Stability of maxillary expansion osteotomy using patient-specific fixation implants without necessitating removable appliances: a retrospective analysis.

OBJECTIVE: This study aimed to evaluate the long-term stability of surgical maxillary expansion using patient-specific fixation implants (PSFIs) without intraoral retention. MATERIALS AND METHODS: Fifteen patients who had undergone segmented Le Fort I osteotomy and PSFIs with available preoperative (t0) early (t1) and 1-year follow-up computed tomography (CT) scans (t2) were evaluated. The early and 1-year 3D models were superimposed to transfer the bony landmarks; the distances between each pair of landmarks at the different time points were then measured. The distances between the canines and second molars were also measured directly on the CT scans. RESULTS: The achieved maxillary expansions ranged from a median of 4.39 (2.00-6.27) mm at the greater palatine foramina to a median of 2.14 (1.56-2 > 83) mm at the canine level of the palatal bone. One year postoperatively, the changes in skeletal diameters ranged from a median of - 0.53 (- 1.65 to 0.41) mm at the greater palatine foramina (p = 0.12) to 0.17 (- 0.09 to 0.32) mm at the canine level of the palatal bone (p = 0.56). Changes in dental arch diameters ranged from a median of - 0.6 (- 2 to 0.00) mm between the second molars to - 1.3 (- 1.8 to - 0.25) mm between the canines (P < 0.05). CONCLUSION: This study showed the stability of maxillary expansion osteotomy using PSFIs, even without postoperative intraoral retention. CLINICAL RELEVANCE: PSFIs are a reliable method for the surgical treatment of transverse maxillary discrepancy. PFSIs are easy-to-use and improve surgical accuracy.

Fully automatic segmentation of craniomaxillofacial CT scans for computer-assisted orthognathic surgery planning using the nnU-Net framework.

OBJECTIVES: To evaluate the performance of the nnU-Net open-source deep learning framework for automatic multi-task segmentation of craniomaxillofacial (CMF) structures in CT scans obtained for computer-assisted orthognathic surgery. METHODS: Four hundred and fifty-three consecutive patients having undergone high-resolution CT scans before orthognathic surgery were randomly distributed among a training/validation cohort (n = 300) and a testing cohort (n = 153). The ground truth segmentations were generated by 2 operators following an industry-certified procedure for use in computer-assisted surgical planning and personalized implant manufacturing. Model performance was assessed by comparing model predictions with ground truth segmentations. Examination of 45 CT scans by an industry expert provided additional evaluation. The model's generalizability was tested on a publicly available dataset of 10 CT scans with ground truth segmentation of the mandible. RESULTS: In the test cohort, mean volumetric Dice similarity coefficient (vDSC) and surface Dice similarity coefficient at 1 mm (sDSC) were 0.96 and 0.97 for the upper skull, 0.94 and 0.98 for the mandible, 0.95 and 0.99 for the upper teeth, 0.94 and 0.99 for the lower teeth, and 0.82 and 0.98 for the mandibular canal. Industry expert segmentation approval rates were 93% for the mandible, 89% for the mandibular canal, 82% for the upper skull, 69% for the upper teeth, and 58% for the lower teeth. CONCLUSION: While additional efforts are required for the segmentation of dental apices, our results demonstrated the model's reliability in terms of fully automatic segmentation of preoperative orthognathic CT scans. KEY POINTS: • The nnU-Net deep learning framework can be trained out-of-the-box to provide robust fully automatic multi-task segmentation of CT scans performed for computer-assisted orthognathic surgery planning. • The clinical viability of the trained nnU-Net model is shown on a challenging test dataset of 153 CT scans randomly selected from clinical practice, showing metallic artifacts and diverse anatomical deformities. • Commonly used biomedical segmentation evaluation metrics (volumetric and surface Dice similarity coefficient) do not always match industry expert evaluation in the case of more demanding clinical applications.

Humanitarian Maxillofacial Mission's Success Requires Experienced Surgeons, Careful Planning, and Meeting With the Local's Care Needs.

