Impact of orthognathic surgery on the body posture.

BACKGROUND: Postural control is classically described as being based on the visual, vestibular, and proprioceptive musculo-articular sensory systems. The influence of mandibular proprioception on postural stabilization remains controversial. Most previous studies analyzed how postural stability is influenced by partial changes in mandibular proprioception (dental occlusion and jaw position). RESEARCH QUESTION: In the present experiment, we asked whether drastic mandibular changes, resulting from orthognathic surgery (including dental, joint and muscular efferents), modify postural control. METHODS: The analyzes were performed in 22 patients tested before, and 2.5 months, after orthognathic surgery for treatment of dysmorphic jaws. Experiments were performed under 4 experimental conditions: 2 visual conditions: Eyes Open (EO) and Eyes Closed (EC), and 2 occlusal conditions: Occlusion (OC: mandible positioned by the contact of the teeth), and Rest Position (RP: mandible positioned by the muscles without tooth contact). The analyses focused on head orientation in the frontal plane and on postural stabilization in a static task, consisting of standing upright. RESULTS: The results show that, 2.5 months after orthognathic surgery, head orientation in the frontal plane was improved, since patient's external intercanthal lines became closer to the true horizontal line when they were tested EC and in OC condition. Postural responses, based on the wavelet transformation data, highlight an improvement in maintaining an upright stance for all the tested sensory conditions. However, such improvement was greater in the EC and RP conditions. SIGNIFICANCE: These results show, for the first time, that after drastic mandibular changes, the weight of proprioceptive cues linked to the mandibular system may be so enhanced that it may constitute a new reference frame to orient the head in space, in darkness, and improve static postural stabilization, even in the presence of visual cues.

Chin wing: Technical note.

The chin may be concerned by morphological abnormalities in its various dimensions. Classical genioplasty techniques can be used to correct these but have some disadvantages. The "chin wing", described by Triaca, is a technique of genioplasty extended to the mandibular angles, considering the mandibular basilar border as an anatomical unit, thus achieving a better harmonious functional and aesthetic result. The preoperative assessment included a mandibular Cone Beam to evaluate the position of the inferior alveolar nerve. The procedure was performed under general anesthesia. The periosteal dissection was limited to the osteotomy area and mental nerves were protected. The osteotomy observed a modification of its orientation in front of the mental foramen to become parallel to the basilar border, which was interrupted at the level of the mandibular angle. The spaces created were filled with bone grafts and maintained by a symphysary plate. Chin wing genioplasty both improves the function and aesthetic of the face because it considers the mandibular basilar border as an entire anatomical unit. It can be performed independently of any procedure to modify the bone bases. Nowadays, chin wing remains a challenging technique hardly performed.

[Mandibular ameloblastic fibro-odontoma in 3-year-old patient]. / Fibro-odontome améloblastique mandibulaire chez une patiente de 3 ans.

INTRODUCTION: The ameloblastic fibro-odontoma (FOA) is a rare benign tumor representing 1-3% of odontogenic tumors. The FOA affects young patients before the age of 20. Surgical treatment allows usually for recovery. Recurrence and malignant transformation are possible. OBSERVATION: A 3-year-old patient, with no medical and surgical history, was referred for a painless swelling of the right cheek progressing for several months. Radiographic examination showed a large mixed lesion. Buccal and lingual cortices were blown out. Surgical resection was performed under general anesthesia. Microscopically, the lesion consisted of dental tissue composed of mature dentin and enamel and of an epithelial component. These elements allowed for the diagnosis of ameloblastic fibro-odontoma. The postoperative course was uneventful. DISCUSSION: The management of this 3-year-old patient was delayed due to late consultation. The size of the lesion, that included all dental structures of sector 4, was big considering the very young age of the patient. The primary conservative surgical treatment allowed for preservation of teeth and of the inferior alveolar nerve, the only sequelae being the removal of the germ of the tooth no 44 directly involved in the tumor.

[Congenital malformations of the temporo-mandibular joint and the mandibular ramus: Grafting vs distraction osteogenesis]. / Malformations congénitales des articulations temporo-mandibulaires et des branches mandibulaires : quand greffer ? Quand distracter ?

