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Biomedical subjects

B Solow

Publications and source records attributed to B Solow.

At least 19 recordsLinked to original sources
PubMed1992

Cervical and craniocervical posture as predictors of craniofacial growth.

The present study aimed to determine whether growth changes in craniofacial structure could be predicted by variables expressing the postural relations of the head and the cervical column. The sample comprised 34 children, 16 girls and 18 boys. Cephalometric radiographs obtained in natural head position (mirror position) were taken on two occasions before orthodontic treatment. Mean age was 9.9 years at time 1 and 12.7 years at time 2. Selection of the sample was based on skeletal maturity at time 2 indicating peak activity in pubertal growth. Forty-one reference points and four fiducial points were digitized on each film. Individual growth changes in craniofacial structure were determined by computerized structural superimposition of the digitized sets of points. Correlation coefficients were calculated between 11 postural variables at the first observation and the subsequent growth rate in 36 structural variables. Uniform fields of low to moderate correlation coefficients significant at the 5%, 1%, and 0.1% levels (0.3 to 0.6) were found for eight structural variables, indicating that a small craniocervical angle and a backward-inclined upper cervical column at time 1 was associated with horizontal facial development characterized by reduced backward displacement of the temporomandibular joint (TMJ), large maxillary growth in length, increased facial prognathism, and larger than average true forward rotation of the mandible; whereas, a large craniocervical angle and an upright position of the upper cervical column at time 1 was associated with vertical facial development characterized by large backward displacement of the TMJ, reduced growth in length of the maxilla, reduced facial prognathism, and less than average true forward rotation of the mandible. The findings are in agreement with a theoretical model for the developmental interaction between head posture and facial structure.

Cephalometry↗
PubMed1991

Nasal airflow characteristics in a normal sample.

The present study aims to describe the characteristics of nasal airflow in terms of the relative contributions of laminar and turbulent flow to the total pressure drop across the nose. The sample comprised 20 dental students with no history of nasal airway obstruction. Rhinomanometric data were recorded by a Mercury NR6 rhinomanometer with a Rohrer programme by the anterior and posterior methods after decongestion. Rohrer equation coefficients were calculated for each respiratory cycle. Method errors ranged from 6.3 to 9.3 per cent of sample variances. At a threshold of 75 Pa, average unilateral NAR was about 300 Pa/l/s and average bilateral resistance about 250 Pa/l/s. Analysis of the Rohrer equation data showed average coefficients of laminar (k1) and turbulent (k2) flow of 113 and 807 in unilateral breathing, indicating a predominance of turbulent flow. In bilateral breathing a switching of airflow characteristics occurred, with k1 and k2 coefficients of 147 and 348 indicating a marked reduction in the turbulent component of flow. It is suggested that Rohrer equation coefficients might provide information about nasal airflow which are physiologically more meaningful than conventional resistance calculations based on a single point on the rhinomanometric pressure-flow curve.

Adult↗
PubMed1991

Age differences in adult dentoalveolar heights.

A previous study of age differences in facial morphology in a dentate sample representing young, middle, and old age (Tallgren and Solow, 1987) indicated an increase in lower anterior face height during adulthood. The aim of the present study was to examine in detail the accompanying age differences in dentoalveolar heights. The material consisted of lateral head films of 191 dentate Finnish women divided into the age groups 20-29, 30-49, and 50-81 years. The present study comprised 26 variables calculated from digitized reference points. The maxillary and mandibular anterior dentoalveolar heights were significantly larger in the middle and old age groups than in the young group, and the mean differences were of the same magnitude for the maxilla and the mandible. Analysis of the dentoalveolar components showed that in the mandible the extra-alveolar height of the incisors was significantly larger in the two older age groups than in the young group, while no significant differences were found in the maxilla. The mean differences in anterior mandibular ridge height between the older age groups and the young group were smaller than in the maxilla. No significant differences in dentoalveolar morphology were observed between the middle and the old age groups.

Adult↗
PubMed1991

Linearity of cephalometric digitizers.

