[Malformations and anomalies associated with labiomaxillopalatal clefts].
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Abnormalities, Multiple↗
Biomedical subjects
G Couly
Publications and source records attributed to G Couly.
[Cell death in organogenesis. Creodes and catastrophies. Cell non-death syndromes of face and hand deformities].
Cell death appears to be a paradoxical process but one that is necessary for embryonic and fetal morphogenesis, being a necessary stage in the morphogenetic creode of the organ considered, as dynamically and qualitatively modelled by René Thom. Subtle environmental processes result in "cell suicide" by liberation of the intracellular necrosis enzyme. This phenomenon exists just as naturally during separation of the fingers, fusion of the facial buds, and craniofacial suture growth. Dysfunction produces the syndrome of "cell non-death" as seen for example in Apert's syndrome in which a stomodeal cleft is associated with syndactylies and craniofaciostenosis.
Cell Survival↗
[Protocol for the radiological examination of facial injuries].
Radiological examination of maxillofacial injuries, though difficult in patients with multiple lesions, should be rigorously conducted and be as complete as possible, depending on the results of clinical investigation. Initially, it must include at least the basic cranial projections: profile, high anteroposterior, Worms, low anteroposterior, and finally Blondeau. Secondarily, or immediately in less severe or isolated maxillofacial injuries: multiple anteroposterior projections by discontinuous scanning for better analysis of fracture lines or disjunctions, computed tomography in three planes, a panoramic radiograph, and particular projections depending on clinical findings and results of initial radiological examination. The CI scan, rapidly becoming more perfected, is essential in skull injuries with brain damage.
Facial Injuries↗
[Temporomandibular fibro-chondromalacia. Physiological basis. Classification on the basis of clinical characteristics and course. Spongialisation (author's transl)].
The temporomandibular joints are neural structures which develop from the cephalic ectomesenchyme of the neural crests. They are analogous to the effector organs. Their lesional abnormalities have two characteristics:--pain sensation,--"foreign body". A classification is suggested on the basis of clinical characteristics and course of articular signs due to temporo-menisco-condylar stress resulting from occlusion problems, and concomitant lesions of the articular fibrocartilage: closed and open fibro-chondromalacia. Emphasis is placed upon the constant dissociation between articular clinical features and nosography. Spongialisation, or the property of regeneration of fibrocartilage from spongy bone tissue fully justifies the technique of condyloplasty to remodel the temporomandibular joints in the presence of fibro-chondromalacia. The future lies in the distinction between fibro-chondromalacia secondary to occlusive stress and that due to primary ischaemia of bone.
Adult↗
[Neurocristopathic classification of dental abnormalities].
The neural crest of the vertebrae provides the odontoblasts, which by migrating in the stomodeal epithelium induce in the latter the formation of predamantoblasts (enamel cell). The odontoblasts are then the point of departure of tissue interactions (ectodermal and neurectodermal) which characterise dental organogenesis. An analytical neurocristopathic classification of this organogenesis based upon the developmental properties of the odontoblast is suggested: --abnormalities of formation (anodontism, hypodontism); --abnormalities of migration (ectopism); --abnormalities of cell differentiation and multiplication (hypodontism, microdontism and macrodontism, disturbances in odontogenesis and their combinations, disturbances in amelogenesis). "No odontoblast, no tooth". The dental organ is an indicator of the developmental biological activity of the neural crest as well as its neurulation. Abnormalities in dental organogenesis are of predictive value in terms of other abnormalities of cephalogenesis, those related to the differentiation of the other cells of the neural crest (bone, muscle, cartilage) and those related to the neural tube with which they are territorialised: these are dysneurulations. This classification covers the clinical features of dental abnormalities seen in pediatric stomatology.
Humans↗
[Do impacted teeth constitute points of biomechanical weakness in the mandible?].
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Biomechanical Phenomena↗
[New concepts of the biology of human cephalic development. Observations and hypotheses].
