Radiation therapy patient treatment planning & post treatment care/dental courses

Dental managementDental management
of aof a
Radiation TherapyRadiation Therapy
PatientPatient
INDIAN DENTAL ACADEMY
Leader in continuing Dental Education
www.indiandentalacademy.comwww.indiandentalacademy.com

CONTENTSCONTENTS
INTRODUCTIONINTRODUCTION
TREATMENT RATIONALETREATMENT RATIONALE
DENTAL EXAMINATIONDENTAL EXAMINATION
PRE RADIATION CAREPRE RADIATION CARE
DENTAL CARE DURING THE THERAPYDENTAL CARE DURING THE THERAPY
POST RADIATION CAREPOST RADIATION CARE
PROSTHODONTIC CONSIDERATIONSPROSTHODONTIC CONSIDERATIONS
CONCLUSIONCONCLUSION
REFERENCESREFERENCES

IntroductionIntroduction
Role of Prosthodontist in improving qualityRole of Prosthodontist in improving quality
of head and neck cancer patients is wellof head and neck cancer patients is well
recognized.recognized.
Prior to the early 1960’s: Ablative surgeryPrior to the early 1960’s: Ablative surgery
Challenged with the task of developingChallenged with the task of developing
treatment regimes for the oraltreatment regimes for the oral
complications associated with radiationcomplications associated with radiation
therapy.therapy.

National institute of Health noted in aNational institute of Health noted in a
consensus development statement :consensus development statement :
““ At a minimum, oral complications are painful,At a minimum, oral complications are painful,
diminish the quality of life, and lead todiminish the quality of life, and lead to
significant compliance problems, oftensignificant compliance problems, often
discouraging patient from treatmentdiscouraging patient from treatment””
Significance of the need of a dentalSignificance of the need of a dental
oncologistoncologist

Principles of radiation therapyPrinciples of radiation therapy
Radiation therapy is defined as theRadiation therapy is defined as the
therapeutic use of ionizing radiation.therapeutic use of ionizing radiation.
Types:Types:

Electromagnetic (photon) radiationElectromagnetic (photon) radiation
X-raysX-rays
Gamma RaysGamma Rays

Particulate radiationParticulate radiation

Cell DeathCell Death
Reproductive cell death Interphase (Direct) cell death

Treatment rationaleTreatment rationale
Preventing the risk of infection duringPreventing the risk of infection during
active phase of chemotherapyactive phase of chemotherapy
Reducing the potential for both short term-Reducing the potential for both short term-
and long term problems in the irradiatedand long term problems in the irradiated
patient.patient.

Ideally, the dental examination and theIdeally, the dental examination and the
necessary dental treatment should benecessary dental treatment should be
performed prior to the onset of theperformed prior to the onset of the
definitive cancer treatment.definitive cancer treatment.
Complete co-operation from theComplete co-operation from the
physician oncologist.physician oncologist.

MucositisMucositis
XerostomiaXerostomia
Change in oralChange in oral
microfloramicroflora
Loss of tasteLoss of taste
Increased sensitivityIncreased sensitivity
to spicy or strongto spicy or strong
tasting foodstasting foods
Reduced potential forReduced potential for
bone healingbone healing
Risk of developingRisk of developing
osteoradionecrosisosteoradionecrosis
Trismus (muscularTrismus (muscular
fibrosis)fibrosis)
SHORT TERM EFFECTS LONG TERM EFFECTS

Understanding the Oral OncologyUnderstanding the Oral Oncology
patientpatient
Dentist’s role:Dentist’s role:

Gain patient’s confidenceGain patient’s confidence

Establish a position as an informationEstablish a position as an information
sourcesource

Explain the causes of concernExplain the causes of concern

Emphasize the importance of totalEmphasize the importance of total
commitment to the treatment regimenscommitment to the treatment regimens
proposed.proposed.
The initial dental appointmentThe initial dental appointment

Make the patient have a basicMake the patient have a basic
understanding of the long and shortunderstanding of the long and short
term effects of radiation therapy.term effects of radiation therapy.

Dental Examination andDental Examination and
Treatment PlanTreatment Plan
Full-mouth or panoramic radiographsFull-mouth or panoramic radiographs
Comprehensive clinical examinationComprehensive clinical examination

periodontiumperiodontium

oral soft tissuesoral soft tissues
Assessment of the patient's oralAssessment of the patient's oral
hygienehygiene
Examine carefully for dental cariesExamine carefully for dental caries

Perform Dental prophylaxisPerform Dental prophylaxis
Review oral hygiene proceduresReview oral hygiene procedures
Place Definitive restorationsPlace Definitive restorations
Teeth considered non restorable orTeeth considered non restorable or
non salvageable with endodonticnon salvageable with endodontic
therapy should be extracted.therapy should be extracted.
Diagnosis & treatment plan

Healing period of atleastHealing period of atleast 10 days to10 days to
3 weeks3 weeks is essential before radiationis essential before radiation
treatment begins.treatment begins.
Proposed extractions must be discussedProposed extractions must be discussed
with the radiation oncologist and anwith the radiation oncologist and an
understanding readied regarding the timeunderstanding readied regarding the time
available for healing.available for healing.

When surgical removal of a tumor isWhen surgical removal of a tumor is
planned prior to radiation, teeth can beplanned prior to radiation, teeth can be
conveniently removed in the operatingconveniently removed in the operating
room at the time of tumor surgery, thusroom at the time of tumor surgery, thus
ensuring an adequate healing period.ensuring an adequate healing period.
Teeth be removedTeeth be removed withwith minimal traumaminimal trauma
and the extraction sites beand the extraction sites be closedclosed
primarilyprimarily..

Antibiotic coverage may improve theAntibiotic coverage may improve the
potential for healing in the case ofpotential for healing in the case of
diabetics and other medicallydiabetics and other medically
compromised individuals.compromised individuals.

