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Le patient sénior tel qu’il est défini dans les modalités de cette monographie est âgé de 55 à 75 ans. La chirurgie orthognathique s’est considérablement développée ces dernières années. Les techniques chirurgicales, les techniques d’anesthésie, le matériel d’ostéosynthèse, la prise en charge orthodontique et les capacités de réhabilitation parodontales et implanto-portées se sont fortement améliorées et ont permis un développement de cette chirurgie avec un élargissement remarquable, tant concernant les indications que la tranche d’âge de patients susceptibles de bénéficier de ce type de chirurgie. Dans cet article nous définissons les modalités, avantages et inconvénients spécifiques, inhérents à la prise en charge d’un patient sénior. L’accent est mis sur les dimensions physiologique, psychologique et esthétique, dont il faut tout particulièrement tenir compte pour optimiser cette chirurgie.

Orthodontic and surgical techniques are constantly evolving and practitioners are facing an increasing demand for shorter treatments, with an expectation of results equivalent to conventional treatments. Corticotomies have made it possible to partly meet this need by facilitating dental movement in adult orthodontic care. Many surgical corticotomy techniques were proposed in the past presenting advantages but also a certain number of disadvantages. After retracing the various surgical techniques proposed and explaining the biological principles, we will introduce a new minimally invasive technique, without mucoperiosteal flap and without piezosurgery. This technique can be performed in the dental chair under local anaesthesia or sedation. It is simple and reproducible. This type of treatment combines comfort, speed and periodontal protection. Our objective is to provide more patients and practitioners with corticotomies while controlling the benefit/risk ratio.

Corticotomies are now an integral part of the orthodontist's therapeutic arsenal in adult orthodontics. In recent years, the number of publications about different surgical techniques has increased significantly. This shows that practitioners and patients have a common interest. It is now accepted that corticotomies cause a regional acceleratory phenomenon, which enables a faster dental movement, a reduction in treatment time, as well as a reduction in the risk of root resorption. The perspective of osteogenesis induced by corticotomies has already been mentioned in literature. It could provide a real advantage in maintaining the periodontium, reducing the risk of fenestration or dehiscence and the stability of long-term treatment by increasing the dental bone envelope. Through a clinical case, treated by mini- invasive surgical technique (as described in the previous article), we highlight the potential for osteogenesis induced by alveolar corticotomies and the utility of this procedure in adults.

Introduction : La symétrie faciale a longtemps été un objectif majeur de la chirurgie orthognathique. Les patients présentant une asymétrie faciale prononcée souhaitent retrouver une occlusion fonctionnelle, mais également améliorer leur esthétique faciale. À ce titre, différentes thérapeutiques chirurgicales ont été proposées pour permettre des corrections volumétriques du visage. Matériels et méthodes : À travers un cas clinique et une revue de la littérature, cet article explore l’utilisation d’implants alloplastiques en titane microporeux dans les corrections volumétriques du visage. Résultats : Il n’existe à ce jour que peu de données dans la littérature relatives à l’utilisation des implants alloplastiques en titane microporeux pour les corrections volumétriques du visage, ces implants étant principalement utilisés dans la reconstruction cranio-faciale de défauts osseux post-traumatiques ou post-chirurgicaux. Discussion : Les avantages et inconvénients respectifs de ces implants sont discutés, ainsi que l’intérêt de cette technique chirurgicale en pratique de chirurgie orthognathique.

L’évolution des thérapeutiques orthodontiques doit faire face à une demande croissante de traitements plus courts pour un même résultat final, en particulier chez les patients adultes. Ces dernières années, l’amélioration des techniques orthodontiques, des techniques chirurgicales et anesthésiques en chirurgie orthognathique ont permis un développement considérable des protocoles orthodontico-chirurgicaux et de la prise en charge orthodontique chez le patient adulte. Les corticotomies alvéolaires font partie de ces nouvelles techniques. Elles permettent une facilitation des déplacements dentaires orthodontiques en modifiant localement le métabolisme osseux et en favorisant une ostéopénie transitoire, facilitatrice du mouvement dentaire. Elles augmentent ainsi l’enveloppe des mouvements dentaires possibles avec les techniques conventionnelles. Bien que la littérature récente apporte une meilleure compréhension des effets biologiques des corticotomies, il n’existe que peu d’informations sur le pouvoir ostéogénique de celles-ci. À travers un cas clinique et une revue de la littérature concernant cette technique et ses principes biologiques, nous décrivons les potentielles perspectives d’ostéogénèse induite par les corticotomies alvéolaires.

