Application of mechanical mobility of periodontal tissues to tooth mobility examination.

Tooth mobility examination is important in planning dental treatment, as it may give an indication of alveolar bone loss and the condition of the periodontal ligament. In clinical dental diagnosis a manual tooth mobility examination is useful. However, its determination of tooth mobility is subjective and depends on the skill and experience of the clinician. The authors have previously reported on a device for measuring the biomechanical properties of human periodontium using an impedance head. Using this device, the mechanical mobility of periodontium can be measured and the mechanical parameters of the periodontal physical model are obtained. Tooth mobility is defined objectively on the basis of discriminant scores of mechanical parameters, and a mobility triangle (MT) figure is drawn as a record for visual interpretation. The paper describes the validation of the mechanical mobility measurements and their interpretation using mobility parameters and a personal computer to produce a mobility triangle figure. The method is compared favourably with clinical mobility measurement. The relationship of the model to underlying pathology is tested by measurements performed on various tooth model systems.