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18. Best clinical practice guidance for prescribing dental radiographs in children and adolescents: an EAPD policy document

Author

Kühnisch, J. Anttonen, V. Duggal, M.S. Spyridonos, M.L. Rajasekharan, S. Sobczak, M. Stratigaki, E. Van Acker, J.W.G. Aps, J.K.M. Horner, K. Tsiklakis, K.

Abstract

Background: The European Academy of Paediatric Dentistry (EAPD) proposes this best clinical practice guidance to help practitioners decide when and how to prescribe dental radiographs in children and adolescents. Methods: Four expert working groups conducted each a systematic review of the literature. The main subjects were radiation protection, intraoral dental radiography (bitewing and periapical radiographs), panoramic radiography (PR) and cone-beam computed tomography (CBCT). In addition, three workshops were held during the corresponding EAPD Interim Seminar in Chania (Crete, Greece) in 2019. On the basis of the identified evidence, all invited experts presented their findings and during the workshops aspects of clinical relevance were discussed. Results: Several clinical-based recommendations and statements were agreed upon. Conclusion: There is no or low-grade evidence about the efficacy of dental radiographic examinations in young populations. The given recommendations and rationales should be understood as best clinical practice guidance. It is essential to respect the radiological principles of an individualized and patient-specific justification. When a dental radiograph is required, its application needs to be optimized, aiming at limiting the patient’s exposure to ionising radiation according to the ALADAIP principle (As Low As Diagnostically Achievable being Indication-oriented and Patient-specific). © 2019, European Academy of Paediatric Dentistry.

Published
2020

28. Structure and function of the codfish ear

Author

Horner, K.

Subjects
590, Zoology
Abstract

The general anatomy of the codfish ear was examined in order togain an insight into the mode of hair cell stimulation. The ability to discriminate between frequencies in the apparent absence of a mechanical frequency analyser; and the directional hearing capabilities of codfish in the apparent absence of adequate interaural time, phase and intensity cues were the two main problems investigated.Using extracellular recording techniques, single units were recorded in the primary afferent fibres from various rami of the auditory nerve. The units were classed according to the types of spontaneous activity displayed. The frequency response of each type of unit was investigated by examining the change in spikes/second, spikes/stimulus cycle, and the degree of synchrony with the stimulus waveform, over a range of frequencies, at different stimulus amplitude levels. The directional characteristics of the units were investigated by rotating the fish relative to a fixed sound source, while recording the change in the auditory response. Central nervous processing of binaural sound stimuli was investigated by interrupting the auditory response, applying an electrical block to one or other of the two posterior saccular rami.The results are discussed in the light of the current state of knowledge of hearing in fish.

Published
1980

46. Shape optimization of dental implants.

Author

Shi L, Li H, Fok ASL, Ucer C, Devlin H, and Horner K

Abstract

Purpose: The purpose of this study was to derive alternative implant shapes which could minimize the stress concentration at the shoulder level of the implant. Materials and Methods: A topological shape optimization technique (soft kill option), which mimics biological growth, was used in conjunction with the finite element (FE) method to optimize the shape of a dental implant under loads. Shape optimization of the implant was carried out using a 2-dimensional (2D) FE model of the mandible. Three-dimensional (3D) FE analyses were then performed to verify the reduction of peak stresses in the optimized design. Results: Some of the designs formulated using optimization resembled the shape of a natural tooth. Guided by the results of the optimization, alternative implant designs with a taper and a larger crestal radius at the shoulder were derived. Subsequent FE analyses indicated that the peak stresses of these optimized implants under both axial and oblique loads were significantly lower than those observed around a model of commercially available dental implant. Conclusion: The new implant shapes obtained using FE-based shape optimization techniques can potentially increase the success of dental implants due to the reduced stress concentration at the bone-implant interface. [ABSTRACT FROM AUTHOR]

Published
2007

50. Radiovisiography for imaging root canals: an in vitro comparison with conventional radiography.

Author

Shearer, A. C., Horner, K., and Wilson, N. H. F.

Subjects
MEDICAL imaging systems, DENTAL pulp cavities, ENDODONTICS, DIGITAL image processing, DENTAL radiography, RADIOGRAPHY, DETECTORS, SCIENTIFIC photography, MEDICAL photography
Abstract

Radiovisiography is a rapid, low-dose, digital imaging system that utilizes a small, intraoral sensor in place of radiographic film. Because of these characteristics, it may be particularly suitable for use in endodontics. Consequently radiovisiography and conventional film radiography for the imaging of root canals were compared in vitro. There was no statistically significant difference between the percentage of length of root canal visible on conventional film and that visible on radiovisiographic images. Thus, radiovisiography may be considered to be of equal value to conventional film radiography for the imaging of root canal systems in vitro. [ABSTRACT FROM AUTHOR]

Published
1990

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