Why is ridge mapping required and what is its alternative

The selection of the implant diameter apart from the mesiodistal space available also depends on the buccolingual width of the alveolar bone available. We need to have at least 0.5 to 1 mm covering on both the buccal and lingual aspect of the implants.

Conventional radiography gives only a 2 dimensional image and it is impossible to judge the width with  conventional x rays (IOPA, OPG).  Also clinically due to the soft tissue thickness which varies from patient to patient and from area to area in the same patient, it is again very difficult to assess the width of available bone at the implant site. Ridge mapping allows for this measurement although it is a time consuming process. The CT scan with multiplanar reformatted images (dentascan) allows paraxial cross sections which can alternatively be used to measure bone width.