Kelly

Front 1

What functional morbidities result if a large maxillary defect is not obturated effectively?

Back 1

• Speech is hypernasal
• Leakage of the blous and fluids into the nose
• Mastication efficiency is compromised.

Front 2

When a large maxillary defect is anticipated secondary to resection of a large tumor, several alterations at surgery are suggested that will enhance the prosthetic rehabilitation. List the three most important and why, in each case they are important?

Back 2

1. Skin grafting the defect
a. Creates an undercut just superior to the skin graft and mucosal jxn
b. Lateral walls of skin lined defect allows enhancement of obturator prosthesis
2. Maintain Access to the defect
a. Closing defect leads to:
i. Lack of monitoring of recurrence
ii. Distortion of palatal contours/eliminate tongue spacepoor speech
iii. Impingement of interocclusal spaceno room for prosthesis
iv. Accumulation of secretions atop the flap in the sinusfoul odor/sinus infxn
3. Retention of Premaxilla
a. Improved support from palatal shelf
b. Improved stability
c. Implant site

Front 3

It is now possible to close large maxillary defects with free vascularized flaps. Why is this practice contraindicated in most patients?

Back 3

• Maintain access to the defect because it facilitates retention, stability, and support
o Monitor the defect for recurrence
o Distortion of palatal contours and elimination of tongue space (speech articulation impairment),
o Impingement of the interocclusal space so no room for prosthesis
o Accumulation of secretions atop the flap in the sinus which can lead to sinus infections and foul odors.

Front 4

Implants are not recommended in patients scheduled to receive radiation therapy after their surgical resection. Please explain.

Back 4

• Back scatter/dose enhancement phenomenon
o Radiation is reflected off of the implants and scatters secondary electrons to the surrounding tissues which render the bone in a 1 mm radius virtually non-vital

Front 5

Tissue bars used to retain maxillary obturator prostheses in edentulous patients should be implant assisted. Please explain.

Back 5

• Implant supportedexcessive occlusal loadsmicrodammagebone resorptionincrease porosity of bonemagnification of excessive loads
• Implant assisted
o Allows implants to facilitate retention and stability but not be the primary means of support
o Minimizes lateral torquing forces on implants(thus implant overload) and directs forces along the long axis of the implant
o Allows prosthesis to be compressed into mucoperiosteum in extension areas and allows tissue to absorb occlusal forces

Front 6

It is not possible to obtain peripheral seal with a complete denture and obturator in an edentulous patient with large defects. What phenomenon contributes to peripheral seal in normal patients?

Back 6

• Atmospheric pressure
• Adhesion and cohesion

Front 7

The acid etched implants surfaces are superior to the original machined implant surface. Please explain!

Back 7

• Acid etched
o Machined surfaces less bioreactive
o Better initial anchorage
o Higher BAI
o Bone deposited is hard/stiffer

Front 8

It is often advisable to splint abutment teeth adjacent to a large edentulous space such as a maxillectomy defect. Please explain!

Back 8

• Splint when teeth are:
o Periodontal and Endodontically compromised
o Provides larger root area and support
 Central + Lateral if central is adjacent to edentulous space, centrals roots are short and conical
Proved to extend the life of teeth if patient has good plaque contron

Front 9

Retention of a maxillary obturator is critical to its function. What oral functions are compromised if retention is suboptimal?

Back 9

• Speech is hypernasal
• Leakage of bolus and fluids into the nose can occur
• Mastication efficiency is compromised because the tongue is preoccupied with keeping the obturator in position.

Front 10

In dentate patients retention for the obturator prosthesis is achieved by what means?

Back 10

Retention is provided by engaging the lateral wall of the defect and engaging the remaining dentition with a RPD casting.

Front 11

Why is the “I” bar considered the retainer of choice on abutment teeth adjacent to a maxillectomy defect?

Back 11

1. Better esthetics
2. Maximum natural cleansing action
3. Passive functional movement of the extension prosthesis
4. Minimal tooth contact
5. Exact placement of retention contact
6. Minimal interference with natural tooth contour

Front 12

What biologic mechanisms are set in motion when an implant is over loaded?

Back 12

Osteocytes in the trabeculae send signals to the marrow which causes the remodeling response. Old bone is removed and new bone is laid down to replace the damaged bone. The deposition of bone does not keep up with the breakdown of bone which causes impairment to the anchorage bone of the implants.

• Excessive occlusal loadsmicrodammageresorption remodelingincreased porosity of bone at implant interfaceincreased loading

Front 13

What is the difference between an implant assisted tissue bar and an implant supported tissue bar?

Back 13

An implant assisted tissue bar shares the occlusal forces with tissue bearing surfaces. An implant supported tissue bar bears all the occlusal forces.

Front 14

What is the purpose of the rest on the implant assisted tissue bar design used in edentulous maxillectomy patients?

Back 14

The rests control the axis of rotation and allow the ERA attachments to function vertically as designed. The rests serve to direct most of the occlusal forces axially.

Front 15

What is the purpose of altered cast impressions?

Back 15

The altered cast technique ensures maximum coverage of edentulous areas.

Front 16

Implants in edentulous maxillectomy defects achieve much lower success rates than achieved in normal patients. Why?

Back 16

The success rates are lower because in patients with defects there are less options for implant placement and often times the premaxilla is missing or partially missing, so the less desirable areas are used in those cases.

Front 17

In edentulous maxillectomy patients implants are placed in the tuberosity only as a last resort. Please explain.

Back 17

Generally only 1 or 2 implants can be used. It’s very difficult to get primary stability which leads to failure of osseointegration.

