Case-report of an Abrikossoff tumor of the temporomandibular joint Rapport de cas d'une tumeur d'Abrikossoff de l'articulation temporo-mandibulaire.

Granular cell tumors are rare tumors with multiple localizations. The most common localizations are in the cervicofacial region in 45-65% of cases. The characterization of this tumor depends on its clinical and histopathological findings. A few cases have been reported describing more unusual localizations, such as in the juxta-axilla or in the gastrointestinal tract. In this article, we describe an original localization: the region of the temporomandibular joint. This case-report describes a clinical case that was managed in the Department of Maxillofacial and Oral Surgery of the Saint-Joseph Hospital. The tumoral lesions usually described for this anatomical location are usually bony or synovial lesions. Here, the clinical examination didn't correspond to any of those descriptions and the MRI also confirmed that this tumor characteristics weren't compatible with this kind of lesion.

[Sterilisation of patient specific surgical guide for dental implantology made in a hospital: Validation of a sterility test and structural deformation study]. / Stérilisation de guides d'implantologie imprimés sur mesure à l'hôpital : validation d'un essai de stérilité et étude de déformation.

Medical device made to measure by 3D printing are now emerging in hospital. In order to improve the precision of surgery and facilitate the treatment of complicated cases, patient specific surgical guides for dental implantology are made by stereolithography in our facial surgical unit. This new activity requires to ensure the safety of patients and health personnel by validating the various step of the manufacturing circuit. In this context, the goal of this work was to study the quality of autoclave sterilisation of the patient specific surgical guide made to measure in our hospital. A protocol of sterility test was designed and validated. Sterility of implantology guides 0, 7, 14 and 28 days after sterilisation was checked. The impact of the autoclave sterilisation on the medical device structure was evaluated by visual check and during surgeries. The sterility of the implantology guides up to 28 days after sterilisation was also validated. The protocol of sterility test executed can be extended to other hospitals interested in validating a sterility test. No deformation was observed by surgeons during the dental implant process. Future studies may be necessary to check the accurate impact of sterilisation on surgical guide structure.

Reproducibility assessment of Delaire cephalometric analysis using reconstructions from computed tomography.

INTRODUCTION: Cephalometry performed on sagittal teleradiographic X-rays is commonly used for the planification of orthognathic procedures. Tomographic imaging techniques (computer tomography or cone-beam computer tomography) are more and more prescribed for the assessment of complex occlusofacial anomalies. In this study, we intended to evaluate if teleradiographic X-rays reconstructed from computer tomography (CT) can be used to trace reliable cephalometric analyses. We assessed the inter- and intra-observer reproducibility of a simplified Delaire analysis (Top 12), one of the numerous common cephalometric analyses, performed with the Delaire Evolution software on three sets of X-rays: (1) conventional cephalometric X-rays, (2) 2D reconstructions obtained from the CT scans of the same patients and (3) 2D reconstructions obtained from CT scans of dry skulls without a cervical spine (anthropological material). Our primary goal was to assess X-rays reconstructed from tomographies as an alternative for conventional cephalometric X-rays. Our secondary goal was to assess whether computerized cephalometric analysis was a reproducible technique, both on clinical and anthropological material. MATERIALS AND METHODS: We included 10 consecutive adult patients admitted for orthodontic assessment who had benefited from both lateral cephalometric X-rays and from CT-scans. We also included 10 CT-scans from adult dry skulls without a cervical spine, from the collections of the Muséum National d'Histoire Naturelle (Musée de l'Homme, Paris, France). Cephalometric X-rays were reconstructed from CT-scans of both patients and dry skulls using Carestream® (Carestream Health inc., New York, USA). Simplified Delaire analyses (Top12) were conducted by 2 observers using the Delaire Evolution software (JDel, Nantes, France), on the 3 sets of cephalometric X-rays: (1) 10 standard cephalometric X-rays from the orthodontic patients, (2) 10 reconstructed cephalometric X-rays from the CT scans of the orthodontic patients and (3) 10 reconstructed cephalometric X-rays from the CT scans of the dry skulls. A standard statistical assessment of reproducibility was conducted using correlation coefficients. RESULTS: We found good inter- and intra-observer reproducibility for standard cephalometric X-rays and reconstructed cephalometric X-rays (Intraclass Correlation Coeficient > 0.75). We did not find any difference for angle measures between the standard cephalometric X-rays and the reconstructed cephalometric X-rays for the group of orthodontic patients (P > 0.05). Delaire cephalometric analysis was not reproducible for cephalometric X-rays without a cervical spine, that is for cephalometric X-rays reconstructed from the CT-scans of dry skulls. DISCUSSION: Delaire computerized simplified Top12 analysis was reproducible for lateral cephalometric X-rays and for reconstructions obtained from CT scans with similar angle measures for a given patient. This analysis does not seem to be reliable for dry skulls without upper cervical spine. This study uses the example of one particular computerized cephalometric analysis in order to show that cephalometric analyses can be performed on lateral reconstructed cephalometric X-rays obtained from CT scans.

