Cranial base flexion has been used extensively as a baseline or standard from which to interpret differences in craniofacial growth and morphology. Lateral cephalometric radiographs of 414 adults representing seven samples from around the world were compared for variation in cranial base and facial morphology. The samples represent Australian Aboriginal, New Zealand Maori ( Polynesian ), Thai, Chinese, white American, African Sotho / Xhosa / Zulu and African Khoi / San populations. Seven angles of cranial base flexion, five craniofacial angles and nine cranial base and facial dimensions were measured on tracings of lateral cephalometric radiographs. Numerous significant correlations were found between cranial base flexion angles, craniofacial angles and dimensions of the cranial base and craniofacial skeleton. A positive correlation was found between the orientation of the foramen magnum, clivus and the anterior cranial base, with a negative correlation between these angles and the orientation of the hard palate. There was also a parallel relationship between the orientation of the foramen magnum and the anterior cranial base ( measured from pituitary point to nasion ). Cranial base flexion, craniofacial angles and dimensions differed significantly between some samples. Despite this, there was no evidence of distinct facial types between samples. Multivariate statistics revealed some discrimination between some samples for dimensions ; however, if angles were used alone, less than 50 % of individuals could be correctly assigned to their sample of origin. Most of the variation could be attributed to variation between individuals, rather than variation between samples. The range of variation in cranial base flexion is considerable, and needs to be taken into account when comparing samples. Flexion of the cranial base is generally insufficient to distinguish people from different geographic samples. The functional and evolutionary significance of the relationship between the orientation of the foramen magnum and cranial base flexion is discussed for its potential usefulness as a reference line for interpreting craniofacial morphology. / Thesis (Ph.D.)--Medical School and Dental School, 2005.

published_or_final_version / Dentistry / Master / Master of Dental Surgery

Data on the three?dimensional (3?D) morphology of normal faces and facial deformities as well as objective techniques for evaluating postoperative changes are currently unavailable. With the advent of stereophotography and cone?beam CT (CBCT), it is possible to acquire 3?D images of soft and hard tissues of the maxillofacial complex. A series of studies were conducted aimed at 1) establishing 3?D facial anthropometric norms for Hong Kong young adults, 2) determining 3?D facial anthropometric features in skeletal Class II and III deformities, 3) characterizing the oropharyngeal space in Class II and III skeletal deformities, 4) exploring clinical applications of 3?D colour maps, 5) establishing a non?invasive technique for estimating serial volume changes and 6) creating virtual craniofacial models by fusing 3?D photographs and CBCT images. Study 1: A stereophotographic system was used to capture 3?D images of 103 Hong Kong Chinese young adults with normal balanced faces. An anthropometric analysis protocol with linear, angular and proportional measurements was developed to establish a normative database and quantify dysmorphology. The Hong Kong Chinese norms were distinct from Caucasians, especially with regard to ocular and nasal measurements. Facial height and nasolabial measurements differed significantly between Hong Kong males and females. Study 2: Anthropometric analyses of 3?D facial images from 41 skeletal Class II and 43 Class III subjects were performed. The Class II subjects had increased lower facial height compared with Class III, who had longer total facial heights and narrower faces. While Class II deformity primarily resulted from mandibular deficiency with a normal maxilla, Class III presented as combined midfacial hypoplasia and mandibular hyperplasia. Study 3: Anthropometric characteristics of the oropharygeal space in skeletal Class II and III were evaluated using 62 CBCT scans. The retroglossal (RG) and retropalatal (RP) volumes and average cross sectional areas were significantly larger in Class III than Class II skeletal deformity. The RP compartment was larger but less uniform than the RG compartment in both Classes. Study 4: 3?D photographs or CBCT images acquired at two different time points were superimposed using a common unaffected area. 3?D colour maps were generated depicting distance differences between superimposed images in a graphical format. These maps were used as an objective tool for treatment planning and assessing outcomes after orthognathic surgery, bimaxillary distraction and facial trauma. Study 5: 3?D photogrammetry was employed for planning soft tissue expansion (STE) and transplantation of a vascularised scapular flap in hemifacial microsomia. This technique facilitated the identification of extent and degree of tissue deficiency, selection of the appropriate tissue expander, monitoring volumetric changes during STE and estimation of the free flap dimensions. Study 6: 3?D facial photographs and CBCT scans of 29 subjects were merged to create virtual craniofacial models with natural surface texture. Accuracy was assessed with 3?D colour maps and Root Mean Square (RMS) error. The CBCT and 3?D photographic data were integrated while minimizing average RMS error to 0.441mm. These virtual composite craniofacial models permitted concurrent 3?D assessment of bone and soft tissue. / published_or_final_version / Dentistry / Doctoral / Doctor of Philosophy

