Pediatric case of squamous cell carcinoma arising from a keratocystic odontogenic tumor.

Keratocystic odontogenic tumors (KCOT) are exceptional in children and adolescents as they usually occur in the third decade. The present study reports the case of a 15 years old girl who was diagnosed with a KCOT that underwent malignant transformation. KCOT diagnostic was based on clinical, radiological, histopathological and immunohistochemical findings. A conservative treatment by enucleation was performed. Histopathological analysis of the surgical specimen concluded to a KCOT, with an infra-centimetric focus of well-differentiated squamous cell carcinoma. Owing to the well-differentiated character of the squamous cell carcinoma, a single clinical and MRI surveillance every 3 months was decided, without complementary treatment.

Can Early Dissection of Cervical Lymph Nodes Improve Prognosis in Squamous Cell Carcinomas of the Hard Palate.

Squamous cell carcinomas of the hard palate and maxillary alveolar ridge are rare tumours with a poor prognosis. Lymph node dissection is recommended for tumours with nodal involvement, and is rarely performed in the absence of adenopathy. We report a series of patients with squamous cell carcinomas and evaluate the rate of lymph node invasion and its impact on survival. This is a retrospective study of 72 patients treated for squamous cell carcinoma of the hard palate and maxillary alveolar ridge between January 1, 1998 and December 31, 2008 in two cancer centres. Using clinical and radiological assessment, tumours were classified as T1-T2 in 25 patients (34.7%) and T3-T4 in 47 patients (65.3%). At diagnosis, 16 (22.2%) patients had clinical and/or radiological nodal involvement and 7 patients (9.7%) distal metastasis. Among N0 patients, 13 (18%) experienced isolated lymph node recurrence. Two-year global survival was 60%; 5-year survival was 34%. The rate of lymph node invasion observed in squamous cell carcinoma of the hard palate and maxillary alveolar ridge does not differ from other oral cavity sites. Because nodal recurrence worsens the prognosis of such a patient, lymph node dissection should be considered at an early stage, even among N0 patients.

Evaluation of use of acrylic resin-based surgical guide in the function and quality of life provided by mandibular prostheses with microvascular free fibula flap: A four-year, randomized, controlled trial.

STATEMENT OF PROBLEM: The correct positioning of the microvascular-free fibula flap (MFFF) is essential for satisfactory mandibular reconstruction. However, the effect of acrylic resin-based surgical guides on prosthetic rehabilitations has not yet been properly investigated. PURPOSE: The purpose of this randomized clinical trial was to evaluate whether intraoral and extraoral acrylic resin-based surgical guides improve anatomic, functional, esthetic, and quality of life (QoL) results for dental prosthetic rehabilitation with MFFF. MATERIAL AND METHODS: Participants subjected to mandibular reconstruction with MFFF were selected and randomly distributed into 2 groups, control (Co; using conventional surgery) and acrylic resin-based surgical guides (Sg). Functional parameters related to prosthetic rehabilitation and QoL were evaluated by interviews and an oral health impact profile (OHIP)-14 questionnaire. Functional parameters and questionnaire scores were subjected to statistical analysis: the likelihood ratio and the Fisher exact and Mann-Whitney U tests (α=.05). RESULTS: Of 40 participants, 18 were rehabilitated, 10 with tooth-tissue-supported partial removable dentures and 8 with implant prostheses. In Sg, the study measured an enhancement in functional parameters and revealed a significant improvement in QoL (P=.020). CONCLUSIONS: The guides proposed directly improved mandibular reconstruction. Functional aspects may be improved by allowing good intermaxillary relationships and posterior dental rehabilitation. Functional success is directly dependent on soft tissue status and the quality of its reconstruction. Soft tissue evaluation is important before dental rehabilitation.

Assessment of functional improvement with implant-supported prosthetic rehabilitation after mandibular reconstruction with a microvascular free fibula flap: A study of 25 patients.

