Systematic dosimetric evaluation of risk of osteoradionecrosis (DERO): First results of dose reporting for preventing teeth osteoradionecrosis after head and neck irradiation.

PURPOSE: OsteoRadioNecrosis (ORN) is a late complication of radiation for head and neck cancer. Predicting ORN is a major challenge. We developed DERO (Dosimetric Evaluation of Risk of ORN), a semi-automatic tool which reports doses delivered to tooth-bearing sectors, to guide post-therapeutic dental care. We present the method and the first results of a 125-patient prospective cohort. MATERIAL AND METHODS: Dosimetric data of patients treated with IMRT for head and neck cancer were prospectively segmented to the DERO algorithm. Four arches corresponding to 8-tooth sectors were semi-automatically generated. Thirty-two cylindrical Regions Of Interest (ROI) corresponding to each tooth and surrounding periodontium were created by linear interpolation. Mean doses (Dmean) of ROI were extracted and included in a database, along with data about primary tumor site, laterality and dose values from organs at risk. Dmean to tooth sectors were computed for molar sectors, (teeth X5 to X8) and anterior sectors (teeth X1 to X4). An individual dose map was generated and delivered to patients and dentists. RESULTS: Dosimetric data from 125 patients treated with Tomotherapy® were prospectively collected and analyzed: 9 parotid tumors (PA), 41 Sub-Hyoid tumors (larynx, hypopharynx) (SH), 43 Oropharynx tumors (OR), 32 Oral Cavity tumors (OC). Irradiation was unilateral for 100% of PA tumors (9), 12% of OR tumors (5) and 47% of OC tumors (15). For unilateral cervical irradiation, Dmean in ipsilateral molar sectors was 54Gy for OC tumors, 45Gy for OR tumors, 20Gy for PA tumors. For Oral Cavity bilateral irradiation, Dmean was high in all tooth sectors, 49 to 55Gy. For SH tumors, Dmean in molar sectors was 27Gy. A dose gradient of 10 to 20Gy was observed between molar and anterior sectors whether radiation was uni or bilateral. CONCLUSION: Mandibular molar sectors of Oropharynx and Oral Cavity tumors were exposed to high Dmean of 40 to 50Gy. On the other hand, tooth sectors received lower doses for SH radiation. The DERO tool guide post-radiation dental care with a personalized dosimetric cartography to patient. With data update and patient follow-up, we will be able to determine ORN risk after head and neck radiation.

Functional evaluation of mandibular reconstruction with bone free flap. A GETTEC study.

OBJECTIVES: To assess the functional results of oromandibular reconstruction by free bone flap, in terms of swallowing, speech and esthetics. MATERIALS AND METHODS: A transverse multicenter study included 134 patients reconstructed by free bone flap between 1998 and 2016, with more than 6 months' follow-up, in 9 centers. A standardized questionnaire collected data on patients and treatment. Study endpoints comprised: weight loss, mouth opening, gastrostomy dependence, type of feeding, and DHI score. The impact of patient baseline characteristics on these functional criteria was explored by uni/multivariate analysis. RESULTS: Ninety of the 134 patients had cancer. Fibula flap was mainly used (80%). 94% of reconstructions were primary successes. 71% of patients had pre- or post-operative radiation therapy. 88% had less than 50% lingual resection. 97% recovered oral feeding. 89% had intelligible speech. 86% judged their esthetic appearance as good/average. 9% had dental prosthetic rehabilitation. Radiation therapy and extensive lingual resection significantly impacted swallowing function (P=0.04 and P=0.03, respectively). Radiation therapy and oropharyngeal extension significantly increased gastrostomy dependence (P=0.04 and P=0.02, respectively). CONCLUSION: Oromandibular reconstruction by free bone flap enabled return to oral feeding in most cases. More than 80% of patients were satisfied with their result in terms of speech and esthetics. However, the rate of dental rehabilitation was low and the rate of complications was high.

Fibrous dysplasia of the orbital region: Series of 12 cases and review of the literature.