La chirurgie orthognathique a pour objectif le repositionnement de bases osseuses dans le cadre des dysmorphoses maxillo-mandibulaires. Ses conséquences sont à la fois esthétiques et fonctionnelles. Chez l’adulte, elle prend une consonance esthétique de plus en plus importante, au point que certains patients demandeurs d’amélioration esthétique pure y ont recours. Il s’agit plus que jamais d’une collaboration étroite entre orthodontiste, chirurgien et omnipraticien. Toute l’équipe doit être capable de coordonner son approche dans un objectif esthétique. Pour le chirurgien, la parfaite maîtrise de techniques complémentaires (rhinoplastie, apposition osseuse, chirurgie esthétique de la face, injection de graisse ou de produits de comblement) fait de la chirurgie orthognathique une spécialité chirurgicale à part entière. Nous proposons une classification diagnostique centrée sur l’esthétique du sourire de l’adulte et décrivons les différentes modalités thérapeutiques adaptées à chacun.

Facial symmetry has always been a longstanding objective of orthognathic surgery. Patients that present significant facial asymmetry desire functional dental occlusion but also seek to enhance their facial esthetics. In that regard, different surgical techniques have been proposed to enhance facial recontouring.Through a clinical case report and a literature review, this article explores the use of allopastic microporous titanium implants in volumetric corrections of the face.There is a current lack of evidence regarding the use of microporous titanium implants in volumetric corrections of the face, most papers reporting their use in post-traumatic or post-surgical cranio-facial defects repair.Pros and cons of such implants are discussed in association with the usefulness of this surgical technique in daily orthognathic surgical practice.

La chirurgie orthognathique a pour objectif le repositionnement de bases osseuses dans le cadre des dysmorphoses maxillo-mandibulaires. Ses consequences sont a la fois esthetiques et fonctionnelles. Chez l’adulte elle prend une consonance esthetique de plus en plus importante, au point que certains patients demandeurs d’amelioration esthetique pure y ont recours. Il s’agit plus que jamais d’une collaboration etroite entre orthodontiste, chirurgien et omnipraticien. Toute l’equipe doit etre capable de coordonner son approche dans un objectif esthetique. Pour le chirurgien, la parfaite maitrise de techniques complementaires (rhinoplastie, apposition osseuse, chirurgie esthetique de la face, injection de graisse ou de produits de comblement) fait de la chirurgie orthognathique une specialite chirurgicale a part entiere. Nous proposons une classification diagnostique centree sur l’esthetique du sourire de l’adulte et decrivons les differentes modalites therapeutiques adaptees a chacun.

Platelet-rich fibrin (PRF; Choukroun's technique) is a second-generation platelet concentrate for surgical use. This easy protocol allows the production of leukocyte and platelet-rich fibrin clots and membranes starting from 10-ml blood samples. The purposes of this study were to determine the cell composition and three-dimensional organization of this autologous biomaterial and to evaluate the influence of different collection tubes (dry glass or glass-coated plastic tubes) and compression procedures (forcible or soft) on the final PRF-membrane architecture.After centrifugation, blood analyses were performed on the residual waste plasmatic layers after collecting PRF clots. The PRF clots and membranes were processed for examination by light microscopy and scanning electron microscopy.Approximately 97% of the platelets and50% of the leukocytes were concentrated in the PRF clot and showed a specific three-dimensional distribution, depending on the centrifugation forces. Platelets and fibrin formed large clusters of coagulation in the first millimeters of the membrane beyond the red blood cell base. The fibrin network was very mature and dense. Moreover, there was no significant difference in the PRF architecture between groups using the different tested collection tubes and compression techniques, even if these two parameters could have influenced the growth factor content and biologic matrix properties.The PRF protocol concentrated most platelets and leukocytes from a blood harvest into a single autologous fibrin biomaterial. This protocol offers reproducible results as long as the main production principles are respected.