The present study aimed to develop a test procedure to diagnose and visualize errors in linearity of digitizing tablets. Errors of linearity are caused by the distortion of the x- and y-co-ordinates of the digitizing tablet. This results in a given object apparently having different dimensions when recorded on different locations of the digitizing surface. The test is performed by systematic recording of n equally spaced points from a calibrated test foil. Algorithms were developed to calculate the difference matrices DXji and DYji between expected and observed values of the co-ordinates. Three-dimensional mapping of the non-linearity of the x- and y-co-ordinates was performed by the UNIRAS-geopak, a 3-D surface representative system. The tested digitizers showed varying degrees of scaling errors, fields of non-linearity, and random noise. Most digitizers allow for correction of scaling by setting of switches in the control unit. A method is suggested for correction of non-linearities by use of the DXji and DYji matrices in the digitizing programme.

Algorithms↗
PubMed1991

Nasal airway resistance in the newborn.

The present study aimed to provide normative data for nasal airway resistance in the newborn. Anterior rhinomanometry was performed on 17 full term Caucasian infants aged 1 to 4 days, birthweight 3100 to 4150 g. No sedation or decongestion was performed. Average unilateral nasal resistance was 4.86 kPa/l/s (SD = 2.41) at a pressure threshold of 75 Pa. Average nasal resistance calculated from the right and left side recordings was 2.14 kPa/l/s (SD = 0.77). This corresponds to 21.8 cm H2O/l/s (SD = 7.9). The nasal resistance of the newborn thus is approximately 10 times that of the adult.

Airway Resistance↗
PubMed1990

Influence of skin graft pathology on residual ridge reduction after mandibular vestibuloplasty. A 5-year clinical and radiological follow-up study.

The present study is a 5-year clinical and radiographic follow-up of 51 patients who had undergone a combined vestibuloplasty with a split skin graft and lowering of the floor of the mouth. Our purpose was to examine the effect of clinically evident graft pathology on the residual ridge reduction. The clinical records of the graft condition were classified into: healthy graft, partial loss of keratinization, and total loss of keratinization. The residual ridge reduction was monitored by ridge height measurements at different locations, and by the symphyseal and mandibular body areas. Patients with clinical signs of graft pathology (reddening, loss of keratinization) suffered a significantly more severe residual ridge reduction than those with a healthy skin graft (p less than 0.01). Subsequent findings including smear tests showing Candida albicans hyphae, and improvement of graft condition after antimycotic therapy, indicated that the graft pathology observed is a candidiasis.

Adult↗
PubMed1990

Soft tissue profile changes after mandibular vestibuloplasty. A two-year follow-up study comparing the Edlan flap, mucosal and skin graft methods.

It is the aim of the present study to examine the pattern of postoperative changes in the soft tissue profile of 50 edentulous patients after 3 common types of mandibular vestibuloplasty, the Edlan flap operation (n = 15), the buccal mucosal graft (n = 19), and the skin graft vestibuloplasty (n = 16). The soft tissue profile changes were recorded on lateral cephalometric radiographs taken preoperatively, and after 1, 3, 6, 12, and 24 months post surgery. The 3 groups did not differ with respect to clinical features or presurgical cranio-facial morphology. Neither was any significant difference in postoperative profile changes found between the groups. The surgery gave rise, directly and indirectly, to a number of changes in the facial soft tissue profile many of which were interrelated. The chin thickness increased by 2.3 mm, and the lower lip height exhibited a reduction of 1.8 mm at 1 month after surgery as a direct consequence of the operation. After 3 months the profile changes were mostly associated with the reduction of the anterior face height (overclosure).

Adult↗
PubMed1990

Growth displacement of the maxilla in girls studied by the implant method.

The sutural growth displacement of the maxilla between the ages of 8 and 21 years was studied on 14 series of lateral cephalometric films of girls from the Björk implant sample (Björk 1968). The assessment of growth changes was based on the method of superimposition described by Björk and Skieller (1983) supplemented by a new computerized debugging procedure. A new method for angular measurement of the forward displacement of the maxilla and the mandible is described here. The average forward displacement of the maxilla in relation to the anterior cranial base was 6 degrees from 8.5 to 17.5 years. The average path of displacement was inclined about 45 degrees in relation to the nasion-sella line from 8.5 to 14.5 years, and then changes to almost horizontal. The mean distance between anterior and posterior implant points showed a continuous shortening, totalling 0.6 mm for the period 8.5 to 15.5 years, due to maxillary rotation in the transverse plane. The timing of growth differed between the horizontal and vertical components of the maxillary growth translation. Horizontal displacement peaked at 11 and terminated at 18 years, whereas vertical displacement peaked at 12 and terminated at 15 years of age.

