Validation of the multiplier method for leg-length predictions on a large European cohort and an assessment of the effect of physiological age on predictions.

PURPOSE: The Avon Longitudinal Study of Parents and Children (ALSPAC) prospective cohort was used to determine the accuracy of the Paley multiplier method for predicting leg length. Using menarche as a proxy, physiological age was then used to increase the accuracy of the multiplier. METHODS: Chronological age was corrected in female patients over the age of eight years with documented date of first menses. Final sub-ischial leg length and predicted final leg length were predicted for all data points. RESULTS: Good correlation was demonstrated between the Paley and ALSPAC data. The average error in prediction depended on the time of assessment, tending to improve as the child got older. It varied from 2.2 cm at the age of seven years to 1.8 cm at the age of 14 years. When chronological age was corrected, the accuracy of multiplier increased. Age correction of 50% improved multiplier predictions by up to 28%. CONCLUSION: There appears to have been no significant change in growth trajectories of the two populations who were chronologically separated by 40 years. While the Paley data were based on extracting trends from averaged data, the ALSPAC dataset provides descriptive statistics from which it is possible to compare populations and assess the accuracy of the multiplier method. The data suggest that the accuracy improves as the patient gets close to the average skeletal maturity but that results need to be interpreted in conjunction with a radiological assessment of the growth plates. The magnitude of the errors in prediction suggest that when using the multiplier, the clinician must remain vigilant and prepared to perform a contralateral epiphyseodisis if the prediction proves to be wrong. The data suggest a relationship between the multiplier and menarche. There appears to be a factorisation and when accounting for physiological age, one needs to correct by 50% of the difference between chronological and physiological age.

Does human immunodeficiency virus status affect early wound healing in open surgically stabilised tibial fractures?: A prospective study.

We compared early post-operative rates of wound infection in HIV-positive and -negative patients presenting with open tibial fractures managed with surgical fixation. The wounds of 84 patients (85 fractures), 28 of whom were HIV positive and 56 were HIV negative, were assessed for signs of infection using the ASEPIS wound score. There were 19 women and 65 men with a mean age of 34.8 years. A total of 57 fractures (17 HIV-positive, 40 HIV-negative) treated with external fixation were also assessed using the Checkett score for pin-site infection. The remaining 28 fractures were treated with internal fixation. No significant difference in early post-operative wound infection between the two groups of patients was found (10.7% (n = 3) vs 19.6% (n = 11); relative risk (RR) 0.55 (95% confidence interval (CI) 0.17 to 1.8); p = 0.32). There was also no significant difference in pin-site infection rates (17.6% (n = 3) vs 12.5% (n = 5); RR 1.62 (95% CI 0.44 to 6.07); p = 0.47). The study does not support the hypothesis that HIV significantly increases the rate of early wound or pin-site infection in open tibial fractures. We would therefore suggest that a patient's HIV status should not alter the management of open tibial fractures in patients who have a CD4 count > 350 cells/µl.

The effect of HIV on early wound healing in open fractures treated with internal and external fixation.

There are 33 million people worldwide currently infected with human immunodeficiency virus (HIV). This complex disease affects many of the processes involved in wound and fracture healing, and there is little evidence available to guide the management of open fractures in these patients. Fears of acute and delayed infection often inhibit the use of fixation, which may be the most effective way of achieving union. This study compared fixation of open fractures in HIV-positive and -negative patients in South Africa, a country with very high rates of both HIV and high-energy trauma. A total of 133 patients (33 HIV-positive) with 135 open fractures fulfilled the inclusion criteria. This cohort is three times larger than in any similar previously published study. The results suggest that HIV is not a contraindication to internal or external fixation of open fractures in this population, as HIV is not a significant risk factor for acute wound/implant infection. However, subgroup analysis of grade I open fractures in patients with advanced HIV and a low CD4 count (< 350) showed an increased risk of infection; we suggest that grade I open fractures in patients with advanced HIV should be treated by early debridement followed by fixation at an appropriate time.

Femoral torsion in patients with Blount's disease: a previously unrecognised component.