Front 18

What are the principles of partial denture design? Do they apply to patients with maxillectomy defects? Please explain.

Back 18

All the principles of RPD design apply to patients with maxillectomy defects.
1. Major connectors must be rigid.
2. Occlusal rest must direct occlusal forces along the long axis of the teeth
3. Maximum support is gained from the adjacent soft tissue denture bearing surfaces; by engaging the defect for support you can take some load off of the remaining dentition
4. Guide planes are employed to enhance stability and bracing
5. Retention must be within the limits of physiologic tolerance of the PDL
6. Designs must consider the needs of cleansibility

Front 19

What are some of the lessons we have learned when employing implants in edentulous patients with maxillary defects?

Back 19

1. Implants should not be the sole means of retention, stability, and support
2. The residual palatal structures should be engaged effectively
3. The defect should be used to maximum advantage to retain, stabilize, and support the obturator prosthesis

Front 20

Physiologic adjustment of RPD frameworks is particularly important in maxillectomy defects because of the long lever arms and increased movement. What is the purpose of physiologic adjustment?

Back 20

The purposes of the physiologic adjustment are to ensure complete seating of the framework and ensure non-binding movement as planned.

Front 21

What component of speech is most affected by resection of portions of the soft and or hard palate secondary to removal of malignant tumors?

Back 21

The component of speech most affected by soft and/or hard palate defects is resonance.

Front 22

Define
• Velopharyngeal incompetence –
• Velopharyngeal insufficiency –

Back 22

o velopharyngeal structures are normal anatomically, but the intact mechanism is unable to affect velopharyngeal closure.
o Congenital or acquired defects
o Soft palate is functionally impaired by neuromuscular disease.
• Velopharyngeal insufficiency –
o length of the hard and/or soft palate is insufficient to affect velopharyngeal closure, but with movement of the remaining tissues within physiologic limits.
o Secondary to a structural limitation.

Front 23

List the three primary muscles responsible for velopharyngeal closure.

Of these three which muscle plays the biggest role? What is its function?

Back 23

Levator palatini, uvulus muscle, superior constrictor  all are innervated by the vagus via the pharyngeal plexus

The levator palatini elevates the soft palate posterolaterally to contact posterior and lateral pharyngeal walls when contracted.

Front 24

What is Passavant’s pad?

Back 24

The muscular bulge seen during speech and swallowing in some patients with large soft palate defects. It occurs in about 1/3 of patients with velopharyngeal dysfunction.

Front 25

Similar to complete dentures, when border molding a soft palate obturator the compound extensions are “cut back” 1-2mm with a sharp blade or carver prior to refining the impression with wax. What is the purpose of this “cut back?”

Back 25

o border molding is cut back to add thermoplastic wax (Iowa wax)
o Pattern is molded functionally by having the patient speak and swallow for at least 2 hours to ensure the impression is not over extended.

Front 26

In the example provided of the patient with a soft palate defect, an implant assisted tissue bar was proposed to retain an overlay complete denture and obturator. Implant assisted tissue bar designs are favored in the normal edentulous maxilla? Please explain why.

Back 26

Implant assisted are preferred to implant supported tissues bars to minimize the risk of implant overload. This is true for conventional and defect patients.

Front 27

Why are implants so valuable when restoring an edentulous patient with an acquired soft palate defect?

Back 27

o Placement of osseointegrated implants in the premaxilla allows a secure means of retention for the complete denture and obturator. With a secure means of retention, we can develop the contours and extensions of the obturator to maximize the efficiency of the obturator thus helping to allow for normal speech.

Front 28

When is a palatal lift useful?

Back 28

Primarily used in patients with velopharyngeal incompetence who exhibit compromised motor control of the soft palate. Examples on slide 40.

Front 29

The lingual surface of a mandibular complete denture is concave. For similar reasons the oral side of a soft palate obturator is concave. What are the reasons?

Back 29

o Violate the tongue space
o Precipitate gagging
o Interfere with the oral phase of swallowing.

Front 30

Indirect retention is used facilitate the retention of soft palate obturators in patients with intact natural dentition. Define indirect retention as it relates to RPD design and explain how it works in these situations.

Back 30

o Indirect retention is used to counteract the forces of gravity and long lever arms
o The more anterior one gets with either rests or retainers the more indirect retention is gained

Front 31

What are some of the lessons learned from our experience using implants in free vascularized flaps?

Back 31

1. Immediate placement of implants at the time of Md reconstruction is not advised  difficult for good anchorage and immobilization
2. Implants placed in fibulas that receive postop radiation have a lower success rate  due to back scatter/dose enhancement affects the bone around is predisposed to osteoradionecrosis
3. At second stage surgery the tissues surrounding the implants must be thinned  if tissues are too thick, will cause deep peri-implant pockets
4. Abutments with highly polished surfaces reduce the incidence of soft tissue problems around the implants
5. Overlay type prostheses are preferred because of improved hygiene access and better lip support

Front 32

How can these lessons be applied to improve the care of our conventional edentulous implant patients?

Back 32

The same principles apply to the conventional edentulous implant patient as they do to the resected implant patient.

Front 33

Prior to free vascularized flaps oral defects secondary to removal of tongue – floor of mouth cancers were closed primarily. What were the functional morbidities that resulted from this practice?

Back 33

o Speech Articulation
o Loss of tongue bulk and control
o Control of Saliva
o No lip seal
o Altered vestibules
o Motor/sensory deficits
o Swallowing
o Bolus manipulation
o Sensory/motor deficits
o Mandibular deviation
o Soft tissue/bony defects
o Mastication
o Bolus manipulation by tongue compromised
o Sensory/motor deficits
o Mandibular deviation
o Cosmetics
o Mandibular deviation
o Soft tissue and bony defects

Front 34

Implants placed in fibula free flaps have a very high success rate. Please explain why the rate is so high!

