Dental experts have warned against bad oral hygiene habits that people think are a good idea—but are actually causing harm. "Whether you are 80 or eight, your oral health is important," Roopali Kulkarni, a trained dentist , assistant director of the postgraduate oral medicine program at Penn Dental Medicine, and spokesperson for the American Dental Association (ADA), told Newsweek . "Your mouth is a window into the health of your body and touches every aspect of our lives. "It can show signs of nutritional deficiencies or general infection. Systemic diseases, those that affect the entire body, may first become apparent because of mouth lesions or other oral problems." How many teeth do humans have? Humans develop two sets of teeth over our lifetimes. Babies are usually born with 20 baby teeth, although these don't start appearing—or erupting—until the age of about six months old. Usually by the age of three, the full set of 20 teeth has erupted, and commonly by around … [Read more...] about The horrible habits dentists want you to stop doing now
Disease
At-home genetic tests are changing how patients interact with their doctors
Swabbing your cheeks and spitting into vials can open up a whole new world. Send off your samples to a genetic testing company like Ancestry, and you can learn where your forebears came from. But the industry that began by telling people which countries their ancestors inhabited has veered into the realm of medicine—some genetic testing companies can also tell if you're carrying genes that have been linked to serious diseases like cancer, Alzheimer's and diabetes. Yet as scientists continue to puzzle out our DNA and the world becomes increasingly digital, private genetic-testing companies will play a tricky role in health care, blurring the lines between being a patient and being a consumer. Unlike finding out that you share blood with people from an unexpected nation, a list of potentially dangerous DNA mutations isn't the sort of information people keep to themselves. The results of private genetic tests are already starting to leak from living rooms and into the clinical … [Read more...] about At-home genetic tests are changing how patients interact with their doctors
Nearly half of at-home DNA test results could be wrong
Update | At-home DNA tests are "not intended for medical use," meaning that the data they give you shouldn't be used as a replacement for a real medical diagnosis. At-home genetic testing companies like 23andMe, Ancestry.com, Family Tree DNA and My Heritage are gaining popularity as a relatively cheap way to understand one's ethnicity and genetic history. Yet new research suggests that some results identifing genetic issues may be innaccurate—and that as much as 40 percent of analyses of these at-home genetic tests implying genetic disorders could be innacurate. Researchers at AmbryGenetics conducted a study of 49 individuals who had done "direct-to-consumer" DNA tests who then sent their genetic results to third parties for analysis. AmbryGenetics then checked those analyses with a more detailed and expensive genetic test. They found that only 60 percent of the genetic variance results could be confirmed. While this is a relatively small sample of 49 people, the thirteen … [Read more...] about Nearly half of at-home DNA test results could be wrong
The DNA of the American cockroach may give insight into how to better kill it
Cockroaches are extremely difficult to kill and constantly evolve ways to resist our attempts to control their populations. A new study has sequenced the DNA of roaches, revealing exactly what makes them so resilient and perhaps giving insight into how they can be killed. The study, published in Nature Communications , specifically looked at the genome of the Periplaneta americana, also known as the American cockroach. The analysis revealed that cockroach DNA is even more fascinating than scientists previously knew. For example, cockroaches are known for their ability to find food in even the most difficult environments. This is part of the reason they are able to thrive so well in urban areas, Smithsonian magazine reported. The report revealed that this ability to thrive in extreme environments may be due to the roaches' high number of genes that code for chemical receptors. The bugs have over 1,000 of these genes, including 154 genes dedicated to smelling and 522 … [Read more...] about The DNA of the American cockroach may give insight into how to better kill it
Rare genetic condition means this woman is her own twin
A California woman has what appears to be a normal birthmark on her stomach. But the mark is actually the result of a rare genetic disorder that essentially makes the woman her own twin. The disorder, called chimerism, means the woman, Taylor Muhl, has two completely different sets of DNA inside her body. The phenomenon originated in the womb, where, as a developing fetus, Muhl absorbed her fraternal twin. That event created her two different colors of skin pigmentation split evenly down her midsection, as seen in the photo below. Related: NASA twin study: Year in space changed Scott Kelly all the way to his DNA "I actually felt relief. I felt freedom because for the first time in my life I knew why my stomach looks the way it does," Muhl, who learned about her condition about a decade ago but didn't make the news public until last year, told People . "I felt like for the first time I could really breathe. Prior to that, every doctor said my stomach must have just been a … [Read more...] about Rare genetic condition means this woman is her own twin