RESEARCH

Yong-Hee Chun and Joseph Wallace recipients of this year's Dziewiatkowski Award.

A fourth-year candidate in the School of Dentistry's Oral Health Sciences / PhD program, and a fifth-year PhD candidate in the Depart-ment of Biomedical Engineering who is working in SOD laboratories, were the recipients of this year's Dziewiatkowski Award.

Yong-Hee Chun and Joseph Wallace were presented with the award this spring by Jane Damren, daughter of the late Dr. Dominic Dziewiatkowski, for whom the award is named.

"Dr. J," as he was affectionately known, taught at the School of Dentistry for 18 years and directed the Dental Research Institute from 1967 to 1972. Damren and her husband, Samuel, established the Dziewiatkowski Award in 1988 to recognize dental students for their excellence in research. [DentalUM, Fall 2005, pages 74-75.]

Yong-Hee Chun

For the past two years, Chun, who earned a master's degree in periodontics from U-M in 2003, has been studying enamel formation under the mentorship of Drs. Jan Hu and James Simmer.

Chun's research focuses on ameloblastin, one of the three enamel matrix major proteins (the two others are amelogenin and enamelin) that are secreted by ameloblasts during dental enamel formation.

"Mature enamel is the hardest tissue in the human body, but the mechanism of the mineralization process itself is unknown," Chun said. "By identifying the proteins in the enamel matrix that are secreted by ameloblasts, and by analyzing their biochemical structure, eventually their biological function might become clear."

Chun is analyzing ameloblastin to try to determine if that protein is essential for enamel formation.

She said that understanding both the structure and function of enamel proteins "allows dentists to appreciate the complexity of enamel formation. Knowledge gained from the research may help counseling and treating patients with enamel malformations, such as amelogenesis imperfecta, an inherited enamel defect."

Chun, a clinical instructor in one of the School's comprehensive care clinics from 2001 to 2003 and from 2005 to the present, hopes her research will lead to a better understanding by patients about the etiology of their condition and the possibility of passing this along to their children. "If we know the components of enamel and its mineralization processes, we may be able to develop biomaterials to replace lost enamel," she said.

Joseph Wallace

For the last five years, Wallace has been researching the influences of genetic and mechanical factors on the composition and structure of mineralized tissues under the mentorship of Dr. David Kohn in the School's biomimetic and biomechanics laboratory.

"My investigations are focused on understanding changes that occur in bone in response to the addition and removal of the extracellular matrix protein, biglycan," he said. "Bones that lack biglycan develop deficiencies in quality and strength and fail to acquire normal peak bone mass, similar to what patients with osteoporosis experience."

Wallace said that his investigations have led to a discovery that exercise of moderate intensity and duration can lead to changes in pre-existing tissue without adding new bone.

"I'm seeking to learn if exercise can compensate for deficiencies caused by the absence of biglycan," he said. "If further research shows that to be the case, perhaps this could provide a unique and noninvasive way of preventing or treating bone diseases in humans."