PubMed Health⌕ Search

Biomedical subjects

F Lundström

Publications and source records attributed to F Lundström.

14 recordsLinked to original sources
PubMed1999

Occlusal changes from adolescence to adulthood in untreated patients with Class II Division 1 deepbite malocclusion.

A sample of 47 untreated children (M 32:F 15) with Class II Division 1 (II/1) deep-overbite malocclusion was collected from a group of patients who declined orthodontic therapy. Longitudinal records consisted of plaster dental casts and lateral cephalograms at original diagnosis and plaster dental casts at a follow-up observation in adulthood, an average of 11.5 years later. To study retrospectively natural changes in dental occlusion during this interval, plaster-cast millimetric measurements were recorded of sagittal dental relationships (first molar and canine), overjet, overbite, and crowding/spacing at the two registrations. Results showed statistically significant improvements in untreated II/1 deepbite malocclusion from adolescence to adulthood for all measured occlusal variables except development of mild crowding. Therefore, assumptions that untreated II/1 distoclusion will worsen with age appear to be unfounded. The evidence indicates that the absence of orthodontic correction for adolescent patients with Class II Division 1 deepbite malocclusion will not usually lead to measurable occlusal deterioration in young adulthood.

Adolescent↗
PubMed1998

A proportional analysis of some facial height and depth variables in 10 to 16 year old children.

A method for analysing the horizontal and vertical proportions of the face is described, based on natural head orientation (NHO). It demonstrates how individual deviations from the mean proportions can be quantified both horizontally and vertically. Correlation between facial depth to height (index 1) and the mandibular plane angle was determined and found to be fairly strong and highly significant (r = 0.5, P < 0.001). Facial depth to height and lower facial height to total facial height (index 2) relationships were found to be strongly correlated at each age between 10 and 16 years, with only small mean differences. For this reason the norm values presented for 12-year-old children for indices 1 and 2 should be applicable to orthodontic patients within this age range. The relationship between mandible and maxilla (index 3) increases continually between 10 and 16 years in boys, and between 10 and 14 years in girls, about 0.3 units a year. It can provide supplementary information for individual case analysis. For boys the increase was 2.2 units per year between 14 and 16 years of age.

Adolescent↗
PubMed1995

The Frankfort horizontal as a basis for cephalometric analysis.

A random sample of 79 British 12-year-old children was studied from tracings registered in the natural head position (NHP). The angle between the Frankfort horizontal (FH) and the horizontal at right angles to the plumb line was measured. Two experienced assessors checked every tracing; for those children perceived to show unnatural head position this was adjusted to what they considered to be the natural head orientation (NHO). The NHO was defined as the head orientation of the subject perceived by the clinician, based on general experience, as the NHP in a standing, relaxed body and head posture, when the subject is looking at a distant point at eye level. The FHK horizontal angle was then measured, now related to the corrected head position. The standard deviation for the latter angle was smaller than that of the uncorrected, but still too large for the FH to be considered reliable as a basis for clinical cephalometric analysis. No statistically significant difference in variability as found between FH and the sella-nasion line. The extracranial horizontal plane related to NHO was recommended as the least variable of the references studied.

Cephalometry↗
PubMed1995

Natural head position and natural head orientation: basic considerations in cephalometric analysis and research.

Natural head position (NHP) provides the key for meaningful cephalometric analysis because an extracranial reference line is used instead of intracranial reference lines, known to be subject to considerable biological variation in their inclination. Although the principle of natural head position is being recognized in the orthodontic literature, its registration may contain an element of unavoidable error that requires correction. A new concept of natural head orientation (NHO) has been introduced to maximize the contribution of NHP to cephalometrics. It is defined as the head orientation of the subject perceived by the clinician, based on general experience, as the natural head position in a standing, relaxed body and head posture, when the subject is looking at a distant point at eye level. The present study was designed to determine the accuracy and validity of NHO, using lateral profile photographs cut in a circular shape, obtained from 27 orthodontic patients, 10-14 years old. Findings among four investigators showed a high correlation (r = 0.82-0.96), in orientating these profile photographs in estimated natural head position (NHP). Moreover, investigators showed good correlation (r = 0.57-0.84) in head orientation after a 3-week interval. Mean differences for the same period varied between 0.1 and 2.9 degrees. The validity of NHO was supported also by a panel investigation. Clinicians as well as auxiliary personnel can be trained to make a critical judgement of the recorded natural head position and correct head orientation, whenever indicated, to enhance the reliability of cephalometric analysis in clinical practice and research.

