osteo integrated implant in maxillofacial rehabilitaiton hed23993

Osseointegrated Implant Based Dental Rehabilitation in Head and Neck

Reconstruction Patients

Sydney Chng, MD, PhD1,2,3, Roman J. Skoracki, MD1, Jesse C. Selber,

MD1, Peirong Yu, MD1, Jack W. Martin, DDS, MS4, Theresa M. Hofstede,

DDS4, Mark S. Chambers, DMD, MS4, Jun Liu, MD, PhD1, Matthew M.

Hanasono, MD1

1Department of Plastic Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA 2Department of Plastic Surgery, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia 3The Institute of Academic Surgery, University of Sydney, New South Wales, Australia 4Dental Oncology Section, Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA

Running Title: Osseointegrated Implants Funding: No funding was received for this study. Presented at: American Association of Plastic Surgeons 2013 Annual Meeting, New Orleans, LA Key Words: Head and Neck Cancer; Osseointegrated Implants; Microvascular Free Flaps; Fibula Free Flap; Prosthodontics

CORRESPONDING AUTHOR

Matthew M. Hanasono, M.D. Department of Plastic Surgery University of Texas M. D. Anderson Cancer Center 1515 Holcombe Boulevard, Unit 443 Houston, Texas 77030 Telephone: 713-794-1247 Fax: 713-794-5492 Email: [email protected]

This article has been accepted for publication and undergone full peer review but has not beenthrough the copyediting, typesetting, pagination and proofreading process which may lead todifferences between this version and the Version of Record. Please cite this article as anAccepted Article, doi: 10.1002/hed.23993

This article is protected by copyright. All rights reserved.

2

Abstract

Background: Dental restoration is an integral part of head and neck cancer

reconstruction.

Methods: We evaluated the success rate of osseointegrated implants in head

and neck cancer patients, comparing outcomes between implants placed in

fibula free flaps to those placed in native mandibular and maxillary bone.

Results: A total of 1132 implants were placed in 246 patients. The overall

implant loss rate was 3.7% and was higher in fibula flaps (8.2%) compared to

the native mandible (2.6%) and maxilla (2.2%), although these differences did

not reach statistical significance (p=0.059 and p=0.053, respectively). The

failure rate was 8.0% for implants placed after radiation and 3.6% in patients

who did not undergo radiation (p=0.097). Osteoradionecrosis occurred in 19

patients (7.7%) following implant placement, and tobacco use was found to be

a risk factor (p=0.027).

Conclusions: Osseointegrated implants are reliable in head and neck cancer

patients including those undergoing bony free flap reconstruction.

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Introduction

Advances in reconstructive surgery, particularly in the area of

microvascular reconstruction, have resulted in improved aesthetic and

functional outcomes for patients with head and neck cancer. However, in spite

of increasingly sophisticated reconstructive techniques, head and neck cancer

patients frequently lack functional dentition, which not only affects mastication,

but speech, swallowing, and appearance as well. Dental rehabilitation with

conventional prostheses following radiation therapy, tumor resection, and/or

flap reconstruction is often unsuccessful due to altered tissue contours and

lack of adequate dentition for fixation. In many cases, stable prosthetic

retention can only be achieved with the use of osseointegrated implants.1,2

The reliability and efficacy of osseointegrated implants have been well

documented in the non-cancer, edentulous population.3 In contrast, the

reliability, safety, and utility of osseointegrated implant placement in the head

and neck cancer population remains incompletely defined, mainly due to the

limited availability of large, single-center reports in the literature. Successful

dental restoration with implants is more challenging in this population given

the surgical resection of bone and mucosa and irradiation of oral cavity

tissues, as well as a high prevalence of tobacco use and other risk factors for

impaired healing. Additionally, implants in this population are often placed

into osseous free flaps.4-6 While successful osseointegration into osseous free

flaps has been reported in several case series, it is unclear whether they are

as reliable as implants placed into native mandibular and maxillary bone.

Our primary objective was to determine implant success rates in head

and neck cancer patients, comparing the outcomes of osseointegrated

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implants in vascularized osseous free flaps to implants placed in native

mandibular and maxillary bone. A secondary objective was to assess the

effect of risk factors associated with poor healing, such as radiation therapy,

chemotherapy, tobacco use, and diabetes mellitus. Finally, we evaluated how

many patients completed dental restoration, including implant placement,

uncovering, abutment placement, and prosthesis delivery.

