Week 10- Oral Health and Cancer Therapy Flashcards
How does chemoradiotherapy affect salivary glands?
- More than just dry mouth
- Cell death and fibrosis
- Loss of functional architecture of glands
- Serous acini more affected
What are the oral issues associated with chemoradiotherapy?
Salivary gland dysfunction Dysgeusia Radiation caries Radiation damage to teeth Periodontitis Trismus ORN Mucositis
How much radiation reduces salivary flow within 24 hours?
2.2Gy
How much radiation causes permanent hyposalivation?
40Gy
How does saliva appear in patients with salivary gland dysfunction?
Thick, ropey or aerated
What are the functions of saliva?
Lubrication Cleansing Antimicrobial Remin Buffering Mucosal integrity Digestion & taste
How does radiation cause dysgeusia?
Caused by hyposalivation and radiation injury to taste buds
When do taste buds recover following radiation?
Partial restoration of taste 20-60 days post RT.
Full restoration after 2-4 months.
Some report long term changes.
What is graft vs host disease?
Donor T cells react against pt tissues directly or through exaggerated inflammatory responses following HCT.
Acute and chronic forms.
What primary organs/structures are involved in graft vs host disease?
Skin
Liver
GIT
Oral mucosa
What are the oral manifestations and symptoms of graft vs host disease?
Pseudomembranous ulceration Erythema and atrophy (acute) Lichenoid hyperkeratotic changes (chronic) Dysgeusia Salivary gland dysfunction
Why does radiation caries occur?
Shift to cariogenic flora Reduced salivary antimicrobials Loss of bioavailable calcium phosphate Weakens dentine-enamel bonds Alters prismatic enamel structure Denatures collagen in dentine MMPs hydrolyse dentine bonding agents Can alter pulp vascularity & capacity to repair
Is graft vs host disease a consequence of chemoradiotherapy?
No
Where does radiation caries occur?
Different locations than common dental decay.
- Labial surfaces
- Incisal/cuspal tips
- Proximal surfaces of lower anteriors
Why is radiation caries common in lower anteriors
Usually lower anteriors are bathed in saliva so they aren’t susceptible to caries. However, with salivary gland dysfunction, caries can occur frequently here. Distance between proximal surface and pulp is small for md anteriors.
What are prevention strategies for radiation caries?
Tooth mousse plus Bicarb mouth rinses Immaculate OH High F toothpaste low in SLS Dietary advice Regular recalls- 3 monthly
What toothpaste is recommended for patients at risk of radiation caries?
neutrofluor sensitive (low in SLS) as it is less irritant to mouth.
Why is GIC used in patients with radiation caries despite its high chance of crazing and getting lost in dry environment?
Potential to release fluoride so it’s unlikely to get recurrent caries.
Also, better to loose resto than get recurrent caries. Not always bad to lose the filling as the pt keeps coming back.
What are issues with amalgam in patients with radiation caries?
Amalgams cause backscatter and subsequent local mucositis
What are issues with composite in patients with radiation caries?
High rates of loss and recurrent caries.
What are issues with full coronal restorations in patients with radiation caries?
Margins vulnerable to recurrent caries.
If pt develops caries around crown margins how can it be treated?
Place AgF instead of replacing crowns. Can also place GIC
What are the ideal properties of RM-GIC in relation to radiation caries?
Similar recurrent caries rates to GIC.
More resistant to acid and crazing.
Why are dentures contraindicated in patients undergoing chemo-radiotherapy?
Can compromise plaque control and increase risk of ORN. Avoid in partial dentate unless essential aesthetics and function.
What are issues with performing endo in patients undergoing chemoradiotherapy?
Trismus complicates endo- rubber dam, access cavity, instrumentation. Access cavities through incisal or labial aspect or decoronating tooth may improve access.
If teeth are deemed unrestorable in pts undergoing chemoradiotherapy, how should they be treated?
Root fill and seal to control symptoms and infection rather than do exo.
What doses of radiation often cause trismus? When can it start to occur?
