AbstractThis thesis is divided into four Phases. The aim of each phase is to identify facial creases useful in human identification.In Phase 1, creases were analysed on peri- and post-embalmed cadavers in CAHID to establish whether or not there is any change to crease with facial bloating. Embalming was chosen to simulate effects seen on a bloated face during decomposition. The results suggested that creases are quite resilient and changes were only detected relating to creases located on the periphery of the face, particularly at areas where the skin is thick, such as at the cheek region. Two new creases not classified in literature were identified on the face; these creases were called vertical superciliary arch lines and the lateral nose crease. Manifestations of these creases were also seen on faces in Phase 2 and 3 of the research. Phase 2 focused on the application of facial creases for the identification of living individuals. Volunteers were obtained from the University of Aberdeen and University of Dundee. Phase 2 was divided further into Phase 2a and Phase 2b. Phase 2a focused on matching creases from video and photograph sources while Phase 2b focused on matching creases from 3D surface scans to face photographs. A higher match rate was obtained for Phase 2a, where the shadows of the creases on two different sources were similar, as compared to the 3D to 2D analysis in Phase 2b. A Bayesian conclusion scale was utilised to categorise the conclusion.Research in Phase 3 focused on establishing facial crease correlation with skull morphology. Material for the research was obtained from William Bass skeletal collection at the University of Tennessee which provided ante-mortem face photographs with related 3D skull surface scans. Superimposition of the creases on the face photographs with the skulls was conducted to enable the visual analysis of the crease location. The qualitative analysis indicated that the infraorbital crease follows the outline of the orbits in 52% of the total subjects. No correlation was obtained between the nasolabial fold (NLF) and the bony surface inferior to the location of the crease. However, the depth of the selected skeletal region indicated the NLF was detected in 95% of the subjects. Quantitative analysis was carried out with the aid of geometric morphometrics (GMM) to analyse the maxilla morphology to establish whether the morphology indicated crease morphology. Geometric morphometric analysis indicated that people with a strong NLF had a long and narrow maxillary region.
The conclusions obtained in Phase 3 were tested through a blind study in Phase 4. Analyses of the NLF and infraorbital crease were conducted on the Helmer skull collection available in CAHID. Ten skulls were provided to the researcher for analysis without related ante-mortem photographs. Once analyses were completed, the ante-mortem photographs were supplied and conclusions were obtained by comparing the crease reconstruction to the face photograph. Correct reconstruction was obtained in six of the ten specimens (60%). One case was inconclusive due to poor photograph quality though the location of the crease region appeared to be correct. The three inaccurate results showed an overestimation of the NLF strength, though the location of the crease manifestation was correct.
|Date of Award||2012|
|Sponsors||Ministry of Higher Education, Malaysia & Universiti Sains Malaysia|
|Supervisor||Caroline Wilkinson (Supervisor)|
- Facial creases
- Human identification