Objectives The objective of this study was to analyze the effects of Choukroun's PRF (platelet-rich fibrin), a leucocyte and platelet concentrate clinically usable as fibrin membrane or clot, on human primary cultures of gingival fibroblasts, dermal prekeratinocytes, preadipocytes, and maxillofacial osteoblasts. Study design For the proliferation study, these cells were cultivated with or without a PRF membrane originating from the same donor as for the cells. For osteoblasts and fibroblasts, dose-dependent effect was assessed (using 2 membranes). Cell counts and cytotoxicity tests were performed at 3, 7, 14, and 21 days, and even 28 days for osteoblasts. More osteoblast cultures were prepared in differentiation conditions according to 3 modalities (without PRF, with PRF, with PRF the first day and differentiation medium applied only after the first week of culture). Osteoblast differentiation was analyzed using Von Kossa staining and alkaline phosphatase, DNA and total cell proteins dosage. Results PRF induced a significant and continuous stimulation of proliferation in all cell types. It was dose dependent during all the experiment with osteoblasts, but only on day 14 with fibroblasts. Moreover, PRF induced a strong differentiation in the osteoblasts, whatever the culture conditions. The analysis of osteoblast cultures in differentiation conditions with PRF, using light and scanning electron microscopy, revealed a starting mineralization process in the PRF membrane itself after 14 days. Moreover, PRF leucocytes seemed to proliferate and interact with osteoblasts. Conclusions Cultures with PRF are always cocultures with leucocytes. These “chaperone leucocytes” could be the source of differential geographic regulation within the culture and explain the double contradictory effect proliferation/differentiation observed on osteoblasts.

Les corticotomies de l’os alveolaire permettent d’accelerer les mouvements dentaires par rapport a un traitement orthodontique conventionnel. Actuellement, les demandes de traitement chez l’adulte ne cessent d’augmenter, et cette population souhaite que le traitement soit le plus rapide possible. Nous presentons deux cas cliniques d’adultes. Des corticotomies alveolaires ont ete realisees, associees a un traitement orthodontique conventionnel combine a une chirurgie orthognatique. De facon concomitante, nous avons realise une etude experimentale sur de gros animaux. Ces approches complementaires, cliniques et experimentales, ont toutes les deux montre une diminution du temps necessaire au deplacement orthodontique. Les resultats cliniques corroborent les donnees experimentales et confirment que cette technique permet le traitement de malocclusions plus rapidement qu’un traitement orthodontique conventionnel. Notre etude n’a montre aucun effet secondaire, tant sur la vitalite pulpaire que sur la forme radiculaire.

Resume La duree d’un traitement d’orthodontie est d’environ deux ans, ce qui a conduit au developpement de nouvelles techniques, comme les corticotomies, qui permettent d’accelerer le deplacement dentaire orthodontique. Cette technique consiste en une intervention chirurgicale sur la corticale osseuse autour des dents a deplacer. Elle provoque une diminution de la densite de l’os medullaire et une augmentation du remodelage osseux (turn-over). Ces processus biologiques sont a l’origine de l’acceleration du deplacement dentaire, mais permettent aussi d’obtenir des deplacements qui depassent les limites classiques d’un traitement d’orthodontie, permettant parfois de surseoir a la chirurgie orthognathique. Cette technique ouvre de nouvelles perspectives dans le traitement orthodontique de l’adulte.

Resume La duree moyenne d’un traitement orthodontique conventionnel chez l’adulte est comprise entre 18 et 24 mois. Cette duree peut etre un frein a la motivation des patients pour qui le traitement multi-attache peut etre considere comme deletere a l’insertion socioprofessionnelle. Plusieurs techniques ont ete proposees afin de tenter de diminuer la duree d’un traitement. Les techniques chirurgicales de corticotomies alveolaires ont fait l’objet de travaux cliniques et experimentaux. Cependant, elles ont toujours ete realisees de facon segmentaire, sur une dent ou un groupe de dents, mais jamais de molaire a molaire sur une meme mâchoire. Nous nous sommes interesses a cette technique, tant du point de vue de son efficacite et de sa tolerance chez l’animal que par les applications cliniques qui peuvent en decouler chez l’homme. Nous presentons 3 cas de patients adultes relevant d’un traitement orthodontique et chirugical qui ont beneficie de corticotomies vestibulaires et palatines, interdentaires et sus- apexiennes, realisees de facon concomitante a l’ensemble du maxillaire et la mandibule. La duree globale du traitement a ete divisee par deux avec une tolerance excellente. Les avantages et les inconvenients des corticotomies sont discutes a la lumiere de nos resultats cliniques.