published_or_final_version / Dentistry / Master / Master of Dental Surgery

published_or_final_version / Biochemistry / Master / Master of Philosophy

Indiana University-Purdue University Indianapolis (IUPUI) / Frontonasal malformation, FNM, was first described by Hoppe in 1859. FNM is an anomaly that is characterized by ocular hypertelorism, broad nasal root, lack of a nasal tip, V-shaped hair, prolongation onto the forehead (widow's peak), anterior cranium bifidum occultum, median facial cleft affecting the nose, upper lip, and/or palate, and uni- or bilateral clefting of the ala nasi. The anomalies noted in FNM may be explained as a single malformation. If the nasal capsule fails to develop properly, the primitive brain vesicle fills the space normally occupied by the capsule, thus producing anterior cranium bifidum occultum, an arrest in the positioning of the eyes, and a lack of formation of the nasal tip. The condition presents clinically with variable expressions as sporadic cases and infrequently in familial cases. The present study is the first attempting to quantify and characterize FNM via anatomic radiographic measurements. The lateral (LA) and posterior-anterior (PA) cephalometric radiographs of twenty-four individuals, both sporadic and familial, with FNM were analyzed for comparison of linear and angular measurements with previously published data of a "normal," i.e. unaffected, population standard. Usual and customary cephalometric points were identified and located, then digitized into the computer. Twenty-nine measurements included the previously diagnosed anomalous features of hypertelorism, medial nasal cavity, and palatal shelves, as well as other facial features. The radiographs of individuals with FNM have anatomic features that are unusual and distinct to the specific malformation. The data from this research suggest that patients with FNM, regardless of a genetic or sporadic predisposition, have a midface deficiency in height and depth, an increased interorbital width with possible increased orbital socket width, and a longer zygomatic buttress. Also, the familial cases tend to have a flatter cranial base than the sporadic cases. Furthermore, the familial patients might be a different type of FNM since this subgroup shows narrower zygomatic widths. The patients with surgical procedures demonstrated improvement different from the growth of those patients who did not have surgery. The hypothesis that the facies of a patient with frontonasal malformation is different from the "normal" control population is supported by this research. The differences between the familial and sporadic patients tend to support the general theory that genetic predisposition is less severe than FNM that occurs randomly.