PURPOSE: Meeting with local needs of low- and middle-income countries during maxillofacial humanitarian mission is not easy. This article aimed to report on 5 years of experience in humanitarian maxillofacial surgery missions. In addition, several key points for best practices and meeting the medical needs of local populations are discussed. METHODS: In this retrospective case series, all medical charts of patients managed during humanitarian maxillofacial surgery missions organized within the department of maxillofacial surgery of Le Dantec Hospital (Senegal) were analyzed. Disease characteristics, treatments modality, and outcomes were reviewed. Moreover, missions planning and costs were studied. RESULTS: Between 2015 and 2018, 5 humanitarian missions were organized totalizing 177 patients, one-third of which were treated surgically. Tumors (35%) and sequelae from previous surgeries, cancrum oris or trauma (24%) were the most frequently treated disorders. Most patients were treated with free flap reconstructions (35%). Postoperative complications were observed for only 3 patients (5%). With a median follow-up of 13 months, no sequelae requiring specific treatment were observed. The estimated total cost for each mission was $39,000. CONCLUSION: In order to benefit both the locals and the volunteers, humanitarian maxillofacial missions should be carefully planned and volunteers appropriately prepared. Other keys to the success of such missions are setting up training and support programs, reflecting upon ethical considerations, understanding local cultural customs and ensuring mutual respect with the locals. Frequent self-evaluation and long-term mission sustainability are critical. Finally, mission costs should be evaluated.

Standard and Customized Alloplastic Facial Implants Refining Orthognathic Surgery: Outcome Evaluation.

PURPOSE: Conventional orthognathic osteotomies provide appropriate functional outcomes but might be unable to correct midface deficiency, achieve a satisfactory outcome in asymmetrical cases, or allow sufficient chin advancement. We evaluated the outcome of both standard and customized facial high-density porous polyethylene implants used to refine the cosmetic outcome of orthognathic surgery. PATIENTS AND METHODS: We implemented a retrospective study. The sample was composed of all patients who underwent facial alloplastic augmentation between June 2011 and October 2018 in our department. The complication rate was recorded after a mean follow-up period of 41 months postoperatively, and patient satisfaction was assessed through a qualitative evaluation based on an 11-item questionnaire. RESULTS: The sample was composed of 24 implants placed in 14 patients: 13 mandibular angle implants, among which 4 were customized; 8 malar implants; and 3 chin implants. No physical complications such as hematoma, infection, migration, or hypoesthesia were observed. Two implants had to be removed because of early unsatisfactory esthetic outcomes. Of 14 patients, 11 answered our questionnaire. Eighty-two percent strongly agreed that the overall outcome was satisfactory. CONCLUSIONS: The results of this study confirm the low physical complication rate described in the literature, and the esthetic complication rate remains lower than the rates observed in previous reports. A high satisfaction rate was found among patients. The lowest mean satisfaction score was noted for appropriate implant symmetry (3.5), whereas the highest mean satisfaction score (3.8) was achieved when using customized implants. If standard high-density porous polyethylene implants appear to be relevant adjuncts to orthognathic surgery, customized implants seem to achieve higher satisfaction, although their prohibitive cost should be considered.

Evaluation of a Radiological Score in the Management of Pure Fractures of the Orbital Floor.

PURPOSE: The authors had for aim to further assess the predictive power and the relevance of a previously published radiological decision taking score for pure fractures with recording of clinical data. METHODS: The authors retrospectively included all patients managed in the authors' department for a pure orbital floor fracture, from June 2012 to November 2013. The authors collected clinical data including diplopia and enophtalmos, at initial status and after 3-months of follow-up. The radiological data was also recorded: rate of the fractured orbital floor, maximal height of periorbital tissue herniation, and a 4-grade muscular sub score. The treatment determinants were assessed by univariate analysis, with χ tests or Fisher exact tests for qualitative variables, and Student t tests for quantitative ones. A multivariate analysis was then performed with a stepwise logistic regression. RESULTS: The authors included 90 patients. The authors proposed a simple score (with a specificity of 79% and a sensitivity of 56%) for the indication to operate, using the rate, which was a significant predictor of treatment in the multivariate analysis. CONCLUSIONS: The authors' study is another step in the standardization of treatment decision for pure orbital floor fractures. The proposed score requires further clinical research to be validated but already helps to compare series of patients.

Three-dimensional reconstructions from computed tomographic scans on smartphones and tablets: a simple tutorial for the ward and operating room using public domain software.

Handling 3-dimensional reconstructions of computed tomographic scans on portable devices is problematic because of the size of the Digital Imaging and Communications in Medicine (DICOM) stacks. The authors provide a user-friendly method allowing the production, transfer, and sharing of good-quality 3-dimensional reconstructions on smartphones and tablets.

DentalSegmentator: Robust open source deep learning-based CT and CBCT image segmentation.

