Survival of dental implants in patients with oral cancer treated by surgery and radiotherapy: a retrospective study.

BACKGROUND: The aim of this retrospective study was to evaluate the survival of dental implants placed after ablative surgery, in patients affected by oral cancer treated with or without radiotherapy. METHODS: We collected data for 34 subjects (22 females, 12 males; mean age: 51 ± 19) with malignant oral tumors who had been treated with ablative surgery and received dental implant rehabilitation between 2007 and 2012. Postoperative radiation therapy (less than 50 Gy) was delivered before implant placement in 12 patients. A total of 144 titanium implants were placed, at a minimum interval of 12 months, in irradiated and non-irradiated residual bone. RESULTS: Implant loss was dependent on the position and location of the implants (P = 0.05-0.1). Moreover, implant survival was dependent on whether the patient had received radiotherapy. This result was highly statistically significant (P < 0.01). Whether the implant was loaded is another highly significant (P < 0.01) factor determining survival. We observed significantly better outcomes when the implant was not loaded until at least 6 months after placement. CONCLUSIONS: Although the retrospective design of this study could be affected by selection and information biases, we conclude that a delayed loading protocol will give the best chance of implant osseointegration, stability and, ultimately, effective dental rehabilitation.

Hypothyroidism after radiotherapy of head and neck cancer.

AIM: Hypothyroidism is not commonly considered as a complication of radiotherapy to the head and neck region. The purpose of this retrospective study was to determine the frequency of thyroid dysfunction in patients after radiotherapy, to compare thyroid hormone levels in irradiated patients with Control group and to predict development of thyroid hypofunction in time. MATERIAL AND METHOD: Thyroid function was measured by means of thyroid stimulating hormone (TSH), free thyroxine (FT4) and free triiodthyronine (FT3) in 43 patients who had nonthyroid head-neck carcinomas treated by radiotherapy or radiotherapy in combination with other modalities. These data were compared with hormone levels of 40 Control group patients treated solely by surgery. RESULTS: Hypothyroidism was found in 35% of irradiated patients. In comparison with Control group there were significant differences between TSH and FT4 levels, difference between FT3 levels was insignificant. A correlation between hormone levels and follow-up was detected. CONCLUSION: Our results indicate that hypothyroidism is a frequent late side effect of radiotherapy to head and neck. Lifelong monitoring of thyroid function appears to be justified when radiotherapy is a part of treatment protocol.

Computerized tomography, stereolithography and dental implants in the rehabilitation of oral cancer patients.

UNLABELLED: As survival rates improve it is important to consider the quality of life for oral cancer patients post-treatment. The primary goal is removal of the tumour, however, with a gradual increase in survival rates, post-operative rehabilitation is now becoming increasingly important. Specialists in restorative dentistry, along with oral and maxillofacial surgeons, general dental practitioners and other members of the multidisciplinary team play a vital role in planning treatment for, and rehabilitating, these patients. This paper presents a case series to show how recent advances in computerized tomography (CT) and the use of stereolithographic models can help in the rehabilitation of oral cancer patients. CLINICAL RELEVANCE: The principles discussed can also be applied to other patients undergoing dental implant treatment to help plan and carry out treatment and improve the quality of peri-implant tissues.

[Primary intraosseous mucoepidermoid carcinoma of the jaws]. / Carcinome muco-épidermoïde intra-osseux des mâchoires.

INTRODUCTION: A mucoepidermoid carcinoma (MEC) is a malignant salivary gland tumor. Its primitive intraosseous maxillary localization is rare. We report a case with a difficult diagnosis. CASE REPORT: A 42-year-old female patient consulted atypical right sinus area pain. The CT scan revealed a heterogeneous tumor lyzing the right maxillary. The surgical treatment was broad resection. The pathological examination indicated an intramaxillary MEC. The surgical treatment was completed by postoperative radiotherapy. DISCUSSION: Primary intraosseous MEC of the jaws is rare and often affects the mandible. Its intraosseous maxillary localization is even rarer. Its etiopathogenesis is still unknown. The treatment is usually surgical, and the prognosis is based on histological criteria.

Radiation cataract: clinicopathologic report.

