Injury and frequency of use of playground equipment in public schools and parks in Brisbane, Australia.

OBJECTIVE: The purpose of this study was to determine the frequency of use of play equipment in public schools and parks in Brisbane, Australia, and to estimate an annual rate of injury per use of equipment, overall and for particular types of equipment. METHODS: Injury data on all children injured from playground equipment and seeking medical attention at the emergency department of either of the two children's hospitals in the City of Brisbane were obtained for the years 1996 and 1997. Children were observed at play on five different pieces of play equipment in a random sample of 16 parks and 16 schools in the City of Brisbane. Children injured in the 16 parks and schools were counted, and rates of injury and use were calculated. RESULTS: The ranked order for equipment use in the 16 schools was climbing equipment (3762 uses), horizontal ladders (2309 uses), and slides (856 uses). Each horizontal ladder was used 2.6 times more often than each piece of climbing equipment. Each horizontal ladder was used 7.8 times more than each piece of climbing equipment in the sample of public parks. Slides were used 4.6 times more than climbing equipment in parks and 1.2 times more in public schools. The annual injury rate for the 16 schools and 16 parks under observation was 0.59/100 000 and 0.26/100 000 uses of equipment, respectively. CONCLUSIONS: This study shows that annual number of injuries per standardized number of uses could be used to determine the relative risk of particular pieces of playground equipment. The low overall rate of injuries/100 000 uses of equipment in this study suggests that the benefit of further reduction of injury in this community may be marginal and outweigh the economic costs in addition to reducing challenging play opportunities.

Investigative modalities of mandibular invasion by squamous cell carcinoma.

OBJECTIVES/HYPOTHESIS: To compare preoperative investigations with histological findings in squamous cell carcinoma (SCC) of the oral mucosa that abuts the mandible. Both clinical and radiological examinations fail to predict accurately invasion of the mandible by intraoral SCC. STUDY DESIGN: This two-part, prospective study is of a consecutive series of patients whose first malignancy of the upper aerodigestive tract abutted the lingual surface of the mandible. METHODS: AR patients presented to the Queensland Radium Institute Head and Neck Clinic between 1993 and 1997 with a biopsy-proven SCC that abutted the mandible. These tumors were investigated clinically, radiologically, and histologically. Sensitivity, specificity, and predictive values were calculated for various approaches. In the second part of the study, single photon emission computed tomography (SPECT) bone scans were included. Quantification ratios of bone scans compared the average counting statistics in visually identified mandibular abnormal uptake with normal cervical spine and jaw. RESULTS: Sixty-seven patients were followed for 55 months and assessed with orthopantomogram (OPG), computed tomography (CT) scans, and, in the second part of the study, SPECT bone scans. Thirty-six tumors showed histological evidence of bony invasion. Bony involvement was suggested by OPG in 36 and confirmed histologically in 27 patients. CT scans showed evidence of bone invasion in 22 cases, with 18 of these histologically confirmed. Technetium 99m methylene diphosphonate (MDP) bone scans with planar imaging and SPECT were performed in 24 patients, and histological appearance was suitable for analysis in 14. Three patients with tumor (cervical spine ratios greater than 1.5 predicting malignant involvement) had this confirmed histologically. CONCLUSIONS: The first part of the study confirms our hypothesis that currently used investigations, as well as clinical assessment, fail to predict accurately invasion of the mandible by intraoral SCC. The second part suggests that SPECT scanning with high quantification ratios is promising in the prediction of tumor involvement.

Quinine induced coagulopathy--a near fatal experience.

A 67 year old man presented to his local dentist for restorative treatment. He stated he was fit and well and denied taking any medications. When he was given an inferior alveolar nerve block, excessive bleeding was noted at the injection site and the dentist advised the patient see an oral and maxillofacial surgeon. An appointment was made for the patient but he did not attend. Three days later, he presented with evidence of massive deep haemorrhage to the point of airway compromise. He underwent hospital admission, early intubation, intensive care for nine days and hospitalization for six weeks. The cause of his bleeding was a severe thrombocytopoaenia, induced by chronic ingestion of quinine. He was self-medicating with this to relieve muscular cramps. Despite this experience, the patient continued to deny that quinine was the cause of his problem and that he had failed in his obligations to advise the dentist of his drug history. Dentists need to be alert to the risk that patients may not reveal their true medical history. There are, however, obligations on the dentist to ensure the accuracy of information the patient gives and to ensure that patients whom they believe are at risk follow their advice. Teamwork and skillful airway management prevented this patient's demise.

Bicycle riding and oral/maxillofacial trauma in young children.

OBJECTIVES: To investigate the frequency of oral/maxillofacial injuries in children who have had a bicycle incident and to relate this to the wearing of a protective helmet. DESIGN: Part of a larger prospective study in which self-administered questionnaires were completed by each child with bicycle-related injuries and their parents or caregivers. SETTING: Two tertiary-referral children's hospitals (between 1 April 1991 and 30 June 1992) and three general hospitals (between 1 August 1991 and 30 June 1992) in Brisbane. PARTICIPANTS: 813 children aged under 15 years who presented to the accident and emergency departments with bicycle-related injuries. RESULTS: There were 321 children (39.5%) who sustained oral/maxillofacial injuries. Of 1355 injuries, 340 (25.1%) were to the facial region. Of the 153 children admitted to hospital for bicycle-related injuries, 94 (61.4%) had oral/maxillofacial injury as the primary reason for admission (including those with a reduced level of consciousness). Of the 66 children with a reduced level of consciousness, 53 had concomitant facial injuries. The most common oral/maxillofacial injuries were facial abrasions, cuts and lacerations (50.3%); soft tissue injuries to the mouth (30.9%); and dentoalveolar trauma (9.7%). Over half of these children were wearing bicycle helmets. Of the 15 facial fractures (mandibular, nasal, and zygomatico-orbital), 10 were in children wearing helmets. CONCLUSIONS: Oral/maxillofacial injuries are frequent among child bicycle riders, even for those who wear Australian Standards-approved bicycle helmets. Bicycle helmets need design modifications (e.g., lightweight chin protectors) to more adequately protect the face and jaw.