OBJECTIVES: Segmentation of anatomical structures on dento-maxillo-facial (DMF) computed tomography (CT) or cone beam computed tomography (CBCT) scans is increasingly needed in digital dentistry. The main aim of this research was to propose and evaluate a novel open source tool called DentalSegmentator for fully automatic segmentation of five anatomical structures on DMF CT and CBCT scans: maxilla/upper skull, mandible, upper teeth, lower teeth, and the mandibular canal. METHODS: A retrospective sample of 470 CT and CBCT scans was used as a training/validation set. The performance and generalizability of the tool was evaluated by comparing segmentations provided by experts and automatic segmentations in two hold-out test datasets: an internal dataset of 133 CT and CBCT scans acquired before orthognathic surgery and an external dataset of 123 CBCT scans randomly sampled from routine examinations in 5 institutions. RESULTS: The mean overall results in the internal test dataset (n = 133) were a Dice similarity coefficient (DSC) of 92.2 ± 6.3 % and a normalised surface distance (NSD) of 98.2 ± 2.2 %. The mean overall results on the external test dataset (n = 123) were a DSC of 94.2 ± 7.4 % and a NSD of 98.4 ± 3.6 %. CONCLUSIONS: The results obtained from this highly diverse dataset demonstrate that this tool can provide fully automatic and robust multiclass segmentation for DMF CT and CBCT scans. To encourage the clinical deployment of DentalSegmentator, the pre-trained nnU-Net model has been made publicly available along with an extension for the 3D Slicer software. CLINICAL SIGNIFICANCE: DentalSegmentator open source 3D Slicer extension provides a free, robust, and easy-to-use approach to obtaining patient-specific three-dimensional models from CT and CBCT scans. These models serve various purposes in a digital dentistry workflow, such as visualization, treatment planning, intervention, and follow-up.

An innovative 3D hydroxyapatite patient-specific implant for maxillofacial bone reconstruction: A case series of 13 patients.

The study aimed to evaluate and discuss the use of an innovative PSI made of porous hydroxyapatite, with interconnected porosity promoting osteointegration, called MyBone Custom® implant (MBCI), for maxillofacial bone reconstruction. A multicentric cohort of 13 patients underwent maxillofacial bone reconstruction surgery using MBCIs for various applications, from genioplasty to orbital floor reconstruction, including zygomatic and mandibular bone reconstruction, both for segmental defects and bone augmentation. The mean follow-up period was 9 months (1-22 months). No infections, displacements, or postoperative fractures were reported. Perioperative modifications of the MBCIs were possible when necessary. Additionally, surgeons reported significant time saved during surgery. For patients with postoperative CT scans, osteointegration signs were visible at the 6-month postoperative follow-up control, and continuous osteointegration was observed after 1 year. The advantages and disadvantages compared with current techniques used are discussed. MBCIs offer new bone reconstruction possibilities with long-term perspectives, while precluding the drawbacks of titanium and PEEK. The low level of postoperative complications associated with the high osteointegration potential of MBCIs paves the way to more extensive use of this new hydroxyapatite PSI in maxillofacial bone reconstruction.

Can systematic computed tomographic scan assessment predict treatment decision in pure orbital floor blowout fractures?

PURPOSE: To describe and evaluate the reliability and the accuracy of a specific computed tomography-based assessment in predicting treatment decisions for pure orbital floor blowout fractures (BOFs). MATERIALS AND METHODS: In this retrospective cohort study, the charts of all patients presenting with isolated BOFs from January 2009 through April 2011 at the University Hospital of Geneva were reviewed. The systematic computed tomographic assessment included the following 3 parameters: 1) ratio of the fractured orbital floor; 2) maximal height of periorbital tissue herniation, and 3) a 4-grade muscular subscore describing the position of the inferior rectus muscle relative to the level of the orbital floor. The parameters' predictive value regarding the treatment decision (conservative vs surgical) was assessed by logistic regression and relative operating characteristic curves. RESULTS: Forty-eight patients (24 male) were included. The patients' mean age was 49.5 years. The ratio of the fractured orbital floor, the maximal height of periorbital tissue herniation, and the muscular subscore were significant predictors in univariate analysis (P = .02, P = .006, P = .001, respectively), whereas, in a multivariate analysis, only muscular subscore remained a significant predictor (P = .003) and reached a similar predictive ability as the 3 parameters together. CONCLUSIONS: The present study showed that the severity of inferior rectus muscle displacement is the most important independent predictive radiologic factor in the treatment decision-making process for pure BOFs. This systematic computed tomographic assessment is a valuable tool for a better understanding of BOF management overall. Further studies are needed to establish its clinical relevance.