Congenital deformities of the mandibular ramus and of the temporo-mandibular joint are treated by surgery since the early 20th century. However, morphological and functional results are often disappointing, accounting for iterative operations. Today, a clear consensus concerning the type of intervention to be proposed, and at what age it should be carried out does not yet exist. For mild cases, "conventional" orthognathic or osteogenic distraction procedures seem to work well, especially if they are carried out at the end of growth. In severe cases, it is often necessary to proceed in several surgical steps, usually starting with a chondrocostal graft, especially when interceptive surgery, performed before the end of growth, is preferred in order to improve the patient's quality of life.

[TMJ, eating and breathing]. / ATM, manducation et ventilation.

The study of the relationship between temporomandibular joints (TMJ), mastication and ventilation and the involvement of these two functions in the genesis of primary Temporomandibular Disorders (TMD) and in some dentofacial deformities, was initiated in France, more than 30years, by Professor Raymond Gola. Once criticized the weakness of the scientific literature in this domain, the originality of the TMJ within the masticatory system is recalled with its huge adaptation potential to very different biomechanical constraints according to the age and masticatory activities during the day. But the biomechanics of the masticatory system does not stop at night and the positions of the mandible and head during sleep should be studied carefully. In case of nocturnal mouth breathing with open mouth, the predominant sleeping position (generating small but long-term strengths) may be deleterious to the condyle-disc complex, to the surrounding muscles and the occlusal relationships. Some condyle-disc displacements and asymmetric malocclusions occur in this long portion of life what sleep, especially as oral breathing leads to a lot of dysfunctions (low position of the tongue, labio-lingual dysfunctions, exacerbation of bruxism sleep…). The aim of this work was to share our multidisciplinary experience of the biomechanical consequences of the nocturnal mouth breathing on the face involving orthodontists, maxillofacial surgeons, ENT, allergists, speech therapists, physiotherapists and radiologists.

[Chondromatose of the temporomandibular joint: Multicentric study and clarification from 14 cases]. / Chondromatose de l'articulation temporomandibulaire : étude multicentrique et mise au point à partir de 14 cas.

INTRODUCTION: The aim of our study was to analyse a series of patients suffering from temporomandibular joint (TMJ) chondromatosis treated in 2 departments of stomatology and maxillofacial surgery (University hospitals of the Conception in Marseille and of Caen) and to make a general review of this disease. MATERIAL AND METHODS: We conducted a retrospective study including all the patients treated for a TMJ chondromatosis in one of these 2 departments. Following parameters were analyzed: sex, ages at discovery and at surgery, symptoms, side, imaging, histology, recurrence and any other events considered as relevant. RESULTS: Fourteen patients could be included: 85.7 % were women. Average age at diagnosis was 40.14 (σ = 13.82; IC95: 32.90-47.38) (41 for women [σ = 14.74; IC95: 33.28-48.72] and 35 years for men [σ = 5.66, IC95: 27.16-42.84]). Average age at surgery was 40.86 (σ = 14.18; IC95: 33.43-48.28). There was no predominance of side; 57.14 % of the patients had a joint syndrome, 57.14 % a tumor syndrome, 28.57 % had pain and 14.29 % had headaches. Panoramic X-ray was informative in 3 cases only. CT scan showed intra-articular calcifications in half of the cases only but arthrosic modifications in all the cases. Magnetic resonance imaging (MRI) constantly showed intra-articular cartilage fragments. When histology was performed, it found the synovial to be normal in one case and multiple nodules with clear cartilaginous differentiation in another case. One patient suffered from a second contralateral localization 10 years later. DISCUSSION: Chondromatosis has a slow evolution and is asymptomatic for a long time. MRI allows to evoke the diagnosis and to locate precisely the osteochondromas. Diagnosis is confirmed by histology that highlights a synovial metaplasia and more or less calcified chondromas. The main differential diagnosis to be eliminated because of prognostic reasons is the synovial chondrosarcoma. Treatment consists in surgical removing of the chondromas. Evolution is usually favorable.

