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.

Morphologic alterations in Macaca mulatta following destruction of the motor nucleus of the trigeminal nerve

In two adolescent male Macaca mulatta monkeys, small unilateral electrolytic lesions were produced in the motor nucleus of the trigeminal nerve. The side contralateral to the muscle paralysis served as the control side. The animals were killed 130 and 300 days postoperatively. One animal (animal A) was prepared as a dry skull preparation. Alterations in craniofacial form were noted clinically in both animals and included paralysis and atrophy of the muscles of mastication on the lesion side and mandibular asymmetry. In animal A (300 days postoperative survival), alterations in form included dental and mandibular asymmetry, the appearance of an anterior open-bite on the affected side, and a decrease in the size of the intratemporal fossa on the affected side. Remodeling changes were evident in the condylar process, the zygomatic arch, the orbit, and the zygomaticotemporal and zygomaticofrontal sutures on the lesion side but were not apparent on the contralateral side.

Hand involvement in psoriatic arthritis

From a population of 105 patients with confirmed psoriatic arthritis, 25 patients required hand surgery. These 25 surgical patients were evaluated retrospectively both clinically and radiographically. The patterns of hand and wrist involvement as well as the results of surgery differed from those typically seen in rheumatoid disease. Spontaneous fusion of the wrist in a functional position, severe proximal interphalangeal involvement often with marked flexion contractures, severe erosion of the distal interphalangeal joint with spontaneous fusions, and generalized stiffness characterize these hands. Minimal improvement in motion and a significantly increased incidence of infection following arthroplasty were noted.

Preliminary study of the effects of carbamazepine on congenital orofacial defects in offspring of A/J mice

Carbamazepine (CBZ; Tegretol) is an effective anticonvulsant drug. We assessed putative CBZ teratogenicity in a sensitive animal model, the A/J mouse. Plasma CBZ levels were determined by gas-liquid chromatography. To achieve the accepted human plasma therapeutic range (TR) of CBZ (8-12 micrograms/ml), up to a 6X human oral dose was given. Test Group A received 300 mg pure crystalline CBZ/kg, suspended in 1.25% carboxymethylcellulose (CMC), at 6 a.m., noon, 6 p.m., and midnight on gestational day 10 (previously determined to be the peak sensitive time for cleft lip and palate induction in the A/J) and at 6 a.m. on day 11. Test Group B received 150 mg/kg of an experimental CBZ elixir (Tegretal Sirup) on the same regimen. Plasma levels rose to above TR within 15 min, then fell steadily, exiting the TR by 5 hr postgavage. Test Group C was given the experimental CBZ elixir at 4-h intervals for 36 hr. The rapid rise and fall of CBZ plasma levels again occurred, but the time within the therapeutic range was greatly increased (through 6 p.m. day 11). Control groups received the appropriate quantity of the CMC vehicle. Fetuses were harvested on day 17. Compared to control animals, none of the CBZ regimens was associated with a major increase in incidence of cleft lip or palate.

A 2-year longitudinal study of overdenture patients. Part II: Assessment of the periodontal health of overdenture abutments

Eighty-nine patients were examined at 1- and 2-year intervals after treatment with overdentures. The measurements of gingival index, pocket depth, plaque index, and mobility showed little change in the 2-year period. The initial gingival health of some teeth was less than optimal, but the periodontal health did not deteriorate and no teeth were lost during the observation period. The elevated plaque scores of this group of patients clearly shows that periodontal health of the abutments was affected, emphasizes the importance of adequate follow-up care and the need for constant reinforcement of home care instructions. As with any form of dental treatment, proper patient selection is an important step when overdentures are a treatment consideration. Patients should be able to demonstrate that they are motivated and have the ability to clean their teeth. It is doubtful that patients will change their oral hygiene habits after the denture is inserted, and poor hygiene may lead to a loss of abutment teeth from caries and/or periodontal disease.

Synthetic luteinizing hormone-releasing hormone in impotent male diabetics

We compared the effect of luteinizing hormone-releasing hormone (LH-RH) 500 micrograms 8-hourly and placebo on sexual function in impotent diabetic males. These patients had no obvious vascular or neurological disease and no major psychological disorders to account for their impotence. Basal serum testosterone concentrations were normal in all. Five patients had elevated basal gonadotropin concentrations and/or exaggerated gonadotropin responses to LH-RH. During the first week of the LH-RH treatment there was a significant rise in LH and follicle-stimulating hormone (FSH) concentrations. The LH levels remained elevated throughout the second week of treatment, whereas the FSH returned to pretreatment values. There was no change in hormone concentration during placebo therapy. Clinical responses to treatment were assessed by a self-evaluating questionnaire relating to (i) sexual function and libido; (ii) erectile potency; and (iii) general well-being. There was no significant change within each category, but taken together a significant improvement was found with both LH-RH and placebo treatment. There was no difference between the two forms of treatment.

Experimental manipulation of head posture

Variations in natural head position have been noted by previous workers to be associated with both dentoalveolar and craniofacial skeletal morphologic features. The determinants of cranial posture are as yet not known. Three experiments are described, dealing with the influence of (1) total nasal obstruction, (2) visual feedback deprivation, and (3) a combination of (1) and (2) on the posture of the cranium measured relative to a gravity-defined true vertical reference plane. The results indicate that total nasal obstruction results in all cases in an extended head position. Visual deprivation produces adaptation of a smaller magnitude and unpredictable direction. Combination of both experimentally induced conditions indicates a dominance of the respiratory adaptation in terms of postural response to these stimuli.

