Assessment of the positional and morphological differences of unilaterally impacted canines: A cross-sectional study.

INTRODUCTION: This study aimed to use cone beam computed tomography (CBCT) to evaluate the dimensional and morphological characteristics of unilaterally impacted canines, their effects on adjacent teeth, and differences with contralaterally erupted canines. MATERIALS AND METHODS: A sample of 31 patients (22 males, mean age 22.22 ± 4.82 years; 9 females, mean age 23.91 ± 5.16 years) with unilaterally impacted maxillary palatal teeth were included in the study. CBCT images were obtained using a NewTom 5 G unit in standard mode. Three-dimensional multiplanar reconstructions emulating a panoramic view and curved planar reconstructions were evaluated. Individuals were divided into two groups (low- and high-complexity) according to Ericson and Kurol's impaction complexity classification. RESULTS: The crown lengths and mesiodistal crown widths of the impacted canines were similar to the symmetric canine on the opposite arch and significantly larger than adjacent lateral and premolar teeth (p<0.05). The alpha (31.33 ± 8.32) and beta angles (39.53 ± 10.31) and the 'h' height (10.11 ± 2.02) values in the low-complexity group were significantly lower than the high-complexity group (alpha angle=57.40 ± 12.15; beta angle=71.31 ± 13.94; 'h' height=14.35 ± 3.71, and alpha angle: p<0.001; beta angle: p<0.001; 'h' height: p=0.002) CONCLUSION: The root lengths of impacted maxillary canine teeth are significantly shorter than symmetrically erupted canine teeth regarding labiolingual crown width. As the alpha and beta angles and 'h' height increase, the complexity level of the impacted canine also increases.

Clinical comparative study on the accuracy of palatal rugae in models obtained by different impression materials and intraoral scanning.

OBJECTIVE: Palatal rugae are frequently used in the evaluation of tooth movement after treatment in orthodontics and as a stable region in superimposition. It is important to note that the impression method and material used to record the rugae region affect the accuracy of the impression. The aim of this study is to compare the accuracy of palatal rugae, in three-dimensional (3D) by employing both conventional and digital impression methods. MATERIALS AND METHODS: In this study, 22 patients (12 females, 10 males) mean age of 13.5 ± 1.7 years old were selected with complete permanent dentition. Three different impressions were taken from the maxillae of the patients: conventional impression using silicone rubber impression material, conventional impression using alginate impression material, and optical impression using an intraoral scanner. The impressions' digital data were analyzed by the GOM Inspect (Version 2018, Braunschweig, Germany), a 3D analysis software. The Root Mean Square (RMS) values of the total ruga region were evaluated in this software. The data were statistically analyzed using the Jamovi program. The Kruskal-Wallis test and Mann-Whitney U test were performed due to the non-normal distribution of the data. RESULTS: There is no statistically significant difference between the comparison points of the right and left rugae's medial and lateral points and total rugae regions' RMS values. Although there was no statistically significant difference, the total RMS values of alginate and digital scan measurements showed closer results than the RMS values of silicone and digital scan measurements. CONCLUSION: The study found that there was no statistically significant difference in the total RMS values of the ruga region between traditional and digital impression methods. CLINICAL RELEVANCE: The treatment period in orthodontics is long. Different impression materials and methods can be used for diagnostic, mid-treatment, and final impressions. For superimpositions and treatment and post-treatment palatal ruga evaluations, traditional and digital impression methods are clinically acceptable and can be used as alternatives to each other.

The effect of layer thickness on the accuracy of the different in-house clear aligner attachments.

OBJECTIVE: The accuracy of the attachments, one of the key components of clear aligner therapy, is important for obtaining more precise tooth movement. The aim of this study was to evaluate the accuracy of the ovoid, hemi-ellipsoid, and vertical rectangular attachments produced by the digital light-processing(DLP) 3-dimensional printing technologies with 25 µm, 75 µm, and 125 µm layer thickness. MATERIALS AND METHODS: The ovoid, hemi-ellipsoid, and vertical rectangular attachments were positioned onto the convex surface of the central incisor by the software. The printing process was carried out by a DLP printer using a commercially printed resin with 25 µm, 75 µm, and 125 µm layer thickness (n = 30, for each group). All test models' digital data was exported into the reverse engineering software for the superimposition. After selecting the 5 comparison points for the ovoid and vertical rectangular attachments, and 6 comparison points for the hemi-ellipsoid attachment, the Root Mean Square (RMS) was evaluated for each group. RESULTS: There is a statistically significant difference between the 25 µm and 125 µm layer thickness of total RMS values in the ovoid, hemi-ellipsoid, and vertical rectangular attachment groups (p = 0.001, p = 0.03, and p = 0.00 respectively). The printing time with the 25 µm layer thickness was 4 times longer than with the 125 µm layer thickness. CONCLUSIONS: This study revealed that the accuracy of the attachments used for in-house clear aligner therapy is affected by the layer thickness of the 3D printer. CLINICAL RELEVANCE: The layer thickness of the 3D printer is a crucial factor in determining attachment accuracy, but its clinical significance is minimal. Clinicians should make informed decisions about the appropriate layer thickness, taking into account their workflow preferences, time constraints, and other practical considerations specific to their clinical practice.

Evaluation of the accuracy of fully automatic cephalometric analysis software with artificial intelligence algorithm.

OBJECTIVE: The aim of this study is to evaluate whether fully automatic cephalometric analysis software with artificial intelligence algorithms is as accurate as non-automated cephalometric analysis software for clinical diagnosis and research. MATERIALS AND METHODS: This is a retrospective archive study using lateral cephalometric radiographs taken from individuals aged 12-20 years. Cephalometric measurement data were obtained from these lateral cephalometric radiographs by manual landmark marking with non-automated computer software (Dolphin 11.8). Again, the same radiographs were made using fully automatic digital cephalometric analysis software OrthoDx™ (AI-Powered Orthodontic Imaging System, Phimentum) and WebCeph (Assemblecircle, Seoul, Korea) with artificial intelligence algorithm, without manual intervention of the researcher and fully automatic markings and measurements were made by the software. RESULTS: According to the consistency test, a statistically significant good level of consistency was found between Dolphin and OrthoDx™ measurements and Dolphin and WebCeph measurements in angular measurements (ICC > 0.75, P < .01, ICC > 0.75, P < 0, respectively. 01). A weak level of consistency was found in linear measurement and soft tissue parameters in both software (ICC < 0.50, P < .05, ICC < 0.50, P < .05), and the difference between measurements was statistically found to be different from "0." CONCLUSION: The results obtained from fully automatic cephalometric analysis software with artificial intelligence algorithms are similar to the results of non-automated cephalometric analysis software, although there are differences in some parameters. To minimize the margin of error in artificial intelligence-based fully automatic cephalometric software, the manual intervention of the observer is needed.