Authorities are using the bottom tooth of the week-old infant abandoned in a plastic bag outside an apartment complex in Cypress, Texas, as a clue in the search for her parents.
The newborn's early tooth, seen in just one of 2,000 births, is a unique genetic trait that may prove to be a link to her family history, according to investigators.
The baby, named Chloe by rescuers, weighed just four pounds when she was found by a woman walking her dogs near the apartment complex.
"More than likely her mother didn't have any type of prenatal care," Estella Olguin, spokeswoman for Texas Child Protective Services, told ABC's "Good Morning America."
To aid in their investigation, police commissioned Texas sketch artist Lori Gibson to create a rendering of what her parents might look like by studying the newborn's features.
"The people would recognize that smile," Gibson told "Good Morning America," "It's a ready smile, and then all I had to do was put teeth."
Authorities said they are hoping Chloe's mother or other relatives come forward to claim the baby, or officially allow another family to take custody of the newborn. They plan to charge the parents if they can find them, police said.
Texas has an infant safe haven law, which allows mothers to anonymously give up their babies to designated locations where they can receive care until they are placed in a permanent home.
Texas was the first state to enact an infant safe haven law, which was passed in 1999. The laws, now adopted by many other states and known as "Baby Moses laws," are meant to provide mothers with an incentive not to abandon unwanted children, according to the U.S. Department of Health and Human Services.
Meanwhile, Harris County Sheriff's Department spokeswoman Christina Garza said once custody issues are resolved, "[Chloe] will be placed in a loving home."
"There is no shortage of people who want her," she said.