[TMJ arthroscopy. A review]. / Arthroscopie de l'articulation temporo-mandibulaire. Mise au point.

INTRODUCTION: Temporomandibular joint (TMJ) dysfunction associates pain, limited mouth opening and joint noise. Failures of conservative treatments may lead to arthroscopy. The aim of our study was to evaluate the current interest of arthroscopy in the treatment of TMJ dysfunction. MATERIAL AND METHODS: Using the keywords "TMJ" and "Arthroscopy", 1668 articles were found in the Sciencedirect database. We selected 17 papers published between September 2012 and May 2016. Six questions were asked: (1) what treatment should be given to patients suffering from TMJ dysfunction? (2) What treatment should be performed for TMJ disorders when conservative treatments failed? (3) Does Wilkes staging change the surgical indication? (4) What has to be done in case of arthroscopy failure? (5) Can disc position be improved after surgery? (6) Should the disc position be improved? RESULTS AND DISCUSSION: (1) Conservative treatment should always be considered in first intention (2) In case of conservative treatment failures, surgery can be proposed, beginning with the less invasive one (3) Whatever the Wilkes stage, treatment should begin by the less invasive one (4) In case of arthroscopy failure, TMJ arthrotomy can be indicated (5) Disc position may be improved in the long term but it is complex to obtain (only one paper) (6) there is no evidence that disk has to be repositioned.

[Dynamic palatography: Diagnostic tool for dysfunc­tional swallowing? Feasibility study].

Objective: Dysfunctional swallowing may cause transverse occlusal disorders. The speech re-education of dysfunctional swallowing aims to correct or prevent the recurrence of occlu­sal disorders. The main objective was to test the dynamic palato­graphy as a diagnosis and quantification tool of the dysfunctional swallowing. Material and methods: The study was prospective and descriptive. Twelve average 23.5 years old women with a clinical dysfunctional swallowing have been included between January and May 2014. None was aware of presenting an atypical swallowing or dento-facial dysmorphism of class II. The dynamic palatography device measured the pressure force of the language on the palate during the lingual rest, swallowing saliva and water. Parameters measured were the duration and magnitude of support of the tongue on the palate. Results: Dynamic palatography showed a trend to predominant anterior contact during rest position (25%), and lower position of the language with little contact during swallo­wing of saliva and water. Discussion: Palatography results are consistent with the clinical diagnostic criteria of atypical swallo­wing. Our palatography tool has the advantage of being unobtrusive in the mouth compared to other pre existing systems. This device should be tested on larger patient popu­la­tions and could enable monitore atypical swallowing rehabili­ta­tion efficiency. The palatography could complete the swallo­wing assessment and be a monitoring and rehabilitation tool in real time.

[Recovery of maxillary tooth sensibility after Le Fort I osteotomy]. / Récupération de la sensibilité dentaire maxillaire après ostéotomie de Le Fort I.

INTRODUCTION: Upper alveolar nerves, when injured during Le Fort I osteotomies, alter maxillary tooth sensitivity. We had for aim to analyze post-operative maxillary tooth sensitivity recovery. MATERIAL AND METHODS: We conducted a prospective study in a series of patients having undergone Le Fort I osteotomy, with, or without mandibular osteotomy or intermaxillary disjunction (IMD). The direction and range of displacement of the maxillary bone were recorded. One tooth in each alveolar sector (incisivocanine, premolar, molar) was tested with an electric stimulator for each patient. The tests were performed before (D-1), and after surgery (D2 or day+2, D+15, M2 (or month +2), M3, and M6). RESULTS: Twenty-two patients were included. Among the tested teeth, 91.9 % were sensitive at D-1. At D2, only 12.7 % of teeth were sensitive. At D15, M2, M3, and M6, the sensitivity was respectively 33.3 %, 43.1 %, 50 %, and 61.8 %. The recovery of sensitivity was faster in young patients (under 35 years of age) and for upper middle and superior alveolar nerves. There was no difference regarding the direction of maxillary movement. DISCUSSION: Among the teeth that were sensitive before surgery, 87.3 % had not regained sensitivity at D2. The recovery of sensitivity increased at D15. A great displacement of the maxillary bone was an aggravating factor for loss of tooth sensitivity.