To Extract or not to ExtractTo Extract or not to Extract
Following radiation treatment:Following radiation treatment:

Increased risk of osteoradionecrosisIncreased risk of osteoradionecrosis

Wound healing compromisedWound healing compromised

Extensive periodontal surgery contraindicatedExtensive periodontal surgery contraindicated

Periodontally involved teeth exhibiting moderatePeriodontally involved teeth exhibiting moderate
to severe mobility should also be considered forto severe mobility should also be considered for
removal.removal.
Some thought must be given to the long-termSome thought must be given to the long-term
prognosis of the teeth in question.prognosis of the teeth in question.
The patient's ability and willingness to performThe patient's ability and willingness to perform
all recommended oral hygiene procedures willall recommended oral hygiene procedures will
also help determine which teeth can bealso help determine which teeth can be
maintained.maintained.

In questionable situations, it isIn questionable situations, it is
perhaps more prudent to err on theperhaps more prudent to err on the
side of aggressive tooth removalside of aggressive tooth removal

Decision to extract all remainingDecision to extract all remaining
teethteeth
Patient rendered completely edentulousPatient rendered completely edentulous
with no previous denture experience maywith no previous denture experience may
find the process of adjusting to completefind the process of adjusting to complete
dentures a difficult one.dentures a difficult one.
Soft tissues within the radiated field will beSoft tissues within the radiated field will be
easily irritated by the prosthesis.easily irritated by the prosthesis.
Lack of salivaLack of saliva

Consider maintaining strategically positioned,Consider maintaining strategically positioned,
periodontally sound teeth to be used asperiodontally sound teeth to be used as
abutments for removable partial dentures orabutments for removable partial dentures or
complete overdenturescomplete overdentures

Radical alveolectomiesRadical alveolectomies
Removal of tori and exostosesRemoval of tori and exostoses

Partially erupted or impactedPartially erupted or impacted
third molarsthird molars
Amount of time the physician oncologist is willingAmount of time the physician oncologist is willing
to allow for healing.to allow for healing.
Impactions requiring extensive bone removalImpactions requiring extensive bone removal
may take longer to heal and are at greater riskmay take longer to heal and are at greater risk
for infection, necessitating a possible delay infor infection, necessitating a possible delay in
the start of the radiation treatment.the start of the radiation treatment.
These extractions may be a greater problem inThese extractions may be a greater problem in
the older, physically compromised individualthe older, physically compromised individual
compared with a younger, healthier patient.compared with a younger, healthier patient.

Since the fully impacted tooth does notSince the fully impacted tooth does not
precipitate many major, immediateprecipitate many major, immediate
problems following radiation, the decisionproblems following radiation, the decision
to extract or not extract these teeth canto extract or not extract these teeth can
only be reached after careful review of allonly be reached after careful review of all
factors.factors.

Partially erupted teethPartially erupted teeth

previous episodes of pericoronal infectionsprevious episodes of pericoronal infections
Following radiation:Following radiation:

Trismus will limit accessTrismus will limit access

Surgery will result in a risk of compromisedSurgery will result in a risk of compromised
wound healingwound healing
It is certainly an advantage to extract theseIt is certainly an advantage to extract these
partially erupted teeth prior to radiation.partially erupted teeth prior to radiation.

Pre Radiation ProsthodonticPre Radiation Prosthodontic
CareCare
In case of previous denture wearers,In case of previous denture wearers,
regardless of the condition of theregardless of the condition of the
dentures, little definitive prosthodonticdentures, little definitive prosthodontic
care is necessary prior to radiation.care is necessary prior to radiation.

Severity of resulting mucositisSeverity of resulting mucositis

Substantial weight lossSubstantial weight loss

There is little advantage to relining ill-There is little advantage to relining ill-
fitting dentures since the procedure canfitting dentures since the procedure can
be moderately expensive and will not bebe moderately expensive and will not be
a factor in patient comfort during variousa factor in patient comfort during various
stages of mucositis.stages of mucositis.
Soft, temporary reline materials, becauseSoft, temporary reline materials, because
of their surface porosity andof their surface porosity and
abrasiveness, make hygiene proceduresabrasiveness, make hygiene procedures
difficult, serve as a potential reservoir fordifficult, serve as a potential reservoir for
fungal growth, and may be a source offungal growth, and may be a source of
additional mucosal discomfort.additional mucosal discomfort.
Pre Radiation care

All these factors warrant the fabricationAll these factors warrant the fabrication
of new dentures once radiation therapyof new dentures once radiation therapy
is complete.is complete.
Pre Radiation care

Patients are advised that they will bePatients are advised that they will be
better served by not wearingbetter served by not wearing
denturesdentures during therapy.during therapy.
The patient must be cautioned thatThe patient must be cautioned that
continuing to wear the dentures maycontinuing to wear the dentures may
be the source of significant additionalbe the source of significant additional
mucosal irritation and lead to delayedmucosal irritation and lead to delayed
healing following the completion ofhealing following the completion of
radiation therapy.radiation therapy.
Pre Radiation care

Dentate patients with metallic crowns orDentate patients with metallic crowns or
fixed partial dentures in the treatment fieldfixed partial dentures in the treatment field
may suffer significant irritation to adjacentmay suffer significant irritation to adjacent
soft tissue as a result of backscatter.soft tissue as a result of backscatter.
Use of shieldUse of shield
Pre Radiation care

An increasing number of patients withAn increasing number of patients with
dental implants are being seen atdental implants are being seen at
treatment centers. Much controversytreatment centers. Much controversy
exists regarding the need to remove theexists regarding the need to remove the
implants before radiation.implants before radiation.
Pre Radiation care

Dental Management DuringDental Management During
Radiation TherapyRadiation Therapy
MucositisMucositis
Xerostomia and Dental cariesXerostomia and Dental caries
Trismus and FibrosisTrismus and Fibrosis
Shielding and Positioning stentsShielding and Positioning stents

MucositisMucositis
One of the earliest effects of radiationOne of the earliest effects of radiation

MucositisMucositis

Acute mucositis begins during the second or third week of radiation
therapy and subsides within 8 to 10 weeks once treatment is
completed.
MucositisMucositis

Resulting pain and dysphagia make it difficult forResulting pain and dysphagia make it difficult for
the patient to eat a well balanced diet, resultingthe patient to eat a well balanced diet, resulting
in what may be a significant weight loss. It mayin what may be a significant weight loss. It may
be necessary to interrupt therapy if the weightbe necessary to interrupt therapy if the weight
loss becomes critical.loss becomes critical.
MucositisMucositis

