Biomedical subjects

V Lapter

Publications and source records attributed to V Lapter.

12 recordsLinked to original sources

PubMed1991

Orthodontic anomalies and differences in gnathometric variables in twins.

Actuality of gnathometric measurements by means of plaster casts persisting to the present days is stressed and the major research of the kind in twins mentioned. The study included 96 pairs of twins of both sexes (36 monozygotic and 60 dizygotic). Both qualitative and quantitative variables were evaluated and the results computer-processed. For most parameters evaluated, statistical processing revealed a markedly higher compatibility in monozygotes than in dizygotes. This held particularly true for types and severity of anomalies as well as for all qualitative variables, with the exception of over bite, overjet, class and class severity. The maxilla-related variables were shown to be highly genetically determined, which might be explained by the dynamics of mandibular movements and, possibly, a stronger effect of external factors on its growth and development.

Adolescent↗

PubMed1990

[A comparative study of the craniofacial morphology of 2 ethnic groups].

The samples consisting of 200 latero-lateral cephalometric X-rays of examinees with nearly normal occlusion from Mainz are compared with homologous one from Zagreb. The purpose of the investigation was to point out the morphological differences in cranio-facial system. 19 variables were analysed by using essential statistic parameters and discriminative analysis. The results show the differences in the anterior face height, the lower border mandible inclination, the interincisal angle as well as the degree of face convexity. The average examinee from Zagreb, in comparison with the same one from Mainz, shows smaller anterior face height, the marked mandibular basal line inclination in the sense of the anterior rotation, the higher interincisal angle as well as smaller facial convexity.

Adolescent↗

PubMed1990

[Characteristics of the palate and palatine folds in twins].

In a sample of 95 pairs of twins (36 mz and 59 dz) the traits were analysed which define the shape of the palate, the intensity, direction and ramification of the plicae palati, the intensity and location of the raphae palati mediana and the shape and size of the papila incisiva. The impressions of the palates were made with optosil and these models were photographed. The photographs were analysed. The results indicate a significant genetic determination of the shape of the palate and the papilla incisiva and of the direction of the plicae palati. The analysed traits give the greatest values to the Hc index of inheritance.

Adolescent↗

PubMed1990

[Craniofacial dimensions in twins].

In order to estimate the role of the genetic and ecological factors in the craniofacial growth, study has been made on 36 monozygotic (MZ) and 31 dizygotic (DZ) twin pairs of the same sex. Standard anthropological instruments were used. The following dimensions were examined: the stature, Eu-Eu, G-Op, Zy-Zy, Go-Go, N-Gn and N-Pr. The results are represented in 2 tables and 3 histograms. The result indicate the largest variability of N-Pr and the smallest variability of Zy-Zy within the MZ twins while within the DZ twin pairs it is revers, which suggests that the bizygomatic width is more genetically dependent than the upper height of the face. No statistically significant differences occur within the MZ pairs, except for the stature. On the other hand, within DZ pairs the differences are statistically significant (except for G-Op). The intracorrelations are greater for all the MZ variables. The heredity and cultural inheritance index show higher value of c2 for all variables, which suggests a higher influence of the environmental than that of the genetic factors (h2). A hypothesis would be that the shape of the head and the upper facial height are easily influenced than the Zy-Zy and the morphological face height.

Cephalometry↗

PubMed1990

[3. L Cephalometer].

Authors present an original approach to the cephalometric measuring by obtaining absolute coordinates of the cephalometric points in a coordinate system fixed on the skull. An instrument especially constructed for that purpose is shown, and also the way of using it in vivo.

Cephalometry↗

PubMed1990

[Photoocclusion as a complementary method in orthodontic diagnosis].

The sample consisted of 102 individuals, of which 30 were with normal occlusion, and the rest was classified in 6 groups of orthodontic anomalies. They were of both sexes, mean age was 16.8. The purpose of this study was to analyse the number, intensity and location of occlusal contacts within a group and between the groups, also in relation to the type of the tooth and the examined segment of dental arch. Photoocclusion was used as the main method of analysis, and registration with articulating paper was the control method. The results gave no significant difference in relation to age and sex within the same types of anomaly. The greatest number of occlusal contacts, after that in the group with normal occlusion, was in the group with crowding (16.41), and the lowest number of contacts was in the patients with mandibular prognathism (8.13). Between the groups with different anomalies significant difference has been found in relation to the segment of dental arch, intensity and type of tooth: in molars it was 64-65 kg/mm2 decreasing gradually towards the incisors.

Adolescent↗

PubMed1989

[Measurement of orthodontic appliance force using prototype sensors].

In introductory remarks the most important biomechanical principles, which are relevant for the research, and conditions which must be satisfied presented in intraoral measuring of orthodontic forces were pointed out. First the aim of the research was defined, and then the investigation of mechanical properties of acrylics as a material for orthodontic appliances were carried out. The type of strain gauges, bonds and measuring system configurations, as well as measuring amplifiers and recording instruments were discussed. Some of measuring sensors, their principles and applicability were discussed. The calibration apparatus was modified for the sensor developed, and the calibration results were analysed by means of statistical methods (linear regression). The behaviour of all used sensors were found to be linear, which enables their application and reduces the measuring results interpretation.

Acrylic Resins↗

PubMed1987