Comparison of Tooth Size Measurements in Orthodontics Using Conventional and 3D Digital Study Models

(1) Background: The objective of this study was to assess which digitization method produces the biggest deviation in the 3D images of tooth size from plaster models made using alginate impressions, which are considered the gold standard in orthodontics. (2) Methods: The sample used in this study included 30 subjects (10 males and 20 females). Measurements were made on four types of models: (1) digital models obtained through intraoral scanning and digitized models of plaster cast made from (2) alginate impressions, (3) silicone impressions, and (4) conventional plaster models. Mesio-distal (MD) and buccal/labial-lingual/palatal (BL) dimensions were measured on the reference teeth of the right side of the jaw (central incisor, canine, first premolar, and first molar). Comparisons of tooth size between the methods were conducted using a repeated measurement analysis of variance and the Friedman test, while the intraclass correlation coefficient was used to determine agreement between the different methods. (3) Results: The results showed a similar level of agreement between the conventional and digital models in both jaws and the anterior, middle, and posterior segments. Better agreement was found for the MD measurements (r = 0.337-0.798; p ≤ 0.05) compared to the BL measurements (r = 0.016-0.542), with a smaller mean difference for MD (0.001-0.50 mm) compared to BL (0.02-1.48 mm) and a smaller measurement error for MD (0.20-0.39) compared to BL (0.38-0.89). There was more frequently a better level of agreement between 3D images than measurements made using a digital caliper on the plaster models with 3D images. (4) Conclusions: The differences in measurements between the digital models and conventional plaster models were small and clinically acceptable.

Perfectionism, Self-Esteem, and Body Image Related to Self-Perception of Orofacial Appearance-Development and Validation of Psychometric Instrument

PURPOSE

To develop an instrument for the assessment of perception of orofacial appearance and psychologic issues that can affect people's judgment.

MATERIALS AND METHODS

A panel composed of five members (one psychologist, two prosthodontists, one orthodontist, and one final-year dental student) generated 31 items that could draw specific hypothetical dimensions. The questionnaire was self-administered by individuals attending local high schools and a university (n = 261; 26.4% men and 73.6% women) in the 14- to 28-year age range. Internal consistency, construct validity, responsiveness, and temporal stability were assessed.

RESULTS

Factorial analysis and Cronbach alpha identified four dimensions (self-esteem, perfectionism, body image, and smile appearance concern) that could be best addressed using 17 items. Internal consistency was good (α in the .70 to .80 range). The dimensions were correlated with existing instruments that measure similar constructs. In responsiveness testing, tooth whitening did not induce changes in perfectionism or body image; however, it did increase self-esteem and decrease esthetic concern (P < .05).

CONCLUSIONS

The newly created instrument, Orofacial Appearance Perception Questionnaire, is a consistent and reliable short instrument that measures psychologic issues related to the perception of orofacial appearance.

Megalin Expression in Primary Oral Squamous Cell Carcinoma Is Associated with the Presence of Lymph Node Metastases, Vascular Invasion, and Lower Overall Survival

Megalin (LRP2) is a rapidly recycling multiligand endocytic receptor primarily expressed in polarized epithelial cells. Although megalin might be involved in tumor growth and invasiveness through several mechanisms, its role has been understudied in the field of molecular oncology so far. The present study aimed to evaluate the impact of megalin expression in oral squamous cell carcinoma (OSCC) on disease progression. Megalin expression was evaluated immunohistochemically in 63 OSCC specimens. Data obtained were retrospectively compared with patient clinicopathological features and their survival. The proportion of megalin-expressing cells in the primary OSCC tissue was significantly associated with metastatic spreading to lymph nodes, vascular invasion and lower overall survival rate. Results obtained by the study suggest that megalin can be considered as a novel molecule involved in OSCC pathogenesis, but also useful as a potential biomarker for cancer progression.

Metallothioneins and Megalin Expression Profiling in Premalignant and Malignant Oral Squamous Epithelial Lesions

This study aimed to assess the relationship and possible interactions between metallothioneins (MTs) and megalin (LRP-2) in different grades of oral squamous cell carcinoma (OSCC) and premalignant lesions of the oral mucosa (oral leukoplakia and oral lichen planus). The study included archived samples of 114 patients and control subjects. Protein expression was examined by immunohistochemistry and immunofluorescence, and staining quantification was performed by ImageJ software. Protein interaction in cancer tissue was tested and visualized by proximity ligation assay. Mann-Whitney and Kruskal-Wallis tests were used to determine the significance of differences between each group, whereas Pearson correlation coefficient was performed to test correlation. Expression of both proteins differed significantly between each group showing the same pattern of gradual increasing from oral lichen planus to poorly differentiated OSCC. Moreover, MTs and megalin were found to co-express and interact in cancer tissue, and their expression positively correlated within the overall study group. Findings of prominent nuclear and chromosomal megalin expression suggest that it undergoes regulated intramembrane proteolysis upon MTs binding, indicating its ability to directly affect gene expression and cellular division in cancer tissue. The data obtained point to the onco-driving potential of MTs-megalin interaction.

An Enhanced Histopathology Analysis: An AI-Based System for Multiclass Grading of Oral Squamous Cell Carcinoma and Segmenting of Epithelial and Stromal Tissue

Oral squamous cell carcinoma is most frequent histological neoplasm of head and neck cancers, and although it is localized in a region that is accessible to see and can be detected very early, this usually does not occur. The standard procedure for the diagnosis of oral cancer is based on histopathological examination, however, the main problem in this kind of procedure is tumor heterogeneity where a subjective component of the examination could directly impact patient-specific treatment intervention. For this reason, artificial intelligence (AI) algorithms are widely used as computational aid in the diagnosis for classification and segmentation of tumors, in order to reduce inter- and intra-observer variability. In this research, a two-stage AI-based system for automatic multiclass grading (the first stage) and segmentation of the epithelial and stromal tissue (the second stage) from oral histopathological images is proposed in order to assist the clinician in oral squamous cell carcinoma diagnosis. The integration of Xception and SWT resulted in the highest classification value of 0.963 (σ = 0.042) AUCmacro and 0.966 (σ = 0.027) AUCmicro while using DeepLabv3+ along with Xception_65 as backbone and data preprocessing, semantic segmentation prediction resulted in 0.878 (σ = 0.027) mIOU and 0.955 (σ = 0.014) F1 score. Obtained results reveal that the proposed AI-based system has great potential in the diagnosis of OSCC.

ODONTOMAS: PEDIATRIC CASE REPORT AND REVIEW OF THE LITERATURE

Odontomas are benign odontogenic tumors formed from epithelial and mesenchymal cells. They are mostly associated with disorders of tooth eruption, causing impaction and/or delayed tooth eruption, and are an accidental finding on routine radiological examination. The aim of this paper is to present current findings in the etiology and treatment of odontomas, as well as the clinical and radiographic features, describing a case that is rarely found in the literature. A case of multiple complex odontoma in the mandible of an 11-year-old boy is presented, causing impaction of the first permanent right molar, 46. The treatment consisted of surgical enucleation of the multiple complex odontoma with preservation of the impacted tooth, monitoring clinically and radiologically its spontaneous eruption followed by final orthodontic alignment. Odontomas are not an everyday part of clinical practice and given that they are most commonly associated with permanent tooth impaction, it is extremely important to have knowledge of their clinical and radiological features. Early diagnostics and appropriate treatment result in better diagnosis, thus increasing the possibility of preserving the impacted teeth.