What Kind of Doctor Do I Need? Slideshow Dental (Oral) Health Quiz Causes of a Heart Attack Slideshow Aplasia: Failure to develop. This is not to be confused with the word, atrophy, which means that something develops and then wastes away. From Healthy Resources When Prostate Cancer SpreadsHow Well Are You Living With AS?Protecting Your Immune System Featured Centers When Prostate Cancer SpreadsEssential Tips to Manage DiabetesWhat Is Cystic Fibrosis? What Causes It? Health Solutions From Our Sponsors Kept Your Wisdom Teeth? What is TAVR?