Individual Teeth Research Articles

Teeth and tooth whorls of the stem chondrichthyan Doliodus from the Early Devonian of the Gaspé Sandstone Group, Gaspé Peninsula, Quebec, Canada

The Early Devonian (Emsian) vertebrate fauna of the Gaspé Peninsula, Quebec (Canada) shows close affinity with the Emsian fauna from the Atholville beds, New Brunswick (Canada). Specimens collected in the early 2000s from several localities in central Gaspé include molds of tooth whorls and isolated teeth that we assign to the stem chondrichthyan Doliodus. Isolated teeth of this taxon were first described from the Atholville beds in the late 1800s by Arthur Smith Woodward, who erected a new species Diplodus problematicus. Whereas the Atholville beds teeth are usually preserved individually or in tooth families, and as hard tissue, the Gaspé teeth are mostly preserved as molds of tooth whorls, with individual teeth sharing a thin bone base. Thin sections of Doliodus teeth from the Atholville beds show parallel close-set vascular canals extending above the base plate and through tooth bases, with teeth formed of osteodentine and meso- or orthodentine. We consider that all the known dental elements assigned to Doliodus are conspecific with the articulated Doliodus specimen and thus all are assigned to the same species D. latispinosus. The teeth are compared with the diplodont teeth of other stem chondrichthyan taxa, in particular the Omalodontiformes.

Fourier synthesis dispersion engineering of photonic crystal microrings for broadband frequency combs

Dispersion engineering of microring resonators is crucial for optical frequency comb applications, to achieve targeted bandwidths and powers of individual comb teeth. However, conventional microrings only present two geometric degrees of freedom – width and thickness – which limits the degree to which dispersion can be controlled. We present a technique where we tune individual resonance frequencies for arbitrary dispersion tailoring. Using a photonic crystal microring resonator that induces coupling to both directions of propagation within the ring, we investigate an intuitive design based on Fourier synthesis. Here, the desired photonic crystal spatial profile is obtained through a Fourier relationship with the targeted modal frequency shifts, where each modal shift is determined based on the corresponding effective index modulation of the ring. Experimentally, we demonstrate several distinct dispersion profiles over dozens of modes in transverse magnetic polarization. In contrast, we find that the transverse electric polarization requires a more advanced model that accounts for the discontinuity of the field at the modulated interface. Finally, we present simulations showing arbitrary frequency comb spectral envelope tailoring using our Fourier synthesis approach.

Surface wear and adhesive failure of resin attachments used in clear aligner orthodontic treatment.

This study evaluated adhesive and cohesive failures and the surface wear of attachments employed in clear aligner treatment (CAT) using three-dimensional (3D) superimposition. In all, 3D models of 150teeth were obtained from intraoral scans from patients undergoing CAT with at least 4months between each scan. Of the initial sample, 25teeth were discarded, and 125teeth were included in the study. Superimpositions of each individual tooth at the first and second time points were made using computer-aided design (CAD) software (Meshmixer; Autodesk, Mill Valley, CA, USA). Analyses were performed to compare surface wear and failures related to type of attachment (optimized/conventional), dental group (molars/premolars/anterior teeth), and arch (mandibular/maxillary). Mann-Whitney and Kruskal-Wallis statistical tests were applied with significance set at 5%. More surface wear was observed in conventional attachments, mandibular and anterior teeth with statistical significance for surface wear on the distal surface of conventional attachments (p < 0.05). Cohesive failure was observed in 10% of attachments, occurring most frequently on optimized attachments and molar teeth. Adhesive failure was observed in 10% of the samples, more frequently on conventional attachments and posterior teeth. Attachment type (conventional vs. optimized) was significantly correlated with surface wear on the distal surface of the attachment. Arch (mandibular or maxillary) and group of teeth (anterior or posterior) showed no correlation with surface wear. Failure, both adhesive and cohesive, correlated with attachment type and group of teeth, but not with the arch in which they were located.

