Dental implants in irradiated bone

ZWETCHKENBAUM,SAMUEL

1. Marx RE
Clinical application of bone biology to mandibular and maxillary reconstruction.

In: Clin Plast Surg (1994 Jul) 21(3):377-92
CLINICS IN PLASTIC SURGERY

Bony reconstruction of the mandible and maxilla is accomplished through the application of three general approaches: cancellous marrow grafts, cranial bone grafts, and microvascular transfers. This article discusses each of these techniques in detail.

2. Franzen L Rosenquist JB Rosenquist KI Gustafsson I
Oral implant rehabilitation of patients with oral malignancies treated with radiotherapy and surgery without adjunctive hyperbaric oxygen.

In: Int J Oral Maxillofac Implants (1995 Mar-Apr) 10(2):183-7
INTERNATIONAL JOURNAL OF ORAL AND MAXILLOFACIAL IMPLANTS

Five patients treated with radiotherapy and surgery for oral malignant tumors had a total of 20 Brånemark implants placed in irradiated bone of the mandible. The radiotherapy dose varied between 25 and 64 Gy (mean 40.3 Gy) with a biologically effective dose varying between 33.4 and 106.9. One implant did not osseointegrate, but 19 remain stable after 3 to 6 years of observation. The oral surgery procedures were carried out without adjunct hyperbaric oxygen therapy, and the successful results support the view that such adjunctive measures are not always necessary in the oral rehabilitation after radiotherapy.

3. Granstrom G Tjellstrom A Albrektsson T
Postimplantation irradiation for head and neck cancer treatment.

In: Int J Oral Maxillofac Implants (1993) 8(5):495-501
INTERNATIONAL JOURNAL OF ORAL AND MAXILLOFACIAL IMPLANTS

Eleven patients who had undergone surgical treatment for head and neck cancer and had titanium implants placed for skin-penetrating prostheses were irradiated postimplantation. The absorbed doses of irradiation to the implant region varied between 50 and 80 Gy. The time interval between implant surgery and irradiation varied from 4 to 60 months. Of 32 fixtures placed, 2 were removed as part of extended tumor surgery and 2 were lost in conjunction with induced chemotherapy. Five of the patients showed skin dehiscences around 9 implants after completed irradiation. Osteoradionecrosis developed in three of the patients after radiotherapy. If irradiation is to be performed in areas where titanium implants have been placed, it is recommended that all prostheses, frameworks, and abutments be removed before irradiation; the fixtures should be allowed to remain intact but should be covered with skin or mucosa.

4. Johnsson K Hansson A Granstrom G Jacobsson M Turesson I
The effects of hyperbaric oxygenation on bone-titanium implant
interface strength with and without preceding irradiation.

In: Int J Oral Maxillofac Implants (1993) 8(4):415-9
INTERNATIONAL JOURNAL OF ORAL AND MAXILLOFACIAL IMPLANTS

This study investigated the influence of a single 15-Gy dose of irradiation on the capacity of titanium screws to integrate in irradiated bone tissue. The biomechanical force necessary to unscrew the titanium implants 8 weeks after placement was 54% lower for implants in irradiated bone tissue compared to implants in nonirradiated bone tissue. Postirradiation use of hyperbaric oxygen treatment at 2.8 ATA (2-hour daily treatments for 21 days) increased the biomechanical force necessary to unscrew the titanium implants by 44% in irradiated bone and by 22% in nonirradiated bone.

5. Ueda M Kaneda T Takahashi H
Effect of hyperbaric oxygen therapy on osseointegration of titanium
implants in irradiated bone: a preliminary report.

In: Int J Oral Maxillofac Implants (1993) 8(1):41-4
INTERNATIONAL JOURNAL OF ORAL AND MAXILLOFACIAL IMPLANTS

Four patients who had undergone combined surgical and radiotherapeutic treatment for maxillofacial cancer had osseointegrated titanium implants placed in the bone of the treated region at various intervals after irradiation. Preoperatively and postoperatively, hyperbaric oxygen therapy was administered to the patients at the level of 2 or 3 atmosphere absolute (ATA). Of the 21 fixtures placed, one was lost because of lack of osseointegration, rendering the survival rate 92.3%. Hyperbaric oxygen therapy seemed to be a viable method to improve the survival rate of fixtures in irradiated bone tissue.

6. Granstrom G Jacobsson M Tjellstrom A
Titanium implants in irradiated tissue: benefits from hyperbaric
oxygen.

In: Int J Oral Maxillofac Implants (1992 Spring) 7(1):15-25
INTERNATIONAL JOURNAL OF ORAL AND MAXILLOFACIAL IMPLANTS

Since the introduction of osseointegrated titanium implants for bone-anchored facial and dental prostheses, an increasing number of irradiated patients are being treated with this technique. Although the number of patients who have had titanium implants after irradiation is limited, available statistics point to a tendency of a higher implant loss frequency as compared with nonirradiated patients. This review discusses factors behind deleterious tissue effects and implant failures from irradiation and points to possibilities to improve the surgical outcome with special reference to hyperbaric oxygen therapy.

