Biomedical subjects

F Ras

Publications and source records attributed to F Ras.

7 recordsLinked to original sources

PubMed1997

Sagittal position of the left and right maxillary segment in children with cleft lip and palate.

OBJECTIVE: The purpose of the present study was to investigate left-right differences in the sagittal position of the maxillary segments in children with cleft lip and palate. METHOD: The sample consisted of children with operated cleft lip or cleft lip and alveolus [CL/CLA (n = 16) mean age, 9.3 yr], operated unilateral cleft lip and palate [UCLP (n = 27) mean age, 9.1 yr], and operated bilateral cleft lip and palate [BCLP (n = 17) mean age, 9.5 yr]. Computed tomography (CT) horizontal slices of the maxilla were obtained and used to determine the sagittal position of the left and right segment of the maxilla in relation to the mandibular rami and the cranial base. Significant effects were analyzed with multivariate analyses of variance (MANOVA). RESULTS AND CONCLUSIONS: It was concluded that, in contrast to children having CL/CLA or UCLP, children with BCLP showed left-right differences in the sagittal position of the maxillary segments. The segment on the left side was more posteriorly positioned compared to the right side. Because the same results were obtained in relation to the mandibular rami as well as in relation to the cranial base, it can be assumed that the position of these rami are not affected by the different types of oral clefts.

Alveolar Process↗

PubMed1996

Quantification of facial morphology using stereophotogrammetry--demonstration of a new concept.

OBJECTIVES: The purpose of this study was to introduce stereophotogrammetry as a three-dimensional registration method for quantifying facial morphology and detecting changes in facial morphology during growth and development. METHODS: Using stereophotogrammetry, three-dimensional (3-D) co-ordinates for the bilateral landmarks Exocanthion and Cheilion and the midsagittal landmark Pronasale were determined in 10 subjects to ascertain the reproducibility of the method, and in 59 children to detect changes in facial morphology due to growth and development. Linear and angular measurements were calculated by means of the 3-D co-ordinates in order to quantify facial morphology. Significant differences were determined by means of analyses of variance (MANOVA). RESULTS: During the observation period, significant (P < 0.01) changes in facial morphology were determined for the linear measurements. Advantages and disadvantages of current registration methods are discussed. CONCLUSION: It is concluded that stereophotogrammetry is a suitable 3-D registration method for quantifying and detecting developmental changes in facial morphology.

Analysis of Variance↗

PubMed1995

Method for quantifying facial asymmetry in three dimensions using stereophotogrammetry.

A three-dimensional method to quantify facial asymmetry is introduced. Stereophotogrammetry was applied to determine three-dimensional (3-D) coordinates for eight pairs of surface landmarks of 106 individuals, including 16 with an operated complete unilateral cleft lip and palate. Facial asymmetry was quantified from four different reference planes that were defined perpendicular to and bisecting lines between pairs of bilateral landmarks related to the eyes, nose and mouth. Significant differences (P < 0.01) between these four planes were determined using multivariate analyses of variance (MANOVA). It is concluded that the best reference plane to select in studies of facial asymmetry is formed by the one which is perpendicular to and bisects the line that connects the landmarks Exocanthion. Reproducibility and validity of the method is demonstrated.

Child↗

PubMed1995

Longitudinal study on three-dimensional changes of facial asymmetry in children between 4 to 12 years of age with unilateral cleft lip and palate.

The purpose of the present study was to describe three-dimensional developmental changes of facial asymmetry in children with an operated complete unilateral cleft lip and palate (UCLP) and in children without craniofacial anomalies (controls). Using stereophotogrammetry, three-dimensional coordinates for 16 bilateral and 10 midsagittal facial landmarks were determined for the UCLP group (n = 33) and the control group (n = 63) on two occasions. In this mixed-longitudinal study, the children were 4 to 12 years of age. Facial asymmetry and left-right dominance was measured and resolved for transverse, vertical, and sagittal components. Significant effects were analyzed with multivariate analyses of variance (MANOVA). We concluded that individuals with complete unilateral cleft lip and palate, as well as individuals without craniofacial anomalies, show an increase, during growth, in the amount of facial asymmetry in the basal region of the nose. In the region that is related to the cleft, children with complete unilateral cleft lip and palate do not show changes in the amount of facial asymmetry between the occasions. Regarding facial left-right dominance and variation in dominance, no demonstrable growth changes take place in individuals with complete cleft lip and palate, nor in individuals without craniofacial anomalies.

Case-Control Studies↗

PubMed1994

Three-dimensional evaluation of facial asymmetry in cleft lip and palate.

The purpose of the present study was to describe facial asymmetry in three dimensions in individuals with an operated complete unilateral cleft lip and palate (UCLP) and in individuals without craniofacial anomalies (controls). Three-dimensional coordinates for 16 bilateral and 10 midsagittal facial landmarks were determined for the UCLP group (N = 49) and the control group (N = 80) by means of stereophotogrammetry. The total asymmetry was measured and resolved for transverse, vertical, and sagittal components. It can be concluded that all three components are important in studies on facial asymmetry. Individuals with UCLP show more facial asymmetry in the vertical direction than controls. They demonstrate more facial asymmetry in the region related to the cleft than controls. And, males in general demonstrate more asymmetry of the nose than females.

Cephalometry↗

PubMed1994

Facial left-right dominance in cleft lip and palate: three-dimension evaluation.

Studies on facial left-right dominance in individuals without craniofacial anomalies have demonstrated controversial results. This is probably due to the frequent use of two-dimensional methods, yet left-right dominance consists of transverse, vertical, and sagittal components. The aim of the present study was to describe three-dimensionally facial left-right dominance in individuals with an operated complete unilateral cleft lip and palate on the left side (LUCLP), on the right side (RUCLP), and in individuals without craniofacial anomalies (controls). Using stereophotogrammetry, three-dimensional coordinates for 16 bilateral and 10 midsagittal facial landmarks were determined for the LUCLP group (N = 32), the RUCLP group (N = 17), and the control group (N = 80). Left-right dominance was measured in three directions. Individuals without craniofacial anomalies showed a facial left sided dominance in the transverse direction, a facial right sided dominance in the sagittal direction, and no particular dominated side in the vertical direction. Individuals with a unilateral cleft lip and palate demonstrated a facial dominance of the nonaffected side in the vertical direction as well as in the sagittal direction, with no particular side dominant in the transverse direction. Generally, there was more variation in left-right dominance within the face in the vertical and sagittal directions.

Cephalometry↗

PubMed1992

[The stability of orthodontic treatment over the long term].

The long term stability of orthodontic treatment was evaluated in 7 orthodontic patients who were three to 12 years out of retention. Dental relationships and irregularities in the dental arch were recorded and scored on study models taken prior to orthodontic treatment, at the end of active treatment, and at long term follow up. Lateral skull radiographs taken at the start of active treatment were also analysed. According to the (mal)occlusion observed on the post-retention study models it appeared that the sample could be subdivided into three groups. The group of patients with relatively good results after active treatment showed less relapse than the group with relatively moderate results after active treatment. The patients with relatively good treatment results were mostly treated with extractions followed by fixed appliances in both jaws. This observation indicates that treatment planning in this group generally was correct. Patients showing skeletal Class II features before orthodontic treatment showed most relapse in overjet and overbite.

Dental Arch↗