Effectiveness of Geriatric Assessment-Driven Interventions on Survival and Functional and Nutritional Status in Older Patients with Head and Neck Cancer: A Randomized Controlled Trial (EGeSOR).

This study assesses the efficacy of Geriatric Assessment (GA)-driven interventions and follow-up on six-month mortality, functional, and nutritional status in older patients with head and neck cancer (HNC). HNC patients aged 65 years or over were included between November 2013 and September 2018 by 15 Ear, Nose, and Throat (ENT) and maxillofacial surgery departments at 13 centers in France. The study was of an open-label, multicenter, randomized, controlled, and parallel-group design, with independent outcome assessments. The patients were randomized 1:1 to benefit from GA-driven interventions and follow-up versus standard of care. The interventions consisted in a pre-therapeutic GA, a standardized geriatric intervention, and follow-up, tailored to the cancer-treatment plan for 24 months. The primary outcome was a composite criterion including six-month mortality, functional impairment (fall in the Activities of Daily Living (ADL) score ≥2), and weight loss ≥10%. Among the patients included (n = 499), 475 were randomized to the experimental (n = 238) or control arm (n = 237). The median age was 75.3 years [70.4-81.9]; 69.5% were men, and the principal tumor site was oral cavity (43.9%). There were no statistically significant differences regarding the primary endpoint (n = 98 events; 41.0% in the experimental arm versus 90 (38.0%); p = 0.53), or for each criterion (i.e., death (31 (13%) versus 27 (11.4%); p = 0.48), weight loss of ≥10% (69 (29%) versus 65 (27.4%); p = 0.73) and fall in ADL score ≥2 (9 (3.8%) versus 13 (5.5%); p = 0.35)). In older patients with HNC, GA-driven interventions and follow-up failed to improve six-month overall survival, functional, and nutritional status.

Distraction osteogenesis versus fibula free flap for mandibular reconstruction after gunshot injury: socioeconomic and technical comparisons.

BACKGROUND: Since the birth of maxillofacial surgery, ballistic injuries are a real challenge for surgeons. For more than 20 years, fibula free flap (FFF) became the criterion standard for mandibular reconstructions. But FFF is not always the perfect answer for mandibular reconstruction, and a technique named distraction osteogenesis (DO) was raised. The purposes of this study are to estimate the financial cost and reattempt for the patient each techniques in our experience to determine the best-choice criteria for mandibular reconstruction after gunshot injury. METHODS: We performed a retrospective study over the last 15 years, including 15 patients with a mandibular ballistic injury. Ten patients were treated with FFF, and 5 with DO. We evaluated the complications and morbidity encountered with each technique. We also decided to estimate the cost of different rehabilitations, including the cost of the device and hospitalization. RESULTS: In our study, the global cost of the DO protocol appears as not more expensive than the FFF one. Postoperative complications encountered during the FFF protocols were related to donor-site morbidity. The DO patient had pseudoarthrosis, mucosa irritation, or local infection. DISCUSSION: Our study demonstrated both the economic and technical interest of DO compared with the FFF for mandibular reconstruction. Thus, nowadays, DO appears as an alternative to the FFF for mandibular reconstruction, the main decisional criterion being the evaluation of the tissues dilapidated during the initial traumatism, but social environment of the patient shall also be considered.

Biplanar Low-Dose Radiograph Is Suitable for Cephalometric Analysis in Patients Requiring 3D Evaluation of the Whole Skeleton.

BACKGROUND: The biplanar 2D/3D X-ray technology (BPXR) is a 2D/3D imaging system allowing simultaneous stereo-corresponding posteroanterior (PA) and lateral 2D views of the whole body. The aim of our study was to assess the feasibility of cephalometric analysis based on the BPXR lateral skull view to accurately characterize facial morphology. METHOD: A total of 17 landmarks and 11 angles were placed and/or calculated on lateral BPXR and lateral cephalograms of 13 patients by three investigators. Five methods of angle identification were performed: the direct construction of straight lines on lateral cephalograms (LC-A) and on BPXR (BPXR-A), as well as the calculation of angles based on landmark identification on lateral cephalograms (LA-L) and on BPXR with the PA image (BPXR-LPA) or without (BPXR-L). Intra- and interoperator reliability of landmark identification and angle measurement of each method were calculated. To determine the most reliable method among the BPXR-based methods, their concordance with the reference method, LC-A, was evaluated. RESULTS: Both imaging techniques had excellent intra- and interoperator reliability for landmark identification. On lateral BPXR, BPXR-A presented the best concordance with the reference method and a good intra- and interoperator reliability. CONCLUSION: BPXR provides a lateral view of the skull suitable for cephalometric analysis with good reliability.