Back 34

o Thick cortical layers which enables the surgeon to obtain excellent primary stability, which is extremely important if the implants are to osseointegrate.

Front 35

The vertical dimension of occlusion is often closed and the occlusal plane lowered in patients restored with resection dentures. Please explain why!

Back 35

o Facilitate the interaction of the tongue with the palatal structures during speech and swallowing
o Position the bolus onto the occlusal table

Front 36

The neutrocentric concept occlusion is often used in resection dentures. What is the neutrocentric concept of occlusion and when is it employed in conventional edentulous patients?

Back 36

o The neutrocentric concept of occlusion is when all posterior and anterior teeth are set on the same plane of occlusion, with the exception of the lateral incisors (which are slightly higher for esthetic purposes).
o Used when conventional edentulous patient is unable to elevate and spill the bolus on the occlusal table, due to limited tongue mobility.

Front 37

What are some of the challenges we need to overcome when making resection dentures in patients with lateral discontinuity defects of the mandible?

Back 37

1. Loss of Md bearing surface 
a. affects mostly support, but some stability and retention too
2. Compromise of the Mx bearing surfaces 
a. compromised peripheral seal and stability
3. Unilateral occlusal forces 
a. dislodges dentures
4. Angular path of Md closure 
a. lateralizes envelope of motion his increases the lateral component of forces  pushes the denture sideways
5. Compromised motor control of tongue and lip
6. Unfavorable tongue position, loss of tongue bulk and impaired tongue mobility 
a. may not be over palatal vault, may be below plane of occlusion
7. Impaired sensory input 
a. IAN and lingual nerve usually resected along with Md

Front 38

What are some of the potential benefits derived from use of resection dentures.

Back 38

o Restore facial contours
o Restore lip seal
o Mastication

Front 39

What are the three most important prognostic factors when predicting whether a patient will be able to masticate reasonably effectively with a mandibular resection denture. Explain the significance of each of these factors

Back 39

1. Tongue status  tongue manipulates bolus and Md denture and sometimes the Mx denture
2. Radiation therapy  xerostomia induced by radiation therapy will affect the seal of the Mx CD and the tolerance of the Md CD.
3. Md bearing surface  amount of support for Md CD

Front 40

Lip plumpers are often added to labial flange of mandibular resection dentures. Why?

Back 40

o Improve lip contours
o Prevent lip biting
o Permit lip seal thereby improving salivary control.

Front 41

In edentulous patients treated for tongue-floor of mouth tumors it may be difficult to fit the patient with a well retained maxillary complete denture. Please explain!

Back 41

o Buccal pouch negatively impacted by presence of a residual ramus fragment on resected side or excessive deviation of the mandible on normal side difficult to extend the denture around the buccal pouch and over the hamular notch into PPS area.
o Radiation induced xerostomia which reduces peripheral seal.

Front 42

Silicone liners should not be used with complete dentures in irradiated patients. Please explain!

Back 42

Silicones exhibit decreased wetability + reduced salivary flow  increased friction at the denture-mucosa interface during function.
• Deteriorate rapidly secondary to fungus infestation.
• Difficult to adjust

Front 43

Besides the usual exam findings (tongue position, floor of mouth contour etc) what findings are uniquely important in irradiated patients when considering fabrication of complete dentures

Back 43

(MSBST)
•Condition of oral mucous membranes
•Scarring at the tumor site
•Contours of the bony bearing surfaces, presence of bony undercuts
•Salivary flow rates
•Trismus

Front 44

What radiation delivery findings are important to consider when considering an irradiated edentulous patient for complete dentures?

Back 44

o Field of radiation
o If more posteriorless likeliehood of the Mn bearing surface was irradiated
o If tongue/floor of mouth cancerincreased likelihood that Mn bearing surface was irradiated
o If tumor was in floor of the mouthhigh risk of scarring in the areas which the denture flange may extend tohigh risk of mucosal perforation
o Dose to Mn bearing surface
o Less than 65000 Cgy low risk of ORN
o More than 65000Cgyincreased risk of ORN especially w/ mucosal perforation

Front 45

In irradiated patients what criteria are used to selected posterior tooth forms?

Back 45

• Coordination of the patient
• Bony contours of the ridge
• Tongue position and floor of mouth posture
• Jaw relations

Front 46

Following cancerocidal doses of radiation boney changes result which may impair osseointegration. What are those changes?

Back 46

VOFOR
Reduced vasculature
Facial and IA artery lumen reduced, Fine vasculature destroyed
Loss of osteoprogenitor cells
Due to lack of vasulature
Prevents bone depositionquality of bone that anchors implant is compromised and response to loading
Fatty degeneration
Compromised remodeling
More woven bone at interace which affects anchorage and load bearing compacity
Susceptibility to osteoradionecrosis
>65,000CgY

Front 47

The acid etched surfaces are more bioreactive than machine surface implants. Will they (acid etched surfaces) be any more successful in irradiated tissues? Please explain.

Back 47

No. The major problem in the irradiated patient is loss of vasculature and with it the loss of osteoprogenitor cells (stem cells) in the marrow. Initial biologic events leading to deposition of bone on the surface of the implant is compromised.
The remodeling apparatus, which requires the presence of vital osteocytes, osteoblasts and osteoclasts is turned off by cancerocidal doses of radiation.