Severity of the mucositis is influenced by aSeverity of the mucositis is influenced by a
number of factors and is not alwaysnumber of factors and is not always
predictable. Patients with a history ofpredictable. Patients with a history of
alcohol abuse or smoking, for example,alcohol abuse or smoking, for example,
who continue these habits during radiationwho continue these habits during radiation
suffer the greatest morbidity.suffer the greatest morbidity.
MucositisMucositis

Methods to help alleviate theMethods to help alleviate the
patient’s discomfortpatient’s discomfort
Most significant being good oral hygieneMost significant being good oral hygiene
(Flemming 1990)(Flemming 1990)
Frequent daily cleaning of the teeth with aFrequent daily cleaning of the teeth with a
soft brush and mild tasting toothpaste.soft brush and mild tasting toothpaste.
MucositisMucositis

Frequent oral rinses with aFrequent oral rinses with a combination ofcombination of
salt and sodium bicarbonate in water orsalt and sodium bicarbonate in water or
dilute solutions of hydrogen peroxide anddilute solutions of hydrogen peroxide and
waterwater
Other therapies have included rinsing withOther therapies have included rinsing with
Benadryl elixirs, sucrafate solutions, andBenadryl elixirs, sucrafate solutions, and
topicaltopical anesthetics.anesthetics.
MucositisMucositis

Occurs rapidly during the first week or two ofOccurs rapidly during the first week or two of
treatmenttreatment
Gradually returns to normal once the treatmentGradually returns to normal once the treatment
course is completed.course is completed.
Possible contributing factors:Possible contributing factors:

Damage to taste buds and microvilliDamage to taste buds and microvilli

Disrupted innervation as a result of the radiationDisrupted innervation as a result of the radiation

Lack of salivaLack of saliva
Additional cause of weight loss during therapy.Additional cause of weight loss during therapy.

Changes in the quantity and quality of salivaChanges in the quantity and quality of saliva
as a result of radiation have beenas a result of radiation have been
documented in the dental literature (Brown etdocumented in the dental literature (Brown et
al, 1978).al, 1978). www.indiandentalacademy.comwww.indiandentalacademy.com

Beginning withBeginning with
the first course ofthe first course of
treatment,treatment,
salivary flow ratessalivary flow rates
decrease,decrease,
eventuallyeventually
reaching as lowreaching as low
as 1% of normal.as 1% of normal.

The patient experiences a need toThe patient experiences a need to
continually lubricate the mouth and iscontinually lubricate the mouth and is
forced to ingest large quantities of fluid toforced to ingest large quantities of fluid to
aid in swallowing at mealtimes.aid in swallowing at mealtimes.
There is a disconcerting change in eatingThere is a disconcerting change in eating
habits with an increased intake of soft,habits with an increased intake of soft,
moist foods.moist foods.

Food debris accumulates on the oralFood debris accumulates on the oral
mucosa and teeth because of themucosa and teeth because of the
absence of theabsence of the self-cleansing actionself-cleansing action
of saliva, making oral hygiene muchof saliva, making oral hygiene much
more difficult.more difficult.

Attempts have been made to stimulateAttempts have been made to stimulate
salivary flow rates with sialogogues such assalivary flow rates with sialogogues such as
pilocarpine and antholetrithione (Fox et al,pilocarpine and antholetrithione (Fox et al,
1986).1986).
There is no concrete evidence that the drugsThere is no concrete evidence that the drugs
are effective in those individuals receivingare effective in those individuals receiving
high doses of radiation to all major salivaryhigh doses of radiation to all major salivary
glands.glands.

Saliva substitutes have been developed inSaliva substitutes have been developed in
an effort to alleviate the discomfort andan effort to alleviate the discomfort and
harmful effects of xerostomia.harmful effects of xerostomia.
These products consist primarily ofThese products consist primarily of
carboxymethylcellulose with various saltscarboxymethylcellulose with various salts
and flavoring agents added.and flavoring agents added.

Results with the use of the substitutes areResults with the use of the substitutes are
mixed, related more to the subjectivemixed, related more to the subjective
preference of the patient than to anypreference of the patient than to any
appreciable therapeutic effect.appreciable therapeutic effect.

Along with xerostomia, there is aAlong with xerostomia, there is a
concomitant increase in the numbers ofconcomitant increase in the numbers of
acidogenic and cariogenicacidogenic and cariogenic
microorganisms and a decrease inmicroorganisms and a decrease in
noncariogenic microorganisms resulting innoncariogenic microorganisms resulting in
a severe, aggressive form of dental caries.a severe, aggressive form of dental caries.
Radiation cariesRadiation caries

The most effective method of treating thisThe most effective method of treating this
condition was through the daily use of topicalcondition was through the daily use of topical
applications of fluoride (Dreizen et al, 1977).applications of fluoride (Dreizen et al, 1977).
Both stannous or sodium fluoride have beenBoth stannous or sodium fluoride have been
used in a variety of forms (gels, rinses, andused in a variety of forms (gels, rinses, and
toothpastes) with significant success.toothpastes) with significant success.
Gels used with a tray are reported to betterGels used with a tray are reported to better
cover all tooth surfaces than either fluoridecover all tooth surfaces than either fluoride
rinses or gels applied with a brush.rinses or gels applied with a brush.

Neutral sodium fluoride
preferred over stannous
fluoride which can be
more irritating.

The use of a tray as a carrier simplifies theThe use of a tray as a carrier simplifies the
fluoride application procedure andfluoride application procedure and
improves patient compliance, achieving aimproves patient compliance, achieving a
better overall effect.better overall effect.

Patients must be made to understand thatPatients must be made to understand that
they will need to use fluoride once a day,they will need to use fluoride once a day,
every day for the remainder of their lives.every day for the remainder of their lives.
Discontinuing the fluoride applications,Discontinuing the fluoride applications,
even for short periods of time, may resulteven for short periods of time, may result
in renewed cariogenic activity.in renewed cariogenic activity.