Methods

This is a retrospective review of head and neck cancer patients who

underwent osseointegrated implant placement at our institution between 2005

and 2011, during which data was prospectively collected on patients who

received osseointegrated implants for dental restoration. Institutional review

board approval was obtained prior to undertaking this study. Dental

oncologists trained in prosthodontics placed all implants.

In our practice, patients with satisfactory remaining dentition and

dentoalveolar architecture are rehabilitated with conventional non-implant-

retained prostheses. In patients who were judged to require osseointegrated

implants for adequate prosthetic stability or had failed a trial of conventional

prosthesis use, implants were recommended provided the patient was

motivated to undergo the multi-stage procedure and would agree to regular

follow-up and practice adequate hygiene care. Insurance preauthorization

was sought in all potential osseointegrated implant candidates, and, as other

centers have experienced, only obtained in a subset of patients. Those

whose insurance would not reimburse for implant rehabilitation were given the

option of bearing the costs on their own.

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Implant success was defined as a painless and stable fixture without

evidence of peri-implant infection or radiographic lack of osseointegration.

The implant survival time was defined as the time interval from date of implant

placement to the date of implant failure or last follow-up date, whichever

occurred first. The Kaplan-Meier product-limit method was used to estimate

the cumulative survival rates. A log-rank test was used to compare the

cumulative time to first-implant-loss rate among the various groups.

A generalized estimating equation (GEE) model was applied in testing

for risk factors associated with implant loss, accounting for within-patient

correlation in the estimation. The chi-square and Fishers exact tests were

used as appropriate to investigate the association between various

parameters and successful completion of oral rehabilitation. Using step-wise

model selection, a multivariate logistic regression model was used to estimate

the odds ratios (OR) associated with significant risk factors for the

development of osteoradionecrosis. All tests were two-sided. A p-value of

6

extraction if indicated) prior to commencement of radiation therapy. All

osseous free flaps receiving osseointegrated implants in this study were fibula

free flaps.

Astra Tech implants (Dentsply Implants, Mannheim, Germany) were

used in all patients. When present, titanium reconstruction plates and screws

were partially or entirely removed if they interfered with proper placement of

osseointegrated implants in the delayed setting. Free flap skin paddle

debulking was performed as needed to optimize the soft tissue contour over

the alveolar ridge or fibula for prosthetic fitting.

Stage 2. The implants were uncovered, tested for stability (manually,

rather than by resonance frequency analysis, which is an objective measure

of magnet-induced vibration, not available at out center), and fitted with

abutments. Any unstable implants were removed or not used. Final soft tissue

modifications, including further free flap skin paddle debulking and

vestibuloplasty, which involved deepening the gingivolabial or gingivobuccal

sulcus and full-thickness skin grafting held in place with a bolster for 5 days,

were performed when necessary to create an optimal soft tissue platform for

the dental prosthesis. After healing, a removable dental prosthesis was

fashioned to complete the restoration, and revised subsequently as

necessary. Completion of Stage 2, with prosthesis fabrication and functional

loading of the implants, was considered a surrogate marker for successful

completion of dental implant oral rehabilitation in this study.

Results

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A total of 1132 implants were placed in 246 head and neck cancer

patients, including 166 males and 80 females, with a median age of 59 years.

Other demographic information, including potential risk factors for implant loss

is shown in Table 1. The dose of radiation ranged from 60 to 72 Gray and

intensity modulated radiation therapy (IMRT) was the modality used. Due to

the retrospective nature of the study, the precise radiation fields could not be

obtained and, therefore, it was not possible to estimate dosimetry to each of

the implant sites. Active tobacco use was defined as cigarette smoking within

30 days of implant placement. The diagnosis of diabetes mellitus included

patients with non-insulin dependent diabetes mellitus requiring treatment with

oral hypoglycemics (rather than diet-controlled) or insulin-dependent diabetes

mellitus. Primary tumor types, sites, and T and N classifications are shown in

Table 2.

Osseointegrated implants were placed immediately (at the time of

surgical ablation) in 115 patients (46.7%), and delayed in 90 patients (36.6%).

