A comparison of facial and lingual cortical thicknesses in edentulous maxillary and mandibular sites measured on computerized tomograms.

Edentulous ridges suitable for implant treatment depend on cortical bone for implant stability, especially for ridge-expansion procedures. This study was done to find and compare the actual thicknesses of the facial and lingual edentulous cortices of the maxilla and mandible as measured on computerized tomograms. The collected computerized tomographs (CT) of one implantologist's practice (D.F.) were measured. The measurements taken demonstrated that the edentulous lingual cortex is almost always thicker than the facial cortex in the maxilla and mandible. The combined maxillary and mandibular facial cortices measurement sites average was 1.79 mm. The combined maxillary and mandibular lingual cortices measurement sites average was 2.33 mm. The average cortical thickness measurement of the maxillary facial cortices was 1.66 mm. The lingual maxillary average was 2.16 mm. The mandibular facial cortical sites averaged 1.83 mm, while the lingual cortical sites were 2.40 mm. These data confirm that the lingual cortex of the maxilla and mandible is thicker than the facial cortex at a ratio of 1:1.3. This ratio was consistent for maxilla and mandible.