Methods: 1,884 members of the German Army (GA) were examined; those wearing a TP were asked to volunteer for this study (TP group). A control group (C group) of GA members without TP was matched. Each group consisted of 46 male subjects (mean age: TP=22.1 years, C=22.2 years). Enamel fissures (EF), enamel cracks (EC), vestibular and lingual recessions were evaluated. Statistical analysis included Chi-Quadrat-Test and t-Test.
Results: The mean time of the TP in situ was 3.8±3.1 years. 48 dumbbell-shaped TPs (2 subjects wore 2 TPs) were closed with bullets (94 %), cones (4 %), and cylinders (2 %). 45 TPs were placed in the anterior, 3 in the middle third of the tongue. The TPs consisted of titanium (65 %), steel (25 %), and niobium (5 %).
The TP group had a total of 1,260 teeth. 29 subjects (63 %) showed 115 teeth (9.1 %) with EF, (33% vestibular, 67% lingual). In the C group (1,243 teeth) 30 subjects had 60 teeth (4.8%) with EF (78% vestibular, 22% lingual). 38 subjects (83%) of the TP group showed EC in 186 teeth (15%). In the C group 26 subjects (56%) and 56 teeth (4.5%) were affected by EC. 27 subjects of the TP group had 97 teeth (7.7%) with recessions (26% vestibular, 74% lingual). The lingual surfaces of anterior teeth in the lower jaw were affected most frequently (p<0,001): 32=12%, 31=19%, 41=18%, 42=14%). In the C group 8 subjects showed 19 teeth (1.5%) with recessions (65% vestibular, 35% lingual) (32=5%, 31=11%, 41=5%, 42=0%). Differences between both groups were statistically significant (p<0.01).
Conclusions: Wearing TP causes a significantly increased occurrence of EF, EC, and lingual recessions. Patients require information about this complications associated with TP.