STATEMENT OF PROBLEM: Mandibular reconstruction with a microvascular free fibula flap is widely used after oncologic resection because it allows functional and esthetic restoration of the mandibular arch and implant-retained prostheses. PURPOSE: The purpose of this study was to highlight the results that can be expected from an implant-supported prosthesis on a free fibula flap. MATERIAL AND METHODS: Patients treated with a microvascular free fibula flap and rehabilitated prosthetically were included. The number of osteotomies, number of implants, type of prosthesis, follow-up after placement of the prosthesis, preimplant surgery, and periimplant complications were reported. Subjective criteria, including patient satisfaction and improvement of masticatory function, were collected by means of a questionnaire that covered the type of diet, restrictions when eating, intelligibility of speech, and communication levels. RESULTS: Twenty-six patients were included: 11 patients had implant-supported dentures, and 15 had fixed prostheses. Prosthetic follow-up was over 5 years for 15 patients and less than 1 year for 2 patients. Hyperplasia was a periimplant complication for 7 patients. Overall, satisfaction was good for 24 patients (score greater than 5/10; mean score, 7.3/10). Esthetics were improved for 20 patients. Speech was improved for 6 patients, and diet improved for 9 patients. CONCLUSIONS: Implant-retained dentures seem preferable for patients, with notable esthetic alteration, although a screw-retained fixed resin-bonded prosthesis remains a good alternative. Improved mastication is more notable with patients who are completely edentulous and with large reconstructions but nevertheless remains disappointing. Whether dental restoration is necessary in treatments with short lateral flaps is worth questioning.

[Children who received a radiotherapy treatment of the cranio-cervico-facial region: appraisal of the orthodontic treatment need]. / Enfants ayant reçu une irradiation de la région cranio-cervico-faciale : évaluation du besoin de traitement orthodontique.

INTRODUCTION: Currently, 1 out of 900 adults from the ages of 16 to 44 is a survivor of childhood cancer. The global rate of survival for all types of childhood cancer is close to 80% and progress in treatment and care continues to offer promising results. In the years following treatment, these children, just like other healthy children, should have access to orthodontic care in spite of their chronic health problems. OBJECTIVES: A transverse epidemiological study was conducted at the Leon Bernard Cancer Treatment Center in Lyon in order to respond to these requests and to assist orthodontists with the therapeutic difficulties presented by these patients. Our objective was to identify the orthodontic treatment required for children 7 years old or older who received antineoplastic therapy with radiation of the cranio-cervico-facial region. RESULTS: The results show that children who received radiation therapy in the cranio-facial region presented delayed growth, facial asymmetry in 74% of the cases, overbite and overjet increased respectively in 70% and 61% of the cases. Dental discrepancies in development were present in 83% of the patients who presented with stunted teeth, premature closing of the apices and hypoplasias. We found sialopathy such as reduced saliva flow rate. Finally, considerable treatment was necessary in 61% of the cases and moderate treatment for 17% of the cases, because of missing teeth, retained deciduous teeth or an increased overjet.

A model of mandibular irradiation in the rabbit: preliminary results.

Radiotherapy is widely used in the treatment of head and neck cancers. Its major adverse effect is osteoradionecrosis, which can occur during the whole life of the patient, involving the vital prognosis. The aim of the study was to develop a model for irradiation of the rabbit mandible in order to have a better knowledge of radiotherapy-induced bone alterations and thus a better prevention and treatment of osteoradionecrosis. The control group consisted in 7 rabbits and was used to assess anatomical and histological parameters of the rabbit's mandible. A first group of 14 rabbits was weekly irradiated at doses of 5.5 Gy during 5 weeks, at a total dose of 46.8Gy. Sacrifices were done at 1 week, 4 weeks, 12 weeks and 24 weeks. As histological analysis did not reveal statistical differences with the control group, a second group (3 rabbits) was weekly irradiated at 8.0, 8.5 and 9 Gy during 5 weeks. The first histological results seem to show vascular alterations, bone cells decrease and alterations of bone architecture. The role of intra alveolar collagen sponges, PRF®, ultrasounds and stem cells in bone regeneration after radiotherapy will be further studied.