Children and bicycles: what is really happening? Studies of fatal and non-fatal bicycle injury.

OBJECTIVES: The objectives of the study were to ascertain the causes of accidents, injuries, and deaths in children who ride bicycles. Fatality and injury rates were also studied in order to compare with other studies. METHODS: Two studies of children were undertaken in children aged less than 15 years. In the first (retrospective fatality study), children who died as a result of a bicycle incident during the period 1981-92 were reviewed. In the second (prospective injury study) data were obtained prospectively between April 1991 and June 1992 about children who were injured while riding a bicycle and treated at a public hospital in Brisbane. RESULTS: Study 1: fatality rates for boys were twice those for girls. The rate was highest for boys of 14 years in the metropolitan area at 6.23/100,000. All deaths involved vehicles, and the majority involved head injury or multiple injuries including head injury. Study 2: similar numbers of children were injured at onroad and off-road locations. Faculty riding was described by the rider or caregiver as the cause in 62.5% of cases. The most common time of injury was between 3 and 6 pm on both school and non-school days. Only 5.5% of all incidents involved a moving vehicle. CONCLUSIONS: Bicycle riding by children is a common cause of injury, particularly for boys. Equal numbers of injuries occurred on the road as at other locations. Faulty riding caused most accidents. Injury prevention for bicycle riders should involve not only compulsory wearing of helmets, but should also include education and training about safe riding habits, separation of motorised vehicles from bicycles, modified helmet design to incorporate facial protection, and improved handlebar design.

The clementine mission to the moon: scientific overview.

In the course of 71 days in lunar orbit, from 19 February to 3 May 1994, the Clementine spacecraft acquired just under two million digital images of the moon at visible and infrared wavelengths. These data are enabling the global mapping of the rock types of the lunar crust and the first detailed investigation of the geology of the lunar polar regions and the lunar far side. In addition, laser-ranging measurements provided the first view of the global topographic figure of the moon. The topography of many ancient impact basins has been measured, and a global map of the thickness of the lunar crust has been derived from the topography and gravity.

The mandibular infected buccal cyst--a reappraisal.

The mandibular infected buccal cyst was first described over ten years ago as a discrete pathological entity found only in children. The features of this lesion have been consistently described as a buccal location adjacent to erupting first molar teeth, a thick, hyperplastic non-keratinized epithelial lining, expansion of buccal cortex and associated infection. The paradental cyst had been described some years previously. This lesion was noted to have a similar non-specific hyperplastic non-keratinized epithelial lining but was described as being associated predominantly with third molar teeth in young adults. Recently investigators have called for the mandibular infected buccal cyst to be reclassified as a variant of the paradental cyst. In this paper, ten previously unreported cases of mandibular infected buccal cysts are presented and the evidence for their reclassification as paradental cysts is advanced.

Bicycle incidents in children--abdominal trauma and handlebars.

OBJECTIVES: To investigate the frequency and causes of bicycle related abdominal injuries in children and to examine the pattern of presentation. DESIGN: The study was a prospective study of bicycle related injury in children less than 15 years of age presenting to two paediatric hospitals (15 April-30 June 1992) and three general hospitals (1 August 1991-30 June 1992). RESULTS: In a series of 813 children, 41 sustained non-penetrating abdominal trauma due to a bicycle incident. In 21 cases, handlebar trauma was responsible. Ten of these children suffered life-threatening intra-abdominal injury. Handlebars with no plastic or foam covering of the metal ends were involved in all ten cases. In several of these cases, presentation to hospital was delayed and in others confirmation of the extent of injury took up to 48 hours. The length of hospital stay for those with significant intra-abdominal organ damage ranged from two to 156 days. CONCLUSIONS: Intra-abdominal trauma must be considered when dealing with children who are victims of bicycle trauma. Impact with handlebars may have occurred and some form of padded protection of handlebar ends is recommended unless their design can be suitably modified.

Mariner 9 television reconnaissance of Mars and its satellites: preliminary results.

At orbit insertion on 14 November 1971 the Martian surface was largely obscured by a dust haze with an extinction optical depth that ranged from near unity in the south polar region to probably greater than 2 over most of the planet. The only features clearly visible were the south polar cap, one dark, spot in Nix Olympica, and three dark spots in the Tharsis region. During the third week the atmosphere began to clear and surface visibility improved, but contrasts remained a fraction of their normal value. Each of the dark spots that apparently protrude through most of the dust-filled atmosphere has a crater or crater complex in its center. The craters are rimless and have featureless floors that, in the crater complexes, are at different levels. The largest crater within the southernmost spot is approximately 100 kilometers wide. The craters apparently were formed by subsidence and resemble terrestrial calderas. The south polar cap has a regular margin, suggsting very flat topography. Two craters outside the cap have frost on their floors; an apparent crater rim within the cap is frost free, indicating preferentia loss of frost from elevated ground. If this is so then the curvilinear streaks, which were frost covered in 1969 and are now clear of frost, may be low-relief ridges. Closeup pictures of Phobos and Deimos show that Phobos is about 25 +/-5 by 21 +/-1 kilometers and Deimos is about 13.5 +/- 2 by 12.0 +/-0.5 kilometers. Both have irregular shapes and are highly cratered, with some craters showing raised rims. The satellites are dark objects with geometric albedos of 0.05.