Dissertation (PhD)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: Introduction: Fetal alcohol syndrome (FAS) consists of multi-system abnormalities and is caused by the excessive intake of alcohol during pregnancy. The teratogenic effect of alcohol on the human fetus has now been established beyond reasonable doubt and FAS is the most important human teratogenic condition known today. The syndrome, first described by Lemoine in1968 in the French literature and in the English literature by Jones and Smith in 1973, has since been corroborated by numerous animal and human studies. This study has grown out of several epidemiological, prenatal and infant studies in areas of the Western Cape that are currently being undertaken by the Foundation for Alcohol Related Research (FARR). Preliminary data from studies in Wellington have confirmed that a significant proportion of school-entry children have FAS. The prevalence ofF AS in this community exceeds that for Down syndrome by a factor of30 times. The frequency ofFAS in high-risk populations of the Western Cape is the highest reported anywhere in the world. With this background, and the paucity of FAS literature related to dentistry, the aim of this study was to determine the craniofacial and oral manifestations ofF AS in a sample of school-going children in the Western Cape. Methodology: This study is a descriptive, case-control, cross-sectional study using a random cluster sampling method. On the day of examination, children were weighed, and their height and head circumference were measured. They then had photographs and radiographs taken, followed by an oral examination. For each child, the following information was recorded on the data capture sheet: date of birth, gender, head circumference, weight and height, enamel opacities, dental fluorosis, plaque index, gingival bleeding index, dentition status, oral mucosal lesions and dentofacial anomalies. Results: The total sample of90 children with diagnosed FAS and 90 controls, were matched for age, gender and social class. There were no significant age differences between the two groups (p=0.3363) and the mean ages were 8.9 and 9.1 for the FAS and control groups respectively. Head circumference (HC) differed significantly between the two groups (p<O.OOO 1) and the three photographic diagnostic measurements were all influenced by head circumference. The prevalence of enamel opacities between FAS and controls was not significantly different and averaged around 15% for both groups. The opacities were found largely in the maxillary central incisor and lower first molar teeth. More than three quarters of both the cases and the controls demonstrated the presence of plaque and almost two thirds demonstrated gingival bleeding on probing. FAS patients had statistically significantly (p<O.OO 1) more dentofacial anomalies than the controls. The mean dmft score for the FAS sample was slightly higher, though not significantly different from that of the controls and the decayed component (d) made up the largest part of the index in both groups. None of the FAS children had any missing or filled teeth, and in the case of the controls these were also rarely found. Thirty nine children (21.67%) of the total sample were caries-free. Discussion: This study represents one of the largest sample sizes documenting the craniofacial and oral and dental manifestations of the FAS to date. Forty two per cent of the FAS sample manifested growth retardation and this was statistically significant (p<O.OOOl) when compared to their controls. Analysis of the face using anthropometry supports many of the previous clinical descriptions of the effects of neonatal alcohol exposure and offers some new perspectives on the FAS facial phenotype. The characteristic dysmorphic facial features found included ptosis of the upper eyelids, epicanthic folds, short upturned nose, thin vermillion border of the upper lip and a smooth philtrum. Overall the analysis of the caries data for this study in respect of differences between cases and controls was found to be unremarkable. The lack of difference in the primary and permanent dentitions between the cases and controls could have been anticipated in this population due to the high prevalence of dental caries among children from the Western Cape. The FAS children showed significantly lower dental ages when compared to the controls. Dental maturation has previously been shown to be mildly, but consistently, delayed in children with delayed development and therefore this is a not surprising finding for the FAS children in this study. Differences between skeletal age and chronological age were noted for both boys and girls, but as a whole, in the present study groups (FAS and controls) showed little variation in skeletal development. Measurements related to the face height and mandibular size appear to be the most important in distinguishing the FAS children from the controls. Most (5 out of8) of the discriminating linear measurements studied lie in the front of the skull area. Most of the discriminating measurements are vertical measurements and only two of the measurements are lines between soft tissue points. When comparing the photographic analyses of the facial features versus the cephalometric assessments; the four facial features most typical of aF AS child had a Positive Predictive Value (PPV) of92% and a Negative Predictive Value (NPV) of90% and the eight linear measurements from the cephalometric analyses had a PPV of 92% and a NPV of 95%. One can therefore conclude that the external facial features are probably more reliable in discriminating between the two groups than the cephalometric measures. For further analyses, other models where a single angular measurement explains a combination of linear measurements need to be investigated. This might further improve the discriminating abilities of the cephalometric measurements as a whole. Conclusions: This study has shown the importance of the oral and craniofacial features ofFAS. FAS can no longer be viewed as just a rare and peculiar childhood disorder. Awareness and recognition of children with FAS is important so that they can be correctly diagnosed and referred appropriately. Prevention of the secondary disabilities and most importantly, the prevention of FAS in subsequent programmes can be planned. The dentist who treats children with FAS must recognise that such patients might be emotionally and mentally handicapped and may make treatment difficult and there may be a need for the child to be treated with behaviour modification and/or premedication