The effect of splinting on tooth mobility. (2) After osseous surgery

The purpose of this study was to determine if fixed splinting of teeth with intraoral wire and acrylic splints had advantages with respect to tooth mobility, bone level and attachment level over unsplinted teeth following osseous surgery. Ten patients were chosen who exhibited bilaterally similar chronic destructive periodontitis and mobile teeth. One maxillary sextant was splinted, while the other was unsplinted. Both sextants functioned against an unsplinted mandibular arch. Following initial therapy, osseous surgery was performed in both maxillary sextants on the same day. Tooth mobility data was collected 1 week before and at 3, 6, 12, and 24 weeks following surgery. Levels of gingival attachment and bone were recorded before and 24 weeks after surgery. Splints were removed before measurements, then replaced, and the occlusion refined. Prophylaxes and oral hygiene instruction were repeated every 3 weeks throughout the study. For all categories of teeth and mobility examined, tooth mobility increased initially after surgery and subsequently decreased by 24 weeks to about presurgical values. The splinted and unsplinted segments reacted similarly throughout the study; splinting did not significantly reduce the mobility of individual teeth. Pre- and postsurgical bone and gingival attachment levels were also similar for the splinted and unsplinted segments.

The effect of splinting on tooth mobility. I. During initial therapy

The purpose of this study was to assess whether fixed splinting aided in the reduction of posterior tooth mobility during initial therapy. A "split-mouth" approach was used in order to compare splinted segments with similar unsplinted segments. Seven patients were selected, all of whom demonstrated chronic destructive periodontitis and mobile teeth. Initial therapy, consisting of oral hygiene instruction, root curettage and occlusal adjustment, was performed over a 2-week period. At the time of initial therapy, teeth in contralateral segments were splinted with an intracoronal wire-and-acrylic splint. Tooth mobility and gingival inflammation were recorded in all four segments every 3 weeks for a 15-week monitoring period following initial therapy. The splints were removed before each data recording session and then replaced and the occlusion refined. Prophylaxis and oral hygiene instruction were repeated every second week throughout the monitoring period. The reduction in the mobility of teeth splinted during the entire therapy period did not differ from the reduction observed in the unsplinted segments. The reduction in tooth mobility observed in both the splinted and unsplinted segments over the 17-week period can be attributed to the improved occlusal relationships and reduction in inflammation.

Hemophilus influenzae type b disease in a day-care center. Report of an outbreak

Four episodes of serious Hemophilus influenzae type b infection occurred in three children attending a day-care center. This was 100 times the expected annual total. The pharyngeal carriage rate of Hib was 60% for siblings of patients, 20% for adult household contacts, and 5% for well children at the center. No carriers were found in control populations. Escherichia coli K100, which cross-reacts serologically with Hib, was found in rectal swabs of 20% of family contacts of patients and 3.5% of well children at the center. It was recovered from two of seven persons who carried Hib in the pharynx and two of 75 who did not (P = 0.035), suggesting that carriage of one organism may facilitate carriage of the other. In a randomized prospective trial with 85 patient contact, Hib carriage was eradicated in all of four carriers given ampicillin and in all of three given rifampin. There were no statistically significant differences in the rate of adverse reactions in the two treatment groups. No further cases were reported.

Management of malignant pleural effusion

A pleural effusion is a frequent complication of malignant disease. Essential to the care of oncology patients is a fundamental knowledge of the pathophysiology and treatment of such effusions. This article discusses the current thoughts concerning the occurrence of malignant effusions, outlines the current available methods and agents employed for control, and presents a modification of the thoracostomy procedure that appears to be more effective than the standard procedure.

The consultation process

This article is a discussion between two family doctors and three consultants about the problems of consultation from both points of view. Some suggestions are made as to how we might improve the quality of this part of our medical practice.

A study of foldback DNA

Nuclear DNA from eucaryotes contains a significant fraction which forms duplexes very rapidly and also independently of the DNA concentration. This fraction can be isolated by adsorption to hydroxylapatite and has been called foldback DNA (Britten and Smith, 1970). Here we extend previous studies to show that the foldback fraction is due to the existence of a finite number of foldback foci in each genome equivalent of DNA, approximately 10(5) in the case of Xenopus laevis. More significantly, we have isolated the foldback fraction in quantity from DNA of such a size (in one case broken randomly and in another digested with a restriction endonuclease) that only about 10% of the total DNA has foldback properties. If the foldback foci were located in precisely the same positions in all sets of the Xenopus laevis genome, the prediction would be that these foldback fractions would contain sequences representing 20% (random shear) and 10% (restriction endonuclease) of the total genome. In contrast, our results show that in both cases the foldback fraction contains the entire Xenopus laevis DNA sequence. One possible explanation of these observations is that as in procaryotes, eucaryotic DNA is randomly cross-linked. We show that cross-linkage of Xenopus laevis DNA is not sufficient to explain our observations. In consequence, we have adopted the hypothesis that the formation of foldback DNA is mainly an intrastrand phenomenon, but nevertheless occurs at different sites in different sets of the Xenopus laevis genome.