UNLABELLED: We report the case of a 52-year-old woman who developed bilateral anterior and posterior subcapsular cataracts with anterior capsule fibrosis 12 years after exposure to intensive radiation therapy. The woman had uneventful cataract surgery and gained 20/20 corrected distance visual acuity in both eyes. Hematoxylin-eosin staining of the anterior capsule revealed significant subcapsular scar formation in the context of fibroblast proliferation. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Ameloblastoma, a rare benign odontogenic tumour: an interesting tumour review targeting the role of radiation therapy.

Ameloblastoma is known as a benign, slow-growing, rare, odontogenic neoplasm. The solid/multicystic, the unicystic with a fibrous connective-tissue capsule and the peripheral ameloblastoma represent the three well distinguished clinical types of ameloblastoma. Surgical resection with an attempt to achieve adequate free margins constitutes a well documented and accepted treatment modality. Controversies exist, however, with regard to the extent of operative intervention. Patients with inadequate or positive surgical margins or unresectable lesions can be treated with radiation or combined radiation and chemotherapy. The authors present a review of this sparse disease focusing on the special role and efficacy of radiation therapy in its management.

Oral rehabilitation with dental implants after cancer treatment.

BACKGROUND: Patients who undergo surgical management of oral cancer may greatly benefit from an implant-supported prosthesis. This study reports on the clinical experience of dental implant placement in patients following resection of oral cancer over a 15-year period. Controversies including the use of dental implants in irradiated tissues, and hyperbaric oxygen treatment will also be discussed. METHODS: Thirty-one patients who had dental implants placed as part of their oral rehabilitation between 1992 and 2007 were investigated. Demographic data and factors including implant survival, type of prosthesis provided, radiotherapy and the hyperbaric oxygen therapy were analysed. RESULTS: In this retrospective study, there was a retention rate of 110 implants from a total of 115 implants placed. A high rate of implant retention was found, with 5 implant failures from a total of 115 implants placed. The 5 failed implants occurred in free flap bone that had been irradiated. CONCLUSIONS: Dental implants provide an important role in the oral rehabilitation of oral cancer patients. There may be an increased risk of implant failure in free flap bone that has been irradiated.

Extraoral prostheses using extraoral implants.

The aim of this study was to evaluate extraoral prostheses and the use of extraoral implants in patients with facial defects. 10 cases were treated utilizing maxillofacial prostheses employing extraoral implants in five cases. 16 extraoral implants were installed. Seven implants were placed in irradiated sites in the orbital regions. Six implants were placed in mastoid regions and three in a zygoma region that was irradiated. Two implants failed before initial integration was achieved in irradiated areas. Using 14 extraoral implants as anchors, five extraoral prostheses were set. The other five cases were treated with extraoral prostheses without using extraoral implants due to cost and patient-related factors. The data included age, sex, primary disease, implant length, implant failure, prosthetic attachment, radiation therapy, and peri-implant skin reactions. The use of extraoral implants for the retention of extraoral prostheses has simplified the placement, removal, and cleaning of the prosthesis by the patient. The stability of the prostheses was improved by anchors. Clinical and technical problems are presented with the techniques used for their resolution. Using extraoral implants resulted in a high rate of success in retaining facial prostheses and gave good stability and aesthetic satisfaction.

[Test of dose distribution of palatal denture applicator containing (125)I seeds].

OBJECTIVE: to measure the dose distribution (tissue absorbed dose) of palatal denture applicator containing (125)I. METHODS: simulated model of head and neck was used to wear the palatal dental applicator containing (125)I for the postoperative brachytherapy of a simulated tumor at a diameter of 2 cm in the palate. The denture contained 11 (125)I seed with radioactivity of 29.6 MBq per seed. The prescribed dose (edge matched dose) was 80 Gy. The absorbed dose in the simulated target and its adjacent area was measured by thermoluminescence dosimeters. RESULTS: the dose in the target area reached the value of treatment needs, and the dose absorbed by tissue around the target was lower except tongue. CONCLUSIONS: using palatal denture applicator containing (125)I for postoperative brachytherapy of malignant tumors of palate can get satisfied dose distribution, but the tongue needs to be protected.

Radiation effects on bone healing and reconstruction: interpretation of the literature.