> 60Gy
May begin at the end of radiotherapy or anytime in the subsequent 24 months
What happens if TMJ or muscles of mastication are in field of radiation?
Fibrosis and damage
abnormal proliferation of fibroblasts, scar tissue and nerve damage
What are oral issues with trismus?
Eating Speaking Removable dental prostheses Dental exam & tx OH
How can trismus be managed?
Early tx can prevent/minimise effects Stacking wooden tongue depressors together 3-4x/day (add more over time) Therabite device or Dynasplint Trismus system Trigger point injections Analgesics Muscle relaxants Botulinum toxin Heat pack
What is mucositis?
Mucosal damage secondary to cancer therapy occurring in the oral cavity, pharyngeal, laryngeal, esophageal and GI regions
What does mucositis cause?
Pain Ulceration Painful swallowing Dysgeusia Dehydration Malnutrition
What is the pathogenesis of mucositis?
Direct mucosal injury by radiation/chemotherapy interferes with oral epithelial turnover time and induces apoptosis.
What are the phases of mucositis?
1st: Inflammatory/vascular (initiation)
2nd: epithelial (messaging, signalling and amplification)
3rd: ulcerative/bacteriological (pseudomembranous)
4th: healing
What is involved in the 1st phase of mucositis (inflammatory/vascular)?
Tissue injury induces release of reactive oxygen species, proteins and cytokines, causing more damage.
What is involved in the 2nd phase of mucositis (epithelial)?
4-5 days after cytotoxic tx.
Upregulation of pro-inflammatory cytokines, tissue injury and cell death.
What is involved in 3rd phase of mucositis (ulcerative/bacteriological)
Epithelial breakdown 1 week after start of tx.
Colonisation of gram -ve mircrobes and yeast.
Release of inflammatory mediators
What is involved in the 4th phase of mucositis (healing)?
From day 12-16
Restore integrity of epithelium.
What is the degree and duration of radiotherapy induced mucositis related to?
Radiation source Cumulative dose Dose intensity Volume of irradiated mucosa Smoking & alcohol consumption Salivary hypofunction Infection
How does saliva contribute to mucositis?
Decreased production
Reduced buffering capacity
Increase in viscosity & acidity
Reduced oral IgA favoring growth of highly cariogenic and infectious oral flora.
What are the earliest signs and symptoms of mucositis?
Erythema
Oedema
Burning sensation
Inc sensitivity to hot/spicy food
What do erythematous areas (associated with mucositis) develop into?
White desquamative patches and then painful ulcers (high risk of secondary infection)
What are the most vulnerable areas for mucositis?
Movable non-keratinised mucosa of soft palate Cheeks Lips Ventral surface of tongue FOM
Does mucositis scar?
Often no scarring unless complicated by serious infection or xerostomia
What are the 4 grades of mucositis?
Grade 0: none
Grade 1: mild (sore mouth)
Grade 2: moderate (ulcers)
Grade 3: severe (can only swallow liquids)
Grade 4: life threatening (can’t eat or drink)
What is the impact of oral mucositis on QoL?
Pain Poss oral bleeding Impact on communication, speech and expression Difficultly with denture use, OH, dysgeusia, bad breath, dysphagia. Poor nutrition and hydration Oral medication difficult to take Portal for systemic infection Hospitalisation Increased cost of care
What are the 3 management objectives for mucositis?
Prevent/reduce mucositis
Alleviate symptoms
Avoid secondary complications (dehydration, infection, poor nutrition)
What factors may worsen mucositis?
Poor oral care
Ill fitting prosthesis
Ortho appliances
Defective restos
Can dentures be used in patients commencing chemoradiotherapy?
May be able to use dentures to maintain nutrition but may need to leave out if mucositis worsens. Can cause trauma, hang onto plaque and increase risk of bacteria getting into sores.
What should you do prior to pt commencing chemoradiotherapy?
Thorough assessment
Dental procedures performed at least 3 weeks before therapy
Good oral care
What is the typical mucositis and caries management for pts undergoing chemoradiotherapy?