before restorative treatment. The dentist should also be aware of the need for an accurate medical history, and possible medical consultations, before treatment can be undertaken safely. / AFRIKAANSE OPSOMMING: Fetale alkoholsindroom (FAS) bestaan uit multisisteem abnormaliteite en word veroorsaak deur oormatige inname van alkohol tydens swangerskap. Die teratogeniese uitwerking van alkoholop die menslike fetus word nie meer betwyfel nie en FAS is die belangrikste menslike teratogeniese toestand tans bekend. Die sindroom, soos aanvanklik deur Jones en Smith in 1973 beskryf, is sedertdien deur vele studies op mens en dier bevestig. Hierdie studie het gegroei uit vele epidemiologiese-, prenatale- en kleuterstudies in dele van die Weskaap wat tans onderneem word deur die Stigting vir Alkoholverwante Navorsing. Voorlopige data van die studies in Wellington bevestig dat 'n betekenisvolle deel van skoolbeginners FAS het. Die prevalensie van FAS in hierdie gemeenskap oortref dié van Down se sindroom met 'n faktor van 30. Die frekwensie van FAS in die Weskaap is die hoogste wat in die wêreld gerapporteer is. Met hierdie agtergrond, en die skaarste aan FAS literatuur wat op tandheelkunde betrekking het, was die doel van hierdie studie om die kraniofasiale en mondmanifestasies van fetale alkoholsindroom in 'n monster van skoolkinders in die Weskaap te ondersoek. Metodologie: Hierdie studie was 'n beskrywende, gevallebeheerde deursneestudie waarin 'n lukrake gebondelde monstermetode gebruik is. Op die dag van die ondersoek is die kinders geweeg en hulle lengte en kopomtrek bepaal. Hierna is foto's en x-straalopnames geneem, gevolg deur 'n mondondersoek. Die volgende inligting is vir elke kind aangeteken: geboortedatum, geslag, kopomtrek, massa en lengte, glasuur-opasiteite, tandfluorose, plaakindeks, gingivale bloedingsindeks, gebitstatus, mukosale letsels en dentofasiale anomalieë. Resultate: Die totale monster, bestaande uit 90 kinders met gediagnoseerde fetale alkoholsindroom en 90 bypassende kontroles, is vergelyk ten opsigte van ouderdom, geslag en sosiale klas. Daar was geen betekenisvolle ouderdomsverskille tussen die twee groepe nie (p- =0.3363). Kopomtrek het betekenisvol tussen die twee groepe verskil (p<0.0001), en die drie fotografiese diagnostiese afmetings is almal beïnvloed deur kopomtrek. Die prevalensie van glasuur-opasiteite tussen die FAS- en kontrolegroep was nie betekenisvol nie en het rondom 15% vir beide gewissel. Die opasiteite is hoofsaaklik gesien in maksillêre sentrale snytande en mandibulêre eerste molare. Meer as driekwart van beide groepe het plaak getoon, en byna tweederdes het gingivale bloeding met sondering gehad. Die gevallegroep het statisties betekenisvol meer (p<O.OO1) dentofasiale anomalieë getoon. Die gemiddelde dmft telling vir die FAS groep was effens hoër, alhoewel nie betekenisvol nie, as die kontrolegroep, en die "delayed" (vertraagde erupsie) komponent (d) het die grootste deel van die indeks uitgemaak in beide groepe. Geen van die FAS kinders het enige afwesige tande (m) of hers telde tande (f) gehad nie, soos ook gevind in die kontrolegroep. Nege-en-dertig kinders (21.67%) van die totale monster was kariesvry. Bespreking: Hierdie studie verteenwoordig een van die grootste monstergroottes tot op datum waarin ondersoek ingestel is na die kraniofasiale en mond- en tandmanifestasies van die fetale alkoholsindroom. Twee-en-veertig persent van die FAS monster het vertraagde groei getoon en dit was statisties-betekenisvol (p<O.OOOl)vergeleke met die kontrolegroep. Antropometriese analise van die gesig steun die vele kliniese beskrywings van neonatale blootstelling aan alkohol, en bied ook nuwe perspektiewe op die FAS gesigsfenotipe. Die kenmerkende dismorfiese gesigseienskappe wat gevind word, sluit ptose van die boonste ooglede, epikantusvoue, kort opgedraaide neus, dun vermiljoen rand van die bolip en 'n gladde filtrum in. In die geheel was die analise van die karies data ten opsigte van verskille tussen gevalle en kontroles onopvallend. Die afwesigheid van 'n verskil in die primêre en sekondêre gebitte in die gevalle en kontroles kon in hierdie bevolking verwag gewees het as gevolg van die hoë voorkoms van tandkaries onder kinders in die Weskaap. Die FAS kinders het betekenisvol-laer gebitouderdomme gehad as die kontrolegroep. Gebitmaturasie is in geringe maar deurlopende mate vertraag in kinders met vertraagde ontwikkelings, soos voorheen al getoon, en is daarom nie verbasend vir die FAS kinders in hierdie studie nie. Verskille tussen skeletale ouderdom en chronologiese ouderdom is gevind in beide seuns en dogters, maar in die geheel het dié huidige groepe (FAS en kontroles) min variasie in skeletale ontwikkeling getoon. Dit wil voorkom of afmetings wat verband hou met die gesigshoogte en grootte van die mandibula die belangrikste is om FAS kinders van die kontrolegroep te onderskei. Meeste (5 uit 8) van die diskriminerende lineêre afmetings wat bestudeer is, lê op die voorkant van die skedel. Die meeste is vertikale afmetings, terwyl slegs twee lyne tussen sagte weefsel punte. Waneer die fotografiese analises van die gesigseienskappe vergelyk word met die sefalometriese waarnemings, word gevind dat die vier gesigseienskappe tipies van 'n FAS kind 'n Positiewe Voorspelbare Waarde (PVW) van 92% en 'n Negatiewe Voorspelbare Waarde (NVW) van 90% het, en die agt lineêre afmetings vanaf die sefalometriese analise 'n PVW van 92% en 'n NPV van 95% het. Daar kan dus afgelei word dat die eksterne gesigseienskappe waarskynlik meer betroubaar is om te onderskei tussen die twee groepe. Vir verdere analise behoort ander modelle waar 'n enkel hoekige afmeting 'n kombinasie van lineêre afmetings verduidelik, ondersoek te word. Dit mag die diskriminerende vermoëns van sefalometriese afmetings in die geheel verder bevorder. Gevolgtrekking: Hierdie studie het die belang van orale en kraniofasiale eienskappe van FAS getoon. Die toestand kan nie langer as 'n seldsame en eienaardige aandoening van kinders beskou word nie, en bewustheid en herkenning van fetale alkoholsindroom pasiënte is belangrik sodat hulle korrek gediagnoseer en op gepaste wyse verwys kan word. Die tandarts wat FAS pasiënte behandel, moet besef dat sulke pasiënte emosioneel en geestelik belemmer mag wees en dus hantering en behandeling bemoeilik. Daar mag 'n behoefte ontstaan vir gedragsmodifikasie enlofpremedikasie voor herstellende behandeling. Verder moet die tandarts bewus wees van die behoefte aan 'n akkurate mediese geskiedenis, en moontlik konsultasie met 'n geneesheer, voor behandeling veilig ingestel kan word.

