used in office based

surgeries. Surgeon wears a clean dress and over it long sleeved laboratory coat or a surgical scrub

B. Sterile technique- mostly in operating room. Purpose of it is to minimise the number or micro organism that can ener the wound site.

SURGICAL STAFF PREPARATION

Gloving technique Hand and arm scrub

Use a sharp blade of proper size. Use firm continuous strokes. Avoid cutting vital structuresIncise perpendicular to the epithelial surface. Intraoral incisions should be properly placed.

INCISIONS

Blades

1. Outlined by a surgical incision2. Carries its own blood supply3. Allows surgical access to underlying tissues4. Can be replaced in the original position5. Can be maintained with sutures and is expected to

heal

PRINCIPLES OF FLAP DESIGN

Flap necrosisFlap DehiscenceFlap TearingInjury to Local Structures

Why we need principles of flap designing...........to prevent -

1. Base > Free margin• to preserve an adequate blood supply• unless a major artery is present in the base

2. Width of Base > Length of Flap*2• less critical in oral cavity, but length < width• a long, straight incision with adequate flap reflection heals

more rapidly than a short, torn incision.

3. An axial blood supply in the base4. Hold the flap with a retractor resting on intact bone

to prevent tension.

Principles of Flap Design1.Flap Necrosis

The incisions must be made over intact bone If the pathologic condition has eroded the buccocortical plate, the incision must be at least 6 or 8 mm away from it.The incision should be 6 to 8 mm away from the bony defect created by surgery.Gently handle the flap's edgesDo not place the flap under tensionDo not cross bony prominences, ex: canine eminence

Flap Margin Dehiscence(separation)

Flap Margin Dehiscence contd…..

• Is a common problem in procedures using a flap that provides insufficient access

• A proper long flap heals as quickly as a short flap• Envelope flaps

– an incision around the necks of several teeth.– extends 2 teeth anterior and 1 tooth posterior.

If not provide sufficient access…• Vertical (oblique) releasing incisions:

– extends 1 tooth anterior and 1 tooth posterior.– started at the line angle of a tooth.– carried obliquely apically into the unattached gingiva.– If cross the papilla localized periodontal problems

Flap Tearing

Injury to local structuresMandible...

lingual nerve mental nerve

Injury to local structuresMaxilla

Greater palatine artery nasopalatine nerve and vessels

Flap considerations .............

Various types of flaps have been described in oral surgery, whose name is based mainly upon shape:-

trapezoidal, triangular, envelope,semilunar,

Oral Surgical Flaps

The trapezoidal flap is created after a Π shaped incision, which is formed by a

Horizontal incision along the gingivae, and two oblique vertical releasing incisions extending to the buccal vestibule.

Vertical releasing incisions always extend to the interdental papilla and never to the center of the labial or buccal surface of the tooth.

This ensures the integrity of the gingiva proper, because if the incision were to begin at the center of the tooth,contraction after healing would leave the cervical area of the tooth exposed.

Trapezoidal Flap

Advantages. Provides excellent access, allows surgery to be performed on more than one or two teeth, produces no tension in the tissues, allows easy reapproximation of the flap to its original position and hastens the healing process.

Disadvantages. Produces a defect in the attached gingiva (recession of gingiva).

Trapezoidal flap contd…..

This flap is the result of an Lshaped incision with a horizontal incision made along the gingival sulcus and a vertical or oblique incision

The vertical incision begins approximately at the vestibular fold and extends to the interdental papilla of the gingiva.

The triangular flap is performed labially or buccally on

both jaws and is indicated in the surgical removal of root tips, small cysts, and apicoectomies.

Triangular Flap

Advantages. Ensures an adequate blood supply, satisfactory visualization, very good stability and reapproximation; it is easily modified with a small releasing incision, or an additional vertical incision, or even lengthening of the horizontal incision.

Disadvantages. Limited access to long roots, tension is created when the flap is held with a retractor, and it causes a defect in the attached gingiva

Triangular Flap contd……

This type of flap is the result of an extended horizontal incision along the cervical lines of the teeth. The incision is made in the gingival sulcus and extends along four or five teeth.

The tissue connected to the cervical lines of these teeth and the interdental papillae is thus freed. The envelope flap is used for surgery of incisors, premolars and molars, on the labial or buccal and palatal or lingual surface and is usually indicated when the surgical procedure involves the cervical lines of the teeth labially (or buccally) and palatally (or lingually), apicoectomy (palatal root), removal of impacted teeth, cysts, etc.

Envelope Flap

Advantages. Avoidance of vertical incision and easy reapproximation to original position.

Disadvantages. Difficult reflection (mainly palatally), great tension with a risk of the ends tearing, limited visualization in apicoectomies, limited access, possibility of injury of palatal vessels and nerves, defect of attached gingiva

Envelope Flap…. cont

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. The semilunar flap is used in apicoectomies and removal of small cysts and root tips.

