Imprimantes tridimensionnelles grand public compatibles avec la dentisterie ?Vol 13 No 1 (2020)
L’objectif de ce travail est de définir les différents critères qu’un dentiste généraliste doit prendre en compte pour s’équiper d’une imprimante tridimensionnelle (3D) à usage dentaire. Nous avons recensé au total 1037 imprimantes 3D produites par 342 entreprises et 211 imprimantes 3D de 88 entreprises pouvant imprimer avec des couches de 25µm. Pour pouvoir les comparer nous avons évalué 16 caractéristiques différentes: 1) famille de procédé d’impression 3D, 2) épaisseur de couche minimale, 3) présence ou non d’étude scientifique de validation de l’épaisseur de couche minimale, 4) résolution XY minimale, 5) type de calibrage, 6) environnement d’impression, 7) présence d’un plateau d’impression chauffant, 8) vitesse d’impression maximale (en mm/s) avec un lien donnant le détail de l’épaisseur de couche utilisée, de la résolution XY utilisée et du matériau utilisé pour déterminer cette vitesse, 9) dimensions de capacité d’impression, 10) capacité d’utiliser des matériaux ne provenant pas de l’entreprise constructrice, 11) capacité d’utiliser des matériaux biocompatibles, 12) poids (en kg) et dimensions de l’imprimante (en cm), 13) systèmes d’exploitation compatibles, 14) types de fichier d’impression 3D compatibles, 15) gestion du service après-vente et durée de la garantie, 16) prix, en indiquant si les taxes sont incluses ou non. Nous avons constaté une grande hétérogénéité des informations présentes et des informations souvent absentes en ce qui concerne : 1) le type de calibrage, 2) la vitesse d’impression, 3) le prix, 4) le service après-vente, 5) la garantie ainsi que 6) les matériaux qui sont pris en compte par l’imprimante 3D. Nous avons décrit des difficultés de communication multiples avec nos interlocuteurs et un développement très dynamique du monde d’impression 3D. Enfin, nous avons proposé des caractéristiques d’une imprimante 3D dentaire « idéale » et d’une entreprise-partenaire « idéale» pour un dentiste désireux de se procurer l’imprimante 3D de son choix.
Revue illustrée des principales indications de CBCT en orthodontie.Vol 12 No 1 (2020)
Cette revue illustrée porte sur les principales indications actuellement recommandées dans la littérature d’utilisation du cone beam computed tomography (CBCT) en orthodontie. Il s’agit des anomalies dentaires, des canines incluses, des dents surnuméraires, des troubles de l’éruption et des résorptions radiculaires externes liées aux traitements orthodontiques. L’examen CBCT doit être justifié individuellement, au cas par cas, et de pouvoir apporter un bénéfice au patient en terme de diagnostic et/ou de traitement orthodontique. L’orthodontiste prescripteur doit être capable d’interpréter et est responsable de l’interprétation de tout ce qui est visible sur l’ensemble du champs de vue du CBCT.
Artifacts related to cone beam computed tomography (CBCT) technology and their significance for clinicians: illustrated review of medical literature.Vol 11 No 1 (2020)
Objective: to explain the meaning and to illustrate technical artifacts (aliasing as well as the ring artifact) and beam hardening (metal artifact) that can be present in the dentomaxillofacial cone beam computed tomography (CBCT), and to check the accessibility of free illustrations of these artifacts in medical publications.
Material and methods: One observer applied five search equations using database PubMed. The exclusion criteria were: experimental studies, animal studies, studies not related to dentomaxillofacial area, and articles with closed access. There was no time limit for the search of articles. We limited our search to English and French language.
Results: Only 3 articles out of 434 publications were retained after application of inclusion/exclusion criteria. In these articles only 4 annotated figures were freely accessible in medical publications from PubMed.
In this paper we presented examples of aliasing, ring artifact, and beam artifacts from I-CAT, Carestream 9000 3D (Kodak), and Planmeca Promax 3D Mid CBCT. The intensity of beam hardening artifact varies from major degradation of image (i.e., subperiosteal implants, bridges, crowns, dental implants, and orthodontic fix appliances), through mean degradation (screws securing titanium mesh, head of mini-implant) to no beam hardening on metallic devices (orthodontic anchorage, orthodontic contention wire) or on dense objects (endodontic treatments, impression materials, Lego box). Some beam hardening artifacts arising from nasal piercing, hairs, or hearing aid device may be present on the image but they will not disturb the evaluation of the field of view.