Modeling of individual teleroentgenometric indicators using the COGS method in Ukrainian young men with a wide face type

Annotation. Cephalometric techniques for the analysis of lateral teleroentgenograms, for successful use in orthodontist practice, require a preliminary clinical study, which should include as many healthy individuals as possible from the local population for which this technique will be applied. The purpose of the study is to build and analyze regression models of radio-radiographic parameters used in COGS-methodology in Ukrainian young men with an orthognathic bite with a wide face type. 22 Ukrainian young men with an orthognathic bite and a wide face type underwent a cephalometric study using the COGS method. For the correct modeling of cephalometric characteristics, the division of teleroentgenometric indicators into three groups proposed by M. O. Dmitriev (2016, 2017) was used: the first group is the metric characteristics of the skull, which usually do not change during surgical and orthodontic treatment; the second group – indicators of the maxillofacial system, which can be used to change the width, length, angles and position of the upper and lower jaws with the help of orthognathic surgery; the third group – indicators that actually characterize the position of each individual tooth relative to each other, cranial structures and the profile of the soft tissues of the face. Construction of regression models of cephalometric indicators according to the COGS method was carried out in the “Statistica 6.0” license package. It was established that only 4 reliable regression models of teleroentgenometric indicators with a coefficient of determination greater than 0.6 were built using the COGS method for Ukrainian young men with a wide face, which were included in the second and third groups depending on the indicators of the first group (R²= from 0.626 to 0.780 ), as well as 11 reliable models of indicators were built out of 19 possible, which were included in the third group depending on the indicators of the first and second groups (R²= from 0.626 to 0.970). The analysis of the constructed regression equations showed that most often the models of indicators that were included in the second and third groups, depending on the indicators of the first group, include the value of the distances P-PTV (17.64 %) and N-Se (11.76 %) and the value of the angles H (17.64 %) and N-S-Ba (11.76 %); and to the indicator models that were included in the third group depending on the indicators of the first and second groups – the value of the distances ANS-Me (15.00 %), A-B and N-Pog (7.50 % each) and the value of the angles Ar-Go-Gn, H and N-A -Pog (7.50 % each). Further research will make it possible to develop a computer program that will enable dentists to automatically calculate individual normative teleroentgenometric indicators.

PECULIARITIES OF TEETH ERUPTION IN THE PERIOD OF MIXED DENTITION IN CHILDREN WITH DENTAL ALVEOLAR ANOMALIES FROM POLTAVA REGION

The prevalence of dento-alveolar anomalies in the structure of dental morbidity ranks the third position following dental caries and periodontal diseases. Signs of normal teething are the following: timeliness, sequence in relation to certain groups of teeth, evenness, eruption of teeth first in the lower jaw and then in the upper jaw. The timing of the eruption for deciduous and permanent teeth can shift in one direction or another. There is a distinction between premature and delayed teething. According to the literature, there are two options for the eruption of canines and premolars: premolars appear first (at the age of 7-11 years) followed by canines, or canines can erupt first (at the age 8 to 12 years) then followed by premolars. Both patterns are independent of gender and race. The purpose of this study is to determine the timing and sequence of eruption for permanent canines and premolars in children of Poltava Region and to establish the influence of eruption timing on the development of dental alveolar anomalies.&#x0D; The results of our research have demonstrated that the most common pathology is the anomaly of the position of individual teeth, or Class I according to Angle, which is diagnosed in 77.6% (615 cases) of patients over the period of tooth change. Class II malocclusion according to Angle, or distal bite is found in 150 patients (18.9%), in 68 patients in the first period of the mixed dentition and in 82 in the second period. Mesial bite, or class III according to Angle is diagnosed in 3.4% (27) of study subjects.&#x0D; Pathology in the vertical plane, namely, a deep bite is diagnosed in 153 people, 19.31% of them have open bite, and 6.56% (52 cases) have close bite, 2.77% (22) of patients have cross bite.&#x0D; Thus, the commonest orthodontic pathology in the mixed dentition of patients with of dento-alveolar anomalies from the Poltava region is the abnormality of the position of individual teeth, or Class I pathology according to Angle. The number of patients having this diagnosis is 77.6% of all children who searched for orthodontic care at this age.&#x0D; We have not found any special relationship between the nature of teeth eruption, gender and type of dental alveolar anomaly in orthodontic patients of Poltava region during the period of tooth change.