Begins shortly after radiation begins.Begins shortly after radiation begins.
Clinically, the patient gradually loses the abilityClinically, the patient gradually loses the ability
to open the mouth.to open the mouth.
The condition may be exacerbated by surgeryThe condition may be exacerbated by surgery
prior to radiation and by radiation fields whichprior to radiation and by radiation fields which
include muscle of mastication or the TMJ.include muscle of mastication or the TMJ.

TrismusTrismus

It may make eating difficult and theIt may make eating difficult and the
performance of dental procedures almostperformance of dental procedures almost
impossible.impossible.
TrismusTrismus

Primary treatmentPrimary treatment
involves exercising theinvolves exercising the
muscles.muscles.
Positive results arePositive results are
more easily attainedmore easily attained
with dentate patient.with dentate patient.
ImprovementImprovement
regardless of theregardless of the
exercise program is notexercise program is not
permanent and maypermanent and may
regress over a period ofregress over a period of
even a few hours.even a few hours.
TrismusTrismus

Use of Tongue bladesUse of Tongue blades
The simplest and theThe simplest and the
least expensiveleast expensive
methodmethod
A number of tongueA number of tongue
blades are placed onblades are placed on
the occlusal surfacethe occlusal surface
of posterior teeth.of posterior teeth.
The patient isThe patient is
instructed to pauseinstructed to pause
for a few minutesfor a few minutes
before placing eachbefore placing each
additional blade.additional blade.
TrismusTrismus

As trismus becomes chronic, there is anAs trismus becomes chronic, there is an
appreciable amount of discomfort involved inappreciable amount of discomfort involved in
performing the exercises, regardless of theperforming the exercises, regardless of the
method used, resulting in patientmethod used, resulting in patient
noncompliance.noncompliance.
Chronic trismus gradually becomes fibrosis ofChronic trismus gradually becomes fibrosis of
the elevator muscles and at this late stage is notthe elevator muscles and at this late stage is not
amenable to stretching as a solution.amenable to stretching as a solution.
Exercise must begin early in treatment, andExercise must begin early in treatment, and
results are predicated on the patient'sresults are predicated on the patient's
willingness to cope with the exercise regimen.willingness to cope with the exercise regimen.
TrismusTrismus

Shielding and PositioningShielding and Positioning
StentsStents
In an effort to minimize morbidity associatedIn an effort to minimize morbidity associated
with radiation to the oral cavity, soft tissueswith radiation to the oral cavity, soft tissues
not directly involved with tumor can benot directly involved with tumor can be
displaced or shielded (Kaanders et al, 1992).displaced or shielded (Kaanders et al, 1992).
Frequent use of a tongue blade taped to aFrequent use of a tongue blade taped to a
cork, for example, when treating lesions incork, for example, when treating lesions in
involving the tongue. This simple device, ininvolving the tongue. This simple device, in
effect, lowers the mandible and tongue,effect, lowers the mandible and tongue,
preventing radiation to the non affectedpreventing radiation to the non affected
parotid gland and maxilla to some degree.parotid gland and maxilla to some degree.

Over time, dental oncologists inOver time, dental oncologists in
cooperation with radiation therapists havecooperation with radiation therapists have
developed more sophisticated shieldingdeveloped more sophisticated shielding
and positioning devices that have provenand positioning devices that have proven
to be useful in limiting radiation effects.to be useful in limiting radiation effects.

Positioning StentsPositioning Stents
One of the most frequently used positioningOne of the most frequently used positioning
stents serves to lower the tongue and places it instents serves to lower the tongue and places it in
a repeatable position during therapy.a repeatable position during therapy.
Since the stent also serves to separate theSince the stent also serves to separate the
mandible and maxilla in an open position,mandible and maxilla in an open position,
maxillary structures such as the palate, uppermaxillary structures such as the palate, upper
gingiva, and buccal mucosa are spared radiationgingiva, and buccal mucosa are spared radiation
effects.effects.

Maxillary and mandibular impressions areMaxillary and mandibular impressions are
made with irreversible hydrocolloid.made with irreversible hydrocolloid.
In the case of the completely edentulousIn the case of the completely edentulous
patient, the impressions must be properlypatient, the impressions must be properly
extended to ensure stability of the finalizedextended to ensure stability of the finalized
bases.bases.
Positioning stentsPositioning stents

An interocclusal record is obtained at theAn interocclusal record is obtained at the
widest opening necessary to ensure thatwidest opening necessary to ensure that
maxillary structures are not included in themaxillary structures are not included in the
treatment field.treatment field.
Casts are recovered and mounted on aCasts are recovered and mounted on a
simple articulator.simple articulator.

Baseplate wax is softened and placed over the incisal
and occlusal surfaces of all the teeth.
Two pillars that join the maxillary and mandibular
segments and maintain the open interocclusal
relationship are fabricated in wax.

Two sheets of baseplate wax are then attached to
the right and left sides of the mandibular
segment. This flat sheet extends posteriorly as far
as tolerable, covering the entire tongue and
maintaining it in the appropriate treatment
position.

An opening in the anterior portion of the
stent between the pillars acts as a shell
upon which the tip of the tongue rests and
serves to help maintain a repeatable
tongue position.

Shielding StentsShielding Stents
It is possible when treating tumorsIt is possible when treating tumors
of the buccal mucosa, skin, orof the buccal mucosa, skin, or
alveolar ridge with electron beamalveolar ridge with electron beam
therapy to protect uninvolvedtherapy to protect uninvolved
adjacent structures by means of aadjacent structures by means of a
shielding stent.shielding stent.

It is known that a 1 cm thickness of aIt is known that a 1 cm thickness of a
Lipowitz alloy (Cerrobend, CerrometalLipowitz alloy (Cerrobend, Cerrometal
Products, Bellefort, PA) consisting ofProducts, Bellefort, PA) consisting of
silver, copper, tin, antimony, and lead willsilver, copper, tin, antimony, and lead will
effectively reduce an 18 MeV electroneffectively reduce an 18 MeV electron
beam by approximately 95%.beam by approximately 95%.
The metal is only effective, however, whenThe metal is only effective, however, when
electrons are used.electrons are used.
Shielding stentsShielding stents

Generally, an acrylic resin stent is made.Generally, an acrylic resin stent is made.
A portion of the stent is removed and theA portion of the stent is removed and the
metal is heated, poured into the preparedmetal is heated, poured into the prepared
recess, and allowed to cool.recess, and allowed to cool.
The metal is then covered with a layer ofThe metal is then covered with a layer of
acrylic resin to prevent back scatter toacrylic resin to prevent back scatter to
adjacent tissue.adjacent tissue.

