Thesis (M.D.S.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 114-138) Also available in print.

Thesis (M.D.S.)--University of Hong Kong, 1998. / Includes bibliographical references. Also available in print.

Thesis (M.D.S.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 114-138).

When it comes to studying organisms, having size independent measures for maturity are important for many aspects of organismal biology, and may be crucial for determining taxonomic affinity, and morphological signals associated with ontogenetic age (i.e., juvenile vs. adult) and sexual dimorphism. This is because the size of an organism can be the result of many factors that are not necessarily indicators of maturity (Chabreck and Joanen, 1979; Ferguson, 1984; Mazzotti et al., 1986; Deeming and Ferguson, 1989; Brandt, 1991). This problem is particularly pronounced when researchers are studying extinct species. The purpose of my research project was to investigate and understand patterns of morphological variation in the phytosaur premaxilla and maxilla and to determine the degree to which morphological variation is a result of ontogeny. For example, such patterns might include the number, size and location of alveoli or the presence of prenarial crests. I conducted this research by gathering information on the premaxilla and maxilla of all phytosaur elements present in the University of Texas at Austin Vertebrate Paleontology Lab collection. I then performed statistical analysis on the data, and compared my results to those of previous authors to see if I could identify any ontogenetic signal. I did not identify size-independent ontogenetic influence on morphology with certainty but I did find some possible features that merit additional investigation in future studies. Those include the presence of one to three diastemas located primarily at the anterior end of the premaxilla, a wide interpremaxillary fossa but small alveolar ridge, and alveoli whose size mirror the width of the premaxilla (for example wide areas in the premaxilla are associated with larger alveoli whereas narrow areas in the premaxilla are associated with smaller alveoli). My study also confirmed the previous findings of Hungerbühler (2002) that the alveoli of phytosaurs are heterodont and exist in three distinct location-specific patterns, and the work of other researchers that prenarial crests are present only in larger specimens (Camp, 1930; Ballew, 1986; Hungerbühler, 2002; Stocker, 2010). / text

published_or_final_version / Dentistry / Master / Master of Dental Surgery

Aim of study The aim of this clinical retrospective study is to evaluate the clinical outcomes of patients with transverse maxillary hypoplasia who underwent surgical assisted maxillary expansion (SARME) using a bone borne distractor in 2 different surgical centers. Patients and Methods This is a clinical retrospective cross‐sectional study of adult patients diagnosed with maxillary transverse hypoplasia and having had transpalatal distraction by SARME done in two surgical centers (Oral and Maxillofacial Surgery, The University of Hong Kong, Hong Kong and The Baruch Padeh Medical Center, Poriya, Israel) from January 2004 to December 2011. A total of 37 patients were identified. The mean age was 27.1. Each patient underwent a standard Le Fort I osteotomy with midline split with no mobilization under general anesthesia. A bone‐borne palatal distractor was fitted on the hard palate. The distractor was activated at a rate of 0.6mm per day following 5 ‐ 7 days of latency until the amount of expansion was reached according to plan. Occlusal radiographs and lateral cephalographs were obtained at pre‐expansion phase and regular postoperative intervals during the activation and consolidation period. Among the 37 patients, only 15 patients could be contacted by phone, mail or e‐mail and has agreed to participate in the cross‐sectional analysis. Clinical examination was performed and included the following: tooth vitality, tooth mobility, periodontal status and occlusion. Questionnaire was also given to patients to grade their experiences toward the treatment outcome. Results The mean transverse expansion achieved was 9.58mm. The TPD was removed from the patients in the ranged of 2 months to the longest 8 months (mean: 5.2 months). The distraction gap was gradually ossified by bone and then the teeth were aligned into the space achieving stable dental occlusion. No intra‐operative complications were recorded. Post‐operatively, 2 patients had to be re‐operated due to failure to activate the distractor. Others post‐operative complications encountered were pain, fixation screw loosening, insufficient distractor length, infection, asymmetric expansion and tooth migration into the distraction gap. These complications were well managed accordingly. Majority of the patients were satisfied with the treatment and will recommend it to others. Conclusions Correction of maxillary transverse hypoplasia using a transpalatal distractor can reliably achieve large bony expansion of the maxillary arch with few postoperative complications. / published_or_final_version / Dental Surgery / Master / Master of Dental Surgery

Diss. (sammanfattning) Göteborg : Univ. , 2008. / Härtill 5 uppsatser.

Thesis (M.D.S.)--University of Adelaide, Dept. of Dentistry, 1999. / Bibliography: leaves 342-392.

Thesis (M.S.)--University of Michigan, 1985.

Thesis (M.S.)--University of Michigan, 1985.