In 1937 Blount described a series of 28 patients with 'Tibia vara'. Since then, a number of deformities in the tibia and the femur have been described in association with this condition. We analysed 14 children with Blount's disease who were entered into a cross-sectional study. Their mean age was 10 (2 to 18). They underwent a clinical assessment of the rotational profile of their legs and a CT assessment of the angle of anteversion of their hips (femoral version). We compared our results to previously published controls. A statistically significant increase in femoral anteversion was noted in the affected legs, with on average the femurs in patients with Blount's disease being 26 degrees more anteverted than those in previously published controls. We believe this to be a previously unrecognised component of Blount's disease, and that the marked intoeing seen in the disease may be partly caused by internal femoral version, in addition to the well-recognised internal tibial version.

Digital imaging of the human cornea in vivo with ultraviolet light.

We have a developed a novel and practical method of imaging the cornea under ultraviolet (UV) light using a digital medium. Wavelengths of 336-371 nm were used to illuminate the cornea. Images were recorded using a UV Nikkor lens and a digital charged coupled device (CCD). Images obtained showed ferritin lines not visible under white light. This study concluded that 336-371 nm is comparable to shorter wavelengths for the imaging of ferritin in the cornea and that a digital image capture system was comparable to that of film.

Functional regulator treatment of Class II division 1 malocclusions.

This controlled retrospective study aimed to identify the contribution of skeletal and dental changes in the correction of Class II division 1 malocclusions using Fränkel's functional regulator II (FRII), with reference to a concurrently recruited control group. One hundred and thirty-eight patients with Class II division 1 malocclusions were identified, those accepting treatment forming the study group and those declining treatment the control group. The study group (n = 70) were treated with a Fränkel appliance. Pre- and post-treatment observation cephalometric radiographs were analysed and compared. Mean values for both skeletal and dental variables in the control group were remarkably consistent throughout the study period; however, this masked individual variations in this group. The skeletal variables in the study group that showed statistically significant differences from the control group were SNB, ANB, BaNA and ANS-Me, but none of these was sufficiently large to be regarded as clinically significant. Dental variables showed clinically and statistically significant differences, including a 10 degree reduction in UI-Max and 3.1 degree increase in LI-Mand. The Fränkel appliance was thus found to be effective in producing desirable occlusal and dental changes in the majority of patients treated.

Skeletal and dental changes following the use of the Frankel functional regulator.

The purpose of this study was to assess the relative contributions of skeletal and dental components in correction of Class II division 1 malocclusions when treated with Frankel's functional regulator (FR). This was a retrospective study involving analyses of pre- and post-treatment cephalograms of 63 Class II division 1 patients treated with the FR to demonstrate the relative maxillary, mandibular, incisor, and molar movements during treatment compared with normal growth within a control group of untreated 39 Class II division 1 cases drawn from the same demographic population. All cephalograms were digitized and subjected to a Pitchfork analysis, which measured individual anteroposterior skeletal and dental changes during the period of study. It was shown that the FR was effective in treating Class II division 1 cases with the studied group being corrected to a clinically acceptable overjet and overbite of 2-3 mm. The majority of the correction came from dental movements, the most significant being the retroclination of the upper incisor teeth (mean 4.1 mm, 95 per cent CI +/- 0.44) and proclination of the lowers (mean 2.2 mm 95 per cent CI +/- 0.57). As regards skeletal correction, the most significant contribution was the restraint of normal maxillary forward growth (mean -0.2 mm, 95 per cent CI +/- 0.62) with forward mandibular growth not being a significant factor.

Rural palliative care volunteer education and support program.

The present paper looks at the challenges of palliative care delivery in rural and remote areas and proposes the establishment, education and coordination of a network of palliative care volunteers to assist in the delivery of non-clinical services. The development of a rural palliative care volunteer education and support training package is documented, together with details of the trailing of the package and its evaluation. Possible benefits of the program and some key issues to be considered when establishing a volunteer network are raised.

Bonded orthodontic retainers: the wire-composite interface.

