This document discusses criteria for dental extractions prior to radiation therapy. It notes that many patients with oral cancer have significant dental disease and infected teeth may cause problems after therapy. The primary goal of pre-radiation extractions is to minimize risk of dental infection leading to osteoradionecrosis. Key factors in determining need for extractions include dental disease factors like furcation involvement and compliance, as well as radiation delivery factors like dose, volume, and mode of therapy. Extraction of teeth with advanced disease or in poor compliance patients is recommended. Mandibular teeth receive more scrutiny than maxillary teeth due to higher osteoradionecrosis risk with post-radiation extractions.

1. 5. Preradiation Dental Assessment
Criteria for Extractions
John Beumer III, DDS, MS
Eric Sung, DDS
Division of Advanced Prosthodontics,
Biomaterials and Hospital Dentistry and
UCLA School of Dentistry
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2. Preradiation extractions
v Given their demographic profiles most patients with oral
cancer present with significant dental disease prior to therapy
v If left unattended diseased dentition may precipitate serious
infections after therapy
v The primary purpose of preradiation dental extraction is to
minimize the risk of dental infection leading to an
osteoradionecrosis after therapy.

3. Preradiation extractions
v Key issue is still dose and volume
v Up until a few years ago dose and volume were
easy to determine prior to therapy
v Today, this has become quite difficult. Why?
v IMRT
v Chemoradiation

4. Preradiation Dental Consultation
Purpose:
a) Inform the patient that because of tissue changes and
reduction of salivary flow that he/she will be more susceptible to
dental caries and dental and bony infection after radiation
therapy.
b) Examine the dentition and determine which teeth are
salvageable and which teeth need to be removed.
c) Explain to the patient the importance and the methods used
for optimal dental compliance.

5. Preradiation Dental Evaluation
What is the role of preradiation extraction
in the prevention of osteoradionecrosis?

6. Preradiation Extractions
The UCLA Philosophy
v Most authors believe selected tooth removal prior to radiation
therapy, particularly mandibular molars in the field
demonstrating furcation involvement, will reduce the rate of
osteoradionecrosis (ORN) and minimize the risk of a patient
developing a discontinuity defect secondary to ORN
(Silverman and Chierici, 1965; Hayward, 1969; Beumer et al;
Epstein et al, 1997; Bruins et al, 1999; Vissink et al, 2003).
Why?

7. Preradiation Extractions
The UCLA Philosophy
v Wholesale extraction of healthy teeth in the field,
particularly in a compliant patient, is not recommended
and probably increases the rate of osteoradionecrosis
(ORN).
v ORN that develops in association with residual
mandibular dentition is difficult to control with
conservative therapy and often leads to resection of
large mandibular segments.
v ORN secondary to postradiation extractions likewise is
difficult to control with conservative therapy and often
leads to resection of large mandibular segments.

8. Preradiaton Extractions – Rationale
v The rate of ORN secondary to
preradiation extractions is less than
10%.
v ORN caused by preradiation
extractions are almost always
treated successfully with
conservative means with retention of
mandibular continuity whereas ORN
secondary to postradiation
extraction or infections associated
with teeth frequently lead to loss of
major segments of the mandible.

9. Preradiaton Extractions – Rationale
v Therefore, it is logical to
assume that extraction of
diseased mandibular
teeth within the radiation
field will not only reduce
the rate of ORN but also
minimize the morbidity of
ORN secondary to its
treatment.

10. Preradiaton Extractions – Rationale
v For example, this patient
presented with an ORN
several months following
radiation at the site of a
preradiation extraction. This
exposure was of 4 months
duration. The nonvital bone
eventually sequestrated and
the site covered with normal
epithelium after 8 months of
conservative therapy.

11. Preradiation Extraction - Rationale
v The ORN rate in dentulous patients
associated with mandibular teeth left in the
field exceeds 25% (Murray et al, 1980).
v Most of these ORN’s are precipitated by
dental disease post radiation.
v The rate of ORN secondary to postradiation
extraction exceeds 30% in most studies
(Beumer et al, 1984; Marx et al, 1985).
v A substantial number of the ORN’s caused
by dental disease and postradiation
extraction result in resection of the affected
portion of the mandible resulting in a
discontinuity defect.

12. Preradiation Extraction - Rationale
v In “A” the ORN developed as a A
result of a periodontal abscess. In
“B” the ORN was precipitated by
post radiation extractions. These
patients received 6800 cGy and
7000cGy respectively. Both patients
eventually lost their mandibles on
the affected side. B
v The course and progression of
these two ORN’s is typical of those
associated with postradiation
extraction or acute periodontal
infections, even if hyperbaric
oxygen treatment is used.