Maxillary and mandibular impressions are madeMaxillary and mandibular impressions are made
using a combination of modeling plastic andusing a combination of modeling plastic and
irreversible hydrocolloid in an effort to displaceirreversible hydrocolloid in an effort to displace
the tongue laterally.the tongue laterally.
An interocclusal wax record is made in centricAn interocclusal wax record is made in centric
relation at a slightly opened vertical dimension.relation at a slightly opened vertical dimension.
The impressions are poured and the recoveredThe impressions are poured and the recovered
casts are mounted on a simple articulator in thecasts are mounted on a simple articulator in the
open position.open position.

Baseplate-wax is placed over the mandibularBaseplate-wax is placed over the mandibular
teeth on the side to be treated, and theteeth on the side to be treated, and the
articulator is closed to form an index of botharticulator is closed to form an index of both
maxillary and mandibular teeth.maxillary and mandibular teeth.
A wax bolus is formed and attached to theA wax bolus is formed and attached to the
occlusal index. The bolus should extendocclusal index. The bolus should extend
approximately 1 to 2 cm lingually and contactapproximately 1 to 2 cm lingually and contact
both the palate and the floor of the mouth.both the palate and the floor of the mouth.
The lingual surface of the stent is made as flatThe lingual surface of the stent is made as flat
as possible.as possible.

The waxed stent should be tried in the mouth toThe waxed stent should be tried in the mouth to
confirm appropriate extension posteriorly andconfirm appropriate extension posteriorly and
sufficient displacement of the tongue.sufficient displacement of the tongue.
Once the shape has been confirmed, the waxedOnce the shape has been confirmed, the waxed
stent is flasked and processed in clear, heat-stent is flasked and processed in clear, heat-
cured or autopolymerizing acrylic resin.cured or autopolymerizing acrylic resin.
The stent is recovered and polished as carefullyThe stent is recovered and polished as carefully
as possible, making certain that no sharp edgesas possible, making certain that no sharp edges
or rough surfaces exist.or rough surfaces exist.

A recess, extending within 8 to 10 mm of theA recess, extending within 8 to 10 mm of the
entire circumference of the stent, is cut into theentire circumference of the stent, is cut into the
resin to an appropriate uniform depth dependentresin to an appropriate uniform depth dependent
on the megavoltage of the electrons to be used.on the megavoltage of the electrons to be used.
The Cerrobend is heated and the molten metalThe Cerrobend is heated and the molten metal
poured in the hollowed portion of the stent. Thepoured in the hollowed portion of the stent. The
metal melts at 158°F, at which temperature themetal melts at 158°F, at which temperature the
acrylic resin will not be damaged.acrylic resin will not be damaged.

After cooling, the patient's name can be cut intoAfter cooling, the patient's name can be cut into
the metal surface with a round bur forthe metal surface with a round bur for
identification purposes.identification purposes.
The exposed metal is covered with additionalThe exposed metal is covered with additional
acrylic resin to prevent the metal from contactingacrylic resin to prevent the metal from contacting
mucosal surfaces and to minimize backscatter.mucosal surfaces and to minimize backscatter.
The completed stent is tried in the mouth inThe completed stent is tried in the mouth in
consultation with the radiation therapist.consultation with the radiation therapist.

Dental Management FollowingDental Management Following
RadiationRadiation
Mucositis and Loss of TasteMucositis and Loss of Taste
Xerostomia and dental cariesXerostomia and dental caries
CandidiasisCandidiasis
Dental ExtractionsDental Extractions
OsteoradionecrosisOsteoradionecrosis

Xerostomic conditions and the change inXerostomic conditions and the change in
normal oral flora are thought to be thenormal oral flora are thought to be the
causes of increased propensity for thiscauses of increased propensity for this
infectioninfection
One of the early symptoms is anOne of the early symptoms is an
abnormally sore or burning mouth.abnormally sore or burning mouth.

Clinical examination mayClinical examination may
reveal some generalizedreveal some generalized
inflammation involving theinflammation involving the
palate and cheeks, butpalate and cheeks, but
lacking the whitishlacking the whitish
patches generallypatches generally
associated with Candida.associated with Candida.
Since irradiated tissueSince irradiated tissue
may chronically exhibitmay chronically exhibit
some erythema, bacterialsome erythema, bacterial
and fungal culturesand fungal cultures
should be taken toshould be taken to
confirm the presence ofconfirm the presence of
Candida.Candida.

If cultures are positive for the fungus,If cultures are positive for the fungus,
troches or rinses containing chlotrimazole ortroches or rinses containing chlotrimazole or
nystatin are prescribed.nystatin are prescribed.
It has been suggested that meticulous oralIt has been suggested that meticulous oral
hygiene and frequent rinsing with salt andhygiene and frequent rinsing with salt and
soda or dilute solutions of hydrogen peroxidesoda or dilute solutions of hydrogen peroxide
may have a preventive effect.may have a preventive effect.
Some clinicians have reported daily rinsesSome clinicians have reported daily rinses
with chlorhexidine to be beneficial.with chlorhexidine to be beneficial.

Clinical experience has demonstrated thatClinical experience has demonstrated that
Candida may be harbored in or on theCandida may be harbored in or on the
surface of dentures or obturators and playsurface of dentures or obturators and play
a role in chronic reinfection.a role in chronic reinfection.
Soaking prostheses in an antifungalSoaking prostheses in an antifungal
solution of dilute hypochlorite for completesolution of dilute hypochlorite for complete
dentures has proven to be an effectivedentures has proven to be an effective
preventative measure.preventative measure.