Otomandibular dysplasias encompass a broad range of congenital malformations (hemifacial microsomia, mandibulofacial dysostosis) affecting both jaw and ear apparatus. Deciphering the mechanisms of normal embryonic development is a prerequisite for optimal clinical management of those malformations. The development of craniofacial structures is a multi-step process, which involves many developmental events ranging from the migration of neural crest cells from the neural primordium, the molecular interactions that coordinate outgrowth and patterning of the facial primordia, to the fine tuning of the skeletal components. Our knowledge concerning craniofacial development has been gain through experiments carried out in animal developmental models; cell tracing strategies and functional analyses have contributed to significantly increment our understanding of human otomandibular dysplasias. In this review, we discuss classical and recent aspects of otomandibular development. Current proposals for pathogenesis are reviewed and a clinical approach for mandibulofacial dysostosis is proposed.

Current orthodontic treatments must answer an increasing demand for faster yet as efficient treatments, especially in adult patients. These past years, the amelioration of orthodontic, anesthetic and orthognathic surgery techniques have allowed considerable improvement of orthodontico-surgical treatments and of adult orthodontic treatments. Alveolar corticotomy (an example of such techniques) accelerates orthodontic tooth movements by local modifications of bone metabolism, inducing a transient osteopenia. This osteopenia allows greater tooth movements than conventional techniques. Whereas there is a growing understanding of the underlying biological mechanisms of alveolar corticotomies, there is little data regarding the osteogenic potential of such technique. In the present article, we review the literature pertaining to alveolar corticotomies and their underlying biological mechanisms and present a clinical case underlining the osteogenic potential of the technique.

Summary Objectives The authors describe 28 pediatric cases of foreign body inhalation requiring treatment in intensive care units between 1987 and 1999. The purpose of this study was: (1) to analyze the circumstances, diagnostic difficulties and initial treatment of serious foreign bodies and (2) to compare our series with other literature descriptions and define principles for optimal prevention and initial treatment. Methods Twenty-one children presented a penetration syndrome, which was responsible in 13 cases for asphyxia with cardiorespiratory arrest. All these children died, regardless of the initial treatment. Seven children were hospitalized for apparent asthmatic symptoms that did not respond to traditional treatment. Results The inefficiency of external extraction methods like the Heimlich maneuver and the mean delay between clinical signs and initial treatment lead us to propose a new strategy for the emergency treatment of foreign bodies with asphyxia. Conclusions We recommend that emergency teams promote the use of a laryngoscope and Magill forceps. Flexible endoscopy is still recommended as the appropriate diagnostic tool to eliminate doubt in the case of a first severe asthma attack.

Molecular analysis carried out on quail-chick chimeras, in which quail Hensen’s node was substituted for its chick counterpart at the five- to six-somite stage (ss), showed that the floor plate of the avian neural tube is composed of distinct areas: (1) a median one (medial floor plate or MFP) derived from Hensen’s node and characterised by the same gene expression pattern as the node cells (i.e. expression of HNF3β and Shh to the exclusion of genes early expressed in the neural ectoderm such as CSox1); and (2) lateral regions that are differentiated from the neuralised ectoderm (CSox1 positive) and form the lateral floor plate (LFP). LFP cells are induced by the MFP to express HNF3β transiently, Shh continuously and other floor-plate characteristic genes such as Netrin. In contrast to MFP cells, LFP cells also express neural markers such as Nkx2.2 and Sim1. This pattern of avian floor-plate development presents some similarities to floor-plate formation in zebrafish embryos. We also demonstrate that, although MFP and LFP have different embryonic origins in normal development, one can experimentally obtain a complete floor plate in the neural epithelium by the inductive action of either a notochord or a MFP. The competence of the neuroepithelium to respond to notochord or MFP signals is restricted to a short time window, as only the posterior-most region of the neural plate of embryos younger than 15 ss is able to differentiate a complete floor plate comprising MFP and LFP. Moreover, MFP differentiation requires between 4 and 5 days of exposure to the inducing tissues. Under the same conditions LFP and SHH-producing cells only induce LFP-type cells. These results show that the capacity to induce a complete floor plate is restricted to node-derived tissues and probably involves a still unknown factor that is not SHH, the latter being able to induce only LFP characteristics in neuralised epithelium.