13. Criteria for Preradiation Extractions
Supporting Data

14. Preradiation extractions
Number of patients 120
Osteoradionecrosis directly associated with
extraction sites 12
Only one of the 12 patients developing ORN associated
with preradiation extractions required mandibular resection
and developed a discontinuity defect of the mandible.
From Beumer et al, 1984

15. *From Beumer et al, 1983
Postradiation extractions – External beam
dose and mandibular exposures*
Dose Extraction Bone exposures Bone exposures Radical
(cGy) episodes in excess of healed with resection of
(mandible) 3 mths (mandible) conservative measures mandible
0-4999 3 0 (0%) - -
5000-5499 4 1 (25%) 1 -
5500-5999 6 2 (33%) 2 -
6000-6499 10 2 (20%) 2 -
6500-6999 13 4 (31%) - 4
7000- 4 2 (50%) 1 1
Totals 40 11(28%) 6 5
Note the high rate of mandibular resection

16. Postradiation Extractions
No. (%) of No. (%) of pts
Group No. Pts No. teeth sockets with ORN with ORN
Penicillin 37 135 31 (22.9) 11 (29.9)
Hyperbaric 37 136 4 (2.6) 2 (5.4)
oxygen
*Incidence of ORN following tooth removal in irradiated
patients (Tumor doses were 6800 cGy or greater).
*From Marx R, Johnson R and Kline S, 1985

17. Postradiation extractions*
*In these clinical reports the dose to bone was in excess
of 6500 cGy and the patients did not receive HBO.
Incidence of osteoradionecrosis secondary to postradiation extractions
Patients Osteos
Grant and Fletcher, 1966 16 7 44%
Beumer et al, 1984 40 11 28%
Morrish et al, 1980 18 11 61%
Marx, et al, 1984 37 11 30%
Totals 111 40 36%

18. Criteria for Preradiation Extractions
Based upon:
v Dental disease factors
v Radiation delivery factors

19. Criteria for Preradiation Extractions
Dental disease factors
• Condition of the residual dentition
• Advanced caries
• Periapical infection An aggressive policy of
• Periodontal bone loss extraction is recommended in
these situations
• Furcation involvement
• Dental compliance of the patient
• An aggressive policy of extraction is recommended in patients with
poor dental compliance
• Maxillary teeth vs mandibular teeth
• Mandibular teeth are scrutinized more closely than maxillary teeth
since maxillary teeth in the field can be extracted post radiation with
minimal risk of osteoradionecrosis

20. Criteria for Preradiation Extractions
Radiation Delivery Factors
v Urgency of treatment
v Mode of therapy
v Clinical target volume (radiation)
v BED (biologic equivalent dose)
v Prognosis

21. Criteria for preradiation extraction (cont’d)
Condition of the residual dentition
v Furcationinvolvement (red arrows)of mandibular molars
within the gross tumor volume if the dose is above 5500 cGy
In times past, periodontal abscesses were a prime
initiator of osteoradionecrosis, and the osteos (arrows)
initiated in this manner frequently led to resection of
major portions of the mandibular body.

22. Criteria for preradiation extraction
(cont’d)
Condition of the residual dentition
v Furcation
involvement of mandibular molars within the gross
tumor volume if the dose is above 5500 cGy
In times past, periodontal abscesses were a prime
initiator of osteoradionecrosis, and the osteos (arrows)
initiated in this manner frequently led to resection of
major portions of the mandibular body.

23. a b
l Periodontal
infection led to
osteoradionecrosis in this patient.

24. Criteria for preradiaton extraction (cont’d)
Periapical infections and advanced caries
All teeth with such
advanced pathology
should be extracted.

25. Criteria for preradiation extractions (cont’d)
History of poor dental compliance
Given the nature of the oral cancer population it is not surprising that substantial
numbers of patients will be noncompliant (Sennhenn-Kirchner et al, 2008) and so the
less motivated the patient, the more aggressive one should be in the extraction of
mandibular teeth exposed to high dose (above 55 Gy) prior to therapy.
If the patient has a history of poor dental compliance or if the clinician
questions the patient’s ability or commitment to carry out the necessary oral
hygiene maneuvers, an aggressive approach to preradiation extraction is
recommended. In this patient full mouth extractions were performed prior to
therapy.

26. Criteria for preradiation extractions (cont’d)
History of poor dental compliance
Note the plaque accumulations, the periodontal bone loss and the class V
restorations in these two patients. All these are signs of poor oral compliance.
A B
Both these patients presented with squamous carcinomas of the
right lateral tongue and both were scheduled to be treated with
external beam therapy.In patient “A” all the remaining teeth were
removed prior to therapy. In patient “B” the mandibular molars
were removed.

