This study aimed to assess the validity and reliability of a questionnaire on patient acceptance of orthodontic retainers. The original questionnaire was forward- and backward-translated, followed by four validity tests (content validity, face validity, construct validity, criterion validity) and two reliability tests (test-retest reliability, internal consistency). Content validity was assessed by nine orthodontists who appraised the questionnaire’s representativeness, relevance, clarity, and necessity. Face validity was established through semi-structured in-depth interviews with 35 English-literate participants currently wearing orthodontic retainers. Construct validity was established through Exploratory Factor Analysis (EFA). For criterion validity, 107 participants concurrently answered the questionnaire and the Retainer-modified Malaysian Oral Health Impact Profile questionnaire. Test-retest reliability was verified by 34 subjects who responded to the questionnaire again after a two-week interval. Six revised items passed the threshold value of 0.78 for Item-Content Validity Index and Content Validity Ratio and were revised based on findings from the face validity test. Principal Component Analysis of EFA extracted information on only one component, and all items were positively correlated with the component matrix. Spearman’s rho value (rs = 0.490 and rs = 0.416) indicated a moderate correlation between the two questionnaires for criterion validity. Intraclass Correlation Coefficient ranged from 0.687 to 0.913, indicating moderate to excellent test-retest reliability. Cronbach’s alpha ranged from 0.687 to 0.913 indicating that none of the questionnaire items showed unacceptable or poor internal consistency. The questionnaire on patient acceptance of orthodontic retainers has been validated and can be used in both clinical and research settings.

Orthodontic clear aligners, along with their attachments, are used for the corrective alignment of teeth during orthodontic treatment. Although the clear aligner technique has gained widespread popularity due to its aesthetic quality, studies that examine and map the measurement of forces applied to clear aligner attachments are lacking. This investigation describes the topographical visualisation of the force in clear aligner attachments. We describe a method using Prescale® pressure film and an image processing technique to obtain the topographical visualisation of a clear aligner’s distributed force on the attachment in an in-vitro study using resin models. The variation of colour density due to the distributed force is calibrated with a force gauge for validation. The image processing technique is demonstrated through the histogram-based K-means clustering method with 3D visualisation of the distributed force. This method involves pressure film calibration, followed by sample preparation and image processing analysis. The proposed topographical pressure mapping system illustrates the distributed force on the clear aligner attachment as the force applied is directly proportional to intensit. For active aligners, the mean force ranged from 6.2–6.3 N, and for passive aligners, the mean force ranged from 4.8–4.9 N. Therefore, the net force exerted on a single clear aligner attachment in a resin model for this study was 1.3–1.4 N. The preliminary findings of this work can be developed further to be a reference in future clinical orthodontic clear aligner and attachment research.

Objectives: To compare the clinical effectiveness of Hawley retainers (HRs) and modified vacuum-formed retainers (mVFRs) with palatal coverage in maintaining transverse expansion throughout a 24-month retention period and to assess the subjects’ perception toward the retainers.Materials and methods: The trial accomplished blinding only by the outcome assessor and data analyst. Data were collected from post-orthodontic treatment patients who met the inclusion criteria. Thirty-five subjects were randomly allocated using a centralized randomization technique into either mVFR (n = 18) or HR group (n = 17). Dental casts of subjects were evaluated at debond (T0), 3-month (T1), 6-month (T2), 12-month (T3), and 24-month retention (T4). The intercanine width (ICW), interpremolar width (IPMW), interfirst molar mesiobuccal cusp width (IFMW1), and interfirst molar distobuccal cusp width (IFMW2) were compared between groups over time using Mixed ANOVA. A pilot-tested and validated questionnaire consisting of six items were given at T4. Subjects were instructed to rate their retainer in terms of fitting, speech, appearance, oral hygiene, durability, and comfort on a 100-mm Visual Analogue Scale (VAS).Results: No statistically significant differences in arch width were found between the two groups at ICW (P = .83), IPMW (P = 0.63), IFMW1 (P = .22), and IFMW2 (P = .46) during the 24-month retention period. Also, no statistically significant differences were found between perception of both retainers in terms of fitting, speech, oral hygiene, durability, and comfort (P > .05) after 24-month wear. The appearance of mVFRs was rated significantly higher compared to HRs (P < .05).Conclusions: HR and mVFR have similar clinical effectiveness for retention of transverse expansion cases in a 24-month retention period. Both retainers were perceived to be equal in terms of fitting, speech, oral hygiene, durability, and comfort. Subjects in the mVFRs group found their retainers to be significantly more esthetic than those in HRs group.

To investigate the prevalence of adults and children seeking orthodontic treatment at high risk of obstructive sleep apnea (OSA) and pediatric OSA (POSA) and its association with demographic variab...

Background: The introduction of auxiliaries such as composite attachment has improved the force delivery of clear aligner (CA) therapy. However, the placement of the attachment may give rise to a flash, defined as excess resin around the attachment which may affect CA force delivery. This in vitro study aims to determine the differences in the force generated by the attachment in the presence or absence of flash in CA. Materials and methods: Tristar Trubalance aligner sheets were used to fabricate the CAs. Thirty-four resin models were 3D printed and 17 each, were bonded with ellipsoidal or rectangular attachments on maxillary right central incisors. Fuji Prescale pressure film was used to measure the force generated by the attachment of CA. The images of colour density produced on the films were processed using a calibrated pressure mapping system utilising image processing techniques and topographical force mapping to quantify the force. The force measurement process was repeated after the flash was removed from the attachment using tungsten-carbide bur on a slow-speed handpiece. Results: The intraclass correlation coefficient showed excellent reliability (ICC = 0.96, 95% CI = 0.92–0.98). The average mean force exerted by ellipsoidal attachments with flash was 8.05 ± 0.16 N, while 8.11 ± 0.18 N was without flash. As for rectangular attachments, the average mean force with flash was 8.48 ± 0.27 N, while 8.53 ± 0.13 N was without flash. Paired t-test revealed no statistically significant difference in the mean force exerted by CA in the presence or absence of flash for both ellipsoidal (p = 0.07) and rectangular attachments (p = 0.41). Rectangular attachments generated statistically significantly (p < 0.001) higher mean force than ellipsoidal attachments for flash and without flash. Conclusion: Although rectangular attachment generated a significantly higher force than ellipsoidal attachment, the force generated by both attachments in the presence or absence of flash is similar (p > 0.05).

Objective: The present study aimed to determine the influence of gingival display on smile perception of adult patients seeking dental treatment. Materials and methods: A smiling photograph was digitally modified to simulate gingival exposures from -4 mm to +4 mm, each in 2 mm increments. Using a validated questionnaire, 117 subjects were recruited and asked to rate the attractiveness of the smile displayed by the photographs. Friedman tests were applied to compare the perceptions of the overall subjects in addition to subjects within each category. Kruskal–Wallis tests were used to compare perceptions between the genders, different ages, and ethnicity. Statistical significance was set at P < 0.05. Results: The most aesthetic gingival display was at -2 mm and the least aesthetic at -4 mm among all subjects. Females were more critical in evaluating smiles than males. Subjects 50 years or older and the Chinese ethnicity were less sensitive to the range of gingival displays. Conclusions: Smile perception of varying gingival display among adult laypeople was found to be the most aesthetic at -2 mm, least aesthetic at -4 mm and was influenced by gender, age, and ethnicity.