7. Parel SM Tjellstrom A
The United States and Swedish experience with osseointegration and
facial prostheses.

In: Int J Oral Maxillofac Implants (1991 Spring) 6(1):75-9
INTERNATIONAL JOURNAL OF ORAL AND MAXILLOFACIAL IMPLANTS

A survey of experience treating patients with extraoral implants for facial prosthesis retention in 13 United States centers and in Sweden has been completed. Patients who have not received radiation for elimination of malignant disease can be treated with reasonably good expectations for long-term success. Reported success rates indicate that patients who have received radiation should be selected carefully and treated with caution, since overall success rates in this category are disappointingly low.

8. Sindet-Pedersen S
The transmandibular implant for reconstruction following radiotherapy
and hemimandibulectomy: report of a case.

In: J Oral Maxillofac Surg (1988 Feb) 46(2):158-60
JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY

9. Barber HD Seckinger RJ Hayden RE Weinstein GS
Evaluation of osseointegration of endosseous implants in radiated,
vascularized fibula flaps to the mandible: a pilot study.

In: J Oral Maxillofac Surg (1995 Jun) 53(6):640-4; discussion 644-5
JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY

PURPOSE: This study clinically evaluated the osseointegration of implants placed into vascularized fibula flaps used in mandibular reconstruction of cancer patients following radiation treatment and subsequent hyperbaric oxygen (HBO) therapy. MATERIALS AND METHODS: Five head and neck cancer patients had mandibular resection and immediate reconstruction with a vascularized fibula flap. Subsequent therapy included greater than 50 Gy of radiation to the fibula flap over a 6 to 8-week period. Two to 6 weeks following radiation therapy each patient received 20 90-minute daily sessions of HBO at 2.4 atmosphere pressure. Stage 1 implant surgery was performed placing two to six implants (15 mm in length and 3.75 to 4.0 mm in width) into each fibula flap. This was followed by 10 postoperative HBO sessions using the previously mentioned protocol. The stage 2 procedure was performed 6 months after the stage 1 procedure. Osseointegration was assessed clinically using manual force and an electronic device at the time the implants were uncovered and monthly over a 6-month period. RESULTS: All 20 implants placed in the fibula flaps were osseointegrated clinically at the time the implants were uncovered and during the 6-month follow-up. CONCLUSION: In this pilot
study, mandibular reconstruction with a vascularized fibula flap and endosseous osseointegrated implants, following radiation of the fibula, was successful. It was concluded that factors such as the graft having its own blood supply and the use of HBO contributed to the successful osseointegration of these implants.

10. Larsen PE Stronczek MJ Beck FM Rohrer M
Osteointegration of implants in radiated bone with and without
adjunctive hyperbaric oxygen.

In: J Oral Maxillofac Surg (1993 Mar) 51(3):280-7
JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY

A study was undertaken to evaluate the integration of endosseous implants in rabbit tibias that had received a tumoricidal dose of radiation. The effect of hyperbaric oxygen on integration in this compromised situation was also evaluated. Despite clinical and radiographic evidence of success of all implants, there was a significant decrease in amount of histologic bony integration of implants placed in the tibias that had received radiation therapy when compared to contralateral control implants. Adjunctive hyperbaric oxygen therapy significantly improved the amount of histologic integration of implants placed within the radiated tibias evaluated at 10 and 16 weeks after placement. Hyperbaric oxygen was also associated with better soft tissue wound healing in the radiated surgical site. Increased integration time significantly improved the amount of histologic integration in the animals that did not receive hyperbaric oxygen.

11. Mirza FD Dikshit JV
Use of implant prosthesis following radiation therapy.

In: J Prosthet Dent (1978 Dec) 40(6):663-7
JOURNAL OF PROSTHETIC DENTISTRY

12. Ballantyne AJ
A surgeon's view of mandibular resection and replacement.

In: J Prosthet Dent (1977 Jul) 38(1):42-51
JOURNAL OF PROSTHETIC DENTISTRY

13. Taylor TD Worthington P
Osseointegrated implant rehabilitation of the previously irradiated
mandible: results of a limited trial at 3 to 7 years.

In: J Prosthet Dent (1993 Jan) 69(1):60-9
JOURNAL OF PROSTHETIC DENTISTRY

The use of osseointegrated dental implants in patients with defects of the head and neck acquired as a result of ablative surgery for malignancy is an accepted and valuable extension of the well- documented use of these implants for the treatment of edentulism. In patients who have received ionizing radiation as part of tumor therapy, the use of dental implants is poorly documented. A limited trial of 21 Brånemark implants placed in the previously irradiated mandibles of four patients is reported here. The implants have been in place and functioning for periods of 3 to 7 years. No implants have been lost. Patient selection, treatment, and complications encountered are discussed. Guidelines for further use of osseointegrated implants in patients with previously irradiated mandibles are suggested.