Evaluation of root position during orthodontic treatment via multiple intraoral scans with automated registration technology

This study aimed to introduce a method for dynamically monitoring root position with intraoral scans using automated crown registration and root segmentation with artificial intelligence technology and to evaluate its accuracy using a novel semiautomatic root apical distance measurement procedure. The sample consisted of 412 teeth from 16 patients whose intraoral scans and cone-beam computed tomography (CBCT) were obtained before and after treatment. Crowns from intraoral scans and roots segmented from CBCT with artificial intelligence technology before treatment were registered, integrated, and divided into individual teeth. With an automated registration program, the virtual root was constructed by crown registration before and after treatment. The distance deviation of the root position at the apex between the virtual root and the actual root, which served as a control, was measured and decomposed into the distance deviation in the mesiodistal and buccolingual directions. The shell deviation of crown registration between CBCT and oral scan before treatment was 0.19 ± 0.04 mm and 0.22 ± 0.04 mm in the maxilla and mandible, respectively. The apical root position distance deviations were 0.27 ± 0.12 mm in the maxilla and 0.31 ± 0.11 mm in the mandible. There was no significant difference between root position in mesiodistal and buccolingual directions. Applying automated crown registration and root segmentation with artificial intelligence technology in this study improved the accuracy and efficiency of monitoring root position. In addition, the innovative semiautomatic distance measurement procedure can more precisely distinguish the root position discrepancy.

Factors affecting the precision of age determination of sperm whales (Physeter macrocephalus)

Teeth from 92 sperm whales were prepared by etching for age determination. The total number of growth layer groups (GLGs) in the dentine of each tooth was determined from three to five reading sessions by a single reader. Four other readers, as part of a cross-reading experiment, read a subset of these teeth (n = 5). This study investigated: (1) intra- and (2) inter-reader precision in GLG counts; (3) possible variation in growth structure deposition between different teeth within the same individual; (4) the use of photographs to identify and count GLGs and the effect of this technique on the precision of counts; and (5) mineralisation anomalies in tooth sections and the possible effects these may have on GLG count precision. Intra- and inter-reader precision was determined using coefficients of variation (CV) and indices of precision (D). Total numbers of GLGs estimated from individual teeth ranged from 0.75-64 (¯x = 32.8, n = 92). Intra-reader mean CV was 10.6 and mean D was 4.8. Inter-reader mean CV ranged from 4.8-12.3 and mean D ranged from 2.8-7.1. Differences in final counts between readers appeared to be the result of differing interpretation of GLGs and this was the largest factor affecting the precision of GLG counts. While GLG counts between teeth in the same individual varied, it is possible that this variation was due to within reader variation rather than variation in the development of growth structures, but establishment of this cause is confounded by differential tooth wear. Use of photographs increased the definition of growth structures, decreasing the variation between GLG counts within reading sessions. The incidence of mineralisation anomalies and the closure of the pulp cavity increased with increasing GLG counts in individuals, but were not consistent between teeth from the same individual. These factors, while potentially affecting the accuracy of GLG counts in relation to age estimates, had little effect on the precision of GLG counts. The lack of an ability to validate age estimates in this species and the large inter-reader variation seen in this study suggests that age estimates based on GLG counts in this species are subjective and can only be regarded as relative. High-quality photographs of tooth sections should be used to verify GLG counts with other readers, resulting in ‘consensus counts’ generated by a number of readers, ensuring interpretation of the same structures and confidence in comparing GLG counts produced in different studies.

Accuracy of 3-dimensional–printed customized transfer tray using a flash-free adhesive system in digital indirect bonding: An in vivo study

This paper evaluated the accuracy of a computer-aided design and manufacturing indirect bonding technique using a new customized 3D-printed transfer tray and a flash-free adhesive system for orthodontic bonding. This invivo study analyzed 106 teeth selected from 9 patients undergoing orthodontic treatment. Quantitative deviation analysis was performed to evaluate the bonding positioning errors, assessing the differences between the virtually planned and the clinically transferred bracket position after indirect bonding procedures by superimposing 3-dimensional dental scans. Estimated marginal means were evaluated for individual brackets and tubes, arch sectors, and overall collected measurements. A total of 86 brackets and 20 buccal tubes were analyzed. Among individual teeth, mandibular second molars showed the highest positioning errors, whereas maxillary incisors reported the lowest values. Considering arch sectors, the posterior areas showed greater displacements than the anterior areas, as the right side compared to the left side, with a higher error rate reported for the mandibular arch than the maxillary arch. The overall bonding inaccuracy measurement was 0.35 mm, below the clinical acceptability limit of 0.50 mm. The accuracy of a 3-dimensional-printed customized transfer tray using a flash-free adhesive system in computer-aided design and manufacturing indirect bonding was generally high, with greater positioning errors for posterior teeth.

