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Biomedical subjects

M N Spyropoulos

Publications and source records attributed to M N Spyropoulos.

16 recordsLinked to original sources
PubMed1992

Hyoid bone position and orientation in Class I and Class III malocclusions.

Various studies have documented a variability of hyoid bone position in relation to changed mandibular position or head posture. The aim of this study was to investigate the hyoid bone position and inclination on the cephalometric radiographs of two groups of patients exhibiting Class I and Class III malocclusions. The radiographs were taken in both centric occlusion and wide-opened mandibular position, and 17 measurements were performed on both tracings. The findings reveal a statistically significant difference in the position and inclination of the hyoid bone in the two groups; Class III patients, especially the boys, show a more anterior position of the hyoid bone and also a reverse inclination. This might have an implication on the function of the suprahyoid and infrahyoid muscles and thus on the direction of mandibular growth.

Adolescent↗
PubMed1990

[Soft tissue configuration in certain syndromes of the head and neck].

In order to examine the relationship existing between soft tissue configuration and the underlying skeletodental framework, patients presenting severe and representative syndromes of the head and neck were studied. Grouping of these patients in three groups according to the similarities of the skeletal pattern and/or the etiology of the syndrome, provided a basis for evaluation, comparison and contradistinction of the configuration of the hard and soft tissues, in a material where genetic predetermination is dominant. By cephalometric analysis, superimposition and plotting of the soft tissues on an abstraction and relative magnification basis, the following conclusions could be formulated: a) There is a specificity in the soft tissue configuration of the face of patients with specific syndromes and, this specificity, seems to be independent of the underlying skeletodental elements in the area of the nose and the upper lip. b) A genetic predetermination of the soft tissue morphology can be deduced because, in patients with specific syndromes, the same characteristics accompany constantly the same chromosomal or gene mutations. c) Further studies along these lines might throw more light on the role of genetics in soft tissue configuration and function.

Acrocephalosyndactylia↗
PubMed1989

[Management of the cleft patient from birth to completion of the deciduous teeth].

Cleft lip and cleft palate are the most common defects of the craniofacial system. The treatment of children with this craniofacial malformation requires a multidisciplinary approach due to the complexity of their problems. Thus, cleft lip and palate teams have developed in many institutions, in order to provide the necessary medical and psychosocial treatment to these children. The treatment of children with cleft lip and cleft palate should begin right after birth and include their families as well. The purpose of the present paper is to present the problems of children with cleft lip and cleft palate from birth until the completion of their primary dentition. In addition, the systematic and comprehensive treatment planned by the various specialists of the team for the solution of the above problems, is presented in detail.

Cleft Lip↗
PubMed1989

[Orthodontic and maxillofacial confrontation of a hemifacial microsomic mandible, comprising electromyographic check].

A rare case of hemifacial microsomia of the mandible whose etiological entity is delineated from the bad posture of the foetus in the womb during the foetal period, is described. In this case, the combination of orthodontic and maxillofacial treatment, gave satisfactory results as regards the aesthetic problem of the person, the occlusal disturbances and the function, of the masseter and the temporalis-muscles. These functions were checked before, during and after the treatment by means of electromyograms, and a more balanced activity of these muscles could be detected after the combined treatment.

Adult↗
PubMed1978

Prenatal growth patterns of the human mandible and masseter muscle complex.

Since experimental and clinical evidence supports some role of musculature in determining the form and size of facial bones during the active periods of growth after birth, this study addresses the same basic relationships between muscle and bone during the periods of active growth before birth. The relationship between the masseter muscle and the mandible, including its ramal and body components, was chosen as the model for study in nineteen human fetuses (ages 16 to 36 weeks). Cross-sectional cephalometric data indicated that, although increases in the size of the muscle and mandible were linearly related to increasing age, the ramal portion of the mandible was more closely related to changes in the masseter muscle than to changes in the mandibular body. Moreover, it appears that reorientation of the muscle anteriorly and downward precedes a similar reorientation of the ramus, with the combination of both fetal events leading to the typical relationships of the two structures expected after birth. Although this study does not get to cause-and-effect relationships, and although the fetal specimens cannot be monitored longitudinally over time, the parallelisms between our prenatal findings and those reported for postnatal periods certainly lend further support to the observation that many aspects of morphogenesis and growth are continual processes spanning the periods on either side of birth.

Body Height↗
PubMed1977

The morphogenetic relationship of the temporal muscle to the coronoid process in human embryos and fetuses.

The purpose of this investigation was: (a) to study the developmental relationships of the temporal muscle and the coronoid process during the critical initial stages of morphogenesis and (b) to correlate the developmental stages of the muscle and the bone with data describing the functioning of the muscles of mastication in utero. The heads of 41 human embryos and fetuses, 6 to 11 weeks, estimated fertilization age, were sectioned and examined under light microscopy. The findings are described in terms of six successive stages, each characterized by a major developmental change occurring during that stage. The data indicate that the temporal and masseter muscle anlagen begin to develop prior to the skeleton to which they ultimately become attached. The coronoid process differentiates subsequently as a discrete entity within the mass of the temporal muscle anlage at an estimated fertilization age of 7 to 7.5 weeks (23-24 mm CRL). At approximately eight weeks of age, the coronoid process unites with the main portion of the mandibular ramus. The findings here presented do not support the conclusion that the coronoid process is self-differentiating as Washburn ('47) contended. Instead, the development of this feature of the human mandible represents a response that follows the differentiation of the temporal muscle. This conclusion is consistent with the observations drawn from a number of investigations concerning structural and functional development of the face.

Fetus↗
PubMed1976

Vertical control: a multifactorial problem and its clinical implications.

In this article we have tried to analyze the importance of vertical control in orthodontic cases, as well as the factors affecting it. From the cases presented, it can be assumed that: 1. In vertically growing or nongrowing persons (high-angle cases), the application of proper directional forces becomes extremely critical because a clockwise rotation of the mandible can occur very promptly and is very undesirable. 2. In cases with favorable growth potential, the results may be acceptable, even if the forces applied during treatment are not absolutely controlled; in other words, Mother Nature may often compensate for inappropriate or miscalculated treatment procedures.

Adolescent↗