Children with cleft palate may face fewer painful surgeries and spend less time in orthodontic treatment thanks to a therapy developed at the University of California Los Angeles (UCLA) School of Dentistry. The procedure could alleviate a common complication of cleft palate, relapse from maxillary expansion, which reshapes the jaw to help patients speak without impediment.
“Relapse after palatal expansion is a major problem for children with cleft palate anomalies,” said Christine Hong, DMD, MS, first author of the study and assistant professor of orthodontics at the school. “Current therapeutic interventions for these children face a high failure rate. We need to develop a way to stabilize the palate. That’s how we began assessing potential components for this particular use.”
The therapy combines estrogen with nanodiamonds that are so small, 3 million of them could span the diameter of a penny. These miniscule particles result from mining and refining operations and have already demonstrated promise in an array of uses, according to the researchers, including medical imaging, dentistry, and chemotherapy.
Typically, patients with cleft palate can expect years of orthodontic treatment and multiple surgeries starting just months after birth. Expanding the roof of the mouth often is a first step in achieving clear speech. But because the cleft itself has diminished ability to grow bone, the palate later regresses in more than 80% of these patients. This relapse can have a physical, psychological, and financial toll as patients face additional orthodontics and surgeries.
“The potential of reducing hospital visits, complications, and other barriers associated with conventional approaches means that young patients may have a better chance to thrive and be healthy,” said study co-senior author Dean Ho, PhD, MS, professor of oral biology and medicine at the UCLA School of Dentistry.
The researchers began with estrogen’s bone-supporting properties and aimed for a time-released, direct-delivery solution to maximize efficacy and avoid potential risks such of administering the hormone throughout the body as cancer and blood clots. Nanodiamonds presented a potential solution.
“Nanodiamonds form a complex, like a shield, around estrogen and other kinds of therapies, making them temporarily inactive until they are slowly released from the nanodiamond complexes,” said Ho. “This can make the treatment both more effective and safer.”
The researchers embedded estrogen-laden nanodiamonds in a hydrogel. This treatment can be injected directly into the cleft in a watery form and then thickened using a harmless blue light to ensure it stays in place. Using a laboratory model of maxillary expansion, they found that after 2 weeks, the treatment resulted in a relapse rate of just 13% compared to 30% with estrogen alone and 40% in the control group for a two thirds reduction in relapse from no treatment at all.
Also, the researchers noted that the nanodiamond-enhanced treatment doubled the bone volume, resulted in superior growth of bone and new blood veins, and produced more bone-forming cells compared to the control. Plus, they tracked estrogen serum levels for one week, since cleft palate is more common among boys than girls, and found that systemic levels remained constant with the treatment.
“This study showed that our method has a contained, targeted, and sustained effect, so we’re very excited about it,” said Hong.
Previous work found nanodiamonds to be safe in the body and excreted normally. Similarly, earlier research demonstrated that enzymes break down hydrogel. The researchers now plan to continue laboratory studies and bring their treatment to clinical trials. They also said that their approach has implications for treating other craniofacial conditions and sleep apnea, as well as healing wounds and bone injuries.