published_or_final_version / Dentistry / Master / Master of Dental Surgery

published_or_final_version / abstract / Biochemistry / Doctoral / Doctor of Philosophy

This study investigated the interactions of facially deformed infants (FD) with their mothers compared to a facially nondeformed control group (FND). All mother-infant dyads were videotaped for 10 minutes during a free play period. Mothers were instructed to spend time with their baby as they normally would. The videotaped interactions of 14 FD dyads and 14 FND dyads were rated by five raters for quality of interactions, amount of vocalization, touch, and face-to-face gaze. The infants were rated on their level of attractiveness from polaroid pictures and videotapes. Mothers also completed a questionnaire which assessed their infants' temperament. Three of the studies' four hypotheses were confirmed. First, the more attractive an infant was, the better his/her interactions with the mother were judged to be. Second, FD infant dyads were rated as significantly poorer in quality of interaction than FND dyads, although FD* dyads did not spend significantly less time vocalizing, touching, or in face-to-face gaze as predicted. A significantly higher percentage of FD infants were judged as having difficult temperament relative to FND infants. Finally, as predicted it was found that infants with difficult temperaments were more likely to exhibit poorer quality interactions than infants with less difficult temperaments. These results have important implications for providing anticipatory guidance to caregivers of FD infants. Without intervention, FD infants appear at risk for subsequent developmental problems stemming from disrupted early mother-infant interactions. Future research should focus on these interactions soon after the infant's birth, attempt to determine if FD infants' emotions can be reliably understood from their facial expressions (as has been found in normal infants) and extend the current research paradigm to include fathers of FD infants.