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Creating guidelines for the approximation of the eye and periorbital regions of South Africans using cone beam computed tomography scans

Thesis (PhD(Anatomy))--University of Pretoria, 2024.

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Other Authors: Oettlé, Anna Catherina
Format: Thesis
Language:English
Published: University of Pretoria 2024
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access_status_str Open Access
author2 Oettlé, Anna Catherina
author_browse Oettlé, Anna Catherina
author_facet Oettlé, Anna Catherina
collection Thesis
dc_rights_str_mv © 2023 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Thesis (PhD(Anatomy))--University of Pretoria, 2024.
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id oai:repository.up.ac.za:2263/97073
institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:37:48.227Z
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provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2024
publishDateRange 2024
publishDateSort 2024
publisher University of Pretoria
publisherStr University of Pretoria
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source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/97073 Creating guidelines for the approximation of the eye and periorbital regions of South Africans using cone beam computed tomography scans Oettlé, Anna Catherina duplessis.son@gmail.com L'Abbé, Ericka Noelle Ridel, Alison Fanny van der Walt, Soné UCTD Orbital dimensions Palpebral fissure shape Ocular position Prediction equations Prediction model Biological profiling Facial approximation Virtual Sculpture method Automatic approximation Sustainable Development Goals (SDGs) SDG-03: Good health and well-being Health Sciences theses SDG-03 SDG-16: Peace, justice and strong institutions Health Sciences theses SDG-16 Thesis (PhD(Anatomy))--University of Pretoria, 2024. Introduction: South Africa is experiencing a rise in unidentified remains yearly, and due to poor access to healthcare and illegal immigration, standard identification methods often fail. The foundational data used to reconstruct South African faces are based on North American cadavers which result in inaccurate reconstructions. This study aimed to create guidelines for approximating the eyeball and periorbital structures for South African groups using cone-beam computed tomography (CBCT) scans. Methods: Retrospective CBCT scans of 206 South African adults (45 black females, 52 black males, 57 white females, and 52 white males) were included in the study, of which 187 had open eyes (32 black females, 51 black males, 52 white females, and 52 white males). Three-dimensional landmarks were placed manually on the hard- and soft-tissue renderings of the face and skull as well as the outline of the eyeball in 2D using the MeVisLab © v.3.0.2 software. The 3D coordinates of these landmarks were used to calculate the linear dimensions of the orbit, eyeball, palpebral fissure, and the position of the eyeball in relation to the orbital rim. Predictive equations and predictions based on proportionality for the position of the eyeball in relation to the orbital rim, eyeball and palpebral fissure dimensions were derived from these linear dimensions. The effect of sex and population affinity on the shape of the orbit and palpebral fissure was investigated using geometric morphometric methods (GMM). The second part of the study entailed the creation and validation of prediction models based on the relationship between shape of the bony orbit and palpebral fissures using an automatic landmarking method. Results: Sex and population affinity significantly affected the dimensions and shape of the orbit, eyeball and palpebral fissures. Black females had significantly smaller eyeballs which protruded more from the superior orbital margin than the other sex-population groups. Eyeball position, eyeball dimensions and palpebral fissure dimensions could be predicted with greater accuracy based on proportionality compared to linear regression formulae. Variations in the palpebral fissure dimensions in black South Africans were driven by shape, while it was driven by size in white South Africans. Population affinity had a greater effect on the shape of the orbital region and palpebral fissures than on the linear dimensions. The shape analysis based on the automatically placed landmarks concurred with this finding which resulted in the accurate prediction of the open eye from the underlying bony tissue with a small measurement error, especially when population affinity was added as a factor. Conclusion: When reconstructing South African faces, it should be noted that black South African females had significantly smaller eyeballs compared to all other groups, while the eyeball protruded more in the vertical plane in black South Africans than white South Africans. Black compared to white South Africans had a greater inner canthal distance and less upward slanting palpebral fissures. Instead of depending on normative dimensions, the palpebral fissure and eyeball position can be predicted based on the morphology of each individual without considering sex or population affinity. The open eyelids could be accurately predicted from the underlying bony tissue for the use in automatic facial approximations. These prediction results should be combined with prediction models of other facial features to create accurate, objective and less time-consuming automated facial approximations of South Africans. n/a Anatomy PhD (Anatomy) Unrestricted Faculty of Health Sciences SDG-16:Peace,justice and strong institutions 2024-07-17T08:59:01Z 2024-07-17T08:59:01Z 2024-09-03 2024-05-31 Thesis * S2024 http://hdl.handle.net/2263/97073 10.25403/UPresearchdata.26310925 en © 2023 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle UCTD
Orbital dimensions
Palpebral fissure shape
Ocular position
Prediction equations
Prediction model
Biological profiling
Facial approximation
Virtual Sculpture method
Automatic approximation
Sustainable Development Goals (SDGs)
SDG-03: Good health and well-being
Health Sciences theses SDG-03
SDG-16: Peace, justice and strong institutions
Health Sciences theses SDG-16
Creating guidelines for the approximation of the eye and periorbital regions of South Africans using cone beam computed tomography scans
title Creating guidelines for the approximation of the eye and periorbital regions of South Africans using cone beam computed tomography scans
title_full Creating guidelines for the approximation of the eye and periorbital regions of South Africans using cone beam computed tomography scans
title_fullStr Creating guidelines for the approximation of the eye and periorbital regions of South Africans using cone beam computed tomography scans
title_full_unstemmed Creating guidelines for the approximation of the eye and periorbital regions of South Africans using cone beam computed tomography scans
title_short Creating guidelines for the approximation of the eye and periorbital regions of South Africans using cone beam computed tomography scans
title_sort creating guidelines for the approximation of the eye and periorbital regions of south africans using cone beam computed tomography scans
topic UCTD
Orbital dimensions
Palpebral fissure shape
Ocular position
Prediction equations
Prediction model
Biological profiling
Facial approximation
Virtual Sculpture method
Automatic approximation
Sustainable Development Goals (SDGs)
SDG-03: Good health and well-being
Health Sciences theses SDG-03
SDG-16: Peace, justice and strong institutions
Health Sciences theses SDG-16
url http://hdl.handle.net/2263/97073