Front 48

Implants can be used in most edentulous patients who have been treated for oral cancer. Why is this statement true? Please explain your answer.

Back 48

o Mandible
o Many times the field or radiation is posterior to sympheseal region of the mandible allowing implants to retain, stabilize and even support the mandibular denture
o 5500 cGY lower = little risk
o 5500-6500 = individual factors implact decision
o 6500ORN more significant don’t place implants unless with HBO(70-85%)
Maxillarisk negligible unless doses are extremely high 7500cGY
-Failure occur usually after implants have been loaded

Front 49

In the future we will encounter an increasing number of patients with osseointegrated implants who present with oral cancers requiring radiation therapy. If a patient presents with implants in the posterior mandible and this area is to receive 7000 cGy, what would you recommend? Please explain the rationale supporting your recommendation.

Back 49

Recommend abutments and superstructures be removed and skn/mucoa closed over implant fixtures prior to radiation. I would elect not to reexpose implants and replace the prosthesis as bone exposure secondary to infection can lead to osteoradionecrosis.

Front 50

Summarize the tissue changes observed in animal studies when implants are placed in irradiated tissues and note the clinical ramifications.

Back 50

a) Greater component of woven bone at the interface may affect the quality of anchorage and the load bearing capacity of the implants.
b) Death of osteocytes and loss of osteoprogenitor cells in the marrow may compromise the remodeling of bone at the bone implant interface and could alter its response to load.
c) Poor blood supply in the marrow predisposes
a. Infection
b. implant loss
c. doses above 6000 cGy may lead to osteoradionecrosis.
d. Radiation induced tissue effects significantly reduced the bone appositional index as compared to controls and may compromise its load bearing capacity.

Front 51

Based on the tissue changes noted above what clinical assumptions can you make regarding the use of implants in irradiated tissues?

Back 51

1. In the mandible at higher doses (above 6500 cGy with conventional fractionation) the risk of osteoradionecrosis becomes significant.
2. The success rates of osseointegrated implants in irradiated bone will be less than that seen in nonirradiated bone. The higher the dose the lower the success rates.
3. The load carrying capabilities of osseointegrated implants in irradiated bone will be less than seen nonirradiated bone.
4. Because of compromise of the remodeling apparatus of bone, late failures should be expected

Front 52

The bone anchorage achieved with acid etched implants is superior to that achieved with machined surface implants. Please explain why this is the case.

Back 52

o Specific genes are expressed which accelerate and enhance the deposition of bone on the surface of the implant
o Bone deposited is harder and stiffer.

Front 53

What are the benefits derived from implant retained prostheses?

Back 53

Improved retention and stability
Ease and accuracy of prosthesis placement
Elimination of the occasional skin reactions to adhesives
Improve skin hygiene and patient comfort
Decreased daily maintenance associated with application and removal of skin adhesives
Enhanced esthetics of the lines of juncture between the prosthesis and the skin
Increased life span of facial prostheses

Front 54

Please discuss the differences between craniofacial implants and intraoral implants?

Back 54

They are the same type. They are titanium and are designed to osteointegrate. But the craniofacial implants are shorter  4-5mm

Front 55

What anatomical locations are best for implant placement in the nasal, orbital, and auricular prostheses? Why are magnets used in the orbital prosthesis as opposed to Hader Clips?

Back 55

Orbital: supraorbial rim
Auricular: mastoid (posterior and superior the ear canal)
Magnets are preferred due to the lack of depth perception in orbital prosthesis patients

Front 56

What are the steps in fabricating an implant retained prosthesis for prosthetic rehabilitation?

Back 56

Make impression with elastic material
Develop master cast with implant analog imbedded in the cast
Make a trial sculpting of the prosthesis
Try the trial sculpting in the patient
Process the applicance

Front 57

According to Chang et al, treatment satisfaction of facial prostheses was found to be superior in which aspects of life?

Back 57

Home, eating, exercise, perspire

Front 58

1. A patient is referred to you prior to radiation therapy to determine whether or not teeth are to be extracted prior to radiation. What criteria should be considered before making decisions regarding extraction of teeth? In each case indicate whether it would make you more aggressive or less aggressive in recommending preradiation extractions.

Back 58

i. Urgency of treatment
1. Large anaplastic rapid growing tumors need immediate treatmentdefer dental extractions
ii. Radiation fields
1. External Beam
a. More aggressive when body of mandible involved
b. More aggressive with mandibular molars
c. More aggressive with lateral tongue, floor of mouth treated with opposed mandibular fields
d. High posterior lateral facial fieldsORN risk is low so can be more conservative
iii. Mode of therapy
1. External beam + brachytherapy vs. external beam
a. Teeth opposite implant site can be more conservative
b. Teeth adjacent to implant site need to be aggressively removed
iv. Dose
1. Mandible: 6500cGy + high risk be more aggressive in removing teeth
v. Prognosis
1. Prognosis for tumor control:
a. If intent for therapy is just palliation, should try to retain dentition to maximize fxn for remaining days

Front 59

2. List those post radiation sequellae which may effect complete denture fabrication and tolerance.

Back 59

a. Mucositis –
i. Clinical significance: The oral mucosa is easily traumatized or perforated. The ulcerations that develop are slow to heal because of the reduced vascularity and fibrosis of the underlying connective tissue make complete denture tolerance difficult
1. Mucosal is atrophic and thin
2. Scaring: Overextensions of flanges can potentially lead to mucosal perforation and ORN
b. Salivary glands
i. Increased friction at denture-mucosa interfacepoor peripheral seal
ii. Changes in oral floracandidiasis
c. Bone
i. Remdeling apparatus poorirregular ridge contours will not be effectively remodeled

