Adaptations in lip posture and pressure following orthognathic surgery

Lip pressures before and after orthognathic surgery were studied to evaluate the relationship between posttreatment soft-tissue adaptation and incisor stability. After all surgical procedures, physiologic adaptation resulted in the maintenance of pressures during speech and swallowing. When the maxilla was advanced by LeFort I osteotomy, a significant decrease in resting pressure of the upper lip was observed instead of the expected increase and incisor stability did not seem related to soft-tissue influences. When the mandible was advanced by sagittal split osteotomy, resting pressure did not increase as expected, but there was a tendency for incisors to become more upright after fixation release, perhaps as a rebound from labial tipping in fixation. When soft tissues were relaxed as the mandible rotated forward following superior repositioning of the maxilla, resting pressures decreased and lower incisors tended to be positioned forward as predicted by equilibrium theory.

Quantifying discontent in the nursing profession: a study of staff mobility in Victorian nursing homes

Two problems facing the Australian health system are discontent within the nursing profession and matching limited resources to a growing aged population. It is argued in this paper that the solutions to these two problems can only be evaluated by quantifying the scale of the problem. Three measures are used to demonstrate how to measure the size of the problem: participation rates, staff turnover rates and proportion of permanent/casual staff. These three measures are useful to monitor both at a systems level and at the level of individual health services. The discussion refers in particular to staffing in Victorian geriatric nursing homes.

Stability following superior repositioning of the maxilla by LeFort I osteotomy

Cephalometric data from 61 patients who had undergone superior repositioning of the maxilla via LeFort I osteotomy by means of the downfracture technique were analyzed to evaluate stability of skeletal and dental landmarks at various time intervals up to 1 year. None of these patients had concurrent mandibular ramus or body osteotomy except genioplasty and all had at least 2 mm intrusion at the maxillary incisor or molar. In approximately 20% of the patients, there was 2 mm (critical value) or more postsurgical movement of skeletal or dental landmarks. During the first 6 weeks postoperatively, the maxilla showed a strong tendency to move farther upward in the patients in whom it was not stable. The posterior maxilla was vertically stable in 90% of the patients, the anterior maxilla in 80%. Horizontally, skeletal landmarks were stable in 80%, but when changes occurred, there was a tendency for the anterior maxilla to move back when it had been advanced. After the first 6 weeks, the posterior maxilla was stable vertically in all patients, but in 20% anterior maxillary landmarks moved downward, opposite to the direction of movement during fixation. In 11 of the 15 patients who demonstrated vertical changes postsurgery, the movement from fixation release to 1 year follow-up was opposite and approximately equal to the initial change, so that the net movement after 1 year was less than 2 mm. Only 6.5% (four patients) demonstrated 2 mm or greater net vertical movement for any of the variables studied 1 year after surgical treatment. There was no indication that the amount of presurgical orthodontic movement of incisors, the presence of multiple segments at surgery, the age of the patient, the presence or absence of genioplasty, or the presence or absence of suspension wires was a risk factor for instability.

Associations between the postural orientation of sella-nasion and skeletodental morphology

The orientation of the sella-nasion line to true vertical in natural head posture is found to be correlated with some measures that describe internal craniofacial morphology.

The relationship between the dentist's year of graduation and ordering of bitewing radiographs

This article reports the results of a survey of general practice dentists on the relationship of the dentist's year of graduation to the ordering of bitewing radiographs for patients. More recent graduates were more likely to indicate ordering the radiographs at 6-month intervals. There were no differences in ordering associated with the dentist's experience. Shorter intervals between ordering were indicated by all dentists for patient groups at high risk of caries.

Functional morphology of insect neuronal cell-surface/glial contacts: the trophospongium

Ultrastructural studies were carried out on the surfaces of insect nerve cell bodies. Some of the neurons were identified, by using physiological criteria, before filling with dye. Their surface patterns were compared, to provide data needed for understanding dynamic relationships with glial cells, in the trophospongium. The data are also needed in connection with interpretation of electrical signals recorded from the somata and of their roles in integration and in learning and memory. The surfaces were found to be extremely complex and also varied, even for neurons of comparable size and function, as well as for different regions of the same neuron, suggesting that the surface is constantly changing as the neuron receives food and loses waste. There is a variety of cytoplasmic types of invagination of neuron somata by glial processes. The invaginations were classified into four easily recognized types: regular, chunky, filigree, and ridge (present only in axon hillock regions). Motor neurons also make reciprocal invaginations into the glial cells that surround them. Some of these extend for distances up to 40 microns from the surface. The effective surface area is increased, compared with that calculated for a smooth surface, as a result of the invaginations, by from as little as 5% for a small interneuron to as much as 12-fold for a large motor neuron. The axon hillock region of all types of neurons is heavily invaginated.

