Factors influencing the dynamic behaviour of human teeth

Modal analysis is carried out to test the natural frequencies of certain hu man teeth, including central incisors (Cls), canines (CAs), first premolars (FPs) and first molars (FMs). A total number of 1007 teeth are tested, tak ing into account tooth type, oral location, age and gender, to analyse the effects of the above-mentioned factors on the natural frequency of the samp le teeth. The results reveal that no significant difference in the natural frequency is noted among teeth in the four different intra-oral quadrants. Nevertheless, tooth type and age elicit an effect upon the value of the nat ural frequency of teeth. On the other hand, the mean value for the natural frequency of Cls (1.27 +/- 0.15 kHz), CAs (1.30 +/- 0.15 kHz), FPs (1.27 +/ - 0.15 kHz) and FMs (1.16 +/- 0.12 kHz) for males are significantly lower ( p < 0.01) than the analogous figure for females (1.41 +/- 0.21 kHz for Cls, 1.40 +/- 0.18 kHz for CAs, 1.37 +/- 0.20 kHz for FPs, and 1.25 +/-. 0.16 k Hz for FMs). Moreover, the natural frequency of teeth in male subjects vari es with age (p < 0.05). The highest mean frequency of Cls, CAs and FPs for the male subjects is found for the group aged between 40 and 49 years. On t he other hand, the natural frequency for the similar set of teeth for the f emale subjects is shown to be in no way associated with age.