Re: Modification of a bite registration device.
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Equipment Design↗
Biomedical subjects
J W Ferguson
Publications and source records attributed to J W Ferguson.
Empirical evaluation of preservation methods for faecal DNA.
We evaluate the relative effectiveness of four methods for preserving faecal samples for DNA analysis. PCR assays of fresh faecal samples collected from free-ranging baboons showed that amplification success was dependent on preservation method, PCR-product size, and whether nuclear or mitochondrial DNA was assayed. Storage in a DMSO/EDTA/Tris/salt solution (DETs) was most effective for preserving nuclear DNA, but storage in 70% ethanol, freezing at -20 degrees C and drying performed approximately equally well for mitochondrial DNA and short (< 200 bp) nuclear DNA fragments. Because faecal DNA is diluted and degraded, repeated extractions from faeces may be necessary and short nuclear markers should be employed for genotyping. A review of molecular scatology studies further suggests that three to six faeces per individual should be collected.
Animals↗
Acute oral toxicity study of pyridostigmine bromide, permethrin, and DEET in the laboratory rat.
This study investigated the lethal interaction of pyridostigmine bromide (PB), permethrin, and DEET when given to adult male rats by gavage and was separated into two phases. Phase I determined the acute oral lethal dose-response relationship of each compound with the vehicle, propylene glycol. Phase II was divided into two portions: a dose-response study using probit units obtained from phase I [lethal dose (LD) 16, 30, 50, 70, and 84], and an interaction study that contained low levels (calculated LD16, additive LD32) of the two compounds while the concentration of the third compound was varied. Rats were fasted overnight, dosed, and observed for 14 d. A significant increase in lethality occurred when PB, permethrin, and DEET were given concurrently when compared to expected additive values. Furthermore, solutions containing PB and permethrin or PB and DEET also caused a significant increase in lethality when compared to expected additive values. This information suggests that lethality in this study was more than an additive effect.
Animals↗
Eruption of palatal canines following surgical exposure: a review of outcomes in a series of consecutively treated cases.
The records of a consecutive series of 72 patients who had undergone excisional exposure of one or both palatally displaced canines were reviewed. The purpose was to ascertain whether the canine(s) erupted spontaneously following surgery, whether orthodontically-assisted eruption was required or whether the procedure failed completely indicating the need for re-exposure. The results of the study suggest that the majority of canines will erupt once exposed and of those that fail to erupt completely most will still remain exposed to a sufficient extent to allow attachments to be bonded to the palatal surface.
Adolescent↗
Making the best use of consultant orthodontic services, Part 2: How to undertake the referral.
The previous article in this series dealt with the selection of patients who would benefit from referral to a consultant orthodontist. It is equally important to access consultant services in a manner which allows the referral to be processed efficiently. This paper discusses factors related to the actual mechanism of referral.
Correspondence as Topic↗
The stability of facial osteotomies.
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Humans↗
Direct bonding to unerupted teeth using light-cured adhesive.
A technique is described for bonding gold traction chain directly to the enamel surface of unerupted teeth using a visible light-cured adhesive. This method obviates the need for a bracket and relies on direct, rather than transmitted illumination.
Composite Resins↗
A comparison of consecutive orthodontic referrals seen by a consultant unit and specialist orthodontic practitioners.
It has been suggested that the consultant orthodontic service and specialist practitioner service should have different roles, with the former concentrating its treatment input on the management of severe malocclusions. In an attempt to determine whether referring dental practitioners appeared to be aware of these differences, 100 consecutive orthodontic referrals seen at a consultant orthodontist's clinic were compared and contrasted with the same number seen at each of four specialist orthodontic practices located in the same city, and within 4 miles of the consultant unit. Comparisons were made both on the basis of clinical information obtained from study models and from analysis of referral letters. The consultant sample contained a greater proportion of requests for treatment plans, but there were few differences in terms of the range and severity of the actual malocclusions referred to each of these specialist services. The implications of these findings are discussed in relation to possible future developments of orthodontic services in the U.K.
Community Dentistry↗
The assessment and treatment of anterior open bite.
There is no single management strategy for dealing with open bites, which vary greatly in presentation and severity. The general dental practitioner is recommended to assess treatment need on whether the open bite is a problem to the patient: if it is not, then no remedial treatment may be required. To aid the practitioner in the often difficult decision-making process, in this paper the possible causes of open bite malocclusion are reviewed, together with the methods currently available for treatment of this condition and the uncertainties inherent in the prognosis. The need for treatment is also discussed, to assist the general dental practitioner in deciding as to whether referral is necessary.
Combined Modality Therapy↗
Interactive effects of temperature and photoperiod on the daily activity and energy metabolism of pouched mice (Saccostomus campestris: Cricetidae) from southern Africa.
The daily activity and energy metabolism of pouched mice (Saccostomus compestris) from two localities in southern Africa was examined following warm (25 degrees C) and cold (10 degrees C) acclimation under long (LD 14:10) and short (LD 10:14) photoperiod. There was no differential effect of photoperiod on the daily activity or metabolism of pouched mice from the two localities examined, which suggests that reported differences in photoresponsivity between these two populations were not the result of differences in daily organisation. Nevertheless, there was a significant increase in metabolism at 10 degrees C, irrespective of photoperiod, even though seven cold-acclimatized animals displayed bouts of spontaneous torpor and saved 16.4-36.2% of their daily energy expenditure. All but one of these bouts occurred under short photoperiod, which suggests that short photoperiod facilitated the expression of torpor and influenced the daily energy metabolism of these individuals. As expected for a nocturnal species, the amount of time spent active increased following acclimation to short photoperiod at 25 degrees C. However, there was a reduction in mean activity levels under short photoperiod at 10 degrees C, possibly because the stimulation of activity by short photoperiod was masked by a reduction in activity during bouts of spontaneous torpor. Cold temperature clearly had an overriding effect on the daily activity and metabolism of this species by necessitating an increase in metabolic heat production and eliciting spontaneous torpor which over-rode the effect of short photoperiod on activity at an ambient temperature of 10 degrees C.