OBJECTIVE: Reconstructing irradiated mandibles with biomaterials is still a challenge but little investigated. We collected data that could help us understand studies in the field of regeneration with biomaterials and irradiated bone. STUDY DESIGN: Systematic review of the literature. RESULTS: Delay and duration of radiation delivery and total equivalent dose are the most variable parameters in the various studies, resulting in confusion when interpreting the literature. Most reproducible experiments show that radiation reduces osteogenic cell numbers, alters cytokine capacity, and delays and damages bone remodeling. Interindividual variations and how such changes become irreversible lesions are still uncertain. In the case of regeneration using biomaterials, most studies have addressed the question of reconstruction in previously irradiated bone. The results show that osseointegration is often possible, although the failure rate is higher. The sooner the implantation takes place after the end of the radiation, the higher the likelihood of failure. Few studies have focused on primary reconstruction followed by early irradiation, and most of the currently available engineering models would be altered by radiation. Good outcomes have been obtained with bone morphogenetic protein and with total bone marrow transplanation. CONCLUSION: This review points out the difficulties in achieving reproducible experiments and interpreting literature in this underinvestigated field.

Efficacy of He-Ne Laser in the prevention and treatment of radiotherapy-induced oral mucositis in oral cancer patients.

OBJECTIVE: The objective of this study was to evaluate the efficacy of low-level lasers for the prevention and treatment of radiotherapy-induced oral mucositis in oral cancer patients. MATERIAL AND METHODS: Twenty-four hospitalized patients with oral cancer, scheduled to undergo radiotherapy at KMC, Manipal, were enrolled in the present study and assigned to laser (Group I)/control group (Group II). They were treated using He-Ne laser (lambda = 632.8nm, output = 10 mW and energy density = 1.8 J/cm(2)). Patients were subjected to treatment using laser scanner for 8 days and subsequently were treated using laser probe at 6 anatomic sites in the oral cavity for 5 minutes each. The patients were evaluated on each day of treatment for pain severity (NRS), functional impairment (FIS), and oral mucositis (RTOG) and were followed until the end of cancer treatment. Statistical analysis was done using SPSS version 10. RESULTS: Laser therapy applied prophylactically during radiotherapy can reduce the severity of oral mucositis, severity of pain, and functional impairment.

Ameloblastoma.

The purpose of this article is to review the pertinent literature and discuss the optimal treatment and outcomes for patients with ameloblastoma. Ameloblastoma is an uncommon benign, locally aggressive odontogenic neoplasm that usually occurs in the vicinity of the mandibular molars or ramus. Uncontrolled, ameloblastoma may cause significant morbidity and occasionally death. The median age is approximately 35 years and males and females are equally affected. The majority of ameloblastomas are multicystic, which are more difficult to eradicate than the unicystic and peripheral varieties. Although surgery is the mainstay of treatment, the extent of resection is controversial. Radical resections, including marginal and segmental mandibulectomy, result in local control rates exceeding 90%. In contrast, conservative procedures such as enucleation and/or curettage result in local control rates of approximately 80% and 50% for unicystic and multicystic ameloblastomas, respectively. Limited experience with radiotherapy indicates that it may reduce the risk of progression and result in long-term local control in the occasional patient with incompletely resectable disease. The optimal treatment for ameloblastoma is wide en bloc resection. Radiotherapy may improve the likelihood of local control in the occasional patient with incompletely resectable tumor.

Volume-rendered three-dimensional spiral computed tomographic angiography as a planning tool for microsurgical reconstruction in patients who have had operations or radiotherapy for oropharyngeal cancer.

Three-dimensional spiral computed tomographic angiography (3D-SCTA) is a minimally invasive method of delineating vessels in three-dimensional detail. Our aim was to evaluate the clinical usefulness of volume-rendered three-dimensional SCTA for planning microsurgical reconstruction. Eighteen patients had a spiral computed tomogram (CT) of the extracranial carotid arteries. The volume rendering technique (VRT) was used to visualise the cervical vessels, and the three-dimensional SCTA images evaluated by a staff radiologist. Radiographic and operative findings were correlated in 13 of 18 patients. The anatomical and pathological alterations of vascular anatomy identified by three-dimensional SCTA correlated exactly with operative findings and led to a successful microsurgical reconstruction. Oropharyngeal reconstruction with microvascular free flaps requires accurate evaluation of the vascular system of the carotid arteries, and improves the accuracy of diagnostic decisions. Three-dimensional SCTA enables the surgeon to establish an appropriate treatment plan.