The precision of two alternative indirect workflows for digital model production: an illusion or a possibility?

ObjectiveDespite the clear drive from both research and clinical dentistry toward digital transformation, there are limitations to implementing intra-oral scanning (IOS) into daily dental practice. This study aimed to compare the precision of digital models obtained from two alternative indirect workflows to direct IOS.Material and methodsTwo indirect digital workflows were evaluated in this study. In the IOS group (direct), IOS directly obtained digital impressions of participants’ upper and lower dental arches, while in the Scan Impression (Scan Imp) group (indirect), a desktop scanner scanned silicone-based impressions of upper and lower whole arches that were taken with plastic trays. In the cone-beam computed tomography impression (CBCT Imp) group (indirect), a CBCT machine scanned the silicone-based impressions. Then, the precision of the entire arch and individual teeth for all digital impressions was virtually quantified. Following superimposition, differences between standard tessellation language (STL) files obtained from both—direct and indirect—methods were evaluated by color-mapping and measuring the surface distance between superimposed STL files. Furthermore, 18 linear measurements were taken from each digital model. ANOVA with repeated measures, Pearson coefficient, and intraclass correlation coefficient were used for intergroup comparisons.ResultsThe digital models obtained from the two indirect workflows differed from the IOS in some dental and intra-arch measurements but were considered clinically acceptable. Ranked against IOS, CBCT Imp models had greater precision, followed by Scan Imp.ConclusionDigital models obtained from two indirect, alternative workflows, desktop, and CBCT scanning of impression, have clinically acceptable accuracy and reliability of tooth size and intra-arch measurements, providing the use of proper methodologies.Clinical relevanceThere are some limitations to implementing IOS in daily clinical practice. However, several alternative digital model production techniques might provide an affordable solution. Although they may insignificantly differ in accuracy, all can be applied clinically.

Comparative evaluation of bracket bond failure rates of a novel non-primer adhesive with a conventional primer-based orthodontic adhesive - a pilot study.

Bonding is an important step in fixed orthodontic therapy and evaluation of bracket bond failures while using different bonding systems is required. The aim of the present study was to evaluate and compare bracket failure rates of a novel no primer adhesive with conventional primer-based orthodontic adhesives. This split mouth study was conducted among fifteen patients who underwent therapy with fixed orthodontic appliances using metal brackets. Total of 300 brackets were bonded and the bracket bond failure rates were assessed at the end of 3 months. The difference in bond failure rates between the two groups were assessed in different teeth. Descriptive statistics and chi-square test was performed. Evaluation of bracket bond failure rates showed a higher incidence of bond failures in the group bonded with the primerless adhesive (6.3%) compared to conventional adhesive (2.3%) but there was no statistically significant difference (P>0.05). No intergroup difference was found in the bracket failure rates of individual teeth (P>0.05). Higher incidence of bond failures were noted with brackets bonded with primerless adhesive when compared to primer-based adhesive but no significant difference was noted over a period of 3 months. Mandibular canine and premolars had a higher bracket failure rate with no significant difference between the adhesives.

Root canal treatment planning by automatic tooth and root canal segmentation in dental CBCT with deep multi-task feature learning.

