16 research outputs found
ModĂšle dâirradiation mandibulaire chez le lapin et Ă©valuation dâun traitement par ultrasons pulsĂ©s de faible intensitĂ© sur la rĂ©gĂ©nĂ©ration osseuse
External radiotherapy is widely used in the treatment of cancers of head and neck cancers. The main side effect is osteoradionecrosis, which can lead to a major deterioration in the quality of life. Low-intensity pulsed ultrasound (LIPUS) has been described in the stimulation of bone healing in traumatology and orthopaedics. They would have an effect on the early vascular phase of bone consolidation. We therefore wanted to study, through an animal study, their impact on the healing of irradiated maxillary bones. For this, we have developed a model of radiotherapy in rabbits, in order to study the healing after creation of a bone defect on an irradiated mandible. Irradiation was performed according to the following protocol : 8.5Gy/week, with one session per week, for 5 weeks, for a total dose of 42.5Gy. Mandibular surgery consisted of performing a standardized bone defect immediately after irradiation. A control group benefited from the same surgery, without prior irradiation. With this model we obtained an alteration in bone healing, confirmed by histology and microscanner. Once the radio-induced bone alterations were highlighted, we were able to renew the protocol by adding an additional step of applying LIPUS to the surgical sites. The protocol consisted of the postoperative application of LIPUS, for 10 sessions, during 20 minutes, with the following parameters : 30mW/cmÂČ, pulse 1:4, 20 min, 1MHz. Application of LIPUS on the irradiated rabbit model did not appear to have a beneficial effect on bone healing : in histology, healing did not appear to be improved after application of LIPUS ; on the microscan, some parameters even seemed to be negatively impacted by LIPUS. We can however assume an interesting effect on the general state of health of the animals, with in particular an increase in their weight and their water consumption. Our results should be interpreted with great caution. Indeed, the sample studied is very small, and there is a lot of heterogeneity between the different subjects. In addition, several limitations that could question the validity of this study should also be taken into consideration. In the end, even if the LIPUS technology does not seem beneficial on bone healing in irradiated terrain with regard to the results that we obtained, this work validates an animal radiotherapy model. This model could be used to test other possible therapies in the future.La radiothĂ©rapie externe est trĂšs largement utilisĂ©e dans le traitement des cancers des voies aĂ©rodigestives supĂ©rieures. Le principal effet secondaire est lâostĂ©oradionĂ©crose, pouvant conduire Ă une altĂ©ration majeure de la qualitĂ© de vie. Les ultrasons pulsĂ©s de faible intensitĂ© (LIPUS : Low-Intensity Pulsed Ultrasound) ont Ă©tĂ© dĂ©crits dans la stimulation de la cicatrisation osseuse en traumatologie et en orthopĂ©die. Ils auraient un effet sur la phase prĂ©coce vasculaire de la consolidation osseuse. Nous avons donc souhaitĂ© Ă©tudier, au travers dâune Ă©tude animale, leur impact sur la cicatrisation des os maxillaires irradiĂ©s.Pour cela, nous avons mis au point un modĂšle de radiothĂ©rapie chez le lapin, afin dâĂ©tudier la cicatrisation aprĂšs crĂ©ation dâun dĂ©faut osseux sur une mandibule irradiĂ©e. Lâirradiation Ă©tait rĂ©alisĂ©e selon le protocole suivant : 8.5Gy/semaine, Ă raison dâune sĂ©ance hebdomadaire, pendant 5 semaines, pour une dose totale de 42.5Gy. La chirurgie mandibulaire consistait en la rĂ©alisation dâun dĂ©faut osseux standardisĂ©, immĂ©diatement aprĂšs lâirradiation. Un groupe contrĂŽle bĂ©nĂ©ficiait de la mĂȘme chirurgie, sans irradiation au prĂ©alable. Ce modĂšle a permis dâobtenir une altĂ©ration de la cicatrisation osseuse, confirmĂ©e Ă lâhistologie et au microscanner. Une fois mises en Ă©vidence les altĂ©rations osseuses radio-induites, nous avons pu renouveler le protocole en ajoutant une Ă©tape supplĂ©mentaire dâapplication de LIPUS sur les sites opĂ©ratoires. Le protocole consistait