Effects of posterior teeth replacement on temporomandibular joint sounds: a preliminary report

Previous reports have shown the prevalence of jaw clicking to be significantly higher in a population with missing posterior teeth compared with an dentulous population. This study presents a 2- to 5-year assessment of the effects of posterior teeth replacement on the amplitude of jaw clicking in subjects who were asymptomatic in all respects except jaw clicking. Patients requiring removable partial dentures (RPDs) were clinically and anamnestically examined and temporomandibular joint (TMJ) sounds were recorded using a modified stethoscope attached to an adjustable headgear. Amplified signals were displayed on a strip chart recorder. The amplitude of TMJ sounds at preinsertion of RPDs were 27.5 +/- 17.7 dB at opening, and 11.1 +/- 12.7 dB at closing. Similar values after prosthesis insertion were 15.8 +/- 17.0 dB and 7.4 +/- 7.5 dB, respectively. Paired t test analyses showed significant differences in the amplitude of sound for opening and closing before inserting the prosthesis (p = 0.003) and for opening before and after treatment (p = 0.014). Following replacement of posterior teeth, the clicking amplitude decreased in 68% of recordings, remained unchanged in 11%, and increased in 21%.