An additional 41 study patients (16.7%) did not undergo resection or flap

reconstruction. This group was treated with definitive radiation therapy or

combined radiation and chemotherapy, and underwent implant placement

following dental extraction 4 to 6 weeks prior to starting radiation therapy.

Osseointegrated implants were placed prior to beginning radiation therapy in

147 patients (59.8%) and after the conclusion of radiation therapy in 18

(7.3%). Eighty-one patients (32.9%) did not receive any radiation.

Sixty-six patients (26.8%) received soft tissue free flap reconstruction,

including radial forearm free flap (n=32), anterolateral thigh free flap (n=27),

ulnar artery perforator flap (n=4), rectus abdominis myocutaneous free flap

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(n=2), and lateral arm free flap (n=1). Sixty-seven patients (27.2%) had

osseous reconstruction using a fibula free flap. Fifty-four patients (22%) had a

total of 243 osseointegrated implants placed in their fibula free flaps (mean

number of implants, 4.5; range, 2-9). One hundred eighty-five patients had a

total of 618 implants placed in the native mandible, and 90 patients had a total

of 271 implants placed in the native maxilla (Table 3). The rate of successful

implant osseointegration and retention in the mandible, maxilla and fibula free

flap were 97.4%, 97.8% and 91.8%, respectively. There was a trend for

reduced implant survival in fibula free flaps as compared with the native

mandible and maxilla that did not reach statistical significance (p=0.059 and

p=0.057, respectively).

Overall, 42 of the 1132 implants (3.7%) were lost in 22 of 246 patients

(8.9%) at a median time of 33.7 months (range, 0.9 to 92.7 months). Further

analysis revealed that the implant failure rate was progressive over time,

increasing from 1.4% at 12 months to 3.9% with follow-up greater than 36

months, and to 5.1% for those followed over 60 months (Table 4). Most of the

implants lost in the native mandible and maxilla occurred in the first 3 years,

but implants placed in fibula free flaps experienced increasing attrition beyond

60 months (Figure 1). In the group that received surgery with or without

chemoradiation, 37 implants out of 964 were lost (3.8% loss rate). In the

group that received only radiation or radiation plus chemotherapy, 5 out of

168 implants were lost (3.0% loss rate). This difference was not statistically

significant (p=0.82).

Implant failure was more common in the subgroup that had implants

placed after radiation therapy (8.0%), compared to those who did not undergo

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radiation therapy (3.6%). This difference, however, was not statistically

significant (p=0.097) (Table 5 and Figure 2). Further analysis based on the

site of implant placement showed that implants placed in a fibula that never

received radiation were less likely to fail than those placed in bone that had

received radiation prior to or following radiation (5.1% vs.13.0% and 18.6%,

p

10

A univariate analysis examining age>65, diabetes mellitus, active

smoking (vs. prior smoking and nonsmoking status), chemotherapy, and free

flap type (none vs. soft tissue free flap vs. fibula free flap), demonstrated

active smoking to be a significant risk factor for the development of ORN

(p=0.027; other data not shown). Similarly, a multivariate logistic regression

model for the development of ORN also found active smoking to be a

significant risk factor (OR=2.84; 95% confidence interval (CI)=1.01-7.98;

p=0.048).

Long-term follow-up information was incomplete for 16 patients (6.5%),

including 10 who pursued dental rehabilitation at another institution. Of the

remaining 230 patients (93.5%), 184 (80.0%) completed Stage 2 (i.e.,

fabrication of and functional loading with permanent prosthesis). The median

time from implant placement until completion of Stage 2 was 7.0 months

(range, 1.1 to 23.2 months).

Disease recurrence was associated with failure to complete Stage 2

(p

11

Osseointegrated implants provide prosthetic retention that is generally

superior to traditional dentures secured by clasps to the remaining teeth or

dental adhesives in the edentulous. Osseointegrated implants also result in

retention of bone height, while traditional dentures are associated with gradual

bone loss. In edentulous patients, bone loss is frequently progressive over

time to the point that stable fixation is impossible. This is an outcome study of

osseointegrated implant dental rehabilitation in a large oncologic patient

cohort from a single institution. The results demonstrate that osseointegrated

implants are very reliable, even in a cohort of highly challenging patients.