Activity Cycles↗
Cephalometric interpretation and assessment of facial asymmetry secondary to congenital torticollis. The significance of cranial base reference lines.
The anatomic basis of the facial asymmetry resulting from untreated congenital muscular torticollis is discussed, and an objective system for both clinical and cephalometric assessment and measurement is described. Symmetry is assessed by first defining a true midfacial line, which allows both measurement of existing asymmetry and planning for subsequent surgical correction, and which can be applied to clinical as well as radiologic analysis.
Adult↗
Surgical correction of the facial deformities secondary to untreated congenital muscular torticollis.
The facial asymmetry which develops in association with untreated congenital muscular torticollis is principally the result of a subcranial torsional rotation of the face toward the affected side. Principles of management are therefore to firstly release the sternomastoid muscle and achieve maximal improvement in head posture, followed by surgical straightening of the face by bimaxillary surgery and septorhinoplasty. The results of this approach in three patients are discussed and illustrated.
Adult↗
A potential role for costo-chondral grafting in adults with mandibular condylar destruction secondary to rheumatoid arthritis--a case report.
Little attention has been directed towards reconstruction of the mandibular condyles in adult patients with rheumatoid arthritis, other than with allogenic implants which are now known to cause serious complications. There is a relatively high incidence of condylar erosion and breakdown in rheumatoid arthritis, often leading to anterior open bite and retrognathia. Costochondral grafting does not appear to have been considered as a logical option for reconstruction, despite its high success rate in many other situations. A case is described of rapid bilateral condylar destruction occurring in a young woman with rheumatoid arthritis, leading to anterior open bite. Reconstruction was undertaken using bilateral costochondral grafts, giving an excellent clinical result which has been maintained over the follow-up period of two-and-a-half years. Radiologically complete healing of severe glenoid fossa erosion has taken place.
Adult↗
The safe practice of intravenous sedation in dentistry.
All clinicians who administer intravenous sedation should undergo appropriate training according to recognised guidelines. Such guidelines are now established in New Zealand through the joint endeavours of the New Zealand Dental Association, Royal Australasian College of Dental Surgeons, and the Australian and New Zealand College of Anaesthetists. It is essential that there be acceptable staff training and experience, that physical facilities and arrangements for emergency care are adequate, and that parameters for patient selection are adhered to. Adequate knowledge of pharmacology and the therapeutic indications for specific sedative drugs is necessary, and sedation procedures must be undertaken with appropriate monitoring. There are significant medico-legal aspects to this area of dental practice and these should be well recognised by all practitioners.
Adolescent↗
Diagnostic accuracy and observer performance in the diagnosis of abnormalities in the anterior maxilla: a comparison of panoramic with intraoral radiography.
An investigation was undertaken to assess the reliability of radiographic diagnosis of abnormalities of orthodontic significance in the anterior region of the maxilla from intraoral and dental panoramic tomograph (DPT) views. DPT films of 200 patients were scrutinised by two observers on two separate occasions, who also examined intraoral radiographs of the same patients. Sixty-three of these patients were selected because they had previously been diagnosed as presenting with a defined abnormality of orthodontic relevance, such as supernumerary teeth, absent incisors, etc. The remaining cases had been assessed as depicting normal radiographic appearances. Each radiograph was allocated a unique, randomly selected code number as the only means of identification. It was not possible for the observers to match the DPT to the corresponding intraoral films, and this information was only available to the principal investigator (JWF). Both observers were asked to record the presence or otherwise of any abnormalities at each observation of each radiograph, and to record their findings. The overall level of diagnostic accuracy and reproducibility was fairly high, and in general terms the DPT views were as reliable as the intraoral films with regard to the detection of abnormalities; however, there were significant differences between the observers. It was concluded that in many instances supplementary intraoral films would not contribute any additional information compared to the DPT and that selection criteria should be defined for the former.
Chi-Square Distribution↗
Immunohistochemical localisation of substance P in human parotid gland.
Based on the clinical observation that pain is experienced during parotid gland surgery under local anaesthesia, the presence of the sensory neuropeptide substance P (SP) was sought. Using a polyclonal antibody, the presence of SP was demonstrated by an indirect immunofluorescence technique, with rat parotid gland and spinal cord serving as controls. SP-containing neuronal elements occurred around acini, blood vessels and ducts. It is suggested that some of the SP-immunoreactive elements are the unmyelinated and thinly myelinated small diameter (A delta and C) fibres, which are regarded as the peripheral receptors for nociceptive information.
Adipose Tissue↗
Endotracheal tube damage during orthognathic surgery.
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Adult↗
Mucus-producing adenopapillary carcinoma of the oral cavity.
Mucus-producing adenopapillary carcinoma is a rare neoplasm of the oral cavity. The literature is reviewed and a case described, with histological and ultrastructural findings of a tumour which involved the upper lip and recurred following local excision.
Adenocarcinoma, Mucinous↗