Adolescent↗
PubMed1979

Basic method for recording occlusal traits.

This article describes a basic method for the recording of malocclusion that has been developed jointly by the World Health Organization and the International Dental Federation. The method was developed and field-tested in the period 1969-78 and should provide investigators and health authorities with a common basis for assessing the prevalence of malocclusion in various parts of the world. It should also serve as a basic reference tool in the development of methods for assessing the need and demand for orthodontic treatment.

Dental Records↗
PubMed1977

Dentoalveolar morphology in relation to craniocervical posture.

The associations between dentoalveolar morphology and the posture of the head and the cervical column were studied in a sample of 120 Danish male students aged 22-30 years. Two head positions were recorded on lateral cephalometric radiographs, one determined by the subjects's own feeling of a natural head balance (self balance position) and the other by the subject looking straight into a mirror (mirror position). Dentoalveolar morphology was described by 17 linear and angular variables and postural relationships by 18 angular variables. The position of the head in relation to the cervical column showed positive correlations with the anterior upper and lower dentoalveolar heights and with the inclinations of the upper and lower occlusal planes. These correlations were considered to reflect the dentoalveolar compensatory adaptation to the variation in vertical jaw relationship, which in a previous study had been found to be associated with craniocervical angulation. No associations were observed between craniocervical angulation and alveolar prognathism or incisor inclination. This was in accordance with the previous findings of a lack of associations between sagittal jaw relationship and craniocervical angulation.

Adult↗
PubMed1976

Head posture and craniofacial morphology.

The associations between craniofacial morphology and the posture of the head and the cervical column were examined in a sample of 120 Danish male students aged 22-30 years. Two head positions were recorded on lateral cephalometric radiographs, one determined by the subject's own feeling of a natural head balance (self balance position), and the other by the subject looking straight into a mirror (mirror position). Craniofacial morphology was described by 42 linear and angular variables, and postural relationships by 18 angular variables. A comprehensive set of correlations was found between craniofacial morphology and head posture. The correlations were similar for both head positions investigated. Of the postural variables, the position of the head in relation to the cervical column showed the largest set of correlations with craniofacial morphology. Extension of the head in relation to the cervical column was found in connection with large anterior and small posterior facial heights, small antero-posterior craniofacial dimensions, large inclination of the mandible to the anterior cranial base and to the nasal plane, facial retrognathism, a large cranial base angle, and a small nasopharyngeal space. The possible role of functional factors in mediating the relationship between morphology and posture was discussed.

Adult↗
PubMed1975

Sex differences in craniofacial morphology.

An x-ray cephalometric study was performed in a male and a female group of Danish dental students with the object of examining the sex-determined component of the cranial morphology, and of obtaining a control material for subsequent studies of pathologic samples. The cranial morphology was examined on the basis of measurements on x-ray cephalometric lateral and postero-anterior radiographs. The cranium was, on an average, smaller in the female than the male group except as regards the nasal bone, the foramen magnum and the inner orbital distance. The female group showed a more prominent frontal bone, and a less prominent nasal bone, than the male group.

Adult↗
PubMedDate not supplied

Cranial base angulation and prognathism related to cranial and general skeletal maturation in human fetuses.

The purpose of the present study was to describe normal midsagittal craniofacial morphology in second trimester human fetuses. Measurements of the cranial base angle and the prognathism of the maxilla and the mandible were performed on radiographs of cranial midsagittal tissue blocks of 52 fetuses with a gestational age from 13 to 27 weeks. Special procedures were developed for the definitions of the nasion and sella reference points on the radiographs in the early stages of fetal development. Mean data were reported for stages of crown rump length (CRL) and maturation of the fetal cranial base (MSS), usable as reference in assessment of pathological fetal crania in reports and autopsy procedures. Regression equations were determined for the regression of the angular values on CRL, MSS, and general skeletal maturation (TNO). The cranial base angle was found to decrease significantly, and the angles of prognathism to increase significantly with increasing CRL, TNO, and MSS values. It was suggested that these simultaneous and similar changes in the three angles could be accounted for by the upwards movement of the sella point produced by a cranial displacement of the pituitary fossa caused by local cartilagenous growth and bony remodelling during the period of study. The study thus reflects the influence of cranial skeletal maturation on the early development in shape of the craniofacial complex.

Cephalometry↗