Accurate and automatic segmentation of individual tooth and root canal from cone-beam computed tomography (CBCT) images is an essential but challenging step for dental surgical planning. In this paper, we propose a novel framework, which consists of two neural networks, DentalNet and PulpNet, for efficient, precise, and fully automatic tooth instance segmentation and root canal segmentation from CBCT images. We first use the proposed DentalNet to achieve tooth instance segmentation and identification. Then, the region of interest (ROI) of the affected tooth is extracted and fed into the PulpNet to obtain precise segmentation of the pulp chamber and the root canal space. These two networks are trained by multi-task feature learning and evaluated on two clinical datasets respectively and achieve superior performances to several comparing methods. In addition, we incorporate our method into an efficient clinical workflow to improve the surgical planning process. In two clinical case studies, our workflow took only 2min instead of 6h to obtain the 3D model of tooth and root canal effectively for the surgical planning, resulting in satisfying outcomes in difficult root canal treatments.

Investigation of the force reactions’ magnitude around the mounts of orthodontic appliances in the process of orthodontic treatment of children with congenital unilateral cleft lip and palate

For the purpose of orthodontic treatment of children with congenital cleft lip and palate, various orthodontic constructions are used. The use of removable appliances indicated for narrowing or shortening of the dental arches, anomalies of the individual teeth position. The question of determining the magnitude of force reactions around special devices (clasps) that are designed to fix appliances on teeth during treatment, under the conditions of the specificity of the development of the upper jaw and the impact of surgical interventions on it, requires detailing, which determined the purpose of this research. A three-dimensional 3D simulation model was created based on digital data of the spatial geometry of a sample of orthodontic appliance used for orthodontic treatment of children with congenital unilateral cleft lip and palate. Mathematical modeling methods were used to study the stress-deformed state of the appliance and estimate the magnitudes and distribution of the amplitudes of force reactions around its fasteners (clasps). Force reactions around of the supports of the orthodontic appliance when the screw is rotated from 0° to 360° (axial movement by 1 mm) are unevenly distributed, with a minimum value of force amplitudes of 10.3 N and a maximum of 30.9 N. It was noted that in the area of fasteners (clasps) placed more distally, the values are higher (30.9 N and 27.6 N) than in the medially placed fasteners (10.3 N and 12.5 N). It is also worth noting that on the side of the base of the appliance, which corresponds to the location of the small fragment of the jaw, the values of the force amplitudes are greater (30.9 N and 12.5 N) than on the side of the large fragment (27.6 N and 10.3 N). A significant dependence of the values of force reactions on the stiffness characteristics of the jaw and the type of force transmission from the orthodontic appliance to its areas was established. Keywords: 3D simulation model, force reactions, clasps.

PHYSICAL PROPERTIES OF ORAL LIQUID IN CHILDREN WITH MALOCCLUSION AND DIFFERENT ENAMEL RESISTANCE

One of the factors in the development of dental caries in children with malocclusion is the insufficient enamel mineralization in different age periods, that is, its resistance is reduced. An important role in the formation of enamel resistance is played by the oral fluid, in particular its physical properties, mineralization potential and protective mechanisms. Fluctuations in the pH of the oral fluid significantly depend on the hygienic condition of the oral cavity and the nature of the food. At the same time, the possibility of access of mineral elements to the surface of the enamel significantly worsens in case of increased viscosity and decreased rate of saliva secretion of oral fluid. This, in turn, contributes to the reduction of diffusion processes in tooth enamel and the creation of conditions for the development of enamel demineralization.&#x0D; The purpose of the investigation is to study the peculiarities of the physical properties of oral fluid in children with malocclusion at different levels of enamel resistance.&#x0D; Research methods. It was found that the concentration of hydrogen ions in the oral fluid of the examined children with malocclusion is, on average, 6.67±0.05 units, and the viscosity and rate of saliva secretion is 2.32±0.06 rel. unit and 0.43±0.02 ml/min. In children with anomalies of individual teeth, the average pH value of the oral fluid is 6.93±0.08 units, while with anomalies of the dental arches and occlusion, there is a shift of the pH to the acidic side. In 12and 15-year-old children with anomalies of occlusion and caries-resistant enamel, the pH of the oral fluid is higher by 7.46% and 7.85%, respectively, compared to children with conditional-resistant and caries-susceptible enamel, the viscosity of the oral fluid is lower by 40.49% and 33.48%, respectively, and the rate of salivation is higher by 26.19% and 22.92%, which changes the function of oral fluid in the latter towards the demineralizing solution.&#x0D; Conclusions. Thus, the detected changes in the physical properties of the oral fluid in children with malocclusion and reduced enamel resistance may be important in the pathogenesis of dental caries development, as in such conditions the function of the oral fluid changes from mineralizing to demineralizing.

