Laser scanning for the identification of repeatable landmarks of the ears and face

OBJECTIVE

To determine whether or not landmarks of the ears and face could be reliably identified using a laser scaning system.

DESIGN

A single centre study with two assessors jointly agreeing the siting of the landmarks on the ear on two separate occasions from an original laser scanned image.

SETTING

University based research study in London, UK.

SUBJECTS

20 subjects, 11 males, 9 females, aged 16-24 years with normal facial development.

MAIN OUTCOME MEASURES

Differences were determined between the locations of landmarks on the two occasions studied. Differences were assessed for the x, y and z co-ordinates of each point.

RESULTS

The mean difference between the two sitings of 21 landmarks ranged between 0 and 0.85 mm in the x, y and z axes. With a small number of exceptions, the differences were not statistically significant. The three-dimensional mean differences between the two sitings of each landmark ranged between 1 and 2.5 mm. Coefficients of repeatability ranged between 1.6 and 7.0 mm.

CONCLUSIONS

Landmarks of the ears and face from a laser scanned image can be sited consistently by two assessors. Since the landmarks can be located it should be possible to evaluate dimensional measurements of the ear and its position on the face.

Prosthodontic treatment, patient response, and the need for maintenance of complete implant-supported overdentures: an appraisal of 5 years of prospective study

The prosthodontic methods and outcomes of treating 127 patients in nine centres over a period of 5 years is described. The benefits perceived by patients and the changes induced in the denture-bearing tissues and temporomandibular joints are reported. To sustain effective treatment outcomes, the levels of maintenance needed by the overdentures are contrasted for restoration of the edentulous mandibles and maxillae.

Attenuation of early and late phase allergen-induced bronchoconstriction in asthmatic subjects by a 5-lipoxygenase activating protein antagonist, BAYx 1005

BACKGROUND

The cysteinyl leukotrienes (LTC4, LTD4 and LTE4) have been implicated in the pathogenesis of allergen-induced airway responses. The effects of pretreatment with BAYx 1005, an inhibitor of leukotriene biosynthesis via antagonism of 5-lipoxygenase activating protein, on allergen-induced early and late asthmatic responses has been evaluated.

METHODS

Eight atopic subjects with mild asthma participated in a two period, double blind, placebo controlled, cross-over trial. Subjects were selected on the basis of a forced expiratory volume in one second (FEV1) of > 70% predicted, a methacholine provocative concentration causing a 20% fall in FEV1 (PC20) of < 32 mg/ ml, a documented allergen-induced early response (EAR, > 15% fall in FEV1 0-1 hour after allergen inhalation) and late response (LAR, > 15% fall in FEV1 3-7 hours after allergen inhalation), and allergen-induced airway hyperresponsiveness (at least a doubling dose reduction in the methacholine PC20 30 hours after allergen inhalation). During the treatment periods subjects received BAYx 1005 (500 mg twice daily) or placebo for 3.5 days; treatment periods were separated by at least two weeks. On the third day of treatment, two hours after administration of medication, subjects performed an allergen inhalation challenge and FEV1 was measured for seven hours.

RESULTS

Treatment with BAYx 1005 attenuated the magnitude of both the allergen-induced early and late asthmatic responses. The mean (SE) maximal fall in FEV1 during the EAR was 26.6 (3.3)% during placebo treatment and 11.4 (3.3)% during treatment with BAYx 1005 (mean difference 15.2 (95% confidence interval (CI) 9.4 to 21.00) with a mean protection afforded by BAYx 1005 of 57.1%. The mean (SE) maximal fall in FEV1 during the LAR was 19.8 (5.7)% during placebo treatment and 10.7 (4.4)% during BAYx 1005 treatment (mean difference 9.2 (95% CI 1.4 to 17.0) with a mean protection afforded by BAYx 1005 of 46.0%. The area under the time response curve (AUC0-3) was also reduced after treatment with BAYx 1005 compared with placebo by 86.5%.h (mean difference 26.3 (95% CI 17.1 to 38.5)) and the AUC3-7 by 59.6%.h (mean difference 26.9 (95% CI-3.8 to 57.6)).

CONCLUSIONS

These results show that antagonism of 5-lipoxygenase activating protein can attenuate allergen-induced bronchoconstrictor responses and support an important role for the cysteinyl leukotrienes in mediating these asthmatic responses.

Locating angulated abutments: a technical note

A simple laboratory-made acrylic resin guide offers rapid location of angulated abutments after the healing abutments are removed. An impression recording the relation of the implants to the dental arch enables the choice of abutments to be made in the laboratory. The precise position and angulation of each abutment can be transferred to the mouth.