Three-Dimensional Cephalometric Landmarking and Frankfort Horizontal Plane Construction: Reproducibility of Conventional and Novel Landmarks.

In some dentofacial deformity patients, especially patients undergoing surgical orthodontic treatments, Computed Tomography (CT) scans are useful to assess complex asymmetry or to plan orthognathic surgery. This assessment would be made easier for orthodontists and surgeons with a three-dimensional (3D) cephalometric analysis, which would require the localization of landmarks and the construction of reference planes. The objectives of this study were to assess manual landmarking repeatability and reproducibility (R&R) of a set of 3D landmarks and to evaluate R&R of vertical cephalometric measurements using two Frankfort Horizontal (FH) planes as references for horizontal 3D imaging reorientation. Thirty-three landmarks, divided into "conventional", "foraminal" and "dental", were manually located twice by three experienced operators on 20 randomly-selected CT scans of orthognathic surgery patients. R&R confidence intervals (CI) of each landmark in the -x, -y and -z directions were computed according to the ISO 5725 standard. These landmarks were then used to construct 2 FH planes: a conventional FH plane (orbitale left, porion right and left) and a newly proposed FH plane (midinternal acoustic foramen, orbitale right and left). R&R of vertical cephalometric measurements were computed using these 2 FH planes as horizontal references for CT reorientation. Landmarks showing a 95% CI of repeatability and/or reproducibility > 2 mm were found exclusively in the "conventional" landmarks group. Vertical measurements showed excellent R&R (95% CI < 1 mm) with either FH plane as horizontal reference. However, the 2 FH planes were not found to be parallel (absolute angular difference of 2.41°, SD 1.27°). Overall, "dental" and "foraminal" landmarks were more reliable than the "conventional" landmarks. Despite the poor reliability of the landmarks orbitale and porion, the construction of the conventional FH plane provided a reliable horizontal reference for 3D craniofacial CT scan reorientation.

DIVA, a 3D virtual reality platform, improves undergraduate craniofacial trauma education.

Craniofacial fractures management is challenging to teach due to the complex anatomy of the head, even when using three-dimensional CT-scan images. DIVA is a software allowing the straightforward visualization of CT-scans in a user-friendly three-dimensional virtual reality environment. Here, we assess DIVA as an educational tool for craniofacial trauma for undergraduate medical students. Three craniofacial trauma cases (jaw fracture, naso-orbital-ethmoid complex fracture and Le Fort 3 fracture) were submitted to 50 undergraduate medical students, who had to provide diagnoses and treatment plans. Each student then filled an 8-item questionnaire assessing satisfaction, potential benefit, ease of use and tolerance. Additionally, 4 postgraduate students were requested to explore these cases and to place 6 anatomical landmarks on both virtual reality renderings and usual slice-based three-dimensional CT-scan visualizations. High degrees of satisfaction (98%) without specific tolerance issues (86%) were reported. The potential benefit in a better understanding of craniofacial trauma using virtual reality was reported by almost all students (98%). Virtual reality allowed a reliable localization of key anatomical landmarks when compared with standard three-dimensional CT-scan visualization. Virtual reality interfaces such DIVA are beneficial to medical students for a better understanding of craniofacial trauma and allow a reliable rendering of craniofacial anatomy.

In-house 3D printing: Why, when, and how? Overview of the national French good practice guidelines for in-house 3D-printing in maxillo-facial surgery, stomatology, and oral surgery.

3D-printing is part of the daily practice of maxillo-facial surgeons, stomatologists and oral surgeons. To date, no French health center is producing in-house medical devices according to the new European standards. Based on all the evidence-based data available, a group of experts from the French Society of Stomatology, Maxillo-Facial Surgery and Oral Surgery (Société Française de Chirurgie Maxillofaciale, Stomatologie et Chirurgie Orale, SFSCMFCO), provide good practice guidelines for in-house 3D-printing in maxillo-facial surgery, stomatology, and oral surgery. Briefly, technical considerations related to printers and CAD software, which were the main challenges in the last ten years, are now nearly trivial questions. The central current issues when planning the implementation of an in-house 3D-printing platform are economic and regulatory. Successful in-house 3D platforms rely on close collaborations between health professionals and engineers, backed by regulatory and logistic specialists. Several large-scale academic projects across France will soon provide definitive answers to governance and economical questions related to the use of in-house 3D printing.

