Biomedical subjects

Z Smahel

Publications and source records attributed to Z Smahel.

94 records · Page 6Linked to original sources

PubMedDate not supplied

Facial growth and development during puberty in unilateral cleft lip and palate: a longitudinal study.

Roentgencephalometry was used for longitudinal assessment of facial growth and development in 20 boys and 23 girls (age range 10-15 years), with complete unilateral cleft lip and palate. A marked limitation of growth showed the depth of the upper jaw and the height of the upper lip whereas the most intense growth was present in variables characterizing the prominence of the nose. The growth rate was always higher in boys than in girls who had a more pronounced prognathia of the lower jaw. However, the development of the face proceeded identically in both sexes. In contrast with the increasing protrusion of the lower jaw was the increase of the retrusion of the upper jaw, and this led to a flattening of the facial profile and an impairment of sagittal jaw relations. The excessively steep mandibular body and the vertical disproportion of the face remained unchanged. Sagittal jaw relations deteriorated in three fourths of the patients, facial convexity in more than 90%, and neither condition showed any signs of improvement. It was possible to maintain the overjet at the same level as it was at the beginning of puberty; an improvement was attained with fixed appliances. The little scatter of developmental changes of mandibular rotation and the assessment of some correlations were suggestive of an individually constant postoperative character of facial development in clefts. Correlation coefficients disclosed that a more unfavorable condition at the age of 10 years did not imply a subsequent more marked deterioration of development during puberty. Mandibular rotation was not correlated with facial convexity, sagittal jaw relations, or overjet. The possibility of an improvement of overjet by the use of removable appliances was limited by the development of the ANB angle. The use of fixed appliances led to a reduction of this limitation.

Adolescent↗

PubMedDate not supplied

Finite element method analysis of craniofacial morphology in unilateral cleft lip and palate prior to palatoplasty.

The craniofacial morphology in unilateral cleft lip and palate (UCLP) prior to palatoplasty was analyzed with the finite element method (FEM). The study examined cross-sectional data sets of affected and control males aged 4.5 to 6.0 years from Czechoslovakia. The facial skeleton and cranial base were discretized into 26 two-dimensional, triangular finite elements. Cranial base morphology is altered in UCLP. The extensive nature of most craniofacial deformities means that almost any registration is likely to be distorted. The fundamental advantage of the FEM is that biological descriptions are not dependent upon the selected reference plane. The FEM localizes changes in form to discrete anatomical regions. Significant shape and size differences characterize UCLP prior to palatoplasty. Dramatic deformations associated with cheiloplasty are localized to the lips and maxillary alveolar process. Nasal deformation reflects loss of structural support for the nose.

Child↗

PubMedDate not supplied

Facial growth and development in unilateral complete cleft lip and palate from palate surgery up to adulthood.

Mixed longitudinal and cross-sectional roentgen-cephalometric data were used for studies of the growth and development of the face in unilateral complete cleft lip and palate from the time of primary palatoplasty up to adulthood. The results were compared with the data obtained in controls at the age of 5 years and in adults. The vertical growth of the upper and lower face exceeded its sagittal growth. The lower face showed a higher growth rate in both directions than did the upper face. The depth of the maxilla showed the lowest growth rate. The height of the upper lip increased very little as well. The most important deviation in facial development consisted of the deficient growth of maxillary depth and the prolongation of the lower face. Both these deviations develop predominantly after palate surgery and the former resulted in a gradual retrusion of the maxilla, a flattening of the face, and impairment of sagittal jaw relations. The reduction of upper face height, the posterior position of the maxilla, and the shortening of the mandible (both of the body and ramus) represented, on the contrary, early changes. The a persisting posterior rotation of the mandible, changes in the shape of the mandible, and vertical disproportion of the face increased with age, the steep slope of the mandibular body remaining at the level ascertained in early childhood. An improvement in the occlusion of incisors was obtained prior to the age of 12 years, but it regressed during the period of puberty. The prominence of the upper lip gradually decreased and the lip was short.

Adolescent↗

PubMedDate not supplied

Postpubertal growth and development of the face in unilateral cleft lip and palate as compared to the pubertal period: a longitudinal study.

X-ray cephalometry was used for the assessment of 22 boys and 23 girls with complete unilateral cleft lip and palate who were treated with the same surgical method. They were examined at the age of 10 years and in adulthood. In the group of 13 boys and 15 girls, examined also at the age of 15 years, were analysed intersexual differences of facial growth and development during the postpubertal period and the results were compared with those obtained during the pubertal period. The data showed that in boys facial growth persists after the age of 15 years and in the region of the upper face attains about half the values recorded in the period of puberty, while mandibular growth attains almost the same values as during puberty. In girls the growth is almost terminated but for the lower jaw, where it is still significant though several times slighter than during puberty. In both sexes there is only a minimum growth of maxillary depth and of upper lip height during the postpubertal period, as well as during the pubertal period. The highest growth rate shows the depth of the nose. Because of the intersexual differences in the amount of postpubertal growth, developmental changes in facial configuration do not occur in girls during this period, while in boys a further deterioration of maxillary protrusion, of sagittal jaw relations, and of the upper lip prominence continues, as well as an increase of the flattening of the face. In contrast to the pubertal period in both sexes, a proclination of upper incisors and an improvement of overjet was not attained. Contrary to the pubertal period, in the postpubertal period, intersexual differences in the amount of growth and of the developmental changes in the shape and position of facial characteristics were recorded. Therefore during studies of the growth and development of the face, it is not possible to pool both sexes without some reservations. This holds true in particular in the postpubertal period.

Adolescent↗