Important restorative guidelines are presented that will aid the clinician in determining the etiology of tooth wear: (erosion, abrasion, abfraction or attrition). Patients with these disorders are then presented and restored taking into consideration, other factors such as decreased occlusal vertical dimension. Diagnostic criteria for the "Two-Step Occlusion" and the "Rule of Thirds" are presented that will help the clinician determine when to bond, when to place porcelain veneers, and when to use porcelain fused to gold restorations. This videotape/CD-Rom is the first part of another series on "Treatment Planning Advanced Patient Problems" that is now being prepared and will be available soon