Patients receiving cancericidal doses ofPatients receiving cancericidal doses of
radiation to the mandible or maxilla experienceradiation to the mandible or maxilla experience
diminished ability to heal when even mild traumadiminished ability to heal when even mild trauma
causes loss of mucosal integrity and subsequentcauses loss of mucosal integrity and subsequent
exposure of devitalized bone. This condition,exposure of devitalized bone. This condition,
defined as osteoradionecrosis (ORN).defined as osteoradionecrosis (ORN).
Any oral surgery procedures performed followingAny oral surgery procedures performed following
radiation may result in delayed wound healingradiation may result in delayed wound healing
accompanied by considerable pain andaccompanied by considerable pain and
discomfort.discomfort.

Well-planned surgical studies usingWell-planned surgical studies using
antibiotics and precise techniques reportantibiotics and precise techniques report
incidences of ORN from as little as 1% toincidences of ORN from as little as 1% to
as high as 30%.as high as 30%.

It has been suggested that extremelyIt has been suggested that extremely
mobile, periodontally compromised teethmobile, periodontally compromised teeth
can be safely minimal risk of developingcan be safely minimal risk of developing
ORN.ORN.
Localized periapical or periodontalLocalized periapical or periodontal
infection can be managed conservativelyinfection can be managed conservatively
with antibiotics, avoiding the immediatewith antibiotics, avoiding the immediate
need for tooth removal.need for tooth removal.

In situations involving single teeth, endodonticsIn situations involving single teeth, endodontics
should be considered an option even when theshould be considered an option even when the
tooth is considered non restorable. Followingtooth is considered non restorable. Following
endodontic therapy, the badly decayed toothendodontic therapy, the badly decayed tooth
crown is amputated to prevent irritation to thecrown is amputated to prevent irritation to the
tongue or cheek and the exposed portion of thetongue or cheek and the exposed portion of the
root canal is scaled with a permanentroot canal is scaled with a permanent
restoration. A tooth managed in this mannerrestoration. A tooth managed in this manner
may serve no function but, more important,may serve no function but, more important,
extraction is avoided.extraction is avoided.

Teeth located in areas not included in theTeeth located in areas not included in the
radiation fields can be extracted safely.radiation fields can be extracted safely.
All too frequently, patients present whoAll too frequently, patients present who
have need of multiple extractions.With thehave need of multiple extractions.With the
use of hyperbaric oxygen, extensive oraluse of hyperbaric oxygen, extensive oral
surgery can be performed with asurgery can be performed with a
substantially diminished risk of necrosissubstantially diminished risk of necrosis
(Marx, 1983).(Marx, 1983).

Hyperbaric protocols involve a series of upHyperbaric protocols involve a series of up
to 20 "dives" before and after surgery in ato 20 "dives" before and after surgery in a
small, sealed hyperbaric chamber. Eachsmall, sealed hyperbaric chamber. Each
daily dive is 90 minutes long.daily dive is 90 minutes long.
Teeth are extracted following the initial 20Teeth are extracted following the initial 20
dives.dives.

Extractions are generally performed in theExtractions are generally performed in the
operating room.operating room.
Necessary surgery including extractions,Necessary surgery including extractions,
alveolectomies, and tori removal arealveolectomies, and tori removal are
completed using atraumatic technique.completed using atraumatic technique.
The wounds are closed primarily.The wounds are closed primarily.

Following the surgical procedures, theFollowing the surgical procedures, the
patient returns for the completion of thepatient returns for the completion of the
second phase of the hyperbaricsecond phase of the hyperbaric
protocol.protocol.
Additional dives may be necessary ifAdditional dives may be necessary if
wound healing is not complete.wound healing is not complete.

It has been proposed in the past that ORNIt has been proposed in the past that ORN
may result from trauma, exposure ofmay result from trauma, exposure of
radiated bone, and infection.radiated bone, and infection.
Others have more recently advocated thatOthers have more recently advocated that
the cause may be related to thethe cause may be related to the
hypovascular, hypocellular, and hypoxichypovascular, hypocellular, and hypoxic
conditions that exist in bone followingconditions that exist in bone following
radiation.radiation.

Although trauma is thought by some to beAlthough trauma is thought by some to be
a necessary initiating factor, numerousa necessary initiating factor, numerous
spontaneous cases of ORN have beenspontaneous cases of ORN have been
reported.reported.
The type of radiation treatment employed,The type of radiation treatment employed,
dosage, and tissue volume involved aredosage, and tissue volume involved are
also considered contributing factors.also considered contributing factors.

Clinical observation indicates ORN isClinical observation indicates ORN is
more prevalent in the mandible thanmore prevalent in the mandible than
maxilla.maxilla.
Improved radiation techniques and betterImproved radiation techniques and better
cooperation between dentist and radiationcooperation between dentist and radiation
oncologist have reduced the incidences ofoncologist have reduced the incidences of
ORN from highs in the 1960s of 32% toORN from highs in the 1960s of 32% to
about 9% today.about 9% today.

Clinical examination will generally reveal aClinical examination will generally reveal a
soft tissue ulcer and an area of exposedsoft tissue ulcer and an area of exposed
bone.bone.
Any such wound should be viewed withAny such wound should be viewed with
suspicion, and the possibility of recurrentsuspicion, and the possibility of recurrent
tumor must be ruled out.tumor must be ruled out.

Initial treatment should be conservative.Initial treatment should be conservative.
The lesion is carefully cleansed and anyThe lesion is carefully cleansed and any
small sequestered bony fragments aresmall sequestered bony fragments are
carefully removed.carefully removed.
Oral hygiene procedures are reviewed andOral hygiene procedures are reviewed and
the patient is asked to rinse frequently withthe patient is asked to rinse frequently with
dilute hydrogen peroxide or a salt anddilute hydrogen peroxide or a salt and
soda solution in an effort to keep the areasoda solution in an effort to keep the area
moist and clean.moist and clean.

Dentures, if present, are relieved over theDentures, if present, are relieved over the
affected area, and the patient may beaffected area, and the patient may be
cautioned to use the dentures only whilecautioned to use the dentures only while
eating.eating.
Conversely, it is thought by some that theConversely, it is thought by some that the
denture serves to protect the wound anddenture serves to protect the wound and
prevent further irritation from movementsprevent further irritation from movements
of the tongue.of the tongue.