Functional morphology of insect neuronal cell-surface/glial contacts: the trophospongium

Ultrastructural studies were carried out on the surfaces of insect nerve cell bodies. Some of the neurons were identified, by using physiological criteria, before filling with dye. Their surface patterns were compared, to provide data needed for understanding dynamic relationships with glial cells, in the trophospongium. The data are also needed in connection with interpretation of electrical signals recorded from the somata and of their roles in integration and in learning and memory. The surfaces were found to be extremely complex and also varied, even for neurons of comparable size and function, as well as for different regions of the same neuron, suggesting that the surface is constantly changing as the neuron receives food and loses waste. There is a variety of cytoplasmic types of invagination of neuron somata by glial processes. The invaginations were classified into four easily recognized types: regular, chunky, filigree, and ridge (present only in axon hillock regions). Motor neurons also make reciprocal invaginations into the glial cells that surround them. Some of these extend for distances up to 40 microns from the surface. The effective surface area is increased, compared with that calculated for a smooth surface, as a result of the invaginations, by from as little as 5% for a small interneuron to as much as 12-fold for a large motor neuron. The axon hillock region of all types of neurons is heavily invaginated.

Long-term neurosensory deficits following transoral vertical ramus and sagittal split osteotomies for mandibular prognathism

Twenty-six patients who had been treated for mandibular prognathism by either bilateral sagittal split osteotomy or transoral vertical ramus osteotomy were evaluated by neurosensory examination. Neuropathy was demonstrable in 28.8% of the 52 mental nerves examined. The incidence of neuropathy was significantly higher in the bilateral sagittal split osteotomy group than in the transoral vertical osteotomy group.

Analysing access to nursing home care

The aim of this study is to investigate access to nursing home care in selected regions of Australia, Canada and the United States, and to examine the common ways in which nursing homes are used. Firstly, a review of methodological considerations in measuring access to nursing home care is made. Secondly, patient turnover patterns are interpreted with a view to showing differences in nursing home use among the countries studied; aggregate turnover rates, length of stay and outcomes are compared. Thirdly, groups of patients who differ in demographic and morbidity characteristics and in their use of nursing homes are discussed. Finally a number of distributive implications of these results are raised and a framework is outlined for considering redistributive consequences of changes in the use of nursing homes. It is concluded that the rate of flow of patients through nursing homes is as important a determinant of access to nursing home care as the level of bed provision and that adoption of this dynamic view of access indicates considerable scope for redistributing use of resources within the nursing home systems of all three countries.

Age-specific differences in duration of clinical protection after vaccination with meningococcal polysaccharide A vaccine

Sequential case-control studies were used to monitor changes in the clinical protection induced by group A meningococcal polysaccharide vaccine over a 3-year period. Overall, vaccine efficacy declined from 87% 1 year after vaccination to 70% and 54% at 2 and 3 years, respectively. When stratified by age at time of vaccination the data showed that, although vaccine efficacy remained high in children greater than or equal to 4 years of age (vaccine efficacy 85%, 74%, and 67% at 1, 2, and 3 years after vaccination, respectively), it declined dramatically in those less than 4 years of age at time of vaccination (vaccine efficacy 100%, 52%, and 8%, respectively, at 1, 2, and 3 years after vaccination). Thus, a single dose of group A meningococcal vaccine does not yield lasting clinical protection in children less than 4 years of age.

Evaluation of condylar position from temporomandibular joint radiographs

This investigation evaluated the accuracy of three different transcranial TMJ radiographic records of condylar position and joint space dimension. In addition, the study evaluated how reliably observers determined condylar position and joint space dimensions from the radiographs. The results of this investigation support the following conclusions. The classification of condylar position is not the same at different sagittal locations within a TMJ. Skull position and radiographic projection must be identical if joint space measurements from serial radiographs are to be compared. The actual joint space dimensions and the anatomic anterior/posterior position of the condyles in the glenoid fossae cannot be accurately recorded by the radiographic techniques used in this investigation. Condyle/fossa relationships cannot be classified reliably by subjective evaluation of TMJ radiographs.

Photocephalometry: errors of projection and landmark location

A method called photocephalometry was recently described for the possible soft-tissue evaluation of orthognathic surgery patients by the superimposition of coordinated cephalographs and photographs. A grid analysis was performed to determine the accuracy of the superimposition method. In addition, the reliability of landmark identification was analyzed by the method error of Baumrind and Frantz, using three replicates of twelve patients' photographs. Comparison of twenty-one grid intervals showed that the magnification of the photographic image for any given grid plane is not correlated to that of the radiographic image. Accurate comparisons between soft- and hard-tissue anatomy by simply superimposing the images are not feasible because of the difference in the enlargement factors between the photographs and x-ray films. As was noted by Baumrind and Frantz, a wide range exists in the variability of estimating the location of landmarks. Sixty-six percent of the lateral photographic landmarks and 57% of the frontal landmarks had absolute mean errors for all twelve patients that were less than or equal to 2.0 mm. In general, the envelope of error for most landmarks was not circular. Although the photocephalometric apparatus as described by Hohl and colleagues does not yield the desired quantitative correlation between hard and soft tissues, valuable quantitative information on soft tissue can be easily obtained with the standardization and replication possible with the camera setup and enlarged photographs.