Front 60

3. Discuss the difference between electrons and photons (high energy) in regard to penetration, definition of fields, bone absorption and skin sparing

Back 60

a. Photon beam therapy*
i. Superficial (50 keV to 150 keV) - used for treatment of small superficial skin tumors
ii. Orthovoltage (150 keV to 300 keV) – used to treat superficial but thick tumors of the skin
iii. Megavoltage (1 MeV or greater, like cobalt and linear accelerators) – used to treat deeply situated tumors while sparing superficial normal tissues (“skin sparing”)
b. Electron beam is the most commonly employed. It allows for delivery of high doses of radiation to tumors located within 6 cm of the surface. The energy of the beam can be adjusted to the depth of interest. Neutron beam and Proton beam therapy are still considered experimental.

Front 61

dentulous patient is referred to you prior to radiation therapy for a dental evaluation. What information do you need to obtain from the radiation oncologist in order to make treatment recommendations?

Back 61

a. Dosage, field of radiation, type of radiation, chemo or no chemo

Front 62

6. Therapeutic radiation is delivered in a series of fractions. Discuss the biologic phenomenon upon which fractionation is based

Back 62

a. Allows for reoxygenation of hypoxic tumor cells- most tumor cells are anoxic, reoxygenation allows oxygen to reach the anoxic cells and make the more radiosensitive
b. Cell cycle dynamics- gives more opportunity for radiation to affect cells during the radiosensitive phases of the cell cycle
c. Normal cell recovery vs tumor cell recovery-normal cells are able to recover better than tumor cells between treatments
d. Clinical data proves that works

Front 63

7. Patient “A” receives 6900 cGy via the linear accelerator for a lateral floor of mouth sq. CA and develops an osteoradionecrosis adjacent to the tumor site. Patient “B” receives 5000 cGy via the linear accelerator and 3000 cGy with an iridium implant for a lateral floor of mouth and sq. CA develops an osteoradionecrosis adjacent to the tumor site. In both patients the bone exposure extends beyond the mucogingival junction. Would these two patients be treated in a similar way? If yes, outline your treatment recommendations. If no, describe your treatment recommendations for each patient.

Back 63

a. Patient A:
i. Equivalent dose to buccal cortical plate which is = to the dose external beam  is greater than 6500cgy, ORN is past MGJ as well
ii. hyperbaric o2 + surgical sequesterctomy
b. Patient B:
i. Total dose to mandible was 5000cgy via external beam, 3000cGY iridium implant was only to the lateral floor of the mouth
ii. Local delivered iridium implant(brachytherapy) are localized to the lingual plate of the mandible and does not deliver a significant portion to the buccal plate of the mandible, thus the equivalent dose on the buccal plate of mandible is equal to the external bea, only
iii. Conservative treatment is okay

Front 64

8. Describe some of the methods used to minimize the symptoms associated with radiation mucositis.

Back 64

a. Supportive and symptomatic
i. Saline and soda rinses
ii. Viscous xylocaine
iii. Systemic analgesics
iv. Antifungal medications
v. Antibacterial lozenges (combination of amphotericin B, polymyxin, and tobramycin) per Spijkervet (1993)

Front 65

9. How would you describe to a preradiation patient the changes in taste perception they will experience during and after their treatment.

Back 65

a. Architecture of the taste buds is almost completely eliminated at 5000 cGy
b. Alterations in taste acuity are first noticed during the second week of therapy
c. Perception of bitter and acid flavors is more susceptible to impairment than salt and sweet
d. Taste generally returns to normal 2-4 weeks after therapy if salivary flow is reasonable. In patients with severe xerostomia following radiation the number of buds is decreased and their morphology is altered.

Front 66

10. Define dosimetry.

Back 66

a. The purpose of dosimetry is to evaluate the amount of energy absorbed by the tissues subject to radiation.
b. Standard unit of absorbed dose is the gray
c. Accurate treatment planning must consider the characteristics of the different types of radiation beams
d. When a radiation beam penetrates tissue, the dose decreases with the depth of penetration once the maximum dose level is reached

Front 67

11. Define brachytherapy.

Back 67

a. Radioactive sources are implanted locally within the tissues encompassed by the tumor
b. Iridium 192 seeds are most commonly used today primarily in T1 and T2 carcinomas of the tongue and floor of the mouth.
c. Most patients receive 5000-5500 cGy
d. Advantages: dose to the B side of the mandible and the salivary glands is generally limited to the dose delivered by the external therapy.
e. Isodose curves of Ir implants positioned on the floor of the mouth…rapid falloff of tissue dose as distance from sources increases.

Front 68

12. Describe the “late affects” of cancerocidal doses of radiation on the oral mucous membranes histologically. What are the clinical implications of these changes?

Back 68

a. Late effects:
i. Scarring and fibrosis of lamina propria
ii. Telangiectasia – dilation of small venules close to the surface of the epithelium
iii. Epithelial layer is thinner and less keratinized
b. Clinical significance: The oral mucosa is easily traumatized or perforated. The ulcerations that develop are slow to heal because of the reduced vascularity and fibrosis of the underlying connective tissue.
c. Clinical significance: The denture bearing mucosal surfaces are compromised making

Front 69

13. Chronic Candida albicans infections are common after a definitive course of radiation for an oral cavity tumor. Why is this infection common and how is it best treated?