Implementation of a digital chain for the design and manufacture of implant-based surgical guides in a hospital setting.

The digital revolution has led to many recent developments in implantology that have considerably facilitated implant planning and the creation of surgical guides. The purpose of this article is to explain how we set up a digital workflow in a large city hospital and how we met the requirements of the European regulations on the production of custom-made devices in a medical establishment. The internal manufacture of a surgical guide complied with European regulation EU/2017/45 concerning medical devices. This regulation allowed the hospital to create these medical devices locally without CE marking. However, the hospital must be declared as a manufacturer of medical devices and comply with the general requirements in terms of safety and performance related to the manufacture and use of medical devices. In addition, hospitals are large structures involving many different actors. Each step of the digital workflow, which included both the patient course and the creation of the surgical guide, was thus adapted to European regulations by considering local constraints.

Maxillary shape after primary cleft closure and before alveolar bone graft in two different management protocols: A comparative morphometric study.

AIM AND SCOPE: Result assessment in cleft surgery is a technical challenge and requires the development of dedicated morphometric tools. Two cohorts of patients managed according to two different protocols were assessed at similar ages and their palatal shape was compared using geometric morphometrics. MATERIAL AND METHODS: Ten patients (protocol No. 1) benefited from early lip closure (1-3 months) and secondary combined soft and hard palate closure (6-9 months); 11 patients (protocol No. 2) benefited from later combined lip and soft palate closure (6 months) followed by hard palate closure (18 months). Cone-Beam Computed Tomography (CBCT) images were acquired at 5 years of age and palatal shapes were compared between protocols No. 1 and No. 2 using geometric morphometrics. RESULTS: Protocols No. 1 and No. 2 had a significantly different timing in their surgical steps but were assessed at a similar age (5 years). The inter-canine distance was significantly narrower in protocol No. 1. Geometric morphometrics showed that the premaxillary region was located more inferiorly in protocol No. 1. CONCLUSION: Functional approaches to cleft surgery (protocol No. 2) allow obtaining larger inter-canine distances and more anatomical premaxillary positions at 5 years of age when compared to protocols involving early lip closure (protocol No. 1). This is the first study comparing the intermediate results of two cleft management protocols using 3D CBCT data and geometric morphometrics. Similar assessments at the end of puberty are required in order to compare the long-term benefits of functional protocols.

Zygomatic bone shape in intentional cranial deformations: a model for the study of the interactions between skull growth and facial morphology.

Intentional cranial deformations (ICD) were obtained by exerting external mechanical constraints on the skull vault during the first years of life to permanently modify head shape. The repercussions of ICD on the face are not well described in the midfacial region. Here we assessed the shape of the zygomatic bone in different types of ICDs. We considered 14 non-deformed skulls, 19 skulls with antero-posterior deformation, nine skulls with circumferential deformation and seven skulls with Toulouse deformation. The shape of the zygomatic bone was assessed using a statistical shape model after mesh registration. Euclidian distances between mean models and Mahalanobis distances after canonical variate analysis were computed. Classification accuracy was computed using a cross-validation approach. Different ICDs cause specific zygomatic shape modifications corresponding to different degrees of retrusion but the shape of the zygomatic bone alone is not a sufficient parameter for classifying populations into ICD groups defined by deformation types. We illustrate the fact that external mechanical constraints on the skull vault influence midfacial growth. ICDs are a model for the study of the influence of epigenetic factors on craniofacial growth and can help to understand the facial effects of congenital skull malformations such as single or multi-suture synostoses, or of external orthopedic devices such as helmets used to correct deformational plagiocephaly.