Productivity analysis of the private general dental sector in Australia, 1983 to 1998/ Suzanna Mihailidis.

"April 2005"Bibliography: leaves 277-286.xii, 286 leaves : ill. ; 30 cm.Thesis (Ph.D.)--University of Adelaide, Dental School, 200

A Three-Dimensional Computed Tomography Analysis of Craniofacial Asymmetry in Malaysian Infants with Cleft Lip and Palate

Background: The application of three-dimensional computed tomography (3D CT) to analyse craniofacial morphology in individuals with cleft lip and palate (CLP) enables detailed assessments to be made of asymmetry in the region of the cleft and in regions distant from the cleft. The aim of this study was to compare craniofacial morphology in a sample of Malaysian infants with unoperated CLP with a control sample of unaffected Malaysian infants. Methods: The study sample comprised 29 individuals: 10 with unilateral CLP (UCLP), 5 with bilateral CLP (BCLP), 7 with cleft lip and primary palate (CLPP), and 7 with isolated cleft palate (ICP). The control sample consisted of 12 non-cleft (NC) infants. All subjects were between 0.4 and 12.2 months of age. Nine mid-facial and 4 nasal bone landmarks were located on 3D CT scans and compared to a midline reference plane, which was created using the landmarks basion, sella, and nasion. Unpaired t tests and F tests were used to compare means and variances between sample groups, whereas paired t tests were used for comparisons within the UCLP and NC groups. Results: Differences in variances of some mid-facial breadths and nasal bone dimensions were found in both male and female cleft groups when compared to the NC sample. In the UCLP group, some nasal bone and facial breadth dimensions were larger than in the NC sample and the nasal bone tended to deviate to the contralateral side of the cleft. Conclusion: CLP affects the size and orientation of the nasal bones and is associated with an altered morphology of some facial bones at positions distant from the region of the cleft.Nikki Tziavaras, Suzanna Mihailidis, Zainul Rajion, Asilah Yusof, Peter John Anderson, Grant Townsendhttp://www.bioline.org.br/abstract?id=mj10045&lang=e

The influence of chorion type on health measures at birth and dental development in Australian and Dutch twins: a comparative study

Chorion type may significantly influence the prenatal environment of twins. This study explored the associations between chorion type and gestational age, birth weight, birth length, and the timing of emergence of the first primary tooth in two populations of twins, Australian and Dutch. Additionally, we investigated the relationship between chorion type and birth weight discordance (BWD) in order to determine whether a significant relationship existed between discordance in birth weight and discordance in the timing of emergence of the first primary tooth. The two study samples consisted of 409 Australian twin pairs and 301 Dutch twin pairs, all of European ancestry. Data were collected through a combination of questionnaires and recording charts administered to the parents and through linkage with biological databases. In the Australian sample, monozygotic monochorionic (MZMC) twins experienced the shortest mean gestation time (35 weeks), the lowest mean birth length (46 cm) and the lowest mean birth weight (2.3 kg) compared with other twin groups. For the same variables in the Dutch sample, these trends with MZMC twinning were not observed. Chorion type did not significantly affect the mean timing of emergence of the first primary tooth in either sample. Monochorionicity was found to be significantly associated with BWD in both samples, but there was a significant association between BWD in MZMC twin pairs and timing of emergence of the first primary tooth only in the Australian sample. Results from this study support previous findings that the timing of emergence of the first primary tooth is influenced strongly by genetic factors and is well protected from environmental disturbances.Suzanna Mihailidis, Michelle Bockmann, Elise McConnell, Toby Hughes, Toos C. E. M. van Beijsterveldt, Dorret I. Boomsma, Minni McMaster, and Grant Townsen

Genetic, epigenetic, and environmental influences on dentofacial structures and oral health: Ongoing studies of australian twins and their families

The Craniofacial Biology Research Group in the School of Dentistry at The University of Adelaide is entering an exciting new phase of its studies of dental development and oral health in twins and their families. Studies of the teeth and faces of Australian twins have been continuing for nearly 30 years, with three major cohorts of twins recruited over that time, and currently we are working with twins aged 2 years old to adults. Cross-sectional data and records relating to teeth and faces of twins are available for around 300 pairs of teenage twins, as well as longitudinal data for 300 pairs of twins examined at three different stages of development, once with primary teeth, once at the mixed dentition stage, and then again when the permanent teeth had emerged. The third cohort of twins comprises over 600 pairs of twins recruited at around birth, together with other family members. The emphasis in this third group of twins has been to record the timing of emergence of the primary teeth and also to sample saliva and dental plaque to establish the timing of colonization of decay-forming bacteria in the mouth. Analyses have confirmed that genetic factors strongly influence variation in timing of primary tooth emergence. The research team is now beginning to carry out clinical examinations of the twins to see whether those who become colonized earlier with decay-forming bacteria develop dental decay at an earlier age. By making comparisons within and between monozygotic (MZ) and dizygotic (DZ) twin pairs and applying modern molecular approaches, we are now teasing out how genetic, epigenetic, and environmental factors interact to influence dental development and also oral health