Our overall implant survival rate of 96.3% at a median follow-up period

of 33.7 months (92.8% and 92.2% for those followed up to 3 and 5 years,

respectively) is within the range of figures previously reported in the literature,

which includes implant survival rates of 81 to 99%, averaging 87% in studies

ranging from 0 to 10 years in head and neck cancer patients.2,5-12 In keeping

with Shaw et al.2 and Watzinger et al.,13 but in contrast to Schliephake et al.,14

we found the vascularized free flaps to be less reliable in retaining

osseointegrated implants, though still with a relatively high survival rate of

91.8%.2,13,14

In this study, the administration of radiation therapy, and the sequence

of radiation therapy in relation to implant placement did not significantly affect

the implant survival rate, except in fibula free flaps. In our series, 59.8% of

patients who underwent surgical resection of a primary tumor either

underwent implant placement at the time of ablative surgery into the native

mandible or maxilla, or in cases of microvascular osseous free flap

reconstruction, as a secondary staged procedure into the neomandible that

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took place prior to commencement of radiation therapy while 7.3% of patients

had implant placement following the completion of radiation therapy. Primary

or early implant placement has been thought to be more reliable because the

detrimental effects of radiation therapy on bone do not seem to begin until

about 6 weeks after radiation therapy has started.15 Since radiation therapy

does not usually begin until 4 to 6 weeks following the ablative surgery, it is

believed that there is sufficient time for osseointegration to take place prior to

exposure to the damaging effects of radiation therapy.4

The proponents of secondary implant placement have argued that a

delayed approach allows for more comprehensive assessment of disease

status, oral function, and patient motivation, as well as more precise

prosthetic planning.4 Several clinical studies, supplemented by histology

studies in animals, have demonstrated that dental osseointegrated implants

placed in irradiated recipient bed are reliable.2,3,16-18 Most, however, advocate

for a delay of at least nine months following radiation therapy to allow for

recovery of the bony tissue from the deleterious effects of irradiation on

cellularity and vascularity.19,20 While our failure rates for implants placed into

irradiated native mandibular and maxillary bone was 0%, the 18.6% failure

rate for implants placed into fibular bone suggests that irradiation might be

considered a relative contraindication to implant placement in osseous free

flaps.

The incidence of ORN occurring after implant placement in our patient

cohort was 7.7%. A recent paper by Tsai et al.21 from our institution quoted a

7.5% ORN rate among 402 oropharyngeal cancer patients receiving definitive

radiation therapy between 2000 and 2008. Epstein et al.22 found the incidence

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of mandibular ORN in head and neck cancer patients to range from 5.8 to

44.2% based on approximately 4000 subjects in 13 studies combined. These

disparate figures may result from the subjectivity in diagnosis, with the

spectrum of presentation ranging from a clinically inconsequential small area

of bone exposure to a complex orocutaneous fistula or a pathologic fracture,

and the varying clinicodemographic parameters within different patient

population. In our series, several pathologic fractures were noted in implanted

patients and required segmental mandibulectomy and bony free flap

reconstruction. Our experience with implant loss secondary to ORN in fibula

free flaps is limited, but, in all 4 cases recorded, resulted in complete loss of

all implants placed into the free flap, and fibular fracture in 1 case.

Active smoking was a predictor for ORN in our patients. Other factors

reported in the literature to be associated with ORN include radiation therapy

to more than 50% volume of the mandibular body, alcohol consumption,

larger tumors, advanced age, increased radiation dose, hyperfractionation,

dentate (versus edentulous) state, post-radiation dental extractions, tumor

location (retromolar trigone at increased risks), poor oral hygiene and poor

nutritional status. Given the morbidity of ORN observed in our series, we

would recommend that active smoking in irradiated patients be considered a

contraindication to secondary implant placement in all patients, and that it

probably even be considered a contraindication to implant loading in patients

who have had implant placement prior to irradiation.

Some evidence suggests that hyperbaric oxygen (HBO) therapy is

associated with improved outcomes in preventing and healing late radiation

tissue injury in the head and neck.23 However, it has not been found, based

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on the limited amount of clinical research available, to offer any appreciable

clinical benefits specifically in irradiated patients requiring dental implants.24

Because HBO is employed as treatment rather than prophylaxis for ORN in

our practice, we are unable to answer the question of whether it is effective in

preventing implant loss with our data.

