Defining a method to predict mouth morphology in edentulous skulls

Date
2022-04
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: Forensic facial depiction (FFD) is the process whereby a face is modelled to depict a face from an unknown deceased individual’s skull to assist with human identification. The field of FFD that has not been researched extensively, is the edentulous mouth, where edentulism refers to the condition of not having teeth. Therefore, this study attempted to establish whether a method could be produced to predict edentulous mouth morphology for FFD practice. To achieve this, Pearson’s correlation analysis was used and the relationship between the individual’s soft tissue measurements (somatometry) and skull measurements (osteometry) were analysed. Dentate patients, those with teeth, were also included in the study to understand the morphometric difference between the mouths of dentate and edentulous patients. Cone Beam Computer Tomography (CBCT) scans of n=63 patients were retrieved. This included 40 dentate patients (n=24 males and n=16 females) and 23 edentulous patients (n=7 males and n=16 females). The patients’ CBCT scans were retrieved from the Oral Health Centre of the University of the Western Cape’s Picture Archiving and Communication System. The morphometrics software, Stratovan CheckpointTM, was used to perform osteometry and somatometry on these scans. The somatometry of all patients included measuring soft tissue thicknesses (STTs) of the upper mouth as well as the patients’ lip height (LH) and philtrum length (PL). For the edentulous patients, the STTs included the mid-philtrum (H), and mid- upper lip margin (I). For the dentate patients, the STTs measured were the H, I, the upper incisor (II) and lateral supra-labiale (F). For osteometry, all patients’ skulls were measured to retrieve the following skull lengths: the bizygomatic breadth, basion-prosthion length, basion- gnathion length, maxillo-alveolar breadth, maxillo-alveolar length, nasion-prosthion, and the cranial base length. These lengths were then used to calculate the maxilla-alveolar (MAI), upper facial, subnasal gnathic (SGI), and gnathic indices. A Shapiro-Wilk test was performed, and it was found that all osteometry and somatometry were normally distributed. Therefore, the correlation analysis could be applied. For the edentulous patients, the correlation analysis was only applied to the female patients since the male group was below the suggested sample size for correlation analysis (n<10). The results found that no significant correlations exist between female edentulous mouth somatometry and osteometry. For the dentate males, significant correlations were identified in: the MAI, and II- right and II-left; GI and H; and SGI and LH. For the dentate females: SGI, and II-left, F-left, and LH. Based on this study, it cannot be concluded that osteometry is a good predictor of edentulous mouth morphology. Other factors may play a role in the results of this research such as the sample size and certain edentulous anomalies, for example, residual ridge resorption (RRR). In the dentate group, significant correlations were found since RRR did not affect these patients. Therefore, for future studies, it is suggested that a larger sample is retrieved that is strictly controlled for edentulous anomalies.
AFRIKAANSE OPSOMMING: Forensiese beelding van die gesig (FFD) is die proses waardeur ń onbekende persoon wat oorlede is se gesig gemodelleer word vanaf die persoon se skedel, vir die doel van om die persoon te identifiseer. Een deel van FFD wat nog nie omvattend nagevors is nie, is edentulisme, wat verwys na ń toestand van tandeloosheid. Die studie het dus ten doel gehad om ń metode daar te stel waarmee mondmorfologie weens edentulisme voorspel kan word. Dus, was Pearson se korrelasie-analise gebruik om die verhouding tussen die individu se sagteweefselafmetings (somatometrie) en skedelafmetings (osteometrie) te analiseer. Pasiënte met tande is ook by die studie ingesluit om die morfometriese verskille tussen die monde van pasiënte met tande, en edentuleuse pasiënte te verstaan. ń Studiepopulasie van n=63 pasiënte is ingesluit. Dit het 40 pasiënte met tande (n=24 mans en n=16 vrouens), en 23 edentuleuse pasiënte (n=7 mans en n=16 vrouens) ingesluit. Die pasiënte is met behulp van keëlstraal-rekenaartomografiese skanderings wat vanaf die Beeldings Argief- en Kommunikasiestelsel van die Tand- en Mondheelkunde hospitaal van die Universiteit van die Wes-Kaap verkry is, geanaliseer. Stratovan CheckpointTM sagteware is gebruik om die afmetings op hierdie skanderings te doen. Alle pasiënte se somatometriese afmetings het sagteweefseldeursnit (STTs), sowel as liphoogte (LH) en filtrumlengte (PL) ingesluit. Vir edentuleuse pasiënte het STTs die mid-filtrum (H) en mid-bolip-grens (I) ingesluit. Vir pasiënte met tande het STT afmetings die H en I, en afmetings van die boonste snytande (II) en laterale supra-labiale (F) area, ingesluit. Osteometriese afmetings van alle pasiënte se skedels is gedoen om die volgende te bepaal: bisigomatiese breedte, basion-prostion lengte, basion-gnation lengte, maksillo-alveolêre breedte, maksillo-alveolêre lengte, nasion- prostion hoogte, en die kraniale basislengte. Hierdie afmetings is gebruik om die maksillo- alveolêre- (MAI), boonste gesigs-, subnasale gnatiese- (SGI) en gnatiese indekse te bereken. ń Shapiro-Wilk toets het bepaal dat al die osteometrie en somatometrie normaal versprei is. Korrelasie analise kon dus toegepas word. Vir edentuleuse pasiënte is die korrelasie analise slegs toegepas op die vroulike pasiënte omdat die manlike groep minder as die voorgestelde steekproef grootte vir korrelasie analise (n<10), is. Uit dié resultate is gevind dat daar nie ń betekenisvolle korrelasie bestaan tussen die somatometrie en osteometrie vir vroulike edentuleuse monde nie. In manlike patiente met tande is betekenisvolle korrelasies identifiseer in die volgende: die MAI, en II-regs en II-links; GI en H; en SGI en LH. In vrouens met tande is betekenisvolle korrelasies identifiseer in die volgende: SGI, en II-links, F-links, en LH. Uit die studie kan die afleiding gemaak word dat osteometrie nie ń goeie metode is om die edentuleuse mond se morfologie te voorspel nie. Ander faktore kon ń rol speel in die resultate, soos die grootte van die populasie, en sekere anomalieë wat met edentulisme assosieer word, byvoorbeeld, residuele absorpsie van die alveolêre rand (RRR). In die groep met tande is ń betekenisvolle korrelasie gevind omdat RRR nie die pasiënte in die groep affekteer nie. Dus, vir toekomstige studies word voorgestel dat ń groter studiepopulasie gebruik word, met streng kontrole oor anomalieë wat met edentulisme geassosieer word.
Description
Thesis (MSc)--Stellenbosch University, 2022.
Keywords
Forensic anthropology, Biological anthropology, Edentulism, Toothlessness, Mouth morphology, Physical anthropology, Osteometry, Somatometry, Anthropometry, Skull indices, Skull index, UCTD
Citation