Facial pattern differences in long-faced children and adults

Vertical facial morphology has traditionally been studied by examining subjects chosen because of open bite/overbite or mandibular plane angle. The underlying skeletal and dental morphology associated with clinical facial appearance of normal and vertically dysplastic children and adults has not been well documented. The purposes of this study were to (1) describe vertical facial morphology in long-, normal-, and short-faced children and long-faced and normal adults, and (2) identify morphologic factors associated with the clinical evaluation of long-faced and normal subjects. Forty-two children, 6 to 12 years old, and forty-two young adults with varied vertical facial types were examined clinically and separated into three vertical classifications: long, normal, or short face. Lateral cephalometric radiographs were obtained in natural head position and seven angular, eighteen linear, and six ratio measurements were made. Descriptive statistics were used to characterize all groups, and intergroup differences were compared using analysis of variance for the three child groups and the t test for the two adult groups. For both long-faced children and adults, anterior total face height, mandibular plane angle, gonial angle, and mandibulopalatal plane angle were significantly greater than normal. Ramus height was not significantly different from normal in the children, but there was a tendency for long-faced adults to have short rami. Excessive dentoalveolar development was evident in long-faced children but not in adults. Factors associated with the clinical identification of vertical dysplastic subjects were identified by a principal component analysis. For each component, a variable highly correlated with that component was selected.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunological similarity of milk sulfhydryl oxidase and kidney glutathione oxidase

A radioimmunoassay for sulfhydryl oxidase, a membrane enzyme, was developed using antibodies raised to the bovine milk enzyme which had been purified by transient covalent affinity chromatography on a cysteinylsuccinamidopropyl-glass matrix. Bovine milk sulfhydryl oxidase and bovine kidney sulfhydryl oxidase ("glutathione oxidase") appear to be immunologically identical as evidenced by parallel responses in radioimmunoassays. Antibodies raised to the purified milk sulfhydryl oxidase can immunoprecipitate glutathione oxidase activity, but not gamma-glutamyltransferase ("transpeptidase") activity, from bovine kidney preparations.

The conserved nucleotide sequences of Bkm, which define Sxr in the mouse, are transcribed

We have recovered a conserved transcribed component of the snake W chromosome satellite DNA (Bkm) from Drosophila and male mouse libraries. This consists of repeats of the tetranucleotide GATA that are concentrated in the sex-determining region of the Y chromosome of mouse, on the W chromosome of snakes, and in the proximal region of the X chromosome of D. melanogaster, and it appears to be transcribed in a sex-specific and developmentally regulated manner. Sequencing studies show that, unlike most other transcribed repeats, the GATA repeats potentially contain open reading frames. These encode mainly the amino acids leucine, serine, isoleucine, and tyrosine but with occasional variant codons that differ in different clonal isolates. Transcription is exclusive to the GATA strand in different tissues of the same organism and in different unrelated organisms. The complementary strand CTAT contains stop codons in all reading frames. The possible developmental significance of these sequences is discussed.

A survey of radiographs obtained at the initial dental examination and patient selection criteria for bitewings at recall

This paper reports the results of a 1980 survey of a 27% simple random sample of all practicing dentists in North Carolina. The objective of the survey was to establish current practice standards regarding panoramic, full-mouth series, and bitewing radiographs. A total of 414 dentists (76.2% of those surveyed) responded. A questionnaire recorded demographic data on the dentists, age-specific prevalence data on the type of radiograph most often done at a patient's initial visit, and prevalence of radiographs based on need as perceived by the dentist and assessed separately for a variety of patient characteristics (age, oral hygiene, caries activity, fluoride treatment, and systemic medical problems). Results of the survey of a subset of 338 dentists in general practice showed the median age to be 40 with a median length of experience of 13 years. At an initial visit, for patients younger than 12, bitewing radiographs only were most commonly taken; for patients older than 12, bitewings plus a panoramic radiograph were taken. Full-mouth series plus bitewings were rarely performed among patients younger than 6 years (2.1% of the time), but were more commonly performed as patients aged (29.0% for patients aged 40 and older). A variety of patient characteristics were considered for their impact on the need for bitewing radiographs on recall. Caries activity was ranked most important by the general dentist, followed by oral hygiene and periodontal activity.