Ridge

The alveolar ridge is the bony crest of the jaw that houses the tooth sockets. After teeth are lost, the ridge gradually resorbs — reduces in height and width — through a process called alveolar resorption.

Ridge dimensions for implants

Implant placement requires a minimum ridge width of approximately 6mm (to accommodate a standard diameter implant with 1mm of bone on each side) and sufficient height to accommodate the implant length (typically 10mm) with safe clearance from the sinus or nerve.

Ridge augmentation

When the ridge is too narrow or too short for implants, ridge augmentation is performed — adding bone graft material to rebuild the ridge dimensions. Common techniques include:

• Horizontal augmentation: Widening a narrow ridge using bone graft and membrane
• Vertical augmentation: Building up a severely resorbed ridge — technically demanding with higher complication rates
• Split crest technique: Splitting a narrow ridge longitudinally and expanding it — allows simultaneous implant placement

Prevention

Ridge resorption begins immediately after extraction. Socket preservation grafting at the time of extraction is the most effective way to maintain ridge dimensions and simplify later implant placement.