DENTAL COMPLICATIONS OF HEAD & NECK RADIOTHERAPYMultidisciplinary approach in cancer treatmentDental care: early in the patient’s treatmentAims of dental care:- To prevent- To reduce side effects of radiotherapy- To promote good oral health post-radiation
Dental complications of head & neck radiotherapy
All 4 taste are affected:- Salty sensation : all over the tongue- Sweet sensation : anterior surface & tip of the tongue.- Sour sensation : lateral surfaces.- Bitter sensation : circumvallate papillaeXerostomia & Radiation-induced damage to taste buds -> Hypogeusia (2 wks after the start of radiotherapy) -> Ageusia-> partially restored 20-60days & fully restored 2-4 months post-radiation.> 60 Gy: permanent loss of taste.
Radiation-induced salivary gland acinar cellinflammation, fibrosis & degeneration 6 - 10 Gy: Hyposaliva Restored 6-12 months post-radiation.But not restored if > 50 Gy, no saliva if >70 Gy. Alteration of oral environment (candidiasis,dental caries, dysphonia, dysphagia) -> potentiallyserious systemic consequences (malnutrition).
!1. Candidiasis Most common infection during radiotherapy,post-radiation, esp. With persistent xerostomia. Acute: erythema, burning sensation,mistaken for radiation mucositis. Chronic: most common in corners of mouth.2. Cariogenic microorganism (S. mutans,Lactobacillus, Actinomyces,…) predominate
Clinically distinctive pattern:1. Smooth surfaces are the 1st affected: Circumferential caries at the ementoenamel junbction.2. Caries in many sufaces of a tooth, in many teeth3. Caries progression are fast.
TeethXerostomia -> polycaries.Decalcification ???Dental pulp: decrease in vascularity withfibrosis & atrophy -> decrease in response toinfection, trauma, yet pulpal pain is less severe.Tooth development:Prior to calcification: destroy tooth bud.Late stage of dev.: arrest growth, enamel &dentine irregularities.
Circumferentialcaries at thecementoenameljunction-> crown amputation
Osteoradionecrosis (ORN)An irreversible, progressive devitalisation of irradiated bone.A bone ischemic necrosis caused by radiation.One of the most serious sequences of radiotherapy.
Pathophysiology of ORN 1922 Regaud 1926 Ewing: Osteomyelitis in irradiated bone 1971 Titterington: Osteomyelitis secondary to irradiation 1970 Meyer: Radiation+Trauma (initiator)+Infection 1983 Marx:Microorganism may not play a pivotal role.ORN is not a primary infection of irradiated boneSpontaneous ORN may be related to higher radiation dose.However, where trauma is associated with ORN, it is caused by tooth removal (88%).
Team work: Radiation Therapy (RT)1. Determination of radiation: - Fields - Dose, how much to the jaw bones, - Salivary glands included in the RT field2. Dental therapy based on RT plan3. Patient education about oral complications4. Discussion of the importance of oral hygiene.
ORAL MANAGEMENT OF THE CANCER PATIENTS Prior to head and neck radiation therapy1. Extraoral examination: face, neck Intraoral exam: lip, buccal mucosa, gingiva, tongue, floor, palate2. Diagnosis of dental treatment: Panorex diagnosis, evaluation of dental caries, calculus & periodontal disease, endodontic & mucosa lesions.3. Dental treatment: Extraction - Prosthetic surgery – Caries removal, Smoothing of any rough or sharp surfaces - Calculus removal4. Prevent tooth demineralization and radiation caries: daily fluoride5. Oral hygiene instruction6. Tobacco & alcohol cessation, dietary counseling
)0 . . !Indications:1. Root fragment or advanced caries2. Bone pathology: periapical infection3. Advanced periodontitis4. Furcation involvement5. Erupting or unrupted teeth causing complicationAt least 14 days for tissue healing prior to radiotherapy(usually 14-21 days).
ORAL MANAGEMENT OF THE CANCER PATIENTS During radiation therapy1. Monitor patient’s oral hygiene -Keep mouth moist & clean. Treat infections2. Dietary counseling3. Monitor patient for Trismus:- Check for pain or weakness in masticating muscles.- Exercise 3 times/day X 20 times, opening as far as possible.