Back 69

a. Changes in the oral flora - The numbers of fungal organisms increase 100 fold
b. As a result, chronic candidiasis, is very common after therapy. It presents in a variety of forms, as seen here.
c. Nystatin remains the most effective antifungal agent. For acute forms of candidiasis, vaginal suppositories (100,000 units per suppository, Sig.- tid), used as an oral lozenge are preferred over the nystatin oral lozenges because of the latter’s high glucose content.

Front 70

14. Describe the microfloral changes in the oral cavity following a definitive course of radiation for head and neck tumors. What is the clinical significance of these changes?

Back 70

a. Changes in the oral flora
b. Significant increases in the populations of: Streptococcus mutans, Actinomyces, Lactobacillus
c. Predispose the patient to radiation caries and causes caries to progress rapidly and become so extensive that teeth often fracturing at the ginigival margin

Front 71

15. Describe the histologic changes seen in bone after a definitive course of radiation. What is the clinical significance of these changes?

Back 71

a. The mandible absorbs more radiation than the maxilla because of its increased density.
b. Early changes
i. Obliterative endarteritis
c. Late changes
i. Marrow becomes acellular and avascular
ii. Loss of osteocytes
iii. Occlusion of inferior alveolar artery
iv. Loss of endosteum
v. Fatty degeneration
vi. Fibrous degeneration
d. Clinical significance
i. Response to infection is dramatically impaired
ii. Risk of osteoradionecrosis

Front 72

16. Both amalgam and composite resins have used in post radiation patients. Please discuss the pro’s and con’s of each material when used in this patient population.

Back 72

a. Amalgam
i. Preferred over composites
ii. Amalgam restorations can be extended with redecay
iii. Less sensitive to moisture contamination during placement
iv. Polished amalgams promote better tissue responses
b. Composites
i. Preferred when esthetics are at issue
ii. Problems
1. Microleakage and recurrent caries
2. Difficulty in achieving moisture control for cervical restorations will impair performance

Front 73

17. What key facts are important to consider when prescribing topical fluoride for post radiation patients

Back 73

i. Acidulated phosphate fluorides are not recommended for daily applications because its low PH:
1. Dissolves the tooth surface
2. Daily applications will etch glazed porcelains
3. Leads to gingival and mucosal irritation

Front 74

18. What are the strategies employed to maintain the dental health of post radiation patients?

Back 74

a. Topical fluoride applications
b. Hygiene instruction
c. Regular followup (dental prophylaxsis every four months)
d. Antiplague mouth rinses
e. Diet

Front 75

19. Why are radical alveolectomies recommended when extracting teeth prior to radiation that are within the proposed field of radiation?

Back 75

a. Rationale
i. Mucosal healing is occurs more rapidly
ii. Remodeling apparatus after radiation is compromised

Front 76

20. Discuss the issues and clinical procedures that it is necessary to keep in mind when extracting teeth prior to radiation that are in the proposed radiation fields.

Back 76

a. Teeth should be removed in segments to facilitate primary closure
i. Extraction of third molars is not advocated for most patients
b. Antibiotic coverage
c. Seven to ten days of healing required prior to radiotherapy
d. Radical alveolectomy and primary closure are needed to ensure mucosal healing occurs more rapidly and that bone is contoured properly due to loss of remodeling apparatus post radiation.

Front 77

21. Healing times following preradiation extraction and initiation of radiation therapy is dependent on several factors. List them.

Back 77

i. Nature of the infection associated with the dentition and the surrounding bone – more infection requires more healing time
ii. Size of the surgical wound – larger wounds require more healing time
iii. Trauma inflicted during extractions, ie amount of bone removed during the alveolectomy
iv. Individual patient factors

Front 78

22. Discuss the impact of radiation fields upon the risk of osteoradionecrosis and radiation caries

Back 78

a. High posterior fields
i. Risk of caries is high
ii. Risk of osteoradionecrosis is low
b. Opposed mandibular fields
i. Risk of caries is reduced
ii. Risk of osteoradionecrosis is high

Front 79

23. Please provide examples of the so-called “secondary effects” of radiation therapy on oral tissues.

Back 79

a. Muscle wasting - Secondary to changes in the fine vasculature
i. Tongue
ii. Velopharyngeal complex
b. Cranial neuropathies – Secondary to fibrosis and subsequent nerve compression
c. Caries – Secondary to compromise of the quality and quantity of saliva
d. Osteoradionecrosis – Secondary to compromise of the vasculature

Front 80

24. Discuss the pro’s and con’s of the use of pilocarpine in patients with postradiation xerostomia.

Back 80

a. Requires residual salivary gland parenchyma to be effective
i. Useful in patients who have been treated with radiation fields that spare significant amts of salivary gland parenchyma (opposed mandibular fields) but
ii. Not useful in patients with opposed lateral facial fields that are used to treat tumors of the soft palate, nasopharyx
b. Toxic side effects include increased intestinal motility

Front 81

25. Many patients suffer from severe trismus following radiation treatment. What is the most effective method of treatment of trismus in this patient population?

Back 81

a. Treatment consists early initiation of of exercise and use of dynamic bite openers prior to fibrosis setting in

Front 82

26. What is the role of hyperbaric oxygen in the treatment of osteoradionecrosis? Be specific!

Back 82

a. Biologic Basis
i. Stimulation of neovascular proliferation in marginally necrotic tissues
ii. Fibroblastic proliferation
iii. Enahnced antibacterial activity of white blood cells
b. Role
i. Externla beam therapy, 6500cGY+, extended beyond MGJ
1. Osteos that have extended beyond the MGJ that have been treated slowly with external beam therapy where the dose to bone is in excess of 6500cGy using conventional fractionation
ii. External beam therapy + periodontal/periapical infxn
1. Osteos precipitated by periodontal or periapical infections when the patient has been treated with only external beam therapy
iii. Brachy therapy, extend beyond MGJ and not responding to considervative therapy and brachytherapy where dosimetry with implant is unfavorable
1. Osteos associated with brachytherapy that extend beyond the MGJ that have not responded to conservative therapy and where the dosimetry associated with the implant is unfavorable
iv. Osteos resulting in significant resorption of bone extending to the inferior border of the mandible
c. HBO is effective when the tissues are still viable, but delay in the face of high dosage may compromise the chance of success and result in greater bone loss.