en lâapplication postopĂ©ratoire de LIPUS, pendant 10 sĂ©ances, dâune durĂ©e de 20 minutes, avec les paramĂštres suivants : 30mW/cmÂČ, pulsation 1:4, 20 min, 1MHz. Lâapplication de LIPUS sur le modĂšle de lapins irradiĂ©s nâa pas paru avoir un effet bĂ©nĂ©fique sur la cicatrisation osseuse : en histologie, la cicatrisation nâa pas semblĂ© amĂ©liorĂ©e aprĂšs application des LIPUS ; au microscanner, certains paramĂštres semblaient mĂȘme ĂȘtre impactĂ©s de maniĂšre nĂ©gative par les LIPUS. On peut toutefois supposer un effet intĂ©ressant sur lâĂ©tat de santĂ© gĂ©nĂ©ral des animaux, avec notamment une augmentation de leur poids et de leur consommation dâeau.Nos rĂ©sultats sont Ă interprĂ©ter avec une grande prudence. En effet, lâĂ©chantillon Ă©tudiĂ© est trĂšs faible, et il existe une trĂšs grande hĂ©tĂ©rogĂ©nĂ©itĂ© entre les diffĂ©rents sujets. Par ailleurs, plusieurs limites pouvant remettre en question la validitĂ© de cette Ă©tude sont Ă©galement Ă prendre en considĂ©ration. Au final, mĂȘme si la technologie des LIPUS ne semble pas bĂ©nĂ©fique sur la cicatrisation osseuse en terrain irradiĂ© au regard des rĂ©sultats que nous avons obtenus, ce travail a permis de valider un modĂšle de radiothĂ©rapie animal. Ce modĂšle pourrait ĂȘtre utilisĂ© pour tester dâautres thĂ©rapeutiques Ă©ventuelles dans le futur
Model of mandibular irradiation in rabbits and evaluation of low-intensity pulsed ultrasound treatment on bone regeneration
La radiothĂ©rapie externe est trĂšs largement utilisĂ©e dans le traitement des cancers des voies aĂ©rodigestives supĂ©rieures. Le principal effet secondaire est lâostĂ©oradionĂ©crose, pouvant conduire Ă une altĂ©ration majeure de la qualitĂ© de vie. Les ultrasons pulsĂ©s de faible intensitĂ© (LIPUS : Low-Intensity Pulsed Ultrasound) ont Ă©tĂ© dĂ©crits dans la stimulation de la cicatrisation osseuse en traumatologie et en orthopĂ©die. Ils auraient un effet sur la phase prĂ©coce vasculaire de la consolidation osseuse. Nous avons donc souhaitĂ© Ă©tudier, au travers dâune Ă©tude animale, leur impact sur la cicatrisation des os maxillaires irradiĂ©s.Pour cela, nous avons mis au point un modĂšle de radiothĂ©rapie chez le lapin, afin dâĂ©tudier la cicatrisation aprĂšs crĂ©ation dâun dĂ©faut osseux sur une mandibule irradiĂ©e. Lâirradiation Ă©tait rĂ©alisĂ©e selon le protocole suivant : 8.5Gy/semaine, Ă raison dâune sĂ©ance hebdomadaire, pendant 5 semaines, pour une dose totale de 42.5Gy. La chirurgie mandibulaire consistait en la rĂ©alisation dâun dĂ©faut osseux standardisĂ©, immĂ©diatement aprĂšs lâirradiation. Un groupe contrĂŽle bĂ©nĂ©ficiait de la mĂȘme chirurgie, sans irradiation au prĂ©alable. Ce modĂšle a permis dâobtenir une altĂ©ration de la cicatrisation osseuse, confirmĂ©e Ă lâhistologie et au microscanner. Une fois mises en Ă©vidence les altĂ©rations osseuses radio-induites, nous avons pu renouveler le protocole en ajoutant une Ă©tape supplĂ©mentaire dâapplication de LIPUS sur les sites opĂ©ratoires. Le protocole consistait en lâapplication postopĂ©ratoire de LIPUS, pendant 10 sĂ©ances, dâune durĂ©e de 20 minutes, avec les paramĂštres suivants : 30mW/cmÂČ, pulsation 1:4, 20 min, 1MHz. Lâapplication de LIPUS sur le modĂšle de lapins irradiĂ©s nâa pas paru avoir un effet bĂ©nĂ©fique sur la cicatrisation osseuse : en histologie, la cicatrisation nâa pas semblĂ© amĂ©liorĂ©e aprĂšs application des LIPUS ; au microscanner, certains paramĂštres semblaient mĂȘme ĂȘtre impactĂ©s de maniĂšre nĂ©gative par les LIPUS. On peut toutefois supposer un effet intĂ©ressant sur lâĂ©tat de santĂ© gĂ©nĂ©ral des animaux, avec notamment une augmentation de leur poids et de leur consommation dâeau.Nos rĂ©sultats sont Ă interprĂ©ter avec une grande prudence. En effet, lâĂ©chantillon Ă©tudiĂ© est trĂšs faible, et il existe une trĂšs grande hĂ©tĂ©rogĂ©nĂ©itĂ© entre les diffĂ©rents sujets. Par ailleurs, plusieurs limites pouvant remettre en question la validitĂ© de cette Ă©tude sont Ă©galement Ă prendre en considĂ©ration. Au final, mĂȘme si la technologie des LIPUS ne semble pas bĂ©nĂ©fique sur la cicatrisation osseuse en terrain irradiĂ© au regard des rĂ©sultats que nous avons