Guided implant surgery on oral cancer patients: in vitro study.

PURPOSE: Many oral cancer patients (OCPs) are unable to wear conventional prostheses due to the disease and treatment effects, so they are candidates for oral rehabilitation with osseointegrated implants. A guide suitable for OCPs was designed and tested. METHODS: Image-guided systems based on a custom template for oral implant placement are now widespread among healthy patients, but this has not been extended to OCPs. The EasyGuideT system (Keystone Dental, Burlington, MA, USA) for template stabilization is used on healthy edentulous patients, achieved by bone screws, mini-implants or stereolithography with a bone support. All these systems are invasive and cannot be used in many oral cancer patients. We adapted the EasyGuideT to OCP rehabilitation. The first stage focused on developing a template-positioning system for use on edentulous mandibles that is non-invasive, repeatable, stable on the oral mucosa, consistent with the operating room asepsis, and comfortable for the patient. This repositioning system consists of a cube fiducial marker and an extra-oral support using a facial thermoplastic mask. The mask is linked to the surgical template through the cube. The second stage consisted of direct evaluation of the repositioning system reproducibility, performed on 5 adult cadaver skulls. RESULTS: The translation errors and rotation errors obtained using the modified EasyGuideT system were satisfactory in ex vivo experiments on cadaver skulls. CONCLUSION: A non-invasive repositioning system for image-guided implant surgery on oral cancer patients is clinically feasible using a cube fiducial marker and extra-oral support with a facial thermoplastic mask.

Evaluation of two noninvasive repositioning systems for computer-assisted oral implant surgery in oral cancer patients.

PURPOSE: Reconstructive surgery in oral cancer patients uses thick flaps, which may render the placement of miniscrews for stabilizing radiosurgical templates difficult. The realization of noninvasive systems for the repositioning of surgical templates has been proposed. The present study aimed to assess the clinical usefulness of these noninvasive repositioning systems. MATERIALS AND METHODS: Two noninvasive (ie, without osseous anchorage) repositioning systems (one intraoral, one intra- and extraoral) were tested. They were coupled with a computer-aided system for oral implantation. The criteria for evaluation were: accuracy, cost, time for placement and removal, and six additional subjective criteria (ease of use and production, bulk of the device, patient comfort, stability during surgery, and ergonomics). RESULTS: Nine edentulous patients undergoing surgery to the oral cavity, oropharynx, or pharynx; external radiotherapy of the mandible; or microvascular flap reconstruction were included. Twenty-seven implants were placed in the mandibles of seven patients. For the extraoral system, the angular deviation between planned and achieved position was 6.04 degrees, with differences of 2.14 mm at the tip and 2.16 mm at the base. For the intraoral system, deviations were 5.05 degrees, 1.13 mm, and 1.82 mm, respectively. Subjective criteria were consistent with expected values, especially ease of use, comfort, and ergonomics. CONCLUSIONS: Noninvasive systems remain less accurate than templates stabilized by miniscrews and should be reserved for treating arches in which miniscrews cannot be placed. These methods may be unacceptable in areas where vital structures may be damaged by a misguided implant, and further studies are required. More satisfactory results should be obtained in partially edentulous patients.

A new, simple maxillary-sparing tongue depressor for external mandibular radiotherapy: a case report.

BACKGROUND: In external radiotherapy, the use of leaded intraoral devices to shield adjacent tissues is well described, but stabilization of the mandible is often realized with standard bite blocks, which do not allow a good stabilization of the mandible. METHODS AND RESULTS: A 40-year-old patient presenting with a local recurrence of a tumor of the floor of the mouth underwent external radiotherapy. To shield the maxilla during mandibular irradiation and to ensure mandible and tongue immobility during external radiotherapy, a custom-made device was realized. The apparatus consists of a polymethylmethacrylate resin plate and 2 wedges. Only 2 steps are needed. CONCLUSION: The realization is simple and cheap, the apparatus is comfortable, and modifications are easy. It can be used in all patients, except in patients with totally mandibular edentulous with severe bone resorption.