[Relevance of bisphosphonate long-term therapy in radiation therapy of endosteal jaw metastases]. / Zur Relevanz einer Bisphosphonat-Langzeittherapie bei der Strahlentherapie enossaler Kiefermetastasen.

BACKGROUND AND PURPOSE: Bisphosphonates are used in the treatment of bone metastasis and malignant myeloma. They have been associated with osteonecrosis of the jaw (ONJ) since the year 2003. Etiology and pathogenesis of this clinical problem are not clear. The high rate of newly diagnosed cases is alarming. Based on the collective of two departments of oral and maxillofacial surgery, the results of therapy in the coincidence of systemic bisphosphonate treatment and local radiotherapy (RT) are analyzed. PATIENTS AND METHODS: In the course of 33 months (01/2003-09/2005), 63 synchronic or metachronic ONJs were seen in 42 patients as newly diagnosed episodes. Three of the 42 patients had an RT of jaw metastasis. RESULTS: Only one patient was followed over the whole treatment period. Under RT she developed a therapy-refractory ONJ similar to osteoradionecrosis at a dose of 40 Gy. She required a wide segmental osteotomy of the mandible resulting in a total loss of masticatory function. In 39 patients with 60 ONJs without RT not a single segmental resection of the mandible was necessary. CONCLUSION: Local RT in bisphosphonate long-term therapy seems to be a high risk constellation. As long as the pathogenesis of bisphosphonate-associated ONJ is unclear, patients subjected to RT of the head-and-neck area should be examined and dental findings should be treated.

[Dissertations 25 years after the date 13. Sarcomas of the jaws]. / Proefschriften 25 jaar na dato 13. Sarcomen van de kaak.

On the basis of the dissertation 'Sarcomas of the jaws'from 1982, developments in the imaging and treatment of osteosarcoma in general and of jaws in particular are discussed. The majority of osteosarcomas is found outside the craniofacial skeleton (extracraniofacial). The most frequent primary sites are the distal femur and proximal tibia. Most of these patients are children and adolescents. Only 5% of all osteosarcomas is found within the craniofacial skeleton, especially the jaws. Usually these patients are older. During the past 30 years the treatment of extracraniofacial osteosarcoma has changed from being purely surgical to being surgical in combination with multidrug, multicycle chemotherapy within prospective trials; the 5-year survival rate has risen from 10-20% to 60-70%. For craniofacial osteosarcomas such studies are missing and there is no unanimous opinion about the benefits of chemotherapy. In this group the 5-year survival rate has risen from 25-40% to 60-80%. Factors associated with a good prognosis are tumour size < 4 cm and tumour free resection margins. Developments in imaging have made improvements in preoperative evaluations possible. A plea is made for a prospective study.

Maxillofacial restoration after head and neck tumor therapy.

Oral and pharyngeal cancers are among the leading cancer sites. Surgery, radiation, chemotherapy, or combination therapies are common treatment modalities. Radiotherapy and chemotherapy cause significant morbidity and long-term irreversible sequelae in the oral cavity. Surgical resection can be mutilating, disfiguring, and deeply affect self-image. Orofacial defects have unique limitations and challenges for both the surgeon and the maxillofacial prosthodontist. Microvascular surgical techniques and the use of osseointegrated implants improve the rehabilitation potential of the various head and neck defects. This article reviews current treatment modalities of tumor therapy, their consequences, and the restoration of maxillofacial defects.

[Image fusion of bone SPECT and CT - a specific diagnostic method in oral and maxillofacial surgery]. / Bildfusion von SPECT und CT als präzisierende Diagnostik von malignen Tumoren im Mund-Kiefer-Gesichtsbereich.