After radiotherapyFrequent Dental follow-up to reinforce palliative & preventive measures: Recall for the first 1-2 or 3 months, 6 months & 1 year.At each visit:- Check for mucositis (only 2-3 wks), xerostomia, demineralization & caries, signs of infection, trismus, recurrent tumor.- Emphasize oral hygieneDaily fluoride treatment: 1.1 % neutral sodium fluoride gel for 5 minutes/day. 0.4 % stannous fluoride gel
How to Use Custom Fluoride Carriers (Trays)At bedtime, Place a thin ribbon of the fluoride gel into each tray so that each tooth space has some fluoride. The fluoride can be spread into a thin film that coats the inside of the trays, by using a cotton-tipped applicator, finger or toothbrush.Seat the trays on the upper and lower teeth and let them remain in place for 5 minutes.After 5 minutes, remove the trays and thoroughly expectorate (spit out) the residual fluoride. Very Important - do not rinse mouth, drink or eat for at least 30 minutes (1 hour if possible) after fluoride use.For head and neck radiation patients, begin using fluoride in the custom trays no longer than one week after radiotherapy is completed. Repeat daily for the rest of your life!!Remember that tooth decay can occur in a matter of weeks if the fluoride is not used properly.
Care for Fluoride Carriers (Trays)Rinse and dry the trays thoroughly after each use. Clean them by brushing them with a toothbrush and toothpaste.Occasionally, the trays can be disinfected in a solution of sodium hypochlorite (Clorox) and water. Use one tablespoon of Clorox in about one- half cup of water. Soak them for about 15 minutes.If the trays become covered with hard water deposits, soak them in white vinegar overnight and brush them the next morning.Do not boil the trays or leave them in a hot car as they may warp or melt. Pamela Sandow, University of Florida College of Dentistry
After radiation therapy Mucositis- Rinse mouth with salt/bicarbonate ¼ tsp baking soda & 1/8 tsp salt in 1 cup of warm water, several times a day.- 2% viscous lidocaine, analgesics- Sip water- Avoid highly seasoned and coarse foods.- Avoid trauma (use soft-bristle toothbrush)- Maintain good oral hygiene
After radiation therapy Management of the Xerostomic Cancer Patients- Sialogogues: pilocarpine HCl, sulfarlem S25- Saliva substitutes (spray or gel)- Sip water or sugar-free liquid, use sugar-free candy- Lifelong, daily applications of topical high concentration fluoride gel.- Avoid mouth rinse with alcohol- Antimicrobials
& !Dental fillingUse topical Fluoride daily (15 min X 3 times/day)Antimicrobials: eg. ChlorexidineTreatment of xerostomiaFrequent recall visitsRefrain from taking sugar containing food & drink.
New Technology:Intensity Modulation Radiotherapy IMRT
Higher total dose (65 Gy) & dose per fraction (2.17 Gy) to theprimary tumor and involved nodes (red in 3D reconstruction andgreen color wash)Lower total (54 Gy) dose and dose per fraction (1.8 Gy) to theelective nodes (purple in 3D reconstruction & orange color wash).
Parotid gland sparing intensity-modulated radiotherapy (IMRT): A dose distribution to deliver a high dose to the target volume (blue contour and red colour wash) whilst sparing the parotid gland (pink contours) can be achieved with IMRT.
Comparison between conventional and intensity-modulated post-operative radiotherapy for stage III and IV oral cavity cancer in terms of treatment results and toxicity Wen-Cheng Chen, Oral Oncology 2008The aim of this study was to assess the treatment results and toxicity profiles of post-operative conventional radiotherapy (Conv-RT) and IMRT for stage III and IV oralcancer. During the period from 4/2002 to 12/2005, a total of 49 patients with stage IIIand IV OSCC were treated with radical surgery followed by post-operative RT. 27patients received Conv-RT while 22 received IMRT. Only 3 patients receivedadjuvant chemotherapy. With a median follow-up time of 3.3 years, the 3-year overallsurvival and disease-free survival rates for patients who received Conv-RT vs IMRTwere comparable.There was no significant difference in acute toxicity between the twodifferent RT techniques. However, in terms of late toxicity, patients receivingIMRT had significantly less moderate to severe xerostomia anddysphagia than those receiving Conv-RT (36% vs 82%, p = 0.01 forxerostomia and 21% vs 59%, p = 0.02 for dysphagia). Post-operative Conv-RT and IMRT are equally effective in terms of tumor control for locallyadvanced oral cavity cancer. Patients receiving IMRT had comparable acuteand significant less late toxicity than those receiving Conv-RT.