Supervisors info:
Δημήτριος Χαλαζωνίτης, Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Ιωσήφ Σηφακάκης, Επίκουρος Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Ελένη Βασταρδή, Επίκουρη Καθηγήτρια, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Summary:
Aim: The main objective of this research was to measure tooth movement one week post-treatment and assess potential correlation with changes invoked during treatment.
Materials and method: Thirty-eight patients were included in this study (19 males, 19 females). Two Polyvinyl Siloxane impressions were taken after bracket debonding (T1) and one week later (T2), and digitally scanned in 3-dimensions.No retention method was implemented during this period.The digital casts were superimposed on structures of the mucosa of the hard palate. Permanent molars, canines and central incisors were the teeth under study. Translation of the centroid, as well as the rotation of each tooth were documented. Relapse during (T1-T2) period was recorded. Furthermore, each tooth movement from the beginning (T0) until the end of treatment (T1) was assessed. The relapse observed was correlated to tooth movement during treatment. Descriptive statistics were computed. Data were tested for normality of the distribution (Shapiro-Wilk test). Non-parametric statistics were used. Spearman correlation coefficient (r) was used to evaluate correlation in tooth movement between T0-T1 and T1-T2.
Results: The relapse tendency was detectable and reflected changes in tooth position during treatment. Concerning the first molars, relapse was observed in the transverse direction (r=-0.38, P=0.020; r=-0.32, P=0.052 respectively), in tipping (r=-0.40, P=0.015; r=-0.34, P=0.034 respectively), as well as in the anteroposterior direction (r=-0.31, P=0.061; r=-0.36, P=0.027 respectively). For the canines, relapse was reported as rotation around their long axis (r=-0.55, P=0.003; r=-0.58, P=0.002 respectively). Regarding the central incisors,relapse was detected in the anteroposterior direction (r=-0.55, P=0.000; r=-0.48, P=0.03 respectively), transverse direction (r=-0.43, P=0.07; r=-0.32, P=0.047 respectively), and rotation around their long axis (r=-0.53, P=0.001; r=-0.28, P=0.089 respectively).Furthermore, tipping after treatment was correlated with the anteroposterior tooth movement during treatment (r=-0.38, P=0.017; r=-0.37, P=0.024 respectively).
Conclusion:Immediate relapse one week after bracket removal could be substantially correlated to tooth movement during treatment.The associations reported in this article may help clinicians predict the short-term relapse more safely, evaluate the retention need in the long term, as well as guide them to more individualized retention schemes.
Keywords:
Retention, Orthodontic relapse, Three dimensions, Palate