Chez les vertébrés, les somites sont les structures responsables de la mise en place du squelette axial segmenté et de la segmentation du système nerveux périphérique. Les mécanismes moléculaires qui contrôlent la formation progressive des somites le long de l’axe rostro-caudal de l’embryon n’ont pas encore été complètement élucidés. L’analyse des profils d’expression de quelques gènes à expression cyclique dans le mésoderme présomitique et dans son territoire présomptif au niveau de la ligne primitive révèle que les cellules précurseurs des cellules somitiques possèdent dès leur origine une information positionnelle, non seulement selon l’axe rostrocaudal, mais aussi selon l’axe médio-latéral. De plus, ces cellules semblent présenter des propriétés différentes en ce qui concerne le processus de segmentation., Fundação para a Ciência e a Tecnologia (FCT) – Praxis XXI/BD/21583/99 , projet nº 34599., Fundação Calouste Gulbenkian (FCG). Instituto Gulbenkian de Ciência (IGC)., Centre National de la Recherche Scientifique (CNRC)., Association Française pour la Recherche contre le Cancer (ARC) - contrat nº 5578.

The objective of orthognathic surgery is the repositioning of the osseous bases of the jaws. Its consequences are both aesthetic and functional. As adults are increasingly concerned with appearance, orthognathic surgery is today, more than ever, a close collaboration between the orthodontist, surgeon and general dentist. The whole team must be capable of coordinating its approach with an aesthetic objective. For the surgeon, a perfect knowledge of complementary techniques (rhinoplasty, bone grafts, plastic surgery of the face, lipostructure or fillers) makes orthognathic surgery a completely separate surgical speciality. The aim of this article is to establish the philosophy underlying this type of treatment and define relevant fundamental aspects. We propose an esthetic "extra-oral" clinical approach not focused on occlusal anomalies but on classification of tooth positional abnormalities in the smile and the therapeutic options that we have for placing teeth in correct positions in the smile.

In the vertebrate embryo, segmentation is built on repetitive structures, named somites, which are formed progressively from the most rostral part of presomitic mesoderm, every 90 minutes in the avian embryo. The discovery of the cyclic expression of several genes, occurring every 90 minutes in each presomitic cell, has shown that there is a molecular clock linked to somitogenesis. We demonstrate that a dynamic expression pattern of the cycling genes is already evident at the level of the prospective presomitic territory. The analysis of this expression pattern, correlated with a quail/chick fate-map, identifies a ‘wave’ of expression travelling along the future medial/lateral presomitic axis. Further analysis also reveals the existence of a medial/lateral asynchrony of expression at the level of presomitic mesoderm. This work suggests that the molecular clock is providing cellular positional information not only along the anterior/posterior but also along the medial/lateral presomitic axis. Finally, by using an in vitro culture system, we show that the information for morphological somite formation and molecular segmentation is segregated within the medial/lateral presomitic axis. Medial presomitic cells are able to form somites and express segmentation markers in the absence of lateral presomitic cells. By contrast, and surprisingly, lateral presomitic cells that are deprived of their medial counterparts are not able to organise themselves into somites and lose the expression of genes known to be important for vertebrate segmentation, such as Delta-1, Notch-1, paraxis, hairy1, hairy2 and lunatic fringe.