obtenus, ce travail a permis de valider un modĂšle de radiothĂ©rapie animal. Ce modĂšle pourrait ĂȘtre utilisĂ© pour tester dâautres thĂ©rapeutiques Ă©ventuelles dans le futur.External radiotherapy is widely used in the treatment of cancers of head and neck cancers. The main side effect is osteoradionecrosis, which can lead to a major deterioration in the quality of life. Low-intensity pulsed ultrasound (LIPUS) has been described in the stimulation of bone healing in traumatology and orthopaedics. They would have an effect on the early vascular phase of bone consolidation. We therefore wanted to study, through an animal study, their impact on the healing of irradiated maxillary bones. For this, we have developed a model of radiotherapy in rabbits, in order to study the healing after creation of a bone defect on an irradiated mandible. Irradiation was performed according to the following protocol : 8.5Gy/week, with one session per week, for 5 weeks, for a total dose of 42.5Gy. Mandibular surgery consisted of performing a standardized bone defect immediately after irradiation. A control group benefited from the same surgery, without prior irradiation. With this model we obtained an alteration in bone healing, confirmed by histology and microscanner. Once the radio-induced bone alterations were highlighted, we were able to renew the protocol by adding an additional step of applying LIPUS to the surgical sites. The protocol consisted of the postoperative application of LIPUS, for 10 sessions, during 20 minutes, with the following parameters : 30mW/cmÂČ, pulse 1:4, 20 min, 1MHz. Application of LIPUS on the irradiated rabbit model did not appear to have a beneficial effect on bone healing : in histology, healing did not appear to be improved after application of LIPUS ; on the microscan, some parameters even seemed to be negatively impacted by LIPUS. We can however assume an interesting effect on the general state of health of the animals, with in particular an increase in their weight and their water consumption. Our results should be interpreted with great caution. Indeed, the sample studied is very small, and there is a lot of heterogeneity between the different subjects. In addition, several limitations that could question the validity of this study should also be taken into consideration. In the end, even if the LIPUS technology does not seem beneficial on bone healing in irradiated terrain with regard to the results that we obtained, this work validates an animal radiotherapy model. This model could be used to test other possible therapies in the future
Comment prévenir les complications des extractions des dents de sagesse?
LYON1-BU Santé Odontologie (693882213) / SudocSudocFranceF
Sécheresse buccale et médicaments : étude épidémiologique chez les résidants d'EHPAD du CHU de Reims
REIMS-BU Santé (514542104) / SudocSudocFranceF
Ostéochimionécrose extensive de la mandibule chez un patient présentant une ostéomalacie et traité par dénosumab pour une tumeur osseuse sphénoïdale
Observation : Le cas dâun patient ĂągĂ© de 68 ans, traitĂ© par dĂ©nosumab, cal-
citriol et phosphates pour une ostéomalacie et une tumeur à cellules géantes du sphé-
noïde est rapporté. Le signe clinique inaugural était une douleur sourde au niveau de la
mandibule. Lâorthopantomographie montrait un double contour au niveau de lâensemble de la
mandibule et la scintigraphie une hyperfixation de toute la mandibule. AprĂšs plusieurs
mois de polyantibiothĂ©rapie et une tentative dâarrĂȘt du dĂ©nosumab, de larges plages
dâexposition osseuse Ă©taient notĂ©es au niveau de tout le versant alvĂ©olaire lin- gual de
la mandibule. La limitation dâouverture buccale a Ă©tĂ© brutalement suivie dâun blocage de
la fermeture buccale par fracture comminutive des branches montantes man- dibulaires
Discussion : LâostĂ©ochimionĂ©crose souvent imputable aux bisphosphonates,
peut Ă©galement ĂȘtre associĂ©e Ă la prise de dĂ©nosumab. Le dĂ©nosumab est un anticorps
monoclonal anti RANKligand ciblant les ostĂ©oclastes. LâĂ©tendue de lâostĂ©onĂ©crose est
probablement liĂ©e Ă lâexistence dâune altĂ©ration du remodelage osseux (ostĂ©omalacie).