In this series the oral rehabilitation completion rate was 80%. Other

studies have quoted completion rates of 35 to 75%.7 While patient selection in

this series may be considered liberal, our practice is governed to a large

extent by practicality; many of our patients are referred from distant locations,

and desire to consolidate surgical procedures, favoring primary implant

placement. Patients are asked to opt for implant placement many times at the

start of their cancer treatment, in order to minimize the number of surgical

procedures as well as to avoid implant placement following radiation therapy.

However, at that time, the final oral function (i.e., speech and swallowing) is

unknown, as is the potential other functional problems, such as oral

incompetence or trismus that might result in patients not completing dental

rehabilitation. In this initial experience, we did try to select for patients who

had good oncologic and functional prognosis to undergo implant placement,

but acknowledge that functional outcomes in head and neck cancer are often

hard to predict and may change over time, resulting in failure to complete

dental restoration or a prosthesis that is primarily cosmetic in nature, which

may still be of considerable value to many patients. Because cancer

recurrence is the predominant obstacle to completion of oral rehabilitation, an

argument can be made for delaying implant placement, for example, until after

the median time to diagnosis of recurrence (11.2 months following definitive

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treatment), particularly in patients with more advanced disease. Of note, in

our practice, osseointegrated implant dental rehabilitation has been generally

funded by health insurance or, less commonly, self-funded.

Some have advocated the replacement of free flap skin paddle around

osseointegrated implant with mucosal grafts because the latter protect against

marginal bone loss and peri-implant inflammation.25 We routinely debulk the

fibula free flap soft tissue and skin paddle for implant placement, but have not

found peri-implant skin to be problematic enough to prompt a change in

practice. In non-irradiated patients in whom the soft tissue component is

bulky, the skin paddle can be excised in a delayed setting and the periosteum

left to mucosalize.

One challenge in studying implant loss is the most appropriate way to

count and analyze endpoints.13 Comparison of outcomes from previously

published papers on osseointegrated dental rehabilitation has to be

undertaken with caution. There is reasonable overall agreement on the criteria

for implant survival/success, but there continues to be a lack of consensus on

the most appropriate form of statistical analysis. Varied treatment protocols

and reconstructive techniques further compound making effective

comparisons. We decided to study our patients undergoing osseointegrated

implant placement utilizing a simple input/output analysis when presenting

implant survival/loss, Kaplan-Meier curves to depict time to first implant loss in

a patient, and a GEE model in testing for risk factors associated with implant

survival in order to account for within-patient correlation.

Conclusions

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Osseointegrated dental rehabilitation is safe and reliable in head and

neck cancer patients. Implant failure rates are higher in fibula free flaps

compared to the native mandible or maxilla, but success rates still exceed

91%. Radiation therapy adversely affects implant survival in fibula free flaps

but not the native mandible or maxilla. Disease recurrence is the biggest

impediment to successful completion of rehabilitation.

Based on our findings, we consider patients who have received or will

receive cancer treatment for curative intent, demonstrate motivation for dental

rehabilitation and compliance with proper oral hygiene, and have the financial

and social resources to complete the dental rehabilitation process candidates

for osseointegrated implant placement. If patients have received prior

irradiation, we require that they not be active smokers. We consider prior

irradiation a relative contraindication to implant placement in fibula free flap

bone. We are now actively exploring the effect of hyperbaric oxygen on

improving success rates in this subgroup.

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References 1. Teoh KH, Huryn JM, Patel S, Halpern J, Tunick S, Wong HB, Zlotlow IM.

Implant prosthodontic rehabilitation of the fibula free flap reconstructed

mandibles: a Memorial Sloan-Kettering Cancer Center Review of

prognostic factors and implant outcomes. Int J Oral Maxillofac Implants.

2005;20:855-863.

2. Shaw RJ, Sutton AF, Cawood JI, Howell RA, Stat DL, Brown JS, Rogers

SN, Vaughan ED. Oral rehabilitation after treatment for head and neck

malignancy. Head Neck. 2005;27:459-470.