Facial morphology changes after total maxillary setback osteotomy.

PURPOSE: To evaluate the morphologic outcome after total maxillary setback osteotomy (TMSO) in dentofacial Class II deformity patients with marked upper jaw prognathism. PATIENTS AND METHODS: The assessments of 9 patients before and after TMSO were compared. The evaluation was based upon x-ray superimpositions and standardized photographic comparison. TMSO was performed through a conventional Le Fort I operation with resection of the inferior end of the pterygoid processes. RESULTS: All patients presented with marked upper jaw prognathism initially and have had a bimaxillary surgery with a mean maxillary setback of 3.1 mm. All patients ended in Class I occlusion after at least 1-year of follow-up. An opening of the nasolabial angle (mean 8.9 degrees) was noted for all but 2 patients. At the same time, the suborbital profile was nicely modified as a result of substantial heightening of the prezygomatic soft tissues in all patients, even without vertical maxillary intrusion. CONCLUSIONS: These results challenge the notion of unavoidable facial alteration commonly associated with upper setbacks. TMSO allows combining satisfactory functional and cosmetic results for a number of carefully selected patients. Pronounced maxillary protrusion with acute nasolabial angle is a prerequisite. The release of the deforming strains of the dysmorphosis upon the midface will improve the suborbital profile. Bimaxillary surgery is recommended to leverage the setback and the opening of the naso-labial angle.

Experiences with a new biplanar low-dose X-ray device for imaging the facial skeleton: A feasibility study.

BACKGROUND: This study aimed to evaluate the feasibility of a new biplanar low-dose X-ray device for facial skeletal imaging. METHODS: We evaluated 48 biplanar radiographs from 12 patients (posteroanterior/lateral), originally taken for a scoliosis examination with a biplanar low-dose X-ray device. For this study, the images were further evaluated for the perceptibility of 38 facial skeleton landmarks. To determine the reliability and reproducibility of perceptibility, two independent observers determined the landmarks twice, during a time interval of at least two weeks. RESULTS: Both interoperator and intraoperator reliability were excellent for all landmarks [intraclass correlation coefficient (ICC) > 0.92]. CONCLUSIONS: The biplanar low-dose X-ray device demonstrated good feasibility for precisely assessing the anatomical landmarks of the facial skeleton. Given its excellent precision, the biplanar low-dose X-ray device data sets should be forwarded from the treating orthopedic surgeon or neurosurgeon to the orthodontist or dentist for further assessment in their field.

[Dysfunction of the manducatory apparatus]. / Dysfonction de l'appareil manducateur.

Temporo-mandibular disorders -TMD- involve a whole set of anatomical, physiological and clinical disorders that exceed by far the sole temporo-mandibular joint. The main symptom of this condition, most frequent in female patients, is pain. Three syndromes are associated with TMD: a muscular syndrome, not only involving masticatory muscles but also muscles of the neck and pain in seemingly unrelated anatomical regions, which can be misleading; an inflammatory articular syndrome; a mechanical syndrome affecting mouth-opening path. The main treatment of this very common and benign disorder is based on physical therapy. However, physicians should be warned that some patients might exhibit similar symptoms in rare cases of malignant tumor.

DYSFONCTION DE L'APPAREIL MANDUCATEUR La notion de dysfonction de l'appareil manducateur doit être considérée selon un ensemble anatomoclinique et physiopathologique qui dépasse largement l'articulation temporomandibulaire. Cette symptomatologie essentiellement féminine et douloureuse s'exprime selon trois syndromes volontiers intriqués : un syndrome musculaire qui, au-delà des muscles de la mastication, peut intéresser la musculature cervicale et provoquer des douleurs dont le siège égare aisément le diagnostic ; un syndrome articulaire inflammatoire ; un syndrome mécanique qui altère le chemin d'ouverture de la mandibule. Le traitement est avant tout fonctionnel, s'appuyant sur la rééducation. Mais cette symptomatologie d'apparence et d'étiologie si banales ne doit pas laisser ignorer qu'elle peut avoir une cause plus sombre à type de tumeur maligne régionale.