Changes in the arch width and buccal corridor after fixed orthodontic treatment with Damon self-ligating system: premolar extraction vs. non-extraction.

INTRODUCTION: Extraction vs. non-extraction is a crucial decision in orthodontic therapy. OBJECTIVE: The aim of the present study was to investigate the changes in the dental arch width and buccal corridor after orthodontic treatment using extraction and non-extraction therapy with Damon self-ligating system. MATERIAL AND METHODS: This retrospective study consisted of 35 patients (20 female and 15 male patients with median age of 12.5 years), treated by extracting 4 or 2 premolars, and 37 patients (16 female and 21 male patients with the median age of 12.8 years), treated without premolar extraction. Both groups were treated with Damon self-ligating system. Plaster models before (T0) and after (T1) treatment were measured, and the arch width values were determined at the level of the first molars, second premolars, canines and palatal rugae. Buccal corridor width was measured using the extraoral images at T0 and T1. Paired t-test was used for the analysis of the normally distributed data, and Wilcoxon Mann-Whitney U test was used for the data with non-normal distribution. Values of p<0.05 were set as statistically significant. RESULTS: The upper intercanine width increased significantly in both groups (p<0.01). In the non-extraction group, the arch width increased significantly in the maxillary second premolar and first molar region (p<0.01) as well as in the region of the canines (p=0.04), second premolars (p=0.01) and first molars (p<0.01) of the mandible. The buccal corridor decreased significantly in the non-extraction group (p<0.01). CONCLUSION: Premolar extraction in combination with Damon self-ligating system did not lead to reduction of the dental arch width in the maxilla, nor did it increase the size of the buccal corridors.

Evaluation of thickness of 3D printed versus thermoformed aligners: A prospective in vivo ageing experiment.

BACKGROUND: To compare and investigate the effects of intraoral ageing on the thickness of one group of directly printed and two groups of thermoformed aligners on the labial surface of maxillary central incisors. MATERIALS AND METHODS: Six groups (12 samples per group) were included in this prospective in vivo experiment. Groups DP-Clin, INV-Clin and CA-Clin consisted of directly printed (Tera Harz TC-85 DAC resin), thermoformed (Invisalign, PU based polymer) and in house thermoformed (CA-Pro, PET-G based polymer) aligners, retrieved after 1 week of intraoral service. Groups DP-Ctr, INV-Ctr and CA-Ctr included unused aligners samples. Thickness measurements were conducted using confocal laser scanning microscopy (CLSM). Data that underwent log-10 transformation was analysed by multiple linear regression analysis (p < .05). RESULTS: Statistically significant differences were found between the materials in both Clin and Ctr categories (p < .001). Group DP had the highest thickness among the groups and the least thickness was observed in the CA group (p < .001). However, intraoral ageing did not significantly affect the aligner thickness of any groups. CONCLUSIONS: Both thermoforming and direct printing of clear aligners led to thickness deviations in terms of increase for printed aligners and decrease for thermoformed aligners. Intraoral ageing did not affect the aligner thickness in any of the groups.

Observation of factors associated with visceral swallowing pattern in 2-6 year old children: A cross-sectional study.

Introduction: The association between the visceral swallowing pattern (VSP) and dentofacial abnormalities remains controversial. This cross-sectional study aimed to investigate the association between the VSP and various factors including type of birth, gender, tongue posture, lip incompetence, eruption of primary molars, habits and the presence of malocclusions in children with primary and early mixed dentition. Material and method: A total of 219 children (102 boys and 117 girls) were evaluated using a combination of a questionnaire and a structured clinical examination by one pediatric specialist dentist. Kittel's method of tongue posture evaluation and the Payne technique for assessment of swallowing pattern were included in the clinical examination of myofunctional status. After checking for normality, normal and non-normal distributed data were analyzed using two-sample t-test and Mann-Whitney U test, respectively. Analysis of categorical variables was done using a chi-square test, and Bonferroni correction was used as correction for multiple comparisons. Results: A total of 56.2 % of the study population had a VSP. The chi-square test indicated a statistically significant higher presence of VSP in male gender. Statistically significant associations were seen between the VSP and lip incompetency, pathologic resting tongue position, habits, anterior open bite and increased overjet. On the other hand, no statistically significant associations were found between VSP and children's age within the sample population, type of birth, uni- or bilateral crossbites, increased overbite, edge-to-edge anterior bite or completion of eruption of primary molars and/or permanent incisors. Conclusions: The association between VSP and male gender, pathologic tongue posture, lip incompetency and habits and occlusal traits such as anterior open bite and increased anterior overjet is supported by the results of the present study.

Impact of two different patient decision aids in prosthodontic consultations: a prospective randomized controlled study.

OBJECTIVES: Different approaches to prosthodontic consultation, all involving a strong focus on shared decision-making, were analyzed from the perspective of patients by inter-group comparisons. No patient decision aid (PDA) was used in the control group, a paper-based PDA in test group 1, and a software-based PDA in test group 2. MATERIALS AND METHODS: Seventy-five patients were prospectively randomized to the control group or a test group. All patients then rated the consultation on a questionnaire, six key items of which were analyzed, along with the time spent on each consultation. RESULTS: Overall satisfaction was highest in test group 2, with a significant difference from the control group (p = 0.015). Test group 2 showed the most favorable ratings for all six questionnaire items, which invariably was significant compared to the control group (p = 0.032). Test group 1 significantly differed from test group 2 based on two items (consultation was adequately intelligible: p = 0.011; consultation was adequately comprehensive: p = 0.034) but not from the control group based on any item (p = 0.070). CONCLUSIONS: Within the limitations of this study, the use of a software-based PDA, in particular, can be recommended based on patient satisfaction and was associated with the shortest sessions for consultation. CLINICAL RELEVANCE: Patients are routinely faced with a wealth of information in dental offices and may be overwhelmed especially by prosthetic treatment options and decision requirements. Our findings shed some light on the nature of aids that may truly be helpful in the process of shared decision-making. TRIAL REGISTRATION: ClinicalTrials.gov.Identifier: ISRCTN11472465.

[ZApprO versus ZÄPrO: results of a first comparative study]. / ZApprO versus ZÄPrO: Ergebnisse einer ersten Vergleichsstudie.

BACKGROUND: More than 60 years after the enactment of the first Licensing Regulations for Dentists (ZÄPrO), a new Licensing Regulations for Dentists, the ZApprO, was implemented in 2020. The aims of this study were to evaluate and compare the "Course in Technical Propaedeutics" (TPK) with the course "Dental Propaedeutics with a Focus on Dental Technology" (ZPDT), which are based on different legal foundations. METHODS: The following parameters were compared after completion of the courses: (1) theoretical and practical knowledge, (2) regular department-internal learner evaluation, and (3) special evaluation of learning conditions by the learners and (4) by the instructors. The theoretical and practical exams and the questionnaires were analyzed in terms of their test-statistical characteristics (difficulty, discrimination index, internal consistency). Group comparisons between TPK and ZPDT were conducted using t­tests for independent groups. RESULTS: Significant differences were only detected in the students' evaluation of their learning conditions, with theoretical and practical knowledge transfer being rated lower in the TPK than in the ZPDT. DISCUSSION: The comparable results of the knowledge assessments and the regular learner evaluation, triangulated with the comprehensive learner and instructor evaluation, allowed a broad assessment of both courses. The significant differences identified provide opportunities for optimization of the newly implemented ZPDT course.