Relationship of Root Proximity with Periodontal Disease - A Clinico-Radiographic Retrospective Study

Aim: The present study was conducted with the aim to examine whether root proximity is a risk marker for periodontal disease. Introduction- Root proximity is one of the key factors that the clinician should evaluate to determine the individual tooth prognosis before periodontal treatment. Root proximity was determined as favourable when there was more than 1mm of bone between the roots and unfavourable when less than 1mm was recorded. Methodology: Total 300 individuals were included in the study. 150 patients with advanced periodontal disease with at least one mandibular molar with bone loss greater than one third of the root length and 150 controls without periodontal disease each were included. Interproximal space was assessed on the IOPA (paralleling angle) between 1st molar and 2nd molar and a score was assigned according to severity and location. Consequently, relative risk for periodontal disease was calculated with DIOGRA TM software. A two-digit classification was obtained dividing the root into three locations [apical (A), between (B) and coronal (C)] Results: In patients with advanced periodontal disease, there is more interradicular distance at apical area and less at CEJ which implies that there is more root proximity at CEJ. However, in healthy patients, there is more interradicular distance at CEJ implying lesser root proximity at CEJ. Hence root proximity can be considered as a risk marker for periodontitis. Conclusion: Root proximity can be a predisposing factor for the progression of periodontal disease. However, we should not forget about the impact of other significant factors, such as oral hygiene and the presence of plaque. Keywords: Root Proximity, Periodontal Diseases, Oral Hygiene, Plaque, CEJ

Detecting missing teeth on PMCT using statistical shape modeling

The identification of teeth in 3D medical images can be a first step for victim identification from scant remains, for comparison of ante- and postmortem images or for other forensic investigations. We evaluate the performance of a tooth detection approach on mandibles with missing parts or pathologies based on statistical shape models. The proposed approach relies on a shape model that has been built from the full lower jaw, including the mandible and teeth. The model is fitted to the target, resulting in a reconstruction, in addition to a label map that indicates the presence or absence of teeth. We evaluate the accuracy of the proposed solution on a dataset consisting of 76 target mandibles, all extracted from CT images and exhibiting various cases of missing teeth or other cases, such as roots, implants, first dentition, and gap closure. We show an accuracy of approximately 90% on the front teeth (including incisors and canines in our study) that decreases for the molars due to high false-positive rates at the wisdom teeth level. Despite the drop in performance, the proposed approach can be used to obtain an estimate of the tooth count without wisdom teeth, tooth identification, reconstruction of the existing teeth to automate measurements taken as part of routine forensic procedures, or prediction of the missing teeth shape. In comparison to other approaches, our solution relies solely on shape information. This means it can be applied to cases obtained from either medical images or 3D scans because it does not depend on the imaging modality intensities. Another novelty is that the proposed solution avoids heuristics for the separation of teeth or for fitting individual tooth models. The solution is therefore not target-specific and can be directly applied to detect missing parts in other target organs using a shape model of the new target.

Comparison of alveolar bone thickness and height after slow expansion using quad-helix or clear aligners

ObjectiveThe study was conducted to investigate the thickness and height of the alveolar bone of individual teeth after slow maxillary expansion (SME) with quad helix or clear aligner appliances and hypothesized that there is no difference in buccal alveolar bone thickness or heights in patients treated by either quad helix or clear aligners. Material and MethodsThis is a retrospective study; the records of 22 patients treated between December 2019 to April 2020 by dental arch expansion using either clear aligners or quad helix appliances were retrieved and studied. The results obtained through cone beam computed tomography (CBCTs) before and immediately after maxillary expansion (2 + 1 mm per side) were analyzed (11 in the Quad Helix group and 11 in the clear aligner). The data collected was analyzed using linear and angular measurements obtained through On-demand 3D App software. Furthermore, Statistical Package for Social Sciences (SPSS) version 25.0 was used to present the findings by mean and standard deviations, and Scheffe’s test was applied for comparing forces. ResultsThe results showed that the mean age of patients in the clear aligner group and Quad Helix was 16.27 ± 0.56 years and 15.5 ± 1.53 years, respectively. There was no difference in buccal alveolar bone thickness or heights in patients treated by either quad helix or clear aligners. This is due to the findings that suggest that there was a decrease in bone height and bone width when treated with a quad helix as compared to clear alignment. ConclusionIt can be concluded that the quad helix SME treatment affects alveolar bone integrity; therefore, clear aligners might be better for treating patients than the quad helix.