Front 83

27. Describe the early changes seen in salivary gland tissue histologically during radiation of the salivary glands. Describe the late changes histologically after radiation treatments have been completed. What are the clinical implications of these changes?

Back 83

a. Early changes
i. Vacuolization of serous acinar cells (occurs at about 1800 cGy)
ii. Interstitial fibrosis
iii. Progressive loss of the fine vasculature
b. Late changes
i. Progressive fibrosis
ii. Almost complete loss of acinar elements and the striated duct system

Front 84

28. Describe the late changes seen histologically in the periodontal ligament following exposure to cancerocidal doses of radiation. What is the clinical significance of these changes?

Back 84

a. Changes in the periodontal ligament
i. Loss of cellularity
ii. Loss of vasculature
iii. Disorientation of the periodontal ligament fibers
b. Periodontal procedures, such as deep scaling and flap surgery are therefore contraindicated in heavily irradiated patients.

Front 85

What is the criteria for pre-radiation extractions in terms of dental disease factors and radiation delivery factors?

Back 85

Condition of the residual dentition
Advanced caries
Periapical infection
Periodontal bone loss
Dental compliance of the patient
Maxillary vs mandibular teeth
Maxilla better blood supply and can be removed postradiation, even if develop ORN usually heals well
Mandibular extraction post radiation if dose above 6500 can be hazardous

Front 86

What surgical procedures are completed at the time of extraction to reduce side-effects of radiation therapy?

Back 86

• Radical alveolectomy
• Crown amputation (impacted 3rds are not recommended due to post op bony defects),
• RCT.

Front 87

12. DEFINE IMRT

Back 87

12. DEFINE IMRT
a. Intensity-Modulated Radiation Therapy
b. External radiation from multiple angles to focus most radiation on tumor site
c. Surrouding tissues receive lower dosages, thus morbidity associated is decreased.

Front 88

18. What key facts are important to consider when prescribing topical fluoride for post radiation patients

Back 88

a. Uptake confined to outer 30-50um
b. Penetration is compromised by the presence of plaque
c. Fluoride fails to form stable compounds in the oral environment and much is lost within 24hrs
d. THEREFORE, DAILY APPLICATIONS MUST BE EMPLOYED TO MAINTAIN THERAPEUTIC LEVELS
e. Acidulated phosphate fluorides are not recommended for daily applications because its low PH:
i. Dissolves the tooth surface
ii. Daily applications will etch glazed porcelains
iii. Leads to gingival and mucosal irritation

Front 89

What are the options when a patient presents with non-restorable dental disease, ie, severe periodontal disease or advanced caries post radiation?

Back 89

• Mandibular teeth in field with dose to bone >5500cGyENDO
• Mandibular teeth in field with dose <5500cGyEndo and extraction appropriate
• Mandibular teeth out of filed of radiationEndo and extraction appropriate
• Maxillary teeth both in and out of field of radiationEndo and aextraction appropriate
• NOTE: Not applicable if patient receives adjuvant or comcomitant chemo

Front 90

What are some technical aspects of post-radiation operative dentistry?

Back 90

• Due to extensiveness of caries it is not always appropriate to remove unsupported enamel.
• Pulp capping is not recommended due to the poor reparative potential of the irradiated dental pulp.
• In large cervical caries, preparations and restorations can be done incrementally to ease difficulty in placing restorative material in unsupported cavity preparations.
• Avoid trauma with the rubber dam clamp.

Front 91

What are the benefits of bisphosphonate therapy?

Back 91

– Oral bisphosphonate therapy.
Osteoporosis-low bone mass of deterioration of bone structure
– IV bisphonate therapy.
Metastatic Bone Disease
breast cancer, multiple myeloma, hypercalcemia malignancy
Reduce bone complications from bone diseases
Decreases pain
Reduce need for pain meds
Improves quality of life.

Front 92

What precautions should you take if the patient is on bisphosphonate therapy?

Back 92

– Oral bisphosphonate therapy.
Rare onj, but still…
Pt education
Avoid unnecessary invasive dental procedures
Eval for exposed bone
– IV bisphonate therapy
Baseline dental exam
Onj of jaw especially with chemo and corticosteroids
Renal status
Look for Signs of local infection inc osteomyelitis
Antibiotic to treat infections in oral
Avoid invasive procedures-avoid extractions
Root canal tx
Debride sharp
Look for exposed bone, posterior lingual area

Front 93

What are some clinical manifestation of cancer?

Back 93

Pain
Fatigue
Cachexia – extreme weight loss
Anemia – chronic bleeding, malnutrition, malignancy in blood organs
Lumps or swollen glands

Front 94

Describe the TNM system

Back 94

Size of tumor
TX. Primary tumour cannot be assessed
T0. No evidence of primary tumour
Tis. Carcinoma in situ
T1, T2, T3, T4. Increasing size and/or local extent of the primary tumour
Degree of local invasion – lymph node involvement
NX. Regional lymph nodes cannot be assessed
N0. No regional lymph node metastasis
N1, N2, N3. Increasing involvement of regional lymph nodes
Extent of spread – metastasis
MX. Distant metastasis cannot be evaluated
M0. No distant metastasis (cancer has not spread to other parts of the body)
M1. Distant metastasis (cancer has spread to distant parts of the body)

Front 95

What are some common side effects of chemotherapy?