Conclusions: reduction of aliasing artifact is related with the improvement of detectors quality. The presence of ring artifact means that CBCT device has lost its calibration. The field of view (FOV) needs to be reduce in order to avoid scanning regions susceptible to beam hardening (e.g., metallic restorations, dental implants). Finally, the accessibility to open knowledge on technique -related CBCT artifacts seems extremely limited when searching at PubMed database.
Accessibility to the knowledge on anatomical variations from dentomaxillofacial CBCTVol 10 No 1 (2020)
Objective: to investigate the accessibility of open access article on anatomical variations described on cone beam computed tomography (CBCT) using PubMed database. We wanted to investigate how many journals are sharing articles without pay-wall and how many are sharing articles without author publication charges.
Material and methods: a search equation was designed with exclusion criteria limiting the search in PubMed to articles published in English and French. The search was performed by one observer. We had found 2228 articles; among them 709 were accessible as ‘full text’. After applying exclusion criteria and after full text reading only 50 articles remained for the review.
Results: the 50 selected articles shared 306 annotated (visual marking, explanation like arrows) and 432 not annotated figures with the public. The 76% of articles were single studies on one specific topic. The main topic was endodontics with 22 articles. 28 journals from all continents participated in the effort of sharing of figures on anatomical variations from CBCT. However, only 2 journals were completely free of charges for authors and readers.
Conclusions: we have found only 15 annotated and 3 not annotated figures in 2 articles published in 2 different open access journals (without reader pay-wall and without author publication charges). Sharing the knowledge on anatomical variations from dentomaxillofacial CBCT represents an exception in dental literature.
Computed tomography of the heads of ancient Egyptian mummies: a systematic review of the medical literatureVol 9 No 1 (2020)
Objective: To summarize the current knowledge on CT scanning of Egyptian mummy heads and faces and provide more valid methodology than that previously available.
Material and methods: A systematic review was performed by one observer using two biomedical databases: PubMed and EMBASE. Inclusion and exclusion criteria were applied along with language restrictions. Finally, 2120 articles were found, 359 articles were duplicated among all search equations, 1454 articles were excluded, 307 articles were retained for full review, and 28 articles (31 mummies) were selected for the final study (PRISMA workflow).
Results: The data were categorized into the following groups: 1) general information; 2) 1st author affiliation; 3) CT radiological protocol; 4) excerebration pathways; 5) soft tissue preservation; 6) dental status and displaced teeth; 7) packing of the mouth, ears, nose, and eyes, and 8) outer facial appearance. The evidence-based quality of the studies was low because only case reports and small case series were found.
Discussion: The embalming art applied to a mummified head and face shows great variability across the whole span of Egyptian civilization. The differences among the various embalming techniques rely on multiple tiny details that are revealed by meticulous analysis of CT scans by a multidisciplinary team of experts.
Conclusion: There is a need for more systematization of the CT radiological protocol and the description of Egyptian mumm’y heads and faces to better understand the details of embalming methods.
Complications in surgically assisted rapid maxillary expansion: a systematic review of the medical literature.Vol 8 No 1 (2019)
Our aim was to perform a systematic open-access review of various complications reported for surgically assisted rapid maxillary expansion (SARME) procedures. There were 37 articles found in Pubmed using the search equation. Twelve articles were initially excluded according to the exclusion criteria. The 25 remaining articles were read in full for their descriptions of complications related to the SARME procedure in mature patients. The main reversible complications of SARME were infection, postoperative pain, and bleeding. There were also complications related to distractors, to secondary surgeries, and pterygomaxillary junction. The main non-reversible complications of SARME were associated with teeth, periodontal bone loss, and skull base fractures. Large field-of-view cone beam computed tomography (maxilla and skull base) should be implemented as initial planning tool to prevent many potential complications. The current trend for “minimally invasive” surgery in SARME might be, from an ethical point of view, transformed onto “minimally complicated” surgery as complication is still more harmful for any given patient than any potential perioperative surgical invasiveness.