Managing disabilities in an integrated health environment: the experience of Aetna

Disability-related outlays are increasing at a rate well above the medical inflation rate. This article discusses the experience of one company in its attempt to manage these skyrocketing costs, by developing a new program that integrates health and related benefits by combining the medical and human resources interventions into a unified program. The authors discuss the initiation, development and progress of the program, concluding with measured results revealing reduced lost work time, improved employee health and productivity, and reduced disability costs.

Follow up and maintenance of implant supported prostheses: a comparison of 20 complete mandibular overdentures and 20 complete mandibular fixed cantilever prostheses

Two independently selected groups of 20 patients who were edentulous in te mandible, were followed up on a regular basis over a 5-year period following restoration with a lower implant stabilised prosthesis and conventional upper denture. Significantly more treatment was required by those who received complete mandibular overdentures than those provided with complete fixed mandibular prostheses. In addition to adjustment for the relief of denture trauma to the mucosa, more mechanical problems arose with overdenture implant prostheses.

Effects of inhaled budesonide on allergen-induced airway responses and airway inflammation

Allergen inhalation by sensitized subjects results in acute bronchoconstriction, which can be followed by a later bronchoconstrictor response, allergen-induced airway hyperresponsiveness, and increases in airway inflammatory cells. Treatment with inhaled glucocorticosteroids attenuates allergen-induced asthmatic airway responses. The purpose of this study was to determine whether a 1-wk pretreatment with inhaled budesonide influences allergen-induced changes in inflammatory cells in blood and induced sputum. Seven subjects with mild atopic asthma were treated in a double-blind, placebo-controlled, randomized, crossover fashion with either inhaled budesonide 400 microg/d, or placebo for 7 d. Allergen challenges were carried out the morning after treatment was discontinued and sputum samples were obtained 7 h after allergen inhalation. Methacholine airway responsiveness was measured, and blood and sputum samples were obtained 24 h post-allergen. Budesonide treatment attenuated the magnitude of both the early and the late asthmatic response, reduced allergen-induced methacholine airway hyperresponsiveness, and attenuated allergen-induced increases in total eosinophils and activated eosinophils. These results suggest that the effects of inhaled glucocorticosteroids on allergen-induced airway responses may be mediated through their inhibition of allergen-induced eosinophil migration and activation.

The challenge of replacing complete dentures: Part 2

The purpose of this article is to consider the challenges that arise in replacing complete dentures. The use of conventional techniques incorporating successful features of the existing dentures appropriate to general practice will be discussed and the problems peculiar to the replacement of implant-retained overdentures considered.

The challenge of replacing complete dentures: Part 1

Complete dentures need to be replaced at suitable intervals-either because of changes in the denture-bearing tissues, usually due to alveolar resorption, or because of general deterioration of the existing dentures. The purpose of this and the following article is to consider the challenges that arise in replacing complete dentures. The rationale for using techniques in which features of existing dentures can be employed in the construction of replacement complete dentures will be discussed, together with methods suitable for clinical practice. In the first part diagnosis and treatment planning will be considered and a variety of copying techniques reviewed. The limitations of these techniques will be discussed and alternative treatment strategies will be considered.

A 5-year prospective multicenter follow-up report on overdentures supported by osseointegrated implants

This report presents the results of a 5-year prospective multicenter study including nine centers worldwide. A total of 30 patients received 117 Brånemark implants in the maxillae, and 103 patients received 393 implants in the mandibles. According to the protocol, all integrated maxillary implants were to be loaded; however, only two of four mandibular implants were planned for support of the overdentures, leaving the remaining implants covered by mucosa as backup for possible implant failures. Thirty-five patients (26.3%) who were provided with 127 implants (24.9%) were withdrawn from the study. Six patients treated in the maxilla lost all their implants and resumed wearing complete dentures. The cumulative success rates for implants and for overdentures supported by two implants in the edentulous mandible were 94.5% and 100%, respectively. The corresponding cumulative success rates for implants and for overdentures supported by an optimal number of implants in the maxilla were 72.4% and 77.9%, respectively. Significantly better jawbone characteristics at the time of implant surgery were considered to contribute to the better cumulative success rates in the mandibles. Mean marginal bone loss was 0.8 mm (SD 0.8) and 0.5 mm (SD 0.8) for loaded implants during a 5-year period of time in the maxillae and mandibles, respectively. Measurements of the clinical height of the abutment cylinders indicated a mean recession (0.2 mm) of peri-implant mucosa during the follow-up period in the mandibles. Conversely, hyperplasia was observed in the maxillae.

Monitoring procedures for the single-tooth implant-stabilized crown with an internally located customized abutment

Three procedures to ensure the correct location of components in the orifice of a hydroxyapatite-coated implant cylinder are presented. These facilitate recording of an accurate impression and the correct location of a customized abutment supporting a single-tooth crown. A technique is offered for obtaining the reproducible, comparable radiographs necessary for monitoring horizontal bone levels.