[Computer-assisted temporomandibular joint reconstruction]. / Reconstruction de l'articulation temporomandibulaire assistée par ordinateur.

Prosthetic replacement of TMJ is gradually becoming a common procedure because of good functional and aesthetic results and low morbidity. Prosthetic models available can be standard or custom-made. Custom-made prosthesis are usually reserved for complex cases, but we think that computer assistance for custom-made prosthesis should be indicated for each case because it gives a greater implant stability and fewer complications. Computer assistance will further enlarge TMJ prosthesis replacement indications.

[Presentation of a prototype dynamic palatography for measuring the downforce of the tongue on the palate in the swallowing time]. / Présentation d'un prototype de palatographie dynamique pour la mesure de la force d'appui de la langue sur le palais lors du temps buccal de la déglutition.

The position of the tongue and the forces which it exerts on its dental and osseous environment would be responsible for a certain degree of dysmorphosis. However there is not tool usable in clinic which makes it possible to check the reality of the forces exerted by the tongue on the palate. We developed a prototype made up of an artificial palate in rigid resin including of pressure sensors and we report the feasibility of a study on healthy subjects. The sensors allow indeed of following dynamic visible differences between various "maneuvers" during the swallowing of a water mouthful. The tool will be now adapted for a clinical study comparing of the subjects with and without lingual dysfunction

[Modelization of bone graft reconstruction for posterior mandibular segment using the Simplant® software]. / Modélisation des techniques de reconstruction par greffes osseuses des secteurs mandibulaires postérieurs avec le logiciel Simplant(®).

INTRODUCTION: Pre-implant reconstruction techniques of edentulous molar mandibular ridges take into account the height and the width of the initial ridge, but not the initial geometry. The Simplant(®) software allows modeling these techniques by taking into account this geometry. TECHNICAL NOTE: Four surgical techniques for crestal volume reconstruction (apposition, interposition, distraction, formwork) were used on seven hemi-mandibles and modeled with the Simplant(®) software. This reconstructed volume was visualized according to the initial crestal geometry. The average gain in height was 4.1mm for the onlay graft, 2.3mm for the interposition graft, 4mm for distraction, 5.1mm for the boxing. The average gain of crestal width was -0.3mm for the onlay graft, 1mm for the interposition, -0.5mm for the distraction, and 1.3mm for the boxing. DISCUSSION: Modeling with the Simplant(®) software shows that boxing technique gives the closest bone reconstruction to the ideal crestal geometry, whatever the initial crestal geometry.

[The tongue flap in palatal defect reconstruction]. / Le lambeau de langue dans la reconstruction des pertes de substances du palais.

INTRODUCTION: A palatal defect with bucconasal fistula often follows exeresis of palatal tumors. It cannot be directly sutured. Several techniques have been used to cure such defects: palatal obturator, free, or local flaps. TECHNICAL NOTE: The tongue pediculated flap is an easy, safe, and reliable surgical option to reconstruct palatal defects. The tongue flap is a double-layer muscular and mucosal flap that requires two surgeries. During the first, the flap is harvested on the tongue and partially sutured on the anterior portion of the palatal defect. During the second, the pedicle is freed from the tongue and sutured to the posterior portion of the palatal defect. Between these two surgeries the patient is fed through a nasogastric tube. DISCUSSION: The tongue flap is easy and reproducible. It can be recommended in mediopalatal defects after cancer palatal surgery. Its esthetical and functional results are excellent. It is an alternative to palatal obturator, which are not well tolerated in the long run. Similar but uneven results are obtained with free flaps. Free flaps do not require a second surgery but are more difficult to implement in developing countries.

[Medical and dental digital photography. Choosing a cheap and user-friendly camera]. / Photographie numérique médicale et dentaire. Le choix d'un appareil photo simple et économique.