27. Criteria for preradiaton extractions (cont’d)
Compliance
If patients lack the dexterity or the will to use
hygiene aids, at the very least, mandibular teeth
within the radiation field should be removed

28. Criteria for preradiation extractions (cont’d)
Mandibular teeth vs Maxillary teeth
Key factors to consider
v The maxilla has a better blood supply than the
mandible.
v Maxillary teeth can be removed postradiation
from the maxilla with little risk of the patient
developing an ORN. Even if the patient does
develops ORN they heal spontaneously
causing little morbidity or deformity.
v Removal of mandibular teeth in the field
following radiation, if the dose to bone is
above 6500 cGy, is extremely hazardous. The
rate of ORN is 30-40% and many of these
require resection of the involved portion of the
mandible.

29. Criteria for preradiation extractions (cont’d)
Mandibular teeth vs Maxillary teeth
Therefore, we think that
mandibular dentition should
be scrutinized more carefully
than the maxillary dentition
prior to radiation for
pretreatment extractions.
Extraction of maxillary teeth
with marginal pathology can
often be deferred until after
radiation therapy

30. Criteria for preradiation extractions (cont’d)
Urgency of treatment
Some patients present with large anaplastic, rapidly growing
tumors that need immediate treatment. In such patients dental
extractions need to be deferred.* Control of the tumor is obviously
the most important consideration.
*This situation occurs very rarely. When it does both the
radiation therapist and the dentist must accept the risk of
future dental complications.

31. Criteria for preradiation extractions (cont’d)
Mode of Therapy
CRT vs IMRT vs Combined external beam and
brachytherapy
v Factors to consider
v When brachytherapy is used all patients receive
5000-5500cGy of external beam therapy.
v Below 5500 cGy vascular damage to the mandible is not
profound, i.e. teeth can be removed from the field with
little risk of osteoradionecrosis in most patients.
v Brachytherapy boosts the dose delivered to the primary
site by 2500-3500 cGy.
v This boost is confined to the local tumor volume and so,
much of the adjacent normal tissues are spared.
v Risk of osteoradionecrosis in the mandible adjacent to the
implant is very great.
Clinical significance for patients with combined
external beam and brachytherapy:
a) Teeth opposite the implant site can be viewed
from a more conservative perspective
b) Teeth adjacent to the implant need to be
removed prior to radiation therapy

32. Criteria for preradiation extractions (cont’d)
Mode of Therapy
CRT IMRT
v IMRT focuses radiation to gross tumor volume resulting in
adjacent tissues receiving lower dose. Note how radiation is
more focused around tumor when compared to CRT.

33. Criteria for preradiation extractions (cont’d)
CRT - Radiation fields
The more of the body of the mandible in the field the greater the
risk of osteoradionecrosis and therefore the more aggressive
one should be in removing teeth prior to therapy
Planning film Port film
Opposed mandibular fields
Mandibular molars should be very carefully scrutinized in such patients and if they
display evidence of periodontal pathology, they should be considered for removal.
The risk of caries is low, particularly if a radiation stent is used to depress the tongue
during the therapy. These devices permit lowering of the radiation field thereby sparing
parotid tissue and the palatal glands. Increased salivary flow decreases the caries rate.

34. Criteria for preradiation extractions (cont’d
CRT - Radiation Fields
v Patients with
carcinomas of the
lateral tongue and
floor of the mouth are
treated with opposed
mandibular fields.
These fields can be lowered with a tongue depressor-bite opener ,
sparing some parotid tissue, but the entire body of the mandible will
still be in the radiation field.
In these patients the dentition must be scrutinized very carefully and if
the mandibular molars demonstrate significant periodontal deficiencies,
they should be removed prior to therapy.

35. Criteria for preradiation extractions (cont’d)
CRT - Radiation fields
High posterior lateral facial fields
Planning Port High posterior fields such as these
film film include most of all the major and
much of the minor salivary gland
parenchyma.
Salivary flow rates are reduced as
much as 95% in patients treated with
such fields and therefore the risk of
caries is very high.
The rate of osteoradionecrosis is low, because very little of the body of
the mandible is in the field of radiation. Therefore, a more conservative
approach to preradiation extractions can be used.

36. Criteria for preradiation extractions (cont’d)
Mode of Therapy
CRT IMRT
v Since the high dose areas are confined to the clinical target volume, the
dose to the opposite side is reduced.
v The reduced volume of tissue exposed to high dose appears to reduce the
risk of osteoradionecrosis (Studer et al, 2006; Ben- David et al, 2007).

37. Criteria for preradiation extractions (cont’d)
Mode of Therapy
IMRT v Therefore, one can be
more conservative with
regard to extraction of
teeth on the side opposite
the tumor.
v However, the clinician
must still be aggressive
with regards to scrutiny of
the dentition on the tumor
side, particularly in the
mandible.