Semilunar Flap

Advantages. Small incision and easy reflection, no recession of gingivae around the prosthetic restoration, no intervention at the periodontium, easier oral hygiene compared to other types of flaps

Disadvantages. Possibility of the incision being performed right over the bone lesion due to miscalculation, scarringmainly in the anterior area, difficulty of reapproximation and suturing due to absence of specific reference points, limited access and visualization,tendency to tear.

Gentle handling of tissueMeticulous haemostasisPreservation of blood supplyStrict aseptic techniqueMinimum tension on tissuesAccurate tissue appositionObliteration of deadspace

Also called as Halsted's principles, or Tenets of Halsted

Tissue handling

Is a process which causes bleeding to stopMethods of promoting wound hemostasis –1. Natural hemostatic mechanism2. Use of sponge and applying pressure3. these two cause stasis of blood and promote

coagulation. Small vessels 20 to 30 sec. larger vessels 5- 10 min. it should be dabbed rather than wiped

4. Use of electric current –fuses the cut ends5. Sutures 6. Vasoconstrictors like adrenaline: best if placed in the

site 7 minutes before the surgery begins

HEMOSTASIS

Dead space management: It is any area that remains devoid of tissue after closure of wound

It usually fills in with blood and can lead to hematoma formation

It can be eliminated in 4 waysA. Suturing tissue planes together to minimize

post operative voidB. Place a pressure dressing. This brings the

tissue planes together until either they are bound by fibrin or pressed by edema or both(takes uptp 12 to 18 hours

C. Place a packing in the void and remove when bleeding stops. Done when surgeon cant tack the tissue together , eg bony cavity after cyst removal

D.Through use of drains with or without pressure packs

It is a strand of thread that is used to approximate tissues and to ligate blood vessels

Tools:1. Needle2. Suture material

SUTURES

Source: Ratner et al. 2004

Classification

Sutures

OriginNatural

Synthetic

Absorption

Absorbable

Nonabsorbable

Fiber constructi

on

Multifilament

Monofilament

PhysicalTensile Strength, Dimension, Knot-pull strength,

Knot security, StiffnessHandling

Knot-tie down, First throw hold, Tissue drag, Package memory, Suppleness

BiologicalTissue reaction, Absorption, Biocompatibility,

Tensile strength loss

Properties of suture material

Selection of suture material should be based on healing charecteristics of the tissue being

approximatedA. Rate of tissue healing. – suture that looses its tensile strength at same rate as the tissue gain strength.Tissue that heal slowly are usually closed with non absorbable suturesRapidly healing tissue with absorbable onesB.Tissue contamination. – contaminated areas should be sutured with monofilament materials

Principles of suture material selection

C. cosmetic results- close and prolonged apposition of tissue will produce best results

D. Cancer patients- synthetic non absorbable sutures as the the wound can breakdown.

E. Nutritional status- non absorbable sutures to be used in undernourished cases as the wound healing takes longer

Principles of suture material selection cont.....

Are of two types :- a. Eyed b. Eyeless

Needle

Needle should be grasped at approximately 1/3° the distance from eye or 2/3 from point

Needle should enter perpendicular to tissue surface

Needle should pass through the tissue along its curve

Suture should be passed at an equal depth and distance from incision on both sides

Needle always pass from movable to fixed tissue

Thinner to thicker tissueDeeper to superficial tissue

Principles of suturing

Tissue must never be closed under pressure. Undermining of tissue must be done prior to suturing in such cases

Knot should never lie on the incision lineSuture should only be tied only to approximate and

not to blanchSuture should be placed at a greater depth than the

distance from the incisio, so as to evert the wound margins.

Sutures on the skin are generally removed in 5 days and intra oral in 7 days. If there is tension while suturing, they may be kept for 10 days

Principles of suturingcont.....

1. Suture knot slipping• Inability of the suture to retain until wound healing

complete• Common in absorbable suture

2. Re-infection• Site for microbial growth causing re-infection• the need for suture with antimicrobial activity

3. Failure of wound healing• Improper suturing technique does not allow

collagen formation

Risks and side effects

DECONTAMINATION is done to reduce the bacterial count and hence reduce risk of infection

Mostly done by irrigastion under pressure. Saline or antibiotic solutions can be used

DEBRIMENT is careful removal of necrotic and ischemic tissue and foreign material from injured tissue that would impede wound healing

Is done where either there is a traumatic injury or severe tissue damage is done.

DECONTAMINATION &DEBRIDEMENT

Edema is accumulation of fluid in interstitial space because of transudation from damaged vessels and lymphatic obstruction by fibrin

The degree is determined by :- a. The amount of tissue damage, b. Looser the connective tissue

Prevention – A. Application of iceB. Patient position. Ie patient should keep the

head above the body as much as possible C. Short term high dose corticosteroids (only if

administerd before tissue damage is done)

EDEMA CONTROL

Conclusion