A method of determining tooth displacement comprising: a) performing a first scan of at least a portion of the oral cavity of a subject using an intraoral scanner to generate baseline scan data, wherein said subject is suspected of having periodontal disease, wherein said baseline scan data comprises a baseline image of a first tooth, and wherein said first scan is performed when said first tooth: i) is not engaged with an opposing tooth in a chewing action, and ii) is not being pushed by an outside force; b) performing a second scan of at least a portion of said oral cavity of said subject using an intraoral scanner to generate first test scan data, wherein said first test scan data comprises a first test image of said first tooth, wherein said second scan is performed when said first tooth is being pushed by an outside force selected from the group consisting of a finger, a dental mirror, and a rod; and c) processing said baseline scan data and said first test scan data with a processing system to thereby determine an amount of displacement of said first tooth in at least one direction, wherein said processing system comprises: i) a computer processor, and ii) non-transitory computer memory comprising one or more computer programs, wherein said one or more computer programs, in conjunction with said computer processor, is/are configured to align said baseline image and said first test image and calculate said amount of displacement of said first tooth in said at least one direction. a) performing a first scan of at least a portion of the oral cavity of a subject using an intraoral scanner to generate baseline scan data, wherein said subject is suspected of having periodontal disease, wherein said baseline scan data comprises a baseline image of a first tooth, and wherein said first scan is performed when said first tooth: i) is not engaged with an opposing tooth in a chewing action, and ii) is not being pushed by an outside force; wherein said baseline scan data comprises a baseline image of a first tooth, and wherein said first scan is performed when said first tooth: i) is not engaged with an opposing tooth in a chewing action, and ii) is not being pushed by an outside force; b) performing a second scan of at least a portion of said oral cavity of said subject using an intraoral scanner to generate first test scan data, wherein said first test scan data comprises a first test image of said first tooth, wherein said second scan is performed when said first tooth is being pushed by an outside force selected from the group consisting of a finger, a dental mirror, and a rod; and wherein said first test scan data comprises a first test image of said first tooth, wherein said second scan is performed when said first tooth is being pushed by an outside force selected from the group consisting of a finger, a dental mirror, and a rod; and c) processing said baseline scan data and said first test scan data with a processing system to thereby determine an amount of displacement of said first tooth in at least one direction, wherein said processing system comprises: i) a computer processor, and ii) non-transitory computer memory comprising one or more computer programs, wherein said one or more computer programs, in conjunction with said computer processor, is/are configured to align said baseline image and said first test image and calculate said amount of displacement of said first tooth in said at least one direction. i) a computer processor, and ii) non-transitory computer memory comprising one or more computer programs, wherein said one or more computer programs, in conjunction with said computer processor, is/are configured to align said baseline image and said first test image and calculate said amount of displacement of said first tooth in said at least one direction. <EOS>