3. Granstrm G, Tjellstrm A. Brnemark P, Fornander J. Bone-anchored

reconstruction of the irradiated head and neck cancer patient. Otolaryngol

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4. Kildal M, Wei FC, Chang YM, Chen HC, Chang MH. Mandibular

reconstruction with fibula osteoseptocutaneous free flap and

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5. Chana JS, Chang YM, Wei FC, Shen YF, Chan CP, Lin HN, Tsai CY, Jeng

SF. Segmental mandibulectomy and immediate free fibula

osteoseptocutaneous flap reconstruction with endosteal implants: an ideal

treatment method for mandibular ameloblastoma. Plast Reconstr Surg.

2004;113:80-87.

6. Urken ML, Buchbinder D, Costantino PD, Okay D, Lawson W, Biller HF.

Oromandibular reconstruction using microvascular composite flaps. Arch

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cancer. Curr Opin Otolaryngol Head Neck Surg. 2012;20:109-113.

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8. Barrowman RA, Wilson PR, Wiesenfeld D. Oral rehabilitation with dental

implants after cancer treatment. Aust Dent J. 2011;56:160-165.

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patients with and without radiotherapy. Acta Oncologica. 1998;37:693-696.

11. Cuesta-Gil M, Ochandiano Caicoya S, Riba-Garca F, Duarte Ruiz B,

Navarro Cullar C, Navarro Vila C. Oral rehabilitation with osseointegrated

implants in oncologic patients. J Oral Maxillofac Surg. 2009;67:2485-2496.

12. Cheung LK, Leung AC. Dental implants in reconstructed jaws: implant

longevity and peri-implant tissue outcomes. J Oral Maxillofac Surg.

2003;61:1263-1274.

13. Watzinger F, Ewers R, Henninger A, Sudasch G, Babka A, Woelfl G.

Endosteal implants in the irradiated lower jaw. J Craniomaxillofac Surg.

1996;24:237-244.

14. Schliephake H, Neukam FW, Schmelzeisen R, Wichmann M. Long-term

results of endosteal implants used for restoration of oral function after

oncologic surgery. Int J Oral Maxillofac Surg. 1999;28:260-265.

15. Stoll P, Wachter R, Hodapp N, Schilli W. Radiation and osteosynthesis:

dosimetry on an irradiation phantom. J Craniomaxillofac Surg.

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16. Keller EE. Placement of dental implants in the irradiated mandible: a

protocol without adjunctive hyperbaric oxygen. J Oral Maxillofac Surg.

1997;55:972-980.

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17. Nishimura RD, Roumanas E, Beumer III J, Moy PK, Shimizu KT.

Restoration of irradiated patients using osseointegrated implants: current

perspectives. J Prosthet Dent. 1998;79:641-647.

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previously irradiated mandible: results of a limited trial at 3 to 7 years. J

Prosthet Dent. 1993;69:60-69.

19. Jacobsson MG, Jnsson AK, Albrektsson T, Turesson JE. Short and long-

term effects of irradiation on bone regeneration. Plast Reconstr Surg.

1985;76:841-848.

20. Larsen PE, Stronczek MJ, Liston T. Implant osseointegration in irradiated

rabbit tibia with and without hyperbaric oxygen. J Oral Maxillofac Implants.

1992;7:125-133.

21. Tsai CJ, Hofstede TM, Sturgis EM, Garden AS, Lindberg ME, Wei Q,

Tucker SL, Dong L. Osteoradionecrosis and radiation dose to the

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oxygen therapy for late radiation tissue injury. Cochrane Database Syst

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irradiated patients who require dental implants. Cochrane Database Syst

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Figure Legend

Figure 1. Time to first osseointegrated implant loss by osseointegrated

implant site.

Figure 2. Time to first implant osseointegrated loss by timing of radiotherapy.

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Tables Table 1. Patient characteristics

Variable No. of Patients (%) (n=246)

No. of Implants (%) (n=1132)

Age >65 Years 88 (35.8) 383 (33.8)

Preoperative Radiation 18 (7.3) 100 (8.8)

Postoperative Radiation 147 (59.8) 695 (61.4)

Chemotherapy 99 (40.2) 480 (42.4)

Tobacco Use 102 (41.5) 471 (41.6)

Diabetes mellitus 38 (15.5) 153 (13.5)

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Table 2. Primary tumor type, site, and classification. Subsite