38. a b
v IMRT dose distribution diagrams. Note that higher dose per fractions are
centered on clinical tumor volume.
v Note how parotid tissues receive a lower dose. If parotid dose can be kept
below 30 Gy postradiation salivary flow will be close to normal. In this case,
dose was reduced to less than 50% of the tumor dose.
v Extractions are dependent on the gross tumor volume and the dose
delivered to this volume

39. Criteria for preradiation extractions (cont’d)
IMRT - Gross Tumor Volume (GTV)
v Highest levels of dose delivered to gross tumor volume (GTV)
v Volume of mandible exposed to high levels of dose (above
6500 cGy) will determine the risk of ORN
v The volume of the major salivary glands exposed to doses in
excess of 4000cGy determines the degree of xerostomia anfthe
risk of caries

40. Criteria for preradiation extractions (cont’d)
Prognosis for tumor control
If the intent of
therapy is palliation,
efforts should be
directed towards
pain control and
maintenance of
existing dentition.
Extractions are only
recommended for
pain relief.
This patient has a large lymph node that is fixed to underlying
structures. The node and the primary tumor are unresectable and the
tumor mass too large to be controlled with radiation therapy.
Extractions are only indicated for pain control. Dentition should be
retained to maximize function during his remaining days.

41. Criteria for preradiation extractions (cont’d)
Dose to bone
v When dose to bone to the mandible gets above 6500 cGy
using conventional fractionation, the risk of ORN increases
dramatically. Chemotherapy further increases the
biologically equivalent dose (BED) by 700 to 1000 cGy
(Kasibhatla et al, 2007; Fowler, 2008).
v Asthe dose increases the clinician should be more
aggressive in removing mandibular teeth within the field prior
to therapy

42. Dose to Bone
Incidence of bone necrosis according to
dose*
Incidence of bone necrosis
Dose to bone Dentulous patients Edentulous
patients
<6500 0/36 (0%) 0/3 (0%)
6500-7500 8/29 (28%) 1/15 (7%)
>7500 11/13 (85%) 2/4 (50%)
Total 19/78 (24%) 3/22 (14%)
* Morrish R, et al. Cancer 47:1980-8,1981

43. Preradiation Extractions
Surgical procedures
v Radical alveolectomy
v Edges of the mucoperiosteal
flaps should be freshened, the
edges everted and primary
closure obtained*
v Teeth should be removed in
segments to facilitate primary
closure
v Antibiotic coverage
v Seven to ten days of healing
required prior to radiotherapy
*The lingual flap in the mandible is susceptible to mishandling
during the procedure and perforation or thinning may lead to a
bony exposure during or after therapy.

44. Preradiation extractions (cont’d)
Radical alveolectomy and primary closure
Rationale
v Mucosalhealing is occurs more rapidly
v Remodeling apparatus after radiation is compromised
A radical alveolectomy was not
performed on this patient. Note the
irregular bony bearing surfaces. These
sharp bony projections will not remodel
after therapy and therefore this patient
is not a candidate for complete
dentures.

45. Preradiation extractions (cont’d)
Healing time is based on:
v Nature of the infection associated
with the dentition and the
surrrounding bone - more
infection requires more healing
time.
v Size of the surgical wound –
larger wounds require more
healing time.
v Trauma inflicted during
extractions, i.e. amount of bone
removed during the alveolectomy.
More surgical trauma requires
more healing time.
v Individual patient factors.
Smokers may require extended
healing periods.

46. Preradiation extractions (cont’d)
Extraction of Third Molars
v Bony impactions –
Extraction of impacted third
molars is not advocated for
most patients. Such
extractions create large bony
defects which may take
several weeks to heal and may
delay radiation therapy.
v In this patient there appears to
be a layer of bone over the top
of the third molar.

47. Preradiation extractions (cont’d)
Extraction of Third Molars
v Bony impactions
` As noted previously
extraction of impacted
third molars is not
advocated for most
patients. However in this
patient extraction of the 1st
and 2nd molars exposed
the third molars to the oral
cavity and so they were
removed.

48. Preradiation extractions (cont’d)
Extraction of Third Molars
Bony impactions – Note the third molar (arrow). Following
removal, a radical alveolectomy was performed and the wound
closed primarily.
Extra time was required for this wound to heal prior to radiation
therapy- in this patient three weeks were necessary before
treatment commenced.

49. Preradiation extractions
(cont’d)
Extraction of Third Molars
v Partially
impacted third molars represent a
particularly perplexing problem. What would
you recommend for this patient?
Root canal therapy was performed on the
second molar, thereby avoiding
extraction of the third molar. The crown
was amputated to facilitate oral hygiene.

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55. The End
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