Effects of loss of second molar on masticatory ability and oral health-related quality of life: A comparative cross-sectional study

Background/purpose: Previous studies have reported on changes in masticatory ability and patient satisfaction after restoration of missing second molars. However, there has been no evaluation of the masticatory ability and oral health-related quality of life (OHRQoL) of patients who did not replace their second molar. The purpose of the present study was to analyze the effects of the loss of a second molar on masticatory ability and OHRQoL.

Methods: Twenty-two subjects who had lost a second molar (the missing group) and another 22 subjects with complete dentition (the control group) were enrolled. In the evaluation of masticatory ability, an objective test by measurement of the mixing ability index (MAI) with the occlusal contact area and a subjective test by questionnaire on food intake ability (FIA) were used. In the assessment of the OHRQoL and patient satisfaction, the Korean Oral Health Impact Profile (OHIP-14K) questionnaire was employed.

Results: The inter-group comparison revealed the control group to have significantly higher mean scores of MAI, FIA, key FIA and hard FIA. Although insignificant, the control group also had a larger mean occlusal contact area and a lower mean OHIP-14K score.

Conclusion: Within the limitations of this study, a missing second molar could lead to diminished objective and subjective masticatory ability with poorer OHRQoL. In conclusion, replacement with a suitable implant prosthesis should be performed after the loss of a second molar.