Type Buccal FOM Lip Mandible Nasal/

Maxillary

Pharynx Skin Tongue

ACC 0 2 0 1 4 1 0 2

Adenocarcinoma 0 0 0 1 2 0 0 0

Ameloblastic

Carcinoma

0 0 0 4 2 0 0 0

Desmoid Tumor 0 0 0 4 0 0 0 0

Fibrosarcoma 0 0 0 2 1 0 0 0

Hemangio-

endothelioma

0 0 0 0 1 0 0 0

Melanoma 0 0 0 1 2 0 0 0

MEC 0 0 0 2 1 0 0 0

ORN 0 0 0 22 3 0 0 0

Osteosarcoma 0 0 0 6 1 0 0 0

SCC 9 23 3 46 16 41 5 39

T1 0 4 1 0 0 2 0 0

T2 4 5 1 5 2 7 0 13

T3 2 2 1 3 3 13 3 10

T4 3 9 0 32 11 10 4 8

N0 2 13 3 23 4 9 0 10

N1 0 3 0 4 2 6 1 0

N2a 2 0 0 11 0 2 0 0

N2b 3 4 0 2 3 7 0 13

N2c 1 1 0 0 5 5 0 8

N3 1 0 0 0 0 3 0 0

Recurrent 0 2 0 6 2 9 0 8

Abbreviations: ACC, adenoid cystic carcinoma; FOM, floor of mouth; MEC,

mucoepidermoid carcinoma; ORN, osteoradionecrosis; SCC, squamous cell

carcinoma.

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Table 3. Osseointegrated implant loss by sites

Site

Median Follow- up Time (Yrs.)

Total No. of Patients

No. of Patients With Implant Loss (%)

Total No. of Implants

No. of Implant Loss (%)

All patients

2.8 246 22 (8.9) 1132 42 (3.7)

Mandible 2.8 185 9 (4.9) 618 16 (2.6)

Maxilla 2.6 90 3 (3.3) 271 6 (2.2)

Fibula 3.1 54 10 (18.5) 243 20 (8.2)*

*The implant loss rate in fibula flaps was not significantly lower than in the

native mandible (p=0.059) or native maxilla (p=0.057).

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Table 4. Cumulative osseointegrated implant loss rate

Cumulative implant loss rate

Site 1 year 3 years 5 years

All patients 1.4% 3.9% 5.1%

Free flap 2.6% 7.4% 7.4%

Mandible 0.9% 3.3% 4.5%

Maxilla 1.3% 2.0% 4.7%

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Table 5. Univariate analysis of risk factors for osseointegrated implant loss

Variable No. of Successful Implants (%)

No. of Implants Lost (%)

p-Value

Age >65 years 363 (94.8) 20 (5.2) 0.322

Preoperative Radiation 92 (92) 8 (8) 0.097

Postoperative Radiation 673 (96.8) 22 (3.2) 0.734

Pre- or Postoperative Radiation

765 (96.2) 30 (3.8) 0.704

Active Smoking 457 (97) 14 (3) 0.441

Diabetes Mellitus 147 (96.1) 6 (3.9) 0.832

Chemotherapy 471 (98.1) 9 (1.9) 0.162

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Table 6. Osseointegrated implant loss by site and timing of radiotherapy

Site Timing of Radiation

Total no. of implants placed

Total no. of implants lost (%)

p-Value

No Radiation 177 9 (5.1)

Fibula Preoperative Radiation

43 8 (18.6) 0.041

Postoperative Radiation

23 3 (13.0)


Mandible Preoperative Radiation

38 0 0.769


457 14 (3.1)


Maxilla Preoperative Radiation

19 0 0.303


215 5 (2.3)

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Table 7. Univariate analysis of parameters in completion of dental rehabilitation*

Variable No. of Patients Completing Oral Rehabilitation

p-Value

Age >65 Years 69 (82.1%) 0.609

Preoperative Radiation 12 (66.7%) 0.357

Postoperative Radiation 110 (82.7%) 0.471

Pre- or Postoperative Radiation 122 (80.8%) 0.729

Chemotherapy 69 (75.8%) 0.239

Tobacco Use 73 (77.7%) 0.505

Diabetes Mellitus 27 (75%) 0.496

Recurrence 31 (60.8%)

253x253mm (300 x 300 DPI)

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253x253mm (300 x 300 DPI)

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osteo integrated implant in maxillofacial rehabilitaiton hed23993

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