Following initial treatment, the patient isFollowing initial treatment, the patient is
seen at frequent intervals to evaluate theseen at frequent intervals to evaluate the
wound and reinforce home carewound and reinforce home care
procedures.procedures.
When sequestra are evident, they may beWhen sequestra are evident, they may be
judiciously removed and the area keptjudiciously removed and the area kept
smooth to avoid irritation to surroundingsmooth to avoid irritation to surrounding
tissues.tissues.

Unfortunately, healing does not alwaysUnfortunately, healing does not always
occur with conservative treatment.occur with conservative treatment.
The non responsive affected area willThe non responsive affected area will
enlarge with time, be subject to moreenlarge with time, be subject to more
frequent severe infection, and causefrequent severe infection, and cause
considerable pain.considerable pain.
Pathologic fracture of the mandible mayPathologic fracture of the mandible may
also be a finding.also be a finding.

In these situations the patient is referred forIn these situations the patient is referred for
hyperbaric oxygen therapy.hyperbaric oxygen therapy.
After the initial series of dives, surgery, in mostAfter the initial series of dives, surgery, in most
instances, is performed followed by a secondinstances, is performed followed by a second
series of dives.series of dives.
Substantial portions of the mandible may beSubstantial portions of the mandible may be
removed leading to discontinuity defects.removed leading to discontinuity defects.
Mandibular reconstruction using microvascularMandibular reconstruction using microvascular
surgical techniques may be necessary to restoresurgical techniques may be necessary to restore
patient function.patient function.

Prosthodontic ManagementProsthodontic Management
Patients treated with radiation sufferPatients treated with radiation suffer
substantial changes to the oral mucosasubstantial changes to the oral mucosa
and are often candidates for newand are often candidates for new
complete or partial dentures.complete or partial dentures.
The oral soft tissue must be adequatelyThe oral soft tissue must be adequately
healed before necessary prosthodontichealed before necessary prosthodontic
procedures can be initiated.procedures can be initiated.

Since trauma caused by denturesSince trauma caused by dentures
may increase the potential risk ofmay increase the potential risk of
mucosal irritation and subsequentmucosal irritation and subsequent
bone exposure, some havebone exposure, some have
suggested waiting at least 6 monthssuggested waiting at least 6 months
to a year before dentures areto a year before dentures are
contemplated.contemplated.
Prosthodontic management

Clinical experience has demonstrated thatClinical experience has demonstrated that
dentures can be made for somedentures can be made for some
individuals in a matter of 2 or 3 monthsindividuals in a matter of 2 or 3 months
following radiation with little complication.following radiation with little complication.
Conversely, some patients will never wearConversely, some patients will never wear
dentures successfully because of radiationdentures successfully because of radiation
effects.effects.

Dentures should be carefully fabricatedDentures should be carefully fabricated
using conventional prosthodonticsusing conventional prosthodontics
techniques.techniques.
The dentist may be well served by using aThe dentist may be well served by using a
familiar technique, thereby avoiding thefamiliar technique, thereby avoiding the
need for multiple remakes and anneed for multiple remakes and an
unpredictable result.unpredictable result.

It has been reported that plaster or zincIt has been reported that plaster or zinc
oxide may cause some discomfort relatedoxide may cause some discomfort related
to tissue friability and the lack of saliva.to tissue friability and the lack of saliva.

Denture border extensions are developedDenture border extensions are developed
with modeling plastic.with modeling plastic.
This material must be properly temperedThis material must be properly tempered
prior to placement in the mouth to preventprior to placement in the mouth to prevent
soft tissue irritation.soft tissue irritation.
Soft tissues are manipulated as gently asSoft tissues are manipulated as gently as
possible during the impression process.possible during the impression process.

A closed vertical dimension is believed to placeA closed vertical dimension is believed to place
less stress on the alveolar ridges during functionless stress on the alveolar ridges during function
and parafunction and may also be an advantageand parafunction and may also be an advantage
in positioning the denture should trismus orin positioning the denture should trismus or
fibrosis develop.fibrosis develop.

The plastic, monoplane tooth is frequentlyThe plastic, monoplane tooth is frequently
the tooth of choice.the tooth of choice.

A well-balanced, non interferingA well-balanced, non interfering
occlusion is an absolute necessityocclusion is an absolute necessity
regardless of the tooth form used.regardless of the tooth form used.

Soft materials have been suggested forSoft materials have been suggested for
use as denture bases.use as denture bases.
These materials have offered littleThese materials have offered little
advantage over hard base materialsadvantage over hard base materials
because of their coarse surface andbecause of their coarse surface and
propensity for support of fungal growth.propensity for support of fungal growth.

Delivery procedures must be meticulouslyDelivery procedures must be meticulously
performed.performed.
Indicating paste is used to identify theIndicating paste is used to identify the
areas of excessive pressure.areas of excessive pressure.
Denture borders should be carefullyDenture borders should be carefully
evaluated for areas of overextension,evaluated for areas of overextension,
paying special attention to thepaying special attention to the
retromylohyoid area.retromylohyoid area.

The dentures should be highly polished.The dentures should be highly polished.
Some clinicians advocate that the tissue-bearingSome clinicians advocate that the tissue-bearing
surface of the denture also be polished tosurface of the denture also be polished to
eliminate any surface roughness in an effort toeliminate any surface roughness in an effort to
minimize tissue irritationminimize tissue irritation

The patient should be advised regardingThe patient should be advised regarding
the effect xerostomia and compromisedthe effect xerostomia and compromised
mucosa have on the potential formucosa have on the potential for
prosthodontic success and should beprosthodontic success and should be
cautioned to remove the dentures if anycautioned to remove the dentures if any
soreness or irritation develop and to seesoreness or irritation develop and to see
the dentist as quickly as possible.the dentist as quickly as possible.

The benefits of removing the dentures whileThe benefits of removing the dentures while
asleep and maintaining appropriate oral hygieneasleep and maintaining appropriate oral hygiene
procedures must be explained.procedures must be explained.

