Relapse 1 week after bracket removal: a 3D superimpositional analysis

Abstract

Summary Objectives To measure tooth movement 1 week post-treatment and assess potential correlation with changes invoked during treatment. Subjects and methods Thirty-eight patients were recruited (19 males, 19 females). Polyvinyl siloxane impressions were taken after bracket debonding (T1) and 1 week later (T2) and digitally scanned. During this period no retention was used. The digital casts were superimposed on structures of the hard palate. Translation and rotation of the first molars, canines, and central incisors were recorded. Additionally, movement of these teeth was assessed from the beginning (T0) until the end of treatment (T1). The correlation between the post-treatment relapse (T1–T2) and tooth movement during treatment (T0–T1) was investigated via the Spearman correlation coefficient. Results Relapse was detected and reflected changes in tooth position during treatment. For the first molars (right, left) the correlation between treatment and post-treatment tooth movement was evident in the transverse direction (r = −0.38, P = 0.020; r = −0.32, P = 0.052), tipping (r = −0.40, P = 0.015; r = −0.34, P = 0.034) and the antero-posterior direction (r = −0.31, P = 0.061; r = −0.36, P = 0.027); for the canines (right and left), as rotation around their long axis (r = −0.55, P = 0.003; r = −0.58, P = 0.002); for central incisors (right and left) in the antero-posterior direction (r = −0.55, P = 0.000; r = −0.48, P = 0.03), transverse direction (r = −0.43, P = 0.07; r = −0.32, P = 0.047), and rotation around their long axis (r = −0.53, P = 0.001; r = −0.28, P = 0.089). Conclusions Post-treatment changes in tooth position were mostly related to tooth movement during treatment. The reported correlations may help clinicians predict short-term relapse, evaluate long-term retention need, and design individualized retention schemes.

Comparison and reproducibility of three methods for maxillary digital dental model registration in open bite patients

“…Registration of maxillary dental models has mostly been reported in the permanent dentition 6,7,9‐13,16,18‐20 . Some studies reported the use of these methods in growing patients 8,14,15,17,20 . However, this is the first study evaluating the registration methods in growing patients after treatment of anterior open bite, which poses clinical challenges to quantify vertical changes over time.…”

“…The first approach requires identification of anatomical landmarks, [9][10][11]14,16,18,19,35 and the surface-based approach requires identification of regions of interest (reference area). [6][7][8][12][13][14][15]17,19,20,30,35 A consensus regarding the ideal method for registration has not been established yet. 21 Registration of maxillary dental models has mostly been reported in the permanent dentition.…”

“…The palatal rugae have been reported as a stable and reliable region for maxillary superimposition of dental models, 14‐16,22 even in growing subjects 15 . The palatal rugae have been used to evaluate the dental changes produced by different orthodontic therapies and to assess the maturational changes in individuals with normal occlusion 6,8,9,11,12,16‐20 . Methods for maxillary digital dental model registration usually include the most anterior region of the palate (incisive papilla and first palate rugae) as a reference area 6‐15,19,22 .…”

“…15 The palatal rugae have been used to evaluate the dental changes produced by different orthodontic therapies and to assess the maturational changes in individuals with normal occlusion. 6,8,9,11,12,[16][17][18][19][20] Methods for maxillary digital dental model registration usually include the most anterior region of the palate (incisive papilla and first palate rugae) as a reference area. [6][7][8][9][10][11][12][13][14][15]19,22 This area experiences vertical changes due to growth and/or positional changes of the maxillary incisors.…”

Predictability of rotational tooth movement with orthodontic aligners comparing software-based and achieved data: A systematic review and meta-analysis of observational studies

“…This is important, since inaccurate prediction of tooth movements might be associated with prolonged duration of aligner treatment with an additional need for refinement strategies. Patient burnout and, most likely, increased potential for relapse tendency are further concerns (Papagiannis et al, 2021;Vagdouti et al, 2019;Vagdouti and Koletsi, 2020).…”