In vertebrates the neural tube, like most of the embryonic organs, shows discreet areas of programmed cell death at several stages during development. In the chick embryo, cell death is dramatically increased in the developing nervous system and other tissues when the midline cells, notochord and floor plate, are prevented from forming by excision of the axial-paraxial hinge (APH), i.e. caudal Hensen’s node and rostral primitive streak, at the 6-somite stage (Charrier, J. B., Teillet, M.-A., Lapointe, F. and Le Douarin, N. M. (1999). Development126, 4771-4783). In this paper we demonstrate that one day after APH excision, when dramatic apoptosis is already present in the neural tube, the latter can be rescued from death by grafting a notochord or a floor plate fragment in its vicinity. The neural tube can also be recovered by transplanting it into a stage-matched chick embryo having one of these structures. In addition, cells engineered to produce Sonic hedgehog protein (SHH) can mimic the effect of the notochord and floor plate cells in in situ grafts and transplantation experiments. SHH can thus counteract a built-in cell death program and thereby contribute to organ morphogenesis, in particular in the central nervous system.

Le nœud de Hensen des Oiseaux est considere comme « l’organisateur » c’est-a-dire le centre fonctionnel de la gastrulation au meme titre que la levre dorsale du blastopore des Amphibiens, le nœud des Mammiferes et le bouclier du Poisson zebre. Il a ete demontre recemment que cette structure contient tous les tissus progeniteurs de la ligne mediane de l’embryon (floorplate, notochorde et endoderme dorsal). Cependant, des experiences portant sur cette structure chez l’embryon de Poulet conduisent a penser que la fonction « organisatrice » doit etre attribuee a une zone extremement limitee qui constitue la frontiere entre les territoires presomptifs du tissu axial et du tissu paraxial. Cette region est essentielle pour le recul du nœud de Hensen et la mise en place progressive des structures axiales et paraxiales.

Background Congenital facial paralysis is a rare disorder with an incidence of less than 1 in 1000 live births. Several surgical rehabilitation techniques have been described, such as free flaps or transpositions of the temporalis muscle. We report our experience of transposition of the temporalis muscle in this indication. Materials and methods Retrospective monocentric study between January 2005 and December 2009. Results Five children (mean age at the surgery: 7.3 years, range 6–13) presenting with a congenital facial paralysis were treated by a temporalis muscle transposition during the considered period. An etiological assessment was achieved by carrying out a petrous bone CT, a cerebral and petrous MRI, and audiometric evaluation. Four patients out of 5 (80%) showed a satisfactory and stable functional outcome over time (average follow-up: 26 months). Conclusion Temporalis muscle transposition is a single-stage procedure, easily adapted for the pediatric condition of congenital facial paralysis. It is our opinion that this procedure needs to be carried out at the end of the pre-school period.

Background Choukroun's platelet-rich fibrin (PRF) is an autologous leukocyte- and platelet-rich fibrin biomaterial. The purpose of this study was to analyse the in vitro effects of PRF on human bone mesenchymal stem cells (BMSC), harvested in the oral cavity after preimplant endosteal stimulation. Materials and methods BMSCs from primary cultures were cultivated with or without a PRF membrane originating from the same donor as for the cells, in proliferation or osteoblastic differentiation conditions. After 7 days, the PRF membranes were removed. A series of cultures were performed using 2 PRF membranes, in order to measure the dose-dependent effect. Cell counts, cytotoxicity tests, alkaline phosphatase (ALP) activity quantification, Von Kossa staining and mineralisation nodules counts were performed at 3, 7, 14, 21 and 28 days. A last independent series was carried on up to 14 days, for a morphological scanning electron microscope (SEM) observation. Results PRF generated a significant stimulation of the BMSC proliferation and differentiation throughout the experimental period. This effect was dose-dependent during the first weeks in normal conditions, and during the whole experimentation in differentiation conditions. The cultures without PRF in differentiation conditions did not rise above the degree of differentiation of the cultures in normal conditions with 1 or 2 PRF up to the 14th and 28th day, respectively. The SEM culture analysis at day 14 allowed to show the mineralisation nodules which were more numerous and more structured in the groups with PRF compared to the control groups. Discussion and conclusions This double contradictory proliferation/differentiation result may be due to the numerous components of PRF, particularly the presence of leukocytes: any culture with PRF is in fact a coculture with leukocytes. It could be the source of differential geographic regulation processes within the culture. The combination of oral BMSC and PRF might offer many potential clinical and biotechnological applications, and deserves new studies.

