America's Dental Expert Bone Loss and Sinus Drops / Sinus Pneumatization One of the serious consequences or side effects of losing a tooth is the jaw bone erodes over time. In the lower jaw, bone melts away and develops into a curved area where the tooth once was. In the upper jaw, bone loss occurs from both sides of where the tooth was, the top area called the crest, and the bottom area which is the floor of the sinus. When the sinus area expands into the jaw bone, enough to communicate with the oral cavity, it's called pneumatization. Bone loss and sinus dropping are two big consequences of missing teeth without replacing the spaces with dental implants. Do you have a dental question for America's Dental Expert? Send your dental and other oral health related questions to America's Dental Expert, Dr. Shawn Van de Vyver, at [email protected]