Troubles oro-faciaux dans Fibrodysplasia ossificans progressiva. Revue systématique.Vol 7 No 1 (2019)
Fibrodysplasia ossificans progressiva (FOP) or myositis ossificans is a very rare autosomic dominant disease. Progressive ectopic bone formation occurs in ligaments, muscles and fascia and provoque severe movement limitation with time. The aim of this article is a systematic review of the litterature on FOP and on related problems occurring in oral and maxillofacial region. Some guidance on FOP treatment planning in oral and maxillofacial area are also proposed.
Myosite ossifiante du muscle temporal après polytraumatismeVol 6 No 1 (2019)
Myositis ossificans traumatica (MOT) of the temporal muscle is an extremely rare disease. A limitation of mouth opening is a key symptom. Imaging is very useful for diagnosis. The computed tomography scanner of the face is the most efficient for the detection of the MOT. Complete surgical resection is the best treatment. Cases of MOT in the head and neck area are rare. Cases of isolated temporal muscle involvement are even rarer. We present the case of an isolated ossification of the left temporal muscle after polytrauma. The interest of the clinical observation of the case presented is thus to document the literature. The differential diagnosis and pathognomonic signs present on the imaging examinations will also be detailed.
Quality assessment of instructions for authors in dental, oral and maxillofacial journalsVol 5 No 1 (2019)
Objective: to develop and test inter-observer reproducibility of instructions for authors quality rating (IAQR) tool measuring the quality of instructions for authors at journal level for a possible improvement of editorial guidelines.
Material and methods: instructions for authors of 75 dental and maxillofacial surgery journals were assessed by two independent observers using assessment tool inspired from AGREE with 16 questions and 1 to 4 points scale per answer. Two observers evaluated the instructions of authors independently and blind to impact factor of a given journal. Scores obtained from our tool were compared
with “journal impact factor 2013”.
Results: IAQR presented with an excellent interobserver reproducibility (κ= 0.81) despite a difference in data distribution between observers. There existed a weak positive correlation between IAQR and “journal impact factor 2013”.
Conclusions: The IAQR is a reproducible quality assessment tool at the journal level. The IAQR assess the quality of instruction for authors and it is a good starting point for possible improvements of the instructions for authors, especially when it comes to their completeness.
Nemesis relevance: 28% of dental and maxillofacial journals might revise their instructions for authors to provide more up-to-date version.
Paget’s disease of bone, biphosphonates and jaw osteonecrosis: a case reportVol 4 No 1 (2019)
Objective: Paget’s disease of bone is characterized by a focal increase in bone resorption and accelerated bone formation leading to a weaker and disorganised bone. Bisphosphonates (BPs) have been the treatment of choice of Paget’s disease since the 1990s. Medication related osteonecrosis of the jaw (MRONJ) is a rare event in non oncologic patients. We describe a rare case of Paget’s disease involving the maxilla with osteonecrosis in a context of bisphosphonate treatment.
Case report: an 87-year-old woman presented with 4 episodes of bone necrosis in 15 years. In this case report there is a clear chronologic association between the occurrence of MRONJ and the administration of iv BP for Paget’s disease.
Maxillofacial involvement of Paget’s disease occurs in less than 15% of cases. There is a lack of information in the literature about the association of MRONJ and Paget’s disease. Even if osteonecrosis of the jaw could be a consequence of the disease, in this case, it is more in relation to the BP treatment.
Conclusions: Although MRONJ might be considered a rare condition in Paget’s disease, patients prior to starting antiresorptive therapy and in particular iv BPs should have a complete dental examination and panoramic X-Ray.
Nemesis relevance: side effect of bisphosphonate treatment
Cytotoxicity of three-dimensional paper-based models from a three-dimensional paper-based printerVol 3 No 1 (2018)
Objective: Our study aimed to determine the possibility of using models created with a low-cost, paper based 3D printer in an operating room. Therefore influence of different methods of sterilization on models was tested and cytotoxicity of generated models was determined.