Adolescent↗
PubMed1992

Natural head position as a basis for cephalometric analysis.

In a sample of orthodontic patients (27 boys and 25 girls, 10 to 14 years old), natural head position (NHP) was photographically recorded. A vertical axis was recorded on the photographs with a plumb line and transferred to the lateral head radiographs of the patients. Three cephalometric reference lines (sella-nasion, basion-nasion, and porion-orbitale) were compared with regard to their inclination to the horizontal plane. These angles showed standard deviations of between 4.5 degrees and 5.6 degrees. Reproducibility of NHP, assessed as the error of a single observation, was close to 2 degrees. These findings, in combination with the fact that the NHP represents a realistic appearance of patients, support its use as a basis for cephalometric analysis of dentofacial anomalies. A strong correlation was found between the inclinations of the three cephalometric reference lines to the horizontal plane. The close anatomic relationship between these lines, in combination with the small random movements of the head around NHP, were believed to explain the covariation.

Adolescent↗
PubMed1991

A comparison between estimated and registered natural head posture.

Using tracings of facial profiles, four observers made two independent, subjective estimations of natural head posture (NHP) in 28 adults. The results of these estimations were compared with recordings of NHP obtained through photographic registration of the same subjects. Only minor average differences (between 0 and 1.4 degrees) were found between the two methods. The differences between estimated and registered head posture found at the first and second observation, were positively correlated for both intra- and inter-observer registrations (r = 0.59-0.80 and r = 0.50-0.71, respectively). The inclination of the basion-nasion line was measured; first, in relation to the photographically registered horizontal line and, secondly, in relation to the horizontal line derived from the estimation of NHP. Both methods of measurement gave similar mean values and standard deviations. A panel comprising 18 persons was asked to compare the head orientations of two subjects in whom a marked difference between estimated and registered NHP had been recorded. In the majority of these comparisons, the profiles orientated according to the subjective estimation were judged to have a more 'natural posture' than those orientated by the photographic method. This unexpected finding is discussed.

Adult↗
PubMed1989

Clinical evaluation of maxillary and mandibular prognathism.

This study focuses on the importance of using natural head posture as a basis for cephalometric analysis. It describes a simple method for transferring a vertical plumbline from a lateral head photograph to a profile radiograph. The method is shown to have a relatively small technical error. Means and standard deviations for the angles HOR/N-A and HOR/N-B between the horizontal line (HOR) on one side and the nasion-subspinale (A-point) and nasion-supramentale (B-point) lines on the other, in random individuals, are presented as standards from which individual cases can be evaluated.

Adolescent↗
PubMed1982

Registration of natural head posture in children.

A method for registration of natural head posture is presented. The subject is photographed with contrast markers positioned on one side of the face and an adjacent plumb line as vertical reference. Systematic errors due to rotation and lateral tipping movements of the head were shown to be small and of no clinical importance. The measurement error in the transfer of the plumb line from profile photograph to lateral skull radiograph was shown to be small. Extension-flexion movements were found to have a standard deviation of 2 degrees about the mean in a group of patients between the ages of 12-14 years. Earlier studies show similar results for adults. The study supports the mirror-orientated registration of head posture viewed laterally in children as a biologically acceptable method.

Adolescent↗
PubMed1980

Effect of oral hygiene education on children with and without subsequent orthodontic treatment.

The aim of the present investigation was to study whether an intense period of individual oral hygiene education would result in proper dental health behavior and to compare the effects of such education on 30 individuals undergoing subsequent orthodontic treatment and 30 controls without such treatment. The investigation consisted of two experimental periods: one period of oral hygiene education during which information on proper plaque control was given fortnightly for 6 weeks and one follow-up period of 30 months corresponding to the orthodontic treatment phase. The results suggest that it is possible to achieve and maintain a high standard of dental health behavior following an intense period of individual oral hygiene education. A certain deterioration of the gingival status was observed after 3 months in the orthodontically treated children. This was interpreted as being due to the influence of subgingivally located orthodontic bands. After 30 months a high level of oral hygiene and gingival status as well as a low caries activity were still apparent with only minor and insignificant differences between the children subject to orthodontic treatment and the controls.

Adolescent↗