The ductus arteriosus is a hole that allows the blood to skip the circulation to the lungs. However, when the baby is born, the blood must receive oxygen in the lungs and this hole is supposed to close. If the ductus arteriosus is still open (or patent) the blood may skip this necessary step of circulation. The open hole is called the patent ductus arteriosus.
Caring for a Bleeding Tooth. Some people mistakenly think that while brushing, a bleeding tooth is perfectly normal. It is not. Anytime there is any bleeding in the mouth, it is almost always a sign of periodontal disease. Even if you brush fairly hard, it should not cause healthy teeth and gums to bleed.
Are bleeding gums when flossing reason enough to prompt a call to the dentist? Gums that bleed after daily flossing can be a warning sign of gingivitis, the initial stage of gum disease. Left untreated, gingivitis can progress into the more advanced stages of gum disease, periodontitis and advanced periodontitis. The advanced stages can result in permanent tissue damage and tooth loss.