Additionally, the patient must be seen atAdditionally, the patient must be seen at
frequent intervals during the first fewfrequent intervals during the first few
weeks allowing delivery of the dentures.weeks allowing delivery of the dentures.
Two appointments a week provide ampleTwo appointments a week provide ample
opportunity to intercept any problems thatopportunity to intercept any problems that
may develop.may develop.

Implants in the irradiated boneImplants in the irradiated bone
The long term function of osseointegratedThe long term function of osseointegrated
implants is dependent on the presence ofimplants is dependent on the presence of
viable bone that is capable of remodelingviable bone that is capable of remodeling
as the implant is subjected to the stressesas the implant is subjected to the stresses
associated with the support of a prostheticassociated with the support of a prosthetic
restoration.restoration.

When implants are considered for theWhen implants are considered for the
irradiated patient, several issues requireirradiated patient, several issues require
careful assessment:careful assessment:

Risk of osteoradionecrosis.Risk of osteoradionecrosis.

Potential benefit provided by implantsPotential benefit provided by implants

Potential morbidity associated with implantPotential morbidity associated with implant
failurefailure

Possible use of HBO as an adjunct treatment.Possible use of HBO as an adjunct treatment.

The predictability of endosseous implantsThe predictability of endosseous implants
in irradiated bone depends upon:in irradiated bone depends upon:

Selected anatomic siteSelected anatomic site

Dosage to the siteDosage to the site

Use of HBOUse of HBO

Timing of implant placement in relation to theTiming of implant placement in relation to the
radiation treatment.radiation treatment.

A study by Larsen et al demonstrated thatA study by Larsen et al demonstrated that
the mean integration of implants placed inthe mean integration of implants placed in
a non-irradiated group of dogs wasa non-irradiated group of dogs was
significantly greater than in an irradiatedsignificantly greater than in an irradiated
group.group.

Asikainen et al showed that in an experimentalAsikainen et al showed that in an experimental
dog model, implant survival was dose related.dog model, implant survival was dose related.
The animals received 4000, 5000, or 6000 cGy,The animals received 4000, 5000, or 6000 cGy,
and implants were placed 2 months later. After 4and implants were placed 2 months later. After 4
months of osseointegration, the implants weremonths of osseointegration, the implants were
loaded for 6 months.loaded for 6 months.
The success rates were 100% in the 4,000 cGyThe success rates were 100% in the 4,000 cGy
group, 20% in the 5,000 cGy group, and 0% ingroup, 20% in the 5,000 cGy group, and 0% in
the 6,000-cGy group.the 6,000-cGy group.

Parel and Tjellstroerrv in a survey ofParel and Tjellstroerrv in a survey of
centers in the United States and Sweden,centers in the United States and Sweden,
reported 64.7% and 57% success rates,reported 64.7% and 57% success rates,
respectively, for extraoral implants placedrespectively, for extraoral implants placed
in irradiated facial bones.in irradiated facial bones.

Roumanas et alRoumanas et al reported resultsreported results
accumulated over 14 years for craniofacialaccumulated over 14 years for craniofacial
implants placed in the facial skeleton toimplants placed in the facial skeleton to
retain facial prostheses.retain facial prostheses.
The success rate of implants placed inThe success rate of implants placed in
irradiated bone was 52%, versus 85% forirradiated bone was 52%, versus 85% for
those placed in nonirradiated bone.those placed in nonirradiated bone.
Long-term success rates in the irradiatedLong-term success rates in the irradiated
orbit were particularly low (27%).orbit were particularly low (27%).

Marx’s ProtocolMarx’s Protocol
20 dives before and 10 after implant placement20 dives before and 10 after implant placement
at 2.4 atmospheric pressure for 90 minutes.at 2.4 atmospheric pressure for 90 minutes.
Niimi et al conducted a nationwide survey inNiimi et al conducted a nationwide survey in
Japan on oral implants placed followingJapan on oral implants placed following
radiation. The success rate for implants placedradiation. The success rate for implants placed
in the maxilla without HBO was 62.5%; thein the maxilla without HBO was 62.5%; the
success rate for maxillary implants that receivedsuccess rate for maxillary implants that received
HBO treatment was 80%.HBO treatment was 80%.

Irradiation of Implants in BoneIrradiation of Implants in Bone
Irradiation of titanium implants already inIrradiation of titanium implants already in
place results in backscatter; therefore, theplace results in backscatter; therefore, the
tissues on the ra-diation source side of thetissues on the ra-diation source side of the
implants receive a higher dose than theimplants receive a higher dose than the
other tissues in the field.other tissues in the field.
The dose is increased by about 15% at 1The dose is increased by about 15% at 1
mm from the implant.mm from the implant.

ConclusionConclusion
Dental management of the irradiated patient is aDental management of the irradiated patient is a
serious undertaking since the standard of careserious undertaking since the standard of care
certainly has an effect on the patient's quality ofcertainly has an effect on the patient's quality of
life. Dentists assuming the responsibility forlife. Dentists assuming the responsibility for
treating this group must be willing to make a long,treating this group must be willing to make a long,
term commitment to each individual patient's care.term commitment to each individual patient's care.

They must also have an understanding ofThey must also have an understanding of
basic radiation and dental oncologybasic radiation and dental oncology
techniques and their own limitations.techniques and their own limitations.

REFERENCES
• Clinical Maxillofacial Prosthetics – Thomas D.
Taylor
• Maxillofacial Prosthetics - WR Laney.
• Maxillofacial Prosthetics : Multidisciplinary Practice
– Chalian, Drane & Standish.
• Radiation therapy for oral cavity cancer. DCNA
1990;34(2):205-222.
• Oral tissue changes of radiation oncology and their
management. DCNA 1990;34(2):223-238.

• Fleming TJ, Rambach SC. A tongue shielding
radiation stent. J Prosthet Dent 1983;48:389-392.
• Marx RE. A new concept in treatment of
osteoradionecrosis. J oral maxillofac Surg
1983;41:351-356.
• Marx RE. Osteoradionecrosis: A new concept in
its pathophysiology. J oral Maxillofac Surg
1986;41:283-287.
• Oral management of a radiotherapy patient.
DCNA 2004.

• Oral Tissue and radiation. JPD
1963;72-84.
• Implants in qualitatively
compromised bone. Watzenick 2nd
ed.

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