Lâabsence dâalternative thĂ©rapeutique dans le cas clinique prĂ©sentĂ© et les bĂ©nĂ©fices cli-
niques constatés doivent faire préférer un traitement antirésorptif malgré un risque accru
de développer une ostéochimionécrose
Clinical attitude regarding denosumab drug-holiday for dental extraction in oncologic patients: a national survey
Introduction: Denosumab is indicated in oncology to reduce tumoral development. However, this medication may cause osteonecrosis of the jaw, especially after dental extractions. Drug holiday has been proposed to decrease the risk of osteonecrosis of the jaw. This survey aimed to assess the management of drug holidays for patients who needed both dental extraction and denosumab. Methods: A questionnaire was sent to a panel of healthcare professionals. Results: Of the 33 practitioners interviewed, 28 undertook or âwere used toâ dental extractions in patients on denosumab. 25% (7/28) of the practitioners questioned did not stop patients from taking denosumab before dental extraction and 75% (21/28) used a drug holiday. For those who stopped the treatment, 33% (7/21) waited 2 months before performing dental extraction and 38% (8/21) waited 2 months after the dental extraction before reintroducing the molecule; 2 months being the median duration in both cases. In addition, 89% (25/28) of practitioners, modified their surgical procedure for these patients. Conclusion: Despite a small number of responders, it seemed that a drug holiday of at least 2 months is mandatory before performing tooth extraction. The issue of the drug holiday should always be raised with the patient's oncologist
Sjögren syndrome hidden by previous parotidectomy and cervicofacial radiotherapy
Introduction: Sjögrenâs syndrome (SS) is a chronic inflammatory auto-immune disease of the exocrine glands which incidence increases with age. Sex ratio is 9.9 female for 1 male. Observation: A 67-year-old female patient presented for xerostomia leading to major functional impairment. The medical history of the patient was pulmonary sarcoidosis, with join and adenoid involvement, considered as cured; left partial parotidectomy, with a diagnosis of acinous carcinoma, followed 7 years later by a total parotidectomy due to tumor recurrence, and followed by external radiotherapy (70 Gy). Arterial hypertension, hypothyroĂŻditis and diabetes mellitus were also noticed. She reported xerostomia and xerophtalmia. Seric anti-SSA antibodies were positive and histologic findings were compatible with SS. Commentaries: Despite other co-morbidities, the diagnosis was hidden by previous parotidectomy and cervical radiotherapy. Thus, SS should not be underdiagnosed in patients with complex medical history
Peri implant bone resorption on microvascular free fibula flap: a radiographic retrospective study
Introduction: As the vascularization of the microvascular free fibula flap enables to maintain an osteogenic potential, osseointegrated implants have a 86% to 99% success rate. Thus, only few studies consider peri-implant bone resorption (PIBR). The aim of the study was to radiologically evaluate PIBR on fibula flaps. Materials and methods: Data were retrospectively collected. Gender, age, reason for interruptive mandibulectomy, previous radiotherapy, number of implants placed on the reconstruction, length and number of segments of the reconstruction, height of resorption were collected for each patient. Measurements were made on panoramic radiograph. Results: 85 clinical reports were reviewed for 39 retained. Peri-implant bone resorption was observed in 21 (53.9%) patients. The average age of the resorption group was 55.4 . All of the 5 patients with 4 or 5 implants on their reconstruction did not developed PIBR. 59.1% of patients with 1 segment reconstruction developed PIBR, 54.6% with 2 segments and 33.3% with 3 segments. Discussion: Age and poor oral hygiene appeared to be clearly more related to PIBR. An important number of implant (4 or 5) and a reconstruction with more than 1 segment seemed to decrease PIBR. Further studies are required to confirm these hypotheses
Mandibular ameloblastic carcinoma: case report and literature review
Introduction: Ameloblastic carcinoma is an extremely rare malignant odontogenic tumor with predominantly mandibular localization. In most cases, it is treated surgically. Observation: Here, we describe a case of ameloblastic carcinoma. The patient presented a large expansive mass on the ascending branch of the left mandible, which was ulcerated and communicating with the oral cavity. He refused the proposed surgical treatment after being informed of the risk of facial decomposition. After several years, due to progressive symptomatology, he received palliative radiotherapy of 60 Gy divided into 30 sessions. Local control of the disease was achieved. Discussion: The efficiency of radiotherapy for ameloblastic carcinoma remains controversial. Conclusion: Radiotherapy appears to be a second-line approach when surgery is not feasible for ameloblastic carcinoma treatment