PURPOSE: Fibrous dysplasia (FD) is a benign fibro-osseous developmental disorder of growing bone, sometimes involving the craniofacial skeleton (CFD). We wish to present a patient series with CFD of the orbital region and discuss treatment modalities. METHODS: Twelve patients were referred for orbital CFD in the Nantes University Hospital between 2000 and 2018 and studied according to the clinical parameters, radiological features, and modalities of treatment. RESULTS: The mean age was 25.6 years. Ten patients exhibited facial asymmetry with vertical globe dystopia (75%), proptosis (58%) and facial bump (50%). The disease was monostotic in 83% of patients, involving the frontal bone (25%), the sphenoidal bone (33%), the fronto-sphenoidal complex (25%), and the skull base (17%). Unilateral radiological proptosis was found in 7 patients, with a mean protrusion 3.9mm. The optic canal was involved in 75% of patients, with no functional impairment. Three patients were treated with bisphosphonate therapy to stop progression of the disease; 6 patients were given a bone remodelling procedure with good aesthetic outcomes. CONCLUSION: The orbit is a rare localization for FD causing aesthetic and functional disabilities. Medical and surgical treatment can be proposed as part of a multidisciplinary approach.

Associated relaps factors in Le Fort I osteotomy. A retrospective study of 54 cases.

PURPOSE: The Le Fort I osteotomy (LFI) procedure is commonly used to restore morpho-functional balance. The goal of maxillofacial surgeons with this procedure is to achieve occlusal stability. To identify factors associated with relapse after maxillary advancement in cleft lip and palate patients, the one-year post-operative stability of Le Fort I osteotomy was evaluated. METHODS: Horizontal and vertical relapse were analysed on lateral cephalograms by retrospectively using tracing paper in an orthonormal landmark in 54 patients undergoing unilateral cleft lip and palate surgery who were monitored at Nantes University Hospital. The lateral cephalograms were performed pre-operatively, immediately post-operatively, and after one year. Several variables were studied such as population data, intra-operative and post-operative surgical treatment, and surgical movement. RESULTS: At point A, the subspinale point, the mean advancement during surgery was 4.2 mm, with a relapse of 0.8 mm (20.1%). The mean downward movement was 2.0 mm in 26 patients who had a clockwise rotation of the maxilla, with a relapse of 0.6 mm (28.4%). The mean upward movement was 2.3 mm in 27 patients who had a counterclockwise rotation, with a deterioration of 0.2 mm (7%). A 7-millimetre surgical advancement corresponded to the threshold value beyond which relapse appeared to be significantly greater but still less than two millimetres in 75% of cases. CONCLUSION: The degree of advancement appears to be the only variable correlated with the amplitude of the relapse.

A giant parapharyngeal lipoma causing obstructive sleep apnea.

Lipoma is the most common soft tissue mesenchymal neoplasm. Its occurrence is low in the oral cavity (1 to 4%) and in head and neck region (20 to 25%). Usually asymptomatic and slowly growing, lipoma can compress neighboring cervico-facial structures causing dysphagia, dyspnea, or obstructive sleep apnea. We describe an unusual case of giant cervico-parapharyngeal lipoma causing an obstructive sleep apnea in a 69-year-old man and with the complete remove of OSA after surgical procedure.

[Anterior mandibular bone augmentation techniques. Literature review]. / Les augmentations osseuses mandibulaires antérieures. Revue de la littérature.

INTRODUCTION: Mandibular edentation may lead to major symphyseal resorption making the placement of dental implants impossible. In this situation, bone augmentation techniques are available. The goal of our study was to make a review of the literature of the different techniques in use. METHOD: A bibliographic research was conducted on the Medline, Ovid and Cochrane Library databases with the following keywords: anterior mandible, bone grafting, mandibular symphysis reconstruction. We selected only articles written in English, published from January 1975 to August 2014 and expressly dealing with anterior mandibular bone augmentation techniques. RESULTS: Sixty-nine articles were analyzed. Eight bone augmentation techniques were reported. Bone grafting using iliac or calvarial bone and immediate or delayed implantation was the most popular technique. The main complications were infection, exposure or resorption of the graft, and chin and lip hypo- or anesthesia. The other reported techniques (osteotomies, distraction osteogenesis, transmandibular implants, mandibular reconstruction plates, fibula free flaps) were more confidential or had specific indications. There was no indication for biomaterials excepted if combined with autologous bone.

Direct comparison of current cell-based and cell-free approaches towards the repair of craniofacial bone defects - A preclinical study.

