CAD - Intro to minor surgical technique Flashcards
Define oral surgery
The diagnosis and management of pathology of the mouth and jaws that requires surgical intervention.
Which patients are treated in oral surgery?
The treatment of children, adolescents and adults and the management of dentally anxious and medically complex patients.
List the procedures that may be carried out by an oral surgeon.
- Extractions
- 3rd molar extractions
- ST biopsies, histology
- Implants
- Bone grafts
- Surgical endodontics
- Removal of cysts
- TMJ & facial pain
- Sinus problems
- OAC & OAF
- Impacted canines
- Sedation, Midazolam, Nitrousoxide
- CBCT
Following diagnosis, what are the next two steps?
Determine complexity of tx: straight forward? / Advanced? / Complex?
Formulate a tx plan that involves the patient
Trauma / insult to tissues caused by an extraction should lead to ______ over 6-8 weeks.
Healing
What factors cause physical tissue damage?
- Compromised blood flow
- Crushing
- Desiccation
- Incision
- Irradiation
- Overcooling
- Overheating (removing bone with handpiece that is cooled with water)
What factors cause chemical tissue damage?
- Agents with unphysiologic pH
- Agents with unphysiologic tonicity
- Proteases
- Vasoconstrictors – e.g. adrenaline in LA
- Thrombogenic Agents (blood clotting)
What are the four stages of acute wound healing after an extraction?
- Haemostasis (seconds to hours)
- Inflammatory phase (hours to days)
- Proliferative phase (days to week)
- Remodelling (week to months)
What happens during haemostasis?
- Vasoconstriction
- Platelet aggregation
- Leucocyte migration
What happens in early and late inflammatory phase of acute wound healing?
Early: neutrophil chemoattraction
Late: macrophages carry out phagocytosis and removal of foreign body/bacteria
What happens during the proliferative phase?
- Acute wound healing
- Fibroblasts proliferate
- Collagen synthesis
- Extra-cellular matrix reorganisation
- Angiogenesis
- Granulation tissue formation
- Epithelialization
What happens during the remodelling?
Remodelling:
* Epithelialization (repair of wounded area by epithelial cells).
* Extra-cellular matrix remodelling
* Increase in tensile strength of the wound
Describe what happens in week 1 of a healing tooth socket.
WBCs remove bacteria
Breakdown debris e.g bone fragments
Fibroplasia begins (process of granulation tissue formation by fibroblast proliferation)
Ingrowth of fibroblasts & capillaries
Epithelium migrates down socket wall
Osteoclasts accumulate along crestal bone – bone degradation
What happens in week 2 of a healing tooth socket?
- Granulation tissue fills socket (new connective tissue & microscopic blood vessels)
- Osteoid deposition along alveolar bone lining socket (unmineralized bone tissue)
- Smaller sockets – fully intact epithelium
What happens in week 3-4 of a healing tooth socket?
o Cortical bone resorbs from the crest and walls
o New trabecular bone laid down
o At 4-6 months: cortical bone lining fully resorbed
o Epithelium moves to crest
Difference between cortical bone and trabecular bone?
Cortical bone – dense outer surface of bone that forms a protective layer around the interval cavity. High resistance to bending and torsion.
Trabecular bone- Hierarchical- made of 20% bone and the rest is marrow and fat. It is spongy and porous.
_______ ‘intention’ is where the edges of a wound (no tissue loss) are placed and stabilised in the same anatomical position prior to injury and allowed to heal.
Primary intention.
_______ ‘intention’ implies a ‘gap’ is left between edges of incision / laceration. – wound is left open without stitches to heal by itself. Closes up naturally.
Secondary intention.
What happens during secondary intention of wound healing?
- Tissue loss has occurred around the wound edges
- Significant amount of epithelial migration, collagen deposition etc
- Slower, heals with a scar [e.g. tooth socket, poorly reduced #, deep ulcers]
What are osteogenic cells (stem cell) / osteoprogenitor cells?
- Stem cells that play a role in bone repair and growth.
- Precursor to osteocytes and osteoblasts.
- Reside in bone marrow.
What is an osteoblast?
- Cells that form the bone matrix
- Bone healing
- Found in the periosteum & endosteum
- Pluripotential mesenchymal cells are able to differentiate into osteoblasts
What is an osteocyte?
- Cell that maintains bone tissue
- Derived from osteoblasts
_________: A bone cell that resorbs bone.
Osteoclast
After tissue injury, the inflammatory phase occurs within 3-5 days. Which two phases is this made of?
Vascular and cellular phase occurs.
What happens during the vascular phase of inflammation in a healing socket?
- Initial vasoconstriction of disrupted vessels slows blood flow into injured area promotes coagulation.
- Histamine, prostaglandins and WBCs are released leading to vasodilation which opens small spaces between endothelial cells. Plasma leaks, leukocytes migrate and fibrin exudate forms leading to OEDEMA.
Describe the cellular phase of inflammation in a healing socket.
- Activation of complement and neutrophils leads to redness (rubor), swelling (tumor), heat (calor) and pain (dolor)
What happens in the proliferative phase?
- Fibrin strands form the structure for fibroblasts to lay the ground substance and tropocollagen
- Collagen and capillaries are formed.
- It takes 2-3 weeks for wound strength to develop
What happens in the final stage of wound healing?
Final stage – Remodelling.
Continues indefinitely
Wound maturation & contraction
Previous collagen fibres are destroyed – replaced by new collagen - orientated better. Wound strength slowly increases.
Vascularity decreases (as does erythema)
Redness settles
Which 6 factors influence a healing socket?
Foreign material – bacteria, dirt, suture material that gets infected. Antigenic – chronic inflammatory reaction.
Necrotic tissue – barrier to ingrowth of reparative cells. Prolonged inflammatory stage with WBCs. Acts as a nutrient for bacteria e.g. haematoma.
Ischaemia – good vs poor blood flow
Wound tension- sutures too tight causing tension = ischaemia. Healing with excess scar formation and wound contraction.
Age and MH of pt
Operator technique
Expand on how ischaemia affects healing.
- Reduction in blood supply affects healing = Further tissue necrosis
- Reduction in delivery of: wound antibodies, WBCs, Antibiotics, Nutrients / Oxygen to ensure healing
What are the possible causes of ischaemia in the healing socket?
o Sutures
o Poor flap design
o Excessive external pressure
o Internal pressure
o Systemic BP issues
o Peripheral vascular disease (narrowing, blockage or spasm in blood vessels)
o Anaemia (reduced RBC or Hb)
How can age, MH, drug history, BMI, SH, anxiety / cooperation affect healing?
Age – complications more likely with older pts e.g. mand. third molars
Medical History – Ischemic Heart Disease, CVA, Diabetes Mellitus, neoplasia.
Drug History – anticoagulants, steroids (long term = poor healing), bisphosphonates, immunosuppressants, Antibiotic prophylaxis for cardio problems.
BMI – airway & access – higher BMI = smaller mouth, short fat neck. Additional medical complications.
Social History - smoking - dry socket.
Anxiety / Co-operation - stress