The bonded orthodontic retainer constructed from multistrand wire and composite is an efficient esthetic retainer, which can be maintained long-term. Clinical failures of bonded orthodontic retainers, most commonly at the wire/composite interface, have been reported. This in vitro investigation aimed to evaluate selected multistrand wires and composite materials that are available for use in the construction of bonded fixed retainers. An in vitro model was developed to simulate the forces encountered at the wire/composite interface. No significant difference was detected between different multistrand wire types and diameters with regard to retention in composite. Wires were placed in one of three groups according to surface characteristics identified with scanning electron microscopy. Increasing the thickness of composite overlying the wire increased the force required to detach the wire from the composite. Thickness of composite greater than 1.0 mm overlying the wire may give little clinical advantage. Greater force was required to detach the wire from Concise Orthodontic (3M Unitek) than any other composite tested. In vitro abrasion resistance testing found Heliosit Orthodontic (Vivadent) and Right On (TP Orthodontics, Inc.) to have poor abrasion resistance, whereas Concise Orthodontic and Transbond (3M Unitek) had abrasion resistance comparable with restorative composites. Clinical recommendations are made based on these findings.

Index of Oral Cleanliness (I.O.C.). A new oral hygiene index for use in clinical audit.

Although plaque control influences orthodontic treatment planning, treatment progress and outcome, current national orthodontic clinical audit software does not include an assessment of oral hygiene. This paper presents the development of the Index of Oral Cleanliness, a new simple rapid measure of oral hygiene, and describes its validation and reliability by comparison with the Silness and Loe plaque index in an unselected group of adolescents. It is concluded that the Index of Oral Cleanliness provides a valid quantitative method of scoring oral hygiene, with advantages for use in routine clinical practice.

Ex vivo bond strength of adhesive precoated metallic and ceramic brackets.

Compared with conventional adhesive systems, adhesive precoated (APC) are reported to have advantages in clinical use. The ex vivo bond strength to human premolar teeth of metallic and ceramic APC brackets was compared with that of identical brackets bonded with Transbond (3M Unitek) light cured orthodontic adhesive, and patterns of failure were examined. There was no significant difference (P > 0.05) in mean bond strength between metallic brackets bonded with the two systems. Ceramic brackets bonded with Transbond had significantly higher (P < 0.05) mean bond strength and failure more normally occurred at the composite/enamel interface when compared with APC ceramic brackets and metallic brackets. Following debonding no enamel damage was observed with either APC or conventionally bonded ceramic brackets.

Fracture of polycarbonate brackets--a related photoelastic stress analysis.

In clinical use polycarbonate edgewise bracket designs, patterned on metallic predecessors, have demonstrated slot-wing fracture. A preliminary two-dimensional photoelastic stress investigation is described in which two bracket designs, without angles in the edgewise slot component, are subjected to simulated palatal root torque mechanics.

Fracture of polycarbonate edgewise brackets: a clinical and SEM study.

Fracture experience and fracture form of polycarbonate edgewise brackets, were assessed in a clinical study using four force controlled mechanical systems. The incidence and types of bracket fracture were investigated macroscopically and by Scanning Electron Microscopy (SEM). It was concluded that the engagement of both round and square archwires and stainless steel ligaturing were aetiological factors in bracket fracture.

Spontaneous regression of some mandibular radiolucencies--case report.

Three cases are presented in which asymptomatic radiolucent areas were discovered on routine orthodontic radiographs and which resolved completely without active treatment.

Heat exposure-induced changes in motor outflow component of reaction time.

Conduction velocity, absolute refractory period, and subnormal conduction period measures of the right ulnar motor nerve were obtained during a simple reaction time task. 6 young, healthy, right-arm dominant male subjects were tested following 30 min. exposure in ambient (20 degrees C) and hot (36 degrees C) room air conditions. Motor and premotor components of fractionated reaction time were tested on the same arm. Oral, right forearm skin and a four-site mean skin temperature were monitored. During heat exposure, forearm skin temperature increased 4.7 degrees C and mean skin temperature 2.9 degrees C. Oral temperature did not alter. Conduction velocity increased 11.4%, absolute refractory period decreased 22.7%, and subnormal conduction period decreased 14.1% in the hot condition. Concomitantly, a 5.2% increase in premotor reaction time and 12.2% decrease in motor reaction time were observed. Total RT did not alter significantly. It was concluded that different component parts of reaction time were differentially influenced by exposure to heat.

China's surprising census results.

PIP: A summary of the preliminary results of the 1982 census of China is presented. The author notes that the results indicate a larger urban population than expected, an increased sex ratio of males, and an increasing minority population. A preliminary assessment of census accuracy and the relationship of the census to the household registration system is included.^ieng