The predictability of clear aligner treatment in space opening for permanent maxillary lateral incisors: An observational retrospective cohort study.

A retrospective study of planned and achieved rotational changes of maxillary canines with clear aligner therapy.

INTRODUCTION This retrospective study aimed to assess the accuracy of planned moderate-to-severe rotation changes (≥5°) of maxillary canines with the Invisalign (Align Technology, Tempe, Ariz) appliance. The secondary aim was to evaluate the influence of the planned rotation direction on the accuracy. METHODS Digital models representing the initial malocclusion, the planned occlusions, and the achieved occlusions after the wear of an initial series of Invisalign aligners by adult patients were measured using metrology software. A method to define rotation directions was formulated. The sample was then divided into 5 categories by rotation type: mesial-in, mesial-out, distal-in, distal-out, and combination rotations. This categorization enabled subsequent analyses to determine whether the planned rotation directions were met and whether rotation direction influenced accuracy. RESULTS A total of 114 maxillary canines from 75 patients satisfied the inclusion criteria. Overall, the mean accuracy of the planned rotation was 64%. Rotation direction had no statistically significant influence on the accuracy of the planned rotations. Planned rotation directions were achieved in 77% of the maxillary canines evaluated. Combination rotations demonstrated the greatest variability, with 51% rotating in a direction other than that planned. A 1° increase in rotational velocity per aligner correlated with a 5.35° shortfall in the accuracy of this rotation (P < 0.05). CONCLUSIONS The achieved rotation of maxillary canines after the wear of an initial series of Invisalign aligners differed from the planned movements in both magnitude and direction for planned rotations of ≥5°. A method for classifying rotation types was developed, which may facilitate further research to guide clinicians and optimize treatment outcomes.

Arch width changes following first premolar extractions: a comparison between invisalign and fixed appliances

CLINICAL STUDY Predictability and oral health in clear aligner therapy for mixed dentition: a 12-month prospective study

Does Modifying a Palatal Expander with a Lingual Acrylic Block Create Asymmetric Dental Expansion? A Retrospective Study

Asymmetric dental expansion is a preliminary goal in the treatment of a true unilateral crossbite (CB). The aim of this study was to investigate transverse dental changes following modified asymmetric rapid palatal expansion (ARPE) based on cone-beam computed tomography (CBCT) records. The dataset consisted of CBCT records obtained before and after treatment with a modified ARPE appliance in patients presenting with unilateral skeletal posterior CB and class I skeletal relationship. Eighteen linear and four angular measurements were analyzed based on CBCT images. The Shapiro–Wilk test, paired-samples t-test and Wilcoxon signed-rank test were used for statistical analyses. Maxillary interdental widths showed significant increments on both sides (p < 0.05). Maxillary posterior dental expansion was greater on the CB side compared to the non-crossbite (NCB) side. A significant increase was detected in the mandibular inter-first premolar width (p < 0.05). In addition, the inter-side difference in maxillary first molar inclination between the NCB and CB sides was also significant (p < 0.05). Modified ARPE may be beneficial for treatment of a unilateral CB.

Effectiveness of aligners to correct vertical malocclusions in adult patients : Systematic review.

A multivariable model for treatment duration in nonextraction clear aligner therapy.

INTRODUCTION The objective of this study was to evaluate the associations between pretreatment dentoalveolar characteristics and treatment duration in nonextraction clear aligner therapy (CAT). METHODS This retrospective cohort study included 296 patients treated with nonextraction CAT. Pretreatment variables were extracted from Invisalign ClinCheck (Align Technology, Santa Clara, Calif) digital treatment planning software and included deviations in overjet and overbite from a 3 mm reference, arch irregularities, midline deviation, and posterior crossbite. Treatment duration was defined as the time from initial aligner delivery to the completion of all refinement stages. Multivariable linear regression analysis was performed to evaluate the associations between pretreatment characteristics and treatment duration. Internal validation was performed using bootstrap resampling (5000 iterations). RESULTS The 11 pretreatment variables collectively explained 32.8% of the variability in treatment duration (R2 = 0.328; adjusted R2 = 0.302). Overbite showed the strongest association with treatment duration, followed by mandibular crowding, midline deviation, and posterior crossbite (P <0.001). Each 1 mm increase in overbite and overjet was associated with increases of approximately 41 and 15 days in treatment duration, respectively. The presence of posterior crossbite was associated with an approximately 89-day increase. Bootstrap analysis demonstrated the stability of the regression estimates. CONCLUSIONS Pretreatment dentoalveolar characteristics were significantly associated with treatment duration in nonextraction CAT. Although several baseline characteristics independently contributed to treatment duration, the model explained approximately one-third of its variability, highlighting the influence of biological, behavioral, and treatment-related factors beyond pretreatment records.