14. Hellner D Schmelzle R
[Microvascular anastomoses in irradiated blood vessels in the area of
the mouth, jaw and face]

In: Laryngorhinootologie (1994 Apr) 73(4):202-5
LARYNGO- RHINO- OTOLOGIE (Published in German)

Pedicle and free microsurgical reanastomized vascularised flaps are useful to cover defects in an irradiated area. In 51 patients microvascular anastomoses were performed on irradiated vessels in the neck area. Facial reconstruction was done after radiation by free flaps. Seventeen jejunum, 10 myocutaneous, 21 iliac crest and 3 fibula flaps were transplanted. The time between irradiation and reconstruction varied between 2 and 144 months. Four anastomoses had to be revised, two flaps were totally lost. Although the vessels were damaged by preoperative radiotherapy, 92 percent of the anastomoses were patent. This success rate is as high as in anastomoses on non- irradiated vessels.

15. Granstrom G Tjellstrom A Branemark PI Fornander J
Bone-anchored reconstruction of the irradiated head and neck cancer
patient.

In: Otolaryngol Head Neck Surg (1993 Apr) 108(4):334-43
OTOLARYNGOLOGY - HEAD AND NECK SURGERY

Titanium implants in facial bones for retention of epitheses or dental bridges were used for reconstruction in cancer patients after tumor surgery. Even heavily irradiated bones could integrate the implants and bear the load from the epithesis. No major complications, such as wound infection, fistulation, or osteoradionecrosis, occurred after implant surgery. There was, however, an increased loss of implants with time after irradiation, especially in the orbital region. When hyperbaric oxygen was used as adjunctive treatment, implant losses were reduced.

16. Jacob RF Reece GP Taylor TD Miller MJ
Mandibular restoration in the cancer patient: microvascular surgery
and implant prostheses.

In: Tex Dent J (1992 Jun) 109(6):23-6
TEXAS DENTAL JOURNAL

This article deals with state of the art reconstruction and rehabilitation of the head and neck cancer patient who requires mandibular resection. The mandible can be reconstructed by microvascular free tissue transfer of bone and soft tissue from distant body sites. The dental units and missing soft tissue contours can be supported by osseointegrated implants placed in the grafted bone. This article discusses the rationale for patient selection and sequencing of this complex and rewarding rehabilitation.

17. Shimizu KT Nishimura RD Withers HR
The risk of fracture after placement of dental implants in irradiated
bone (Meeting abstract).

In: International Congress of Radiation Oncology 1993. June 21-25,
1993, Kyoto, Japan, 1993. (1993):422

A randomized pilot study was conducted to determine the effect on risk of bone fracture and histopathology after placement of titanium dental implants in differentially irradiated bone. Thirty six adult New Zealand female rabbits were randomly assigned to 6 conventional XRT dose equivalent groups of 40, 46, 52, 58, 64, or 70 Gy, delivered in 8 treatment fractions given over 32 days. The experimental dose scheme was determined using an alpha/beta ratio of 3.55 Gy derived from literature data. Each animal received megavoltage XRT to both tibias and 3 mo later, each left tibia had endosseous titanium implants placed, while the right tibia acted as an internally matched XRT alone control. Tibial fractures were recorded over the ensuing 3 months and histopathology of the fractured leg and its matched control was performed. At the end of the experiment, 29 rabbits were available for evaluation. In this cohort, a significant increased risk of fracture after XRT and implantation was noted. In the XRT + implant tibias, the incidence of fracture was 11/28, and in the XRT alone control, the incidence of fracture was 1/29 (p=0.0009), by Chi- square analysis. The isolated control fracture occurred in the 64 Gy group 6 wk after treatment. There was a trend toward increased risk of fracture after implantation with doses greater than or equal to 64 Gy (p = 0.27). The distribution of fractures for the XRT + implant bone was 33%, 40%, 33%, 25%, 67% and 50% for XRT dose groups noted above (from 40 to 70 Gy, respectively). All fractures occurred within 3 weeks after implantation (median = 14 days, range = 5-21 days). Correlation of histopathology was also determined. This preliminary study concludes that after high dose XRT (greater than or equal to 64 Gy), placement of endosseous implants can increase the risk of fracture when placed 3 mo after completion of XRT.

18. Beumer J 3rd Roumanas E Nishimura R
Advances in osseointegrated implants for dental and facial
rehabilitation following major head and neck surgery.

In: Semin Surg Oncol (1995 May-Jun) 11(3):200-7
SEMINARS IN SURGICAL ONCOLOGY

Osseointegrated implants can be used to facilitate retention stability and support for facial and intraoral prostheses used to restore head and neck defects. Preliminary studies indicate that in nonirradiated maxillectomy patients the success rates are about 75%. In the reconstructed mandible the results appear to be more favorable- -over 90% for implants placed in free nonvascularized bone grafts and over 90% for free revascularized bone grafts. Similar high success rates have been observed for most sites used to support facial prostheses. Success rates for auricular sites exceed 95% and for floor of nose sites success rates exceed 90%. Success rates have been lower (77%) for implants placed in the frontal bone for retention of orbital prostheses. Success rates for irradiated bone sites have been lower and range from 60.4% in the maxilla to 68.6% in facial bone sites. Of greater concern is that most implants placed in irradiated sites are beginning to show signs of impending failure.