The mandible is a U-shaped bone. It is the only mobile bone of the facial skeleton, and, since it houses the lower teeth, its motion is essential for mastication. It is formed by intramembranous ossification. The mandible is composed of 2 hemimandibles joined at the midline by a vertical symphysis.
1 For example, AT&T charges $23 for a home residential line that includes a few additional basic features such as caller ID, call waiting and voicemail. 2  Home phone service plans that include local and long-distance calling cost $30-$45 per month.
Premium-rate numbers can cost Â£1.50 per minute from a BT landline and more from a mobile. Most people can spot a free-phone number â beginning 0800 â but are puzzled by others. More than 60 per cent of people say they donât know whether 0871, 0870, 0844, 09 and 0845 numbers cost money.