OBJECTIVE: The aim of this study was to evaluate the benefit of image fusion of CT (computertomography) and bone SPECT (single photon emission computed tomography) in diagnosis of head and neck cancer. METHODS AND PATIENTS: Computer based image fusion has been applied in 39 patients with suspected cancer in the oromaxillofacial region following CT and SPECT without any further hazard for the patients. Afterwards image fusion was set in comparision to simultaneously evaluation of CT and SPECT and histological findings. RESULTS: In 5 out of 39 patients SPECT/CT image fusion obtained more precise anatomical findings in tumour expansion than simultaneously evaluation of CT and SPECT. CONCLUSION: For planning of surgical and radiation therapy of oral and maxillofacial cancer, image fusion of CT/SPECT provides efficient and plastical diagnostic imaging. Particularly in complex anatomical regions like maxilla or base of the skull image fusion could be an additional device, if simultaneous evaluation of CT and SPECT is not clear.

[Radioactive seed implantation in treatment of oral and maxillofacial malignancy].

OBJECTIVE: To treat oral and maxillofacial malignant tumors with radioactive seed implantation and observe the therapeutic results and side effects. METHODS: Thirty-six patients with oral and maxillofacial malignancy were treated by radioactive seeds implanting (operation and seed implantation or seed implantation only). The treatment plans were designed before implanting by treatment plan system (TPS). All patients were followed up for 6 - 36 months with an average of 14 months and the results evaluated. RESULTS: In 3 patients treated only by seed implantation, the tumor size reduced obviously and the symptoms alleviated in 2 patients with advanced disease, and the tumor got complete remission in one patient with tongue cancer. In the other 33 patients who were implanted after operation, no recurrence was seen in the target area, but recurrence or lymph node metastasis was found outside the target area in 3 patients. There were no unusual complaint and external radiotherapeutic side effects except for skin hyperemia occurred in 8 patients. CONCLUSIONS: Radioactive seed implantation is very effective for preventing recurrence and metastasis of oral and maxillofacial malignancy.

Retrieved implants from irradiated sites in humans: a histologic/histomorphometric investigation of oral and craniofacial implants.

PURPOSE: The aim of this report was to quantitatively and qualitatively evaluate the tissue response to bone-anchored implants retrieved from irradiated sites in patients. MATERIALS AND METHODS: The material consists of 23 consecutively received Brånemark implants (Nobel Biocare AB, Göteborg, Sweden) placed in pre- or postoperatively irradiated sites. Twenty-two of the 23 implants were suitable for histologic evaluation of undecalcified sections in the light microscope. RESULTS: The oral implants with shorter time in situ demonstrated sparse bone to implant contact with mainly dense connective tissue in the interface. However, for implants with longer time in situ, high amounts of bone-implant contact and bone fill of threads were noted. The mean values of bone-implant contact and bone area within the thread were calculated to 40% (16-94) and 70% (13-96), respectively. The craniofacial implants, with the exception of two implants lined with a capsular formation, demonstrated mature and newly formed bone at the bone-implant interface. The mean value for bone-metal contact was calculated to 45 and 53% for two specimens. The mean value for bone area within the thread ranged from 65 to 88% for three specimens. CONCLUSION; The possibility to achieve bone anchorage of implants in irradiated tissue was supported by the findings in this study. However, due to limited material, conclusions with regard to radiation dose and bone tissue response to implants cannot be stated.

Use of 2-deoxy-2-[F-18]-fluoro-D-glucose positron emission tomography to monitor therapeutic response by rhabdomyosarcoma in children: report of a retrospective case study.

PURPOSE: The purpose of this study was to study the use of 2-deoxy-2-[F-18]-fluoro-D-glucose positron emission tomography (F-18 FDG PET) for monitoring therapeutic response by rhabdomyosarcoma (RMSA) in children. PATIENTS AND METHODS: A retrospective case study was performed by searching a computer database for the patients with RMSA in whom F-18 FDG PET studies were performed pre- and posttreatment. The data of the PET studies from these patients were analyzed in conjunction with clinical treatment and other imaging studies to determine whether interval changes of F-18 FDG uptake by the RMSA reflect response of RMSA to treatment. RESULTS: Four patients with RMSA who received both pretreatment and posttreatment F-18 FDG PET studies were identified from the database and included in this study. A dramatic decrease of F-18 FDG uptake by the tumor was evident in the patients who had a favorable response to the therapy and prolonged remission of the disease. In contrast, persistent abnormal FDG uptake in one patient was associated with early relapse of the RMSA. CONCLUSIONS: F-18 FDG PET may be useful for monitoring therapeutic response by RMSA in children, which needs to be verified with a prospective study in a larger patient population.