Transesophageal echocardiography-guided transvenous endomyocardial biopsy used to diagnose primary cardiac angiosarcoma

Primary cardiac tumors are rare clinical entities with the histologic diagnosis usually made from surgically obtained tissue or at postmortem examination. Transvenous endomyocardial biopsy has been used less frequently, under fluoroscopic or transthoracic echocardiographic guidance. In this case report, we utilized the transesophageal echocardiography to guide the endomyocardial biopsy from a right atrial tumor in a 35-year-old man.

Single tooth, implant-stabilized crowns replacing anterior teeth: a clinical comparison of two systems

Implant-supported single-tooth crowns are suitable alternative restorations to partial dentures and bridges. A number of systems have been developed to create a good aesthetic result without the display of the standard titanium abutment traditionally used in restorations with complete fixed prostheses supported by titanium endosseous implants. This paper reviews two such systems.

Results of treatment of 20 patients with implant-retained auricular prostheses

A prospective study of 20 patients receiving rehabilitation for a missing external ear revealed the failure of three flanged implants in a total of 60 placed for the support of a prosthesis and 10 for retention of a bone-anchored hearing aid. Factors limiting an optimal outcome were health of the cutaneous cuff around the abutments, bonding of the silicone ear to the acrylic-resin substructure, and the ability to minimize disfigurement of a congenitally deformed face.

The effects of prefabricated bar design on the success of overdentures stabilized by implants

Two groups of patients were provided with implant-stabilized mandibular overdentures supported by straight ovoid prefabricated bars with a resilient joint or parallel-sided bars with a rigid joint. Measurements of plaque index, mucosal cuff health and height, marginal bone height, pathology of the denture-bearing mucosa, and patient satisfaction were correlated with the different bar designs. Ovoid bars with a resilient joint between the denture and the bar have been shown to give a slightly increased incidence of problems associated with the denture-bearing mucosa. Furthermore, the only significant mean increase in recession of the mucosal cuff was found on the distal surfaces of the distal abutments in this group of patients.

Modern solutions for limited tooth loss in the dental arch

Replacement of small numbers of teeth in the dental arch has traditionally required the construction of a conventional bridge or a removable partial denture where sound reasons exist to favour restoration. Two alternative treatments now increase the choice; resin-bonded bridgework and implant-supported prostheses. A discussion of their indications and the principles of their use are given.

Implant supported fixed distal extension prostheses

The distal extension fixed implant supported prosthesis is now available as an alternative to a partial denture. However, not all patients will be suitable for such treatment. Limitations imposed on fixture length, the effect of gape upon instrumentation, the size of abutment components and the design of the superstructure are discussed in this article, to assist the general practitioner in case referral.

Effect of inhaled PGE2 on exercise-induced bronchoconstriction in asthmatic subjects

Previous studies have suggested that the endogenous release of inhibitory prostanoids limits the bronchoconstrictor response to repeated exercise. The aim of our study was to determine whether inhaled prostaglandin (PG)E2 attenuates exercise-induced bronchoconstriction or methacholine airway responsiveness in asthmatic subjects. Eight subjects with mild stable asthma and exercise bronchoconstriction were studied on 4 separate days, 48 h apart. Subjects inhaled PGE2 or placebo in a randomized, crossover, double-blind fashion, 30 min prior to an exercise challenge or a methacholine challenge. PGE2 inhalation significantly attenuated exercise bronchoconstriction. The mean maximal %fall in FEV1 after exercise was 26% (SEM 3.7%) after placebo, and was 9.7% (SEM 2.7%) after PGE2 (p < 0.001). PGE2 also significantly reduced the duration of exercise bronchoconstriction (p = 0.034). However, PGE2 did not significantly attenuate methacholine airway responsiveness. The geometric mean methacholine provocative concentration causing a 20% fall in FEV1 (PC20) was 0.77 (%SEM 1.48) after placebo day, and 1.41 (%SEM 2.20) after PGE2 (p = 0.30). These results demonstrate that inhaled PGE2 markedly attenuates exercise bronchoconstriction in asthmatic subjects and suggest that this effect is not occurring through functional antagonism of airway smooth muscle.

Effect of magnitude of airway responsiveness and therapy with inhaled corticosteroid on histamine tachyphylaxis in asthma