For craniofacial bone defect repair, several alternatives to bone graft (BG) exist, including the combination of biphasic calcium phosphate (BCP) biomaterials with total bone marrow (TBM) and bone marrow-derived mesenchymal stromal cells (MSCs), or the use of growth factors like recombinant human bone morphogenic protein-2 (RhBMP-2) and various scaffolds. Therefore, clinicians might be unsure as to which approach will offer their patients the most benefit. Here, we aimed to compare different clinically relevant bone tissue engineering methods in an "all-in-one" study in rat calvarial defects. TBM, and MSCs committed or not, and cultured in two- or three-dimensions were mixed with BCP and implanted in bilateral parietal bone defects in rats. RhBMP-2 and BG were used as positive controls. After 7 weeks, significant de novo bone formation was observed in rhBMP-2 and BG groups, and in a lesser amount, when BCP biomaterials were mixed with TBM or committed MSCs cultured in three-dimensions. Due to the efficacy and safety of the TBM/BCP combination approach, we recommend this one-step procedure for further clinical investigation. STATEMENT OF SIGNIFICANCE: For craniofacial repair, total bone marrow (BM) and BM mesenchymal stem cell (MSC)-based regenerative medicine have shown to be promising in alternative to bone grafting (BG). Therefore, clinicians might be unsure as to which approach will offer the most benefit. Here, BM and MSCs committed or not were mixed with calcium phosphate ceramics (CaP) and implanted in bone defects in rats. RhBMP-2 and BG were used as positive controls. After 7 weeks, significant bone formation was observed in rhBMP-2 and BG groups, and when CaP were mixed with BM or committed MSCs. Since the BM-based procedure does not require bone harvest or cell culture, but provides de novo bone formation, we recommend consideration of this strategy for craniofacial applications.

[Facial asymmetries and their skeletal component]. / Les asymétries faciales à composante squelettique.

The diagnosis and treatment of facial asymmetries is one of the most difficult challenges in orthognathic surgery. In some cases, the involvement of soft tissue defects or, in other cases, an associated basi-cranial asymmetry can complicate the management. The influence of various components of the cephalic end in the development of the face requires a thorough clinical and radiographic examination including the overall posture of the patient. The causes are multiple: congenital, constitutional, acquired with an important esthetic, functional, and psychological and social impact. The classification of these asymmetries can only be incomplete and purely didactic because of the multiplicity of clinical forms. Two elements are mandatory for the diagnosis and surgical treatment: first, the anterior clinical and radiological "craniofacial cross" established from the midline or midplane of the face; second, the clinical and radiological orientation of the maxillary and mandibular occlusal transverse and sagittal planes. The surgical techniques are the same as in conventional orthognathic surgery except for those used for the correction of the vertical posterior dimension of the face: condylectomy, lengthening osteotomy of the mandibular ramus, costochondral graft, and free flap. The contribution of 3D vision of the facial skeleton and its possibilities of measurement have improved the assessment of skeletal structure displacement during surgery. However, traditional radiographic examinations are still useful for pre and postoperative comparison and also to assess results. Computer simulation and computer-assisted surgery should allow achieving better and more stable results because of their reliability and easy access.

[Occipitalization of the atlas. Radiological diagnosis and clinical significance]. / Occipitalisation de l'atlas. Diagnostic radiologique et implication clinique.

INTRODUCTION: Occipitalization of the atlas is the most common malformation of the craniovertebral junction. It can be diagnosed on lateral teleradiography and its finding imposes screening for associated atlantoaxial instability. In case of instability, brisk movements of the cervical spine during surgery may result in compression and distortion of the spinal chord and vertebro-basilar vascular system. OBSERVATION: An 18 year-old female patient was referred to our department for facial dysmorphosis and extraction of the third molars. A lateral teleradiography revealed an occipitalization of the atlas and the fusion of the second and third cervical vertebral body. Further pre-operative investigations allowed ruling out any joint instability or associated craniovertebral junction malformations. DISCUSSION: Occipitalization of the atlas is not usually well-known by maxillofacial surgeons. It may be diagnosed with a lateral teleradiography. Its diagnosis imposes screening for other spinal malformations (spinal fusion, hemivertebra, spina bifida occulta). The major risk is compression and distortion of the spinal chord and vertebro-basilar vascular system, during surgery or anesthesia.