Morphological dynamics controlling vertebrate embryo development, which takes place in flotation in a liquid medium, leads to the hypothesis that the pentameric symmetry of echinodermes, ancestors of the vertebrates, is conserved during evolution. This embryogenesis consists of morphological repetitions: synchronous growth of five expansions specialized in exploration and spatial deplacements (head and four limbs); each of these five expansions consists of five buds or five radii (facial buds, fingers and toes). Homomorphism of the mouth, of the hands, and of the feet--which are capture catastrophes over the environment, installed early during development--allows later functional and sensory connections. These morphological repetitions are also demonstrated by the association of facial, hand, and foot buds, malformations for which a topological correspondence can be shown. During vertebrate morphogenesis by flotation in a liquid medium, other phenomena take place. For instance, the palate is formed anteriorly by a triple junction resulting from the fusion of its three constitutive buds.
Animals↗
[Muscle cheilomeso-ethmoidoplasty. A new surgical approach to treatment of labiomaxillary clefts].
Recent advances in our knowledge of the role of the ectomesenchyme in facial organogenesis, and the biology of fetal and infant cephalic development, supply valid arguments for the application of new principles in cheiloplasty for labial or labiomaxillary clefts. Instead of cutaneoplasty alone, the procedure involves anatomically selective muscle reconstruction of the nasolabial confines, a structure that is predominantly muscular. The alar portion of the cartilaginous mesethmoid ensures support of the nasolabial head of the orbicularis of the lip, and reconstitutes the anterior nasal vestibule by supplying the transverse muscle. Cheilomeso-ethmoidoplasty of the transverse and nasolabial muscles of the orbicularis of the upper lip is therefore as totally valid procedure.
Cartilage↗
[A plea for early arthroplasty of temporomandibular ankylosis in children].
The well-meaning wait-and-see policy when confronted with uni-or bilateral temporomandibular ankylosis in children is now out-of-date. An early conservative arthroplasty with temporal aponeuroplasty should be performed for several reasons. --Recent advances have increased our knowledge of the biology and development of fetal and infant temporomandibular joints. --Anaesthesia by fibroscopy during endotracheal intubation of the child with permanent jaw constriction is now a safe technique. --The developmental anatomy of the temporomandibular joints allows, employing an appropriate approach, the performance of conservative arthrolysis, associated with a local temporal aponeuroplasty in interposition, and thus avoids recurrence of ankylosis.
Ankylosis↗
[Cell populations of the human mandibular condyles during growth and in the adult (author's transl)].
Tumours of cartilaginous origin dominate the group of tumours of the mandibular condyles. These cartilaginous tumours consist in fact of hyperplasia of the growth zone or osteochondroma in the young adult or reawakening of the latter in the older adult in whom an occlusion problem originally is not without aetiological interest. Osteomas of the condyles are stabilised and ossified forms of such hypercondylism. Other tumours may be seen and are related to the original cell. Malignant tumours are rare.
Adolescent↗
[Ante-occlusal growth of human mandibular condyles. The palatal sensory network. Applications (author's transl)].
The description of a dense sensory network, first reported by Paccini-Vater, in the still undentated maxillary and mandibular crests, is given. This network has the same functional significance as the future teeth, and constitutes, with the tongue, a means of regulating ante-occlusal condylar growth. The model described by Petrovic is valid during this period. The Pierre Robin syndrome is therefore a "non-afferentation" of the mandibulolingual massive: glossopexy of any type is of no value. Only postural nursing from birth can enable the mandibular gesture to be "ingrained".
Humans↗
[Neurocristopathies of the human nasofrontal bud. Ethmoidal syndromes (hypo- and hyper-septoethmoidism) (author's transl)].