Histamine challenge testing is used to measure airway responsiveness in asthma. Histamine tachyphylaxis has been demonstrated after repeated challenges in mild asthmatics not using inhaled corticosteroid. Other studies, using subjects with variable severity of asthma, have not demonstrated histamine tachyphylaxis. Forty patients with stable asthma were studied and stratified according to severity of airway hyperresponsiveness and use of inhaled corticosteroid, to examine the effects of these factors on histamine tachyphylaxis. Airway responsiveness was measured as the histamine provocative concentration causing a 20 percent fall in FEV1 (PC20). Twenty subjects had mildly increased airway hyperresponsiveness (PC20 > 1 mg/ml), of whom 10 were using inhaled corticosteroid. Twenty subjects had moderate to severely increased airway hyperresponsiveness (PC20 < 1 mg/ml), of whom 10 were using inhaled corticosteroid. On each of two study days, 1 week apart, two histamine challenges were performed 1 h apart. Histamine tachyphylaxis was found for the entire group on both study days. The geometric mean PC20 increased from 1.0 mg/ml (percent SEM 1.2) to 1.3 mg/ml (percent SEM 1.2) 1 h later on day 1 (p < 0.0005), and 1.1 mg/ml (percent SEM 1.2) to 1.3 mg/ml (percent SEM 1.2) 1 h later on day 2 p < 0.05). Subgroup analysis demonstrated that tachyphylaxis only occurred consistently in subjects with mildly increased airway hyperresponsiveness not receiving inhaled corticosteroid. In this group, the PC20 increased from 2.2 mg/ml (percent SEM 1.2) to 3.2 mg/ml (percent SEM 1.2) on day 1 (p < 0.001), and from 2.5 mg/ml (percent SEM 1.3) to 3.4 mg/ml (percent SEM 1.2) on day 2 (p < 0.05). This study confirms that histamine tachyphylaxis occurs in asthmatics, but is consistently present only in mild, noncorticosteroid-dependent asthmatics.

Neonatal lupus erythematosus. Report of serological and immunogenetic studies in twins discordant for congenital heart block

Autoantibody, HLA studies and C4 phenotypes were performed on twins discordant for isolated congenital heart block. Serum from the mother and cord blood from the infants revealed Ro(SSA) and La(SSB) antibodies in all three sera. No significant difference in Ro(SSA) antibody titre was noted in the cord blood of either twin when compared with maternal titres, as detected by a sensitive ELISA assay. The infants' mother was HLA-DR3 positive. Both infants had identical HLA and C4 phenotypes. Immunoblot analysis revealed that sera from both mother and infants reacted with the 52-kDa Ro(SSA) macromolecule. Quantitative cord blood IgM levels were not elevated in either twin. This study indicates that placental transfer of anti-Ro(SSA) or anti-La(SSB) alone to the fetus is not sufficient for the expression of congenital complete heart block. We conclude from this experiment of Nature that there must be a second event determining which infant develops complete heart block, but this is unknown at present.

The use of two implant systems for providing implant supported overdentures in the mandible--a clinical appraisal

The objective of this paper is to compare the Nobelpharma implant system with that designed by Astra-Tech. The main difference between the two is in the design of the fixture-abutment linkage. With the Astra system, the abutment and screw form one unit, whilst with the Nobelpharma system there is a separate abutment screw. Both systems have been used to support overdentures. Linked bar retention between two implants has been used with the Nobelpharma implants, and individual magnetic or stud retention has been used with the Astra system. Each attachment mechanism has produced patient satisfaction.

Exercise-induced refractoriness in asthmatic subjects involves leukotriene and prostaglandin interdependent mechanisms

Exercise-induced bronchoconstriction is caused, in part, by leukotriene (LT)D4 release in asthmatic airways. Asthmatics become refractory to exercise bronchoconstriction with repeated challenges, due to inhibitory prostaglandin release. The purpose of this study was to test the hypothesis that exercise refractoriness is caused by LTD4-induced inhibitory prostaglandin release. Fourteen stable asthmatic subjects with exercise-induced bronchoconstriction were studied. On the first 2 days, subjects underwent two challenges, 1 h apart, with either exercise or inhaled LTD4. Eight subjects then took part in three double-blind, randomized, placebo-controlled, crossover studies with flurbiprofen, a prostaglandin synthetase inhibitor, to determine whether cross refractoriness occurs between exercise and LTD4, whether flurbiprofen attenuates this effect, and whether flurbiprofen attenuates LTD4 tachyphylaxis. There was a reduction in the intensity of bronchoconstriction to the second challenge both with exercise (refractoriness) and with LTD4 (tachyphylaxis). The degrees of refractoriness and tachyphylaxis were correlated (r = 0.72, p = 0.005). Flurbiprofen attenuated LTD4 tachyphylaxis. Cross refractoriness occurred between exercise and LTD4, and flurbiprofen treatment also attenuated this effect. One hour after LTD4 challenge, the mean fall in FEV1 after exercise was 12.3% (%SEM 2.3) on placebo and 17.1% (%SEM 3.8) on flurbiprofen (p = 0.027). Similarly, 1 h after exercise, the LTD4 PC20 increased to 0.73 (%SEM 1.4) microgram/ml on placebo and 0.30 (%SEM 1.8) microgram/ml on flurbiprofen (p = 0.026). These results suggest that LTD4 released in asthmatic airways as a result of exercise stimulates inhibitory prostaglandin release, resulting in exercise refractoriness.