Otomandibular dysplasias encompass a broad range of congenital malformations (hemifacial microsomia, mandibulofacial dysostosis) affecting both jaw and ear apparatus. Deciphering the mechanisms of normal embryonic development is a prerequisite for optimal clinical management of those malformations. The development of craniofacial structures is a multi-step process, which involves many developmental events ranging from the migration of neural crest cells from the neural primordium, the molecular interactions that coordinate outgrowth and patterning of the facial primordia, to the fine tuning of the skeletal components. Our knowledge concerning craniofacial development has been gain through experiments carried out in animal developmental models; cell tracing strategies and functional analyses have contributed to significantly increment our understanding of human otomandibular dysplasias. In this review, we discuss classical and recent aspects of otomandibular development. Current proposals for pathogenesis are reviewed and a clinical approach for mandibulofacial dysostosis is proposed.

Malformations affecting the nervous system in humans are numerous and various in etiology. Many are due to genetic deficiencies or mechanical accidents occurring at early stages of development. It is thus of interest to reproduce such human malformations in animal models. The avian embryo is particularly suitable for researching the role of morphogenetic movements and genetic signaling during early neurogenesis. The last ten years of research with Nicole Le Douarin in the Nogent Institut have brought answers to questions formulated by Etienne Wolff at the beginning of his career, by showing that Hensen's node, the avian organizer, is at the source of all the midline cells of the embryo and ensures cell survival, growth and differentiation of neural and mesodermal tissues.

ObjectiveThe nasal dermoid sinus cyst (NDSC) is an uncommon congenital lesion presenting as a large panel of midline craniofacial anomalies. The objective of this study was to review and reanalyze embryological hypotheses concerning NDSCs and to propose an embryological theory unifying the various anatomical characteristics of these lesions. The first case of frontal localization of a NDSC extending within the diploetic bone in a 9-month-old boy, presenting as a median frontal fistula with recurrent frontal swelling, 6 months after a mild frontal trauma is presented.ResultsComplete surgical removal was performed, and there was no evidence of either persistent or recurrent disease 2 years after his surgery. The embryological and anatomical origins of NDSCs are reviewed. This article reexamines and discusses major embryological theories on NDSC pathogenesis and proposes to refute the “prenasal space” theory of Grünwald and rehabilitate a forgotten embryological hypothesis, which unifies the main various clinical presentations of NDSCs.

ObjectivesCongenital sinuses or fistulas of the lip are uncommon malformations, yet true medial upper-lip fistulas (MULFs) are extremely rare. We present a new case of congenital upper-lip fistula located in the midline of the philtrum of an 8-month-old girl.InterventionComplete surgical removal was performed with a combined extra- and intraoral approach. Histological examination revealed that the fistula was lined by squamous epithelium with sebaceous and mucous glands and hair follicles.ResultsSeveral embryological hypotheses have been proposed concerning these anomalies. This article reexamines and discusses major embryological theories on pathogenesis of sinuses or fistulas of the upper lip. We propose that early ectodermal inclusion events may occur in the medial fusion area during formation of the intermaxillary process. This embryological approach is highly concordant with our recent hypothesis on nasal dermoid sinus cysts (NDSCs) pathogenesis, in which we proposed an embryological hypothesis with early ectodermal inclusion phenomenon in the midline suture area to explain NDSCs pathogenesis.ConclusionsCommon early ectodermal inclusion phenomena could be involved in both NDSCs and MULFs pathogenesis.

Background Paragangliomas are unusual tumors in the head and neck originating from the paraganglia or glomus cells of neural crest origin. Methods We describe the first case of a primitive paraganglioma of the floor of the mouth presenting in childhood. Results Complete surgical removal was performed after embolization of the left lingual artery. There was no evidence of either persistent or recurrent disease 5 years after surgery. The embryologic and anatomic origins of head and neck paragangliomas are reviewed. Conclusions An embryologic theory based on the common neural crest origin and migration pathways of both autonomic viscerocranium appended ganglias and paragangliomas is proposed that unifies the topographically heterogeneous group of viscerocranium-appended paragangliomas. © 2001 John Wiley & Sons, Inc. Head Neck 23: 510–513, 2001.