Material and methods: 30 cuboids divided into three groups were used for verification of shape stability after sterilization. Each group was sterilized either with: Ethylene oxide in temperature 55˚C, Hydrogen peroxide gas plasma in temperature 60˚C or Gamma irradiation at 21˚C, 25kGy. Each cuboid was measured using calliper three times before and three times after sterilization. Results were analysed statistically in Statgraphics Plus. Statistical significance was determined as p< 0.05. Sixty cylinders divided into six groups were used for cytotoxicity tests. Three of those groups were covered before sterilization with 2-octyl-cyanoacrylate. Each group was sterilized with one of the previously described methods. Cytotoxicity was tested by Nanostructural and Molecular Biophysics Laboratory in Technopark Lodz using normal adult human dermal fibroblasts. Survival of cells was tested using spectrophotometry with XTT and was defined as ratio of absorbency of tested probe to absorbency of control probe. Calcein/Ethidium dyeing test was performed according to LIVE/DEAD Viability/Cytotoxicity Kit protocol. Observation was done under Olympus GX71 fluorescence microscope. Results: There was no statistically significant difference for established statistical significance p=0.05 in cuboids dimensions before and after sterilization regardless of sterilization method. In XTT analysis all samples showed higher cytotoxicity against normal, human, adult dermal fibroblast culture when compared to positive control. ANOVA statistical analysis confirmed that 2-octyl cyanoacrylate coating of paper model improved biological behaviour of the material. It decreased cytotoxicity of the model independently of sterilization method. In calcein/ethidium dyeing test due to the high fluorescence of the background caused by cylinders of analysed substance it was impossible to perform the exact analysis of the number of marked cells.
Conclusions: Acquired results allow to conclude that Mcor Technology Matrix 300 3D paper-based models can be used in operating room only if covered with cyanoacrylate tissue adhesive.
Nemesis relevance: no statistically significant difference in cuboids dimensions before and after sterilization regardless of sterilization method. Presence of high cytotoxicity of 3D paper-based models without coating.
Three-dimensional analysis of airway space and mandibular morphology in Pierre Robin sequence using cone beam computed tomography.Vol 2 No 1 (2018)
Objectives: The Pierre Robin sequence (PRS) is defined by retromicrognathia, glossoptosis, and sleep apnea and can also be associated with cleft palate. Diagnosis, management and mandibular catch-up growth are still controversial issues in PRS patients. The aim of our retrospective study was to evaluate in three dimensions (3D) the airway space and mandibular morphology in PRS compared to a normal control group patients in the pre-orthodontic period of life. The null hypothesis was that we would not find a significant difference between the PRS and control group patients in oropharyngeal airway volume measurements. Material and methods: We analyzed 9 PRS patients (mean age: 8 years-old) who underwent cleft palate surgery in the first four months of life, performed by the same surgeon using the same technique. Cone-beam computed tomography (CBCT) was performed in these patients after local ethical committee approval. The control group consisted of 15 patients (mean age: 9 years-old) with CBCT already performed for other reasons. 3D Slicer was used in both groups for semi-automatic segmentation of the airway space. Two independent observers performed semi-automatic segmentations twice in each patient with a one- week interval between the two series of measurements. Airway volume was automatically measured using 3D Slicer. We also developed a 3D cephalometric analysis with Maxilim software in order to define a 3D mandibular morphology which consisted of 25 landmarks, 4 planes, and 23 distances. Two independent observers performed the 3D cephalometric analysis twice for each patient, with a one- week interval between the two series of measurements. Results: There was no significant difference in the intra- and inter-observer measurements between the PRS and control groups for airway space volume (p<0.05). However, there was a significant difference in the shape of the mandible between the PRS group and the control group (p<0.05). Conclusions: Vertical ramus width and mandibular global anteroposterior length were significantly lower in the PRS group. Mandibular hypoplasia could be found in PRS patients not only in the horizontal dimension. Nemesis relevance: the null hypothesis was confirmed. Moreover we failed to find exactly the same control group under 9 years-old due to radioprotection restrictions of application of cone beam CT in children.
Pathologies osseuses des maxillaires récidivantesVol 1 No 1 (2018)
Maxillofacial bone diseases represent a heterogeneous group involving benign and malign tumors, and metabolic, malformative, and infectious diseases. They have a tendency to relapse even with a good initial treatment. Therefore, we need to start with active surveillance based on medical imaging (CT scanner). The treatment of maxillofacial bone diseases is based mainly on clinical examination, radiological findings, and pathological diagnosis. The treatment consists of curettage or maxillary/mandibulary interruptive or not-interruptive bone resection. Development of guidelines seems impossible due to the heterogenicity of clinical presentations. The individualized treatment should prevail.