MUCOSITIS MANAGMENT: Start difflam oral rinse at commencement of chemoradiotherapy (delays mucositis onset)
If they get mucositis, switch to 0.12% Curasept (helps keep mouth clean).
CARIES RISK MANAGMENT: Get them to use CCP and high fluoride toothpaste
What is the typical prevention regime for patients undergoing chemoradiotherapy?
Topical fluoride followed by CPP-ACP, starting 1 week before radiotherapy & continued
Foam brushes and rinses to reduce risk of microtrauma.
Avoid removable prosthesis (except while eating)
Refrain from smoking and food/drink that can cause irritation.
Saliva substitutes
Bicarb rinse after eating
Difflam, curasept
Natural yoghurt
Xylocaine gel
How should candidosis be treated?
Miconazole
Why is nystatin rubbish at treating candidosis?
Full of sugar so feeds the candida as well
Why are amphotericin b lozenges ineffective at treating candidosis in chemoradiotherapy patients?
They need saliva to dissolve them.
How can pain relief be provided for patients with mucositis?
Topical anaesthetics Difflam (anti-inflamm) Bicarb/salt rinse Systemic analgesics Crytherapy
Why is cryotherapy effective in reducing severity of oral mucositis?
Causes vasoconstriction so may reduce amount of chemotoxic agent being delivered to oral mucosa.
What mouth rinse should be used prior to development of ulceration and what should be used following?
Prior: Difflam
Following: 0.12% Curasept
What is osteoradionecrosis?
Exposed and necrotic bone associated with ulcerated or necrotic soft tissue which persists for >3months in an area that has been previously irradiated
What are the 3 classes of ORN?
Notani I: confined to dentoalveolar bone
Notani II: ORN limited to dentoalveolar bone &/or mandible above the inferior dental canal
Notani III: ORN involving the md below the inferior dental canal or pathological fracture or skin fistula.
What are the effects of ORN?
Pain Infection Loss of function Malodour Pathological md fracture Disfigurement Social isolation
What is the triad in pathophysiology of ORN?
Radiation
Trauma
Infection
Where is bacteria present in ORN?
Only present on surface of bone and not in the necrotic area.
What is theory of pathogenesis 2 for ORN?
Major driving force behind pathogenesis was hypoxia resulting in the hypoxic-hypocellular-hypovascular theory (hyperbaric oxygen is used to treat ORN)
What is radiation induced fibroatrophic theory for ORN?
Activation & deregulation of fibroblastic activity.
Imbalance between between tissue synthesis and degradation.
Results in fragile healed tissues.
Why is the buccal cortex of the mandible the most common place of ORN?
Dense bone and higher mineral content absorb a higher radiation dose.
What are risk factors for ORN?
Location (tongue, FOM, alveolar ridge, retromolar pad, tonsil) Stage of cancer Dose of radiation (>60Gy) Prior surgery for tumour in jaw Having teeth Poor OH Smoking & alcohol Poor nutrition
How can you prevent ORN post radiotherapy?
Dental exam prior to radiotherapy Perform exos 2-3 weeks prior to tx Management of OH and preventative strategies Dietary advice Regular dental recalls
What the are the guidelines for management of patients who require dento-alveolar surgery and have previously had radiotherapy or been diagnosed with ORN? (tx planning, preop, peri-op, post op).
Tx planning: informed consent, place on operating list with senior staff.
Pre-op: rinse with mouthwash containing CHX, prophylactic AB.
Peri-op: Conservative surgical technique, primary closure of soft tissues where poss.
Post-op: CHX rinse for 2 weeks, post op antibiotics for 5 days.
How should ORN be managed conservatively?
Systemic AB saved for episodes of acute infection.
Gentle removal of sequestra.
Reduction of local irritants (smoking, alcohol)
How does Pentoxfiylline-Tocopherol-Clodronate (Pentoclo) work?
Vasodilation
Inhibits inflammatory reactions
Vit E scavenges for reactive oxygen species
Inhibits osteoclastic destruction and osteolysis
How can ORN be managed surgically in advanced cases?
Radical resection and reconstructive surgery.
