Surgery for Dentists Flashcards
What are the causes of surgical disorders?
Congenital
Or
Acquired: • Trauma ( mechanical, thermal, chemical, electrical, ionising radiation) • Inflammation • Infection • Neoplasia • Vascular • Degenerative • Metabolic disorders • Endocrine disorders • Other abnormalities of tissue growth • Iatrogenic • Drugs, toxins, diet, exercise, environment
What kind of congenital defects that require surgery are most common?
Cleft lip and palate are among the most common of all birth defects. Others are very rare.
How do congenital defects affect the face/head and what is required as a result?
Mostly affect how a person’s face or head looks. These
conditions may also affect other parts of the body.
Treatment depends on the type of problem
Reconstructive surgery may help the person’s
appearance
How common is cleft lip? How common is cleft palate?
Cleft lip occurs 1 in 750 live births, cleft palate 1 in every
2000
Half the cleft lip also have a cleft palate
10% patients with cleft have other malformation
What kinds of trauma can result from chemical injuries?
Sodium hypochlorite solution commonly used in root canal
treatments (Strongly alkaline with pH 11 to 13)
Complications of accidental spillage are damage to clothing,
damage to eye, damage to skin and damage to oral mucosa
Complications from hypochlorite extrusion into peri-radicular soft tissue include chemical burns and tissue necrosis and
neurological complications like anaesthesia or paraesthesia
Using sodium hypochlorite for root canal irrigation without adequate isolation of the tooth can lead to leakage of the solution into the oral cavity and ingestion or inhalation by the patient, resulting in throat irritation and in severe cases, upper airway compromise
What causes inflammation?
Often stems from infection
Can result from physical irritation (noxious chemicals for example)
What causes inflammation of salivary glands?
Calculus
Viruses
Bacterial infection
How can infection spread?
Bacterial diffuse through the dentinal tubules toward the
pulp and evoke inflammatory changes resulting in pulpitis
and pulp necrosis
Bacteria from the pulp spreads into periapical tissues and soft tissues and bones of the face and neck
What is the metabolic response to injury?
Often occurs in 2 phases:
Catabolic phase: High metabolic rate, breakdown of proteins/fats, negative nitrogen balance and weight loss.
Anabolic phase: Protein and fat stores are restored and weight gain (positive nitrogen balance)
What kinds of conditions can diabetes have on the mouth?
Periodontal disease
Candidosis
Dry mouth and increased caries
Glossitis
Burning mouth syndrome
Orofacial dysaesthesia
Poor healing
What factors mediate the metabolic response to injury?
Acute inflammatory response
Endothelium and blood vessels
Neuroendocrine response
Bacterial infection
What happens during the acute inflammatory response?
Injury -> activation of macrophages -> Cytokine release -> Neutrophils + macrophages recruited to site to clear dead tissue and bacteria -> Cytokines in circulation initiate systemic features (IL-1 fever, and acute phase protein IL-6) -> Other pro-inflammatory cytokines released and anti-inflammatory cytokines are also released
What does clinical condition of someone with acute inflammation depend on?
Clinical condition of patient depends on extent to which inflammation remains localized and the balance between pro and anti-inflammatory processes
What are the pro inflammatory cytokines released durign the acute inflammatory response?
Prostaglandins, kinins, complement, proteases, and free radicals
What anti-inflammatory cytokines are released during the acute inflammatory response?
Antioxidants, protease inhibitors, and IL-10
What happens to the endothelium and blood vessels?
Expression of adhesion molecules upon endothelium leads to leukocyte adhesion
Release of kinins, prostaglandins and nitric oxide leads to vasodilation and increased local blood flow.
Increased capillary permeability leads to delivery of inflammatory cells, oxygen and nutrient substrates which are important for healing.
What causes adhesion and coagulation during inflammation?
Oedema is caused from colloid particles (albumin) leaking into the injured tissues
Coagulation and platelet activation is promoted by exposure of tissue factor.
How does sympathetic activation occur during the acute inflammatory response?
Tissue injury and inflammation leads to impulses in afferent pain fibres that reach the thalamus and mediate
metabolic response
What happens when the sympathetic nervous system is activated during the acute inflammatory response?
Activation of sympathetic nervous system leads to release of noradrenaline from sympathetic nerve fibre endings and adrenaline from adrenal medulla.
This results in tachycardia, increased cardiac output, and carbohydrate, fat and protein metabolism
What is the neuroendocrine response to acute inflammation?
Changes in the circulating
What are the consequences of metabolic response to injury?
Hypovolaemia
Increased energy metabolism and substrate cycling
Catabolism and starvation
Changes in red blood cell synthesis and coagulation
Anabolism
What causes hypovolaemia following the acute inflammatory response?
Loss of blood, fluid or water.
Sequestration of protein-rich fluid into interstitial space caused by the increased vascular permeability.
Decreased circulating volume will reduce oxygen and nutrient delivery and increased healing and recovery time.
What are the neuroendocrine responses to hypovolaemia?
Release of ADG and aldosterone = oliguria + sodium and water retention.
Reduced cardiac preload = Lower cardiac output + decreased blood flow to tissues and organs this results in activation of Sympathetic NS = increased cardiac output, peripheral vasoconstriction and rise in BP.
What happens to BMR following surgery?
The overall energy expenditure rises by 50% due to increased generation of heat, fever, and BMR.
How is catabolism different to starvation?
Catabolism is a breakdown of complex substances to glucose, amino acids, and fatty acids mediated by increase in catecholamines, cytokines, and hormones.
Total energy expenditure is increased in proportion to injury severity.
Starvation occurs when intake is less than the metabolic demand. Can be acute or chronic.
What patient factors are associated with the magnitude of metabolic response to injury?
Genetic predisposition
Coexisting disease
Drugs
Nutritional status
What trauma factors are associated with magnitude of metabolic response to injury?
Severity
Nature
Ischaemia-reperfusion
Temperature
Infection
Anaesthetic technique
What changes are seen in red blood cell synthesis and coagulation following surgery?
Anaemia is common after major surgery or trauma
Following tissue injury the blood is hypercoagulable and increased risk of thromboembolism