Knowledge of human brain development biology has increased rapidly over the last decade due to fundamental acquisitions in the fields of organogenesis, fetal development, and post-natal growth. The role of the neural crests during cephalic organogenesis, recently studied by Mme Nicole Le Douarin, has given new biological dimensions to the head : it is an organic complex, globally neural in character, and of encephalofacial territorialization. The cervicocephalic region derives this original segmentation from the migratory property of this contingent of the neural crests. In this perspective, the nasofrontal bud is therefore an embryonic cephalic segment, in which appears the pro-encephalon, the eyes, the olfactory bulb, and the median facial zones (bone, cartilage, teeth). Any morphogenetic anomaly in this original craniofacial segment creates associated malformation of the brain, the base of the skull, and the face (eyes and olfactory bulbs) : the neurocristopathies. In this respect, and from the semiological point of view, the face is the "predicate" of the brain. A new classification of these malformations is proposed, based on the clinical study of the ethmoid, a cartilaginous median organ which is accessible clinically. Epigenesis lasts for 18 months in this organ, which forms a part of the face and the neurocranium, and which is known to play a "motor" morphogenetic role on the osteomembranous face : the ethmoidal syndromes (hypo- and hyper-septoethmoidism). Future reports will discuss the neurocristopathies of the branchial arches.
Abnormalities, Multiple↗
[Biological development of temporomandibular joints. New attainments (author's transl)].
Insofar as they are mobile, coupled organs of the masticatory system, the two human temporomandibular joints, true membranous sutures, are bound by their relations with the central nervous system and by the general laws of osteoarticular biomechanics. Certain invariants of temporomandibular morphogenesis are described, these concerning human cephalization phenomena, and more particularly the role of the neural crests in the elaboration of the temporomandibular relationship, its biomechanical features, and articular kinematics. The role of Marsch Robinson's theory, neurocristopathic malformations, and total temporomandibular joint prostheses are discussed. Fundamentally biomechanical in nature, dentomaxillofacial, and by extension, cephalic orthopedics require a multidisciplinary approach.
Humans↗
[The human cartilaginous mesethmoid (author's transl)].
The existence of a cartilaginous facial structure, the mesethmoid, has been demonstrated in the newborn human infant. This structure is the peri- and post-natal tissue developed from the embryonic cartilaginous nasal capsules. Unrecognized during facial development, the cartilaginous mesethmoid, partly because of its multidirectional growth, is responsible for frontonasomaxillary osteomembranous centrofacial morphogenesis. Practical aspects are discussed, and studies to determine the post-natal structures derived from the mesethmoid are in progress.
Cartilage↗
[Functional structure of the growing human mandibular condyle (author's transl)].
This histological study describes the functional structure of the growing human mandibular condyle at birth. It consists of a dense conjunctive membrane of meniscal origin covering over the pre-osteoblastic condylar zone. The two muscle bundles of the external pterygoid muscle, the meniscal and condylar bundles, ensure, because of their contractile forces acting in opposite directions, the dissociation of the conjunctive and pre-osteoblastic zones, followed by a mitotic response of the latter. This mechanism is of prime importance during the period of somatotropic hormone secretion, that is to say, during the growth period. This structure and mechanism of growth validate the hypothesis of the predominance of postural and functional phenomena during mandibular condylar growth. The behaviour of human temporomandibular joints during growth would therefore be analgous to that of a membranous suture.
Cartilage, Articular↗
[Cephalic neural crests and disorders of craniofacial morphogenesis. Neurocristopathies (author's transl)].
To establish the pathogenicity, and attempt to define a classification of craniofacial malformations is a difficult task, both in animals and humans. Mention is often made of the classification developed by Paul Tessier, which according to this author "is neither based on a theory nor on an embryonic definition. It is the by-product of anatomical findings during clinical examination and operative dissections" (31). The authors propose an embryologic classification of facial malformations, based on disorders of embryonic development of cells derived from the neural crests (NC) of cephalic origin, and constituting the craniofacial ectomesenchyme. The importance of the cephalic NC derivatives in craniofacial morphogenesis is stressed, and the principal malformations of the cephalic shelf outlined, as a function of disorders occurring during the formation of the NC; migrations, proliferation, and differentiation of their derivatives. The main objective of this study was to formulate pathogenetic hypotheses, to propose a classification, and to stimulate interest in further studies in the realm of physiological and pathological craniofacial morphogenesis.
Bone Diseases, Developmental↗
[Diagnosis of large cystic images of the mandible].
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Adult↗