Back 95

Mucositis / stomatitis
Nausea and vomiting
Hair loss
Myelosupression

Front 96

What is the difference from direct vs. indirect stomatotoxicity?

Back 96

Direct
Reduction in renewal rate of cells in basal layers of epithelium
Mucosal atrophy and ulceration
GI ulceration and mucositis
The effects of chemotherapy on a cell pool other than the oral mucosa
Neutropenia – infection
viral hsv,vzv, cmv, ebv
Fungal
Bacterial
thrombocytopenia

Front 97

Which classifications of chemotherapeutic agents have the highest incidence of oral mucositis?

Back 97

Alkylating agents
Antimetabolites
Antitumor antibiotics

Front 98

What is the incidence and consequence of oral mucositis?

Back 98

10% adjuvant, 40% primary, 80$ stem cell
pain, infection, wasting
Inability to take oral intake-lose weight
Dehydration

Front 99

Define induction, adjuvant, salvage, and neoadjuvant chemotherapy.

Back 99

Induction: given when no alternative treatment is available
Adjuvant: used after initial surgical or radiation therapy to minimize recurrence
Salvage: used after recurrence of refractory tumor after previous chemotherapy
Chemosensitive: given concurrently with radiation to increase radiosensitivity
Neoadjuvant: given prior to definitive treatment (surgery or radiation) to reduce tumor burden

Front 100

If a patient of yours tells you that he/she will be initiating chemotherapy in the next couple of weeks, what should be you plan in regards to dental care?

Back 100

MD consult
Check Labs
Need for Premedication?
Eliminate gross infection
Periapical
Periodontal
Soft tissue
Treat advanced carious lesions
Provide oral hygiene instructions
Adjust ill-fitting dentures
Remove Orthodontic appliances
Children and young adults
Remove mobile primary teeth
Remove gingival operculum

Front 101

In consulting the medical oncologist for planned dental care, what pertinent questions should you ask in the following type of care?

Back 101

– Restorative care: Neutrophils, Platelets, RBC, need for premedication
– Surgical care: Same as above plus is it emergency

Front 102

Definition of ORN

Back 102

of bone within the field of radiation of 3 months duration or longer

Front 103

ORN most common where and which kind of patients?

Back 103

Mandible, dentulous

Front 104

External vs. Brachy + External

Back 104

Brachy+ External high risk of getting ORN but easier to treat

Front 105

Goal or ORN treatment

Back 105

maintain mandibular continuity

Front 106

Stages of HBO treatment

Back 106

 Stage I-These patients present with bone necrosis but without pathologic fracture of the mandible, orocutaneous fistula or radiographic evidence of bone resorption of the inferior order of the mandible
• 30 HBO treatments
• If no improvement, another 20 treatments
• If no improvements, considered a non-responder, advance to Stage II
 Stage II-Nonresponders are taken to surgery and surgical sequestrectomy of the local area is performed
• Additional 10 HBO treatments are added
• If wound dehisces, the patient is considered a nonresponder and advanced to Stage III
 Stage III-Nonresponders from stage II, patients with orocutaneous fistuals, pathologic fractures or bone resorption of the inferior border of the mandible
• Following 30 treatments, bony segments of the nonvital mandibular bone are resected
• Soft tissue deficits if present are restored with local or distant flaps and orocutaneous fistulas are closed
• Another 10 HBO treatments are administered and patient is advanced to Stage IIIR
 Stage IIIR
• Ten weeks after resection, the mandible is reconstructed with a free bone graft using a transcutaneous exposure
• Mandibular fixation is achieved and the patient is given another 10 HBO treatments

Front 107

In consulting with the oncologist, he/she mentions that the patient’s blood count will be at nadir in a week. What does that mean to you?

Back 107

– Lowest count that blood cell levels fall is called NADIR. This can occur at different time for different cells, usually white and platelet reach this in 7-14 days. Red will not reach for several weeks.
– This would mean it is THE WORST time to perform treatment. Emergency treatment must be done with MD consult, antibiotics, and transfusion.

Front 108

What is the most debilitating side effect of PBSCT and BMT?

Back 108

Oral Mucositis : Mouth sores.

Front 109

If a patient of yours tells you that they will be initiating a BMT or PBSCT in the next couple of weeks, what should be you plan in regards to dental care?

Back 109

Remove all potential sources of infections
80% chance of severe mucositis. palliative management
Remove sharp edges
Antibiotic prophylaxis
Palliative treatment : IV morphine

Front 110

In consulting the oncologist for planned dental care, what pertinent questions should you ask in the following type of care? (This should include immediate post transplant and greater than 1 year post transplant)

Back 110

– Restorative care?(TI-MAC G)
Current Labs
Antibiotic prophylaxis
Graft vs Host Disease status
Current infections
Planned medications/tx
Need for transfusion prior to care
– Surgical care?(TI-MAC C)
Current labs
Antibiotic Prophylaxis
Pt’s ability to form clots / coagulate
Patient’s immune function status
Planned Medications/tx
Need for transfusion prior to care

Front 111

What are common oral findings in post allo BMT patients?

Back 111

Leukemic - Lesions in the Gingiva
Graft vs Host Disease
New Solid Tumors in mouth (SCC in oral cavity)