Hensen's node, also called the chordoneural hinge in the tail bud, is a group of cells that constitutes the organizer of the avian embryo and that expresses the gene HNF-3(β). During gastrulation and neurulation, it undergoes a rostral-to-caudal movement as the embryo elongates. Labeling of Hensen's node by the quail-chick chimera system has shown that, while moving caudally, Hensen's node leaves in its wake not only the notochord but also the floor plate and a longitudinal strand of dorsal endodermal cells. In this work, we demonstrate that the node can be divided into functionally distinct subregions. Caudalward migration of the node depends on the presence of the most posterior region, which is closely apposed to the anterior portion of the primitive streak as defined by expression of the T-box gene Ch-Tbx6L. We call this region the axial-paraxial hinge because it corresponds to the junction of the presumptive midline axial structures (notochord and floor plate) and the paraxial mesoderm. We propose that the axial-paraxial hinge is the equivalent of the neuroenteric canal of other vertebrates such as Xenopus. Blocking the caudal movement of Hensen's node at the 5- to 6-somite stage by removing the axial-paraxial hinge deprives the embryo of midline structures caudal to the brachial level, but does not prevent formation of the neural tube and mesoderm located posteriorly. However, the whole embryonic region generated posterior to the level of Hensen's node arrest undergoes widespread apoptosis within the next 24 hours. Hensen's node-derived structures (notochord and floor plate) thus appear to produce maintenance factor(s) that ensures the survival and further development of adjacent tissues.

Corrigendum to ‘Autologous fat transfer in velopharyngeal insufficiency: Indications and results of a 25 procedures series’ [International Journal of Pediatric Otorhinolaryngology 75 (2011) 1404–1407] Nicolas Leboulanger *, Marion Blanchard , Francoise Denoyelle , Fergal Glynn , Jean-Baptiste Charrier , Gilles Roger , Jean-Paul Monteil , Erea-Noel Garabedian a,d,e Otolaryngology, Head and Neck Surgery Department, Armand-Trousseau Children Hospital, Paris, France Otolaryngology, Head and Neck Surgery Department, Bicetre Hospital, Bicetre, France Otolaryngology, Head and Neck Surgery Department, Lariboisiere Hospital, Paris, France Assistance Publique, Hopitaux de Paris, France UPMC, Universite Pierre et Marie Curie Paris VI, France

Orthognathic surgery has as its objective the repositioning of basal bone in the framework of maxillo-mandibular deformities. Its results are both esthetic and functional. For adults, improved aesthetics results is becoming increasingly important in these procedures to the point where some patients seek only an esthetic amelioration and not a functional one. To achieve their aesthetic purpose, it is becoming progressively more necessary for orthodontists, oral surgeons, and general dentists to collaborate effectively in a well-coordinated effort. In what has now become a true sub-specialty, orthognathic surgeons must master the complementary techniques of rhinoplasty, osseous apposition, aesthetic facial surgery, fat injection or injectable anti-aging tratments. In this article we propose a diagnostic classification based on the aesthetics of the adult smile and describe the therapeutic modalities appropriate for each element.

Indications for orthodontic treatments are in constant augmentation in the adult population. Patients want the shortest possible treatments. Alveolar corticotomies speed up the tooth movement in comparison to conventional orthodontic treatments, therefore decrease treatment duration.This technique consists in the surgical section of cortical bone that leaves the medullar bone uninjured. The biological effects of corticotomies rely on decreasing medullary bone density and increasing bone remodelling activity (RAP regional acceleratory phenomenon).We are currently testing this combined approach of alveolar corticotomies and orthodontic treatments on a pig model with special attention given to potential secondary effects on pulp vitality, dental root morphology and length.We also present here two adult patients with malocclusion cases who underwent alveolar corticotomies as part of their surgical-orthodontic treatments.These experimental and clinical preliminary studies confirm that corticotomy requires a shorter time of orthodontic movement. Our clinical results showed that this technique resolves malocclusion at least twice as fast as conventional orthodontic treatment.No secondary effects of corticotomies on pulp vitality dental root morphology were observed.