INTRODUCTION: Digital photography is more and more important in our everyday medical practice. Patient data, medico-legal proof, remote diagnosis, forums, and medical publications are some of the applications of digital photography in medical and dental fields. A lot of small, light, and cheap cameras are on the market. The main issue is to obtain good, reproducible, cheap, and easy-to-shoot pictures. TECHNICAL NOTE: Every medical situation, portrait in esthetic surgery, skin photography in dermatology, X-ray pictures or intra-oral pictures, for example, has its own requirements. For these reasons, we have tried to find an "ideal" compact digital camera. The Sony DSC-T90 (and its T900 counterpart with a wider screen) seems a good choice. Its small size makes it usable in every situation and its price is low. An external light source and a free photo software (XnView((R))) can be useful complementary tools. The main adjustments and expected results are discussed.

[Occlusal plane orientation and postoperative anterior open bite relapse]. / Orientation du plan d'occlusion et récidive postopératoire des béances antérieures.

INTRODUCTION: Most published data on relapse in open bite maxillo-mandibular deformities give raw results but do not suggest any specific therapy. Indeed, their authors compare the various osteotomy techniques but without identifying risk factors for relapse (dysfunctional or architectural). We studied the predictive value of occlusal plane tilting, in the long-term relapse of open bite maxillo-mandibular deformity. MATERIAL AND METHOD: Fifty patients were included between 1996 and 2007. For each patient, Delaire cephalometric analysis was performed on preoperative, immediate and late postoperative teleradiographs. Immediate real postoperative occlusal plane tilting was analyzed and compared with "ideal" theoretical occlusal plane tilting (calculated with Delaires' analysis). The patients were classified in two groups: one with slight discrepancy between these two planes (+/-3.75 degrees) and one with large discrepancies between these two planes (greater than 3.75 degrees or lesser than 3.75 degrees). RESULTS: Postoperative relapse was seven times more frequent when the postoperative plane tilting was superior to +/-3.75 degrees in reference to the ideal plane. DISCUSSION: Postoperative occlusal plane tilting is a predictive factor of postoperative open bite relapse.

[Transoral removal of submandibular hilar calculi]. / Exérèse des lithiases postérieures de la glande submandibulaire par abord endobuccal.

INTRODUCTION: Sialolithiasis is the most common non-neoplastic salivary gland disease, accounting for 1.2% of the autoptic population. More than 80% of salivary calculi are located in the submandibular ductal system. Hilar calculi are usually removed by transcervical submandibular sialadenectomy. However, intra-oral removal of hilum submandibular calculi is an interesting alternative. INDICATIONS: The main criterion for intra-oral removal is the calculi palpability, knowing that calculi under 8mm of diameter are often treated by other techniques (sialendoscopy and lithotripsy). OPERATIVE PROCEDURE: We describe a conservative and gland-preserving transoral surgical technique for hilar submandibular calculi with postoperative sialendoscopic control. The different surgical steps are illustrated. DISCUSSION: Preservation of the submandibular gland has been attempted in the treatment of sialotithiasis by transoral resection of calculi from the hilum of the gland. This technique features a low morbidity and leads to a complete recovery of glandular function.

[Transoral removal of submandibular hilar calculi: 36 cases]. / Exérèse endobuccale des lithiases submandibulaires postérieures: 36 cas.

INTRODUCTION: Proximal submandibular calculi are usually removed by transcervical submandibular sialadenectomy. The aim of this study was to show that intraoral removal of hilar submandibular calculi gives the same results with fewer complications than submandibulectomy. PATIENTS AND METHODS: The surgical indication is assessed by palpability of the stone and confirmed by simple CT scan. The surgical procedure is performed under local or general anaesthesia. At the end of the procedure, the duct is controlled with a sialendoscope to remove remaining concretions. We prospectively followed 36 patients with a mean follow-up of six months (one to 36 months). RESULTS: The transoral removal of calculi was performed in 34 patients without any definitive neurological complication. The procedure failed in two patients with nonpalpable calculi. Two patients had a recurrence of symptoms due to small intraglandular calculi, which were evacuated later. DISCUSSION: The transoral removal of submandibular hilar calculi is a safe and reproducible procedure with less morbidity than submandibulectomy. It should be recommended for posterior palpable submandibular calculi.