ЦИФРОВЫЕ ТЕХНОЛОГИИ ИНДИВИДУАЛЬНОГО ПРОГНОЗИРОВАНИЯ РАЗВИТИЯ КАРИЕСА ОТДЕЛЬНЫХ ЗУБОВ

Objective. To develop a utilitarian technology for predicting the development of caries in individual teeth of adult patients for up to 2 years.&#x0D; Material and methods. A clinical examination was carried out with the subsequent entry of data into the author's questionnaire. With the help of system programming, a technology for individual prediction of the development of caries of individual teeth has been developed. We used the methods of descriptive statistics, discriminant analysis, digital technologies.&#x0D; Results. A technology has been developed for digital registration and assessment of risk factors (age, profession, marital status, dietary commitment, bad habits, time for brushing teeth, fluoridation, taking vitamins and dietary supplements) for the development of caries. The technology allows you to effectively predict the development of caries for up to 2 years on 1.2, 1.6, 1.7, 2.2, 2.3, 2.5, 2.6, 2.7, 2.8 teeth of the upper and 3.2, 3.3, 3.4, 3.6, 3.7, 4.4, 4.6, 4.7, 4.8 of the lower jaw with a classification accuracy of 50.0–92.6% and 50.4–77.3%, respectively.&#x0D; Conclusion&#x0D; 1. The use of digital technologies in dentistry for reliable registration and effective analysis of the studied risk factors makes it possible to predict the development of caries for up to 2 years on 1.2, 1.6, 1.7, 2.2, 2.3, 2.5, 2.6, 2.7, 2.8 teeth of the upper and 3.2, 3.3, 3.4, 3.6, 3.7, 4.4, 4.6, 4.7, 4.8 of the lower jaw with a classification accuracy of 50.0-92.6% and 50.4-77.3%, respectively.&#x0D; 2. Digital technology for predicting the development of caries of individual teeth contributes to the timely implementation of dental monitoring with high forecast accuracy for individual preventive hygiene measures, which is especially important to reduce the risk of enamel demineralization and the progression of dental diseases.&#x0D; 3. A technology has been developed for predicting the development of caries based on system programming with access and subsequent possibility of posting on the Internet.

Comparison of maxillary anterior tooth movement between Invisalign and fixed appliances

This research project aimed to compare the number of maxillary incisors and canine movement between Invisalign and fixed orthodontic appliances using artificial intelligence and identify any limitations of Invisalign. Sixty patients (Invisalign, n= 30; braces, n= 30) were randomly selected from the Ohio State University Graduate Orthodontic Clinic archive. Peer Assessment Rating (PAR) analysis was used to indicate the severity of the patients in both groups. To analyze the incisors and canine movement, specific landmarks were identified on incisors and canines using an artificial intelligence framework, two-stage mesh deep learning. Total average tooth movement in the maxilla and individual (incisors and canine) tooth movement in 6 directions (buccolingual, mesiodistal, vertical, tipping, torque, rotation) were then analyzed at a significance level of α= 0.05. Based on the posttreatment Peer Assessment Rating scores, the quality of finished patients in both groups was similar. In maxillary incisors and canines, there was a significant difference in movement between Invisalign and conventional appliances for all 6 movement directions (P<0.05). The greatest differences were with rotation and tipping of the maxillary canine, along with incisor and canine torque. The smallest statistical differences observed for incisors and canines were crown translational tooth movement in the mesiodistal and buccolingual directions. When comparing fixed orthodontic appliances to Invisalign, patients treated with fixed appliances were found to have significantly more maxillary tooth movement in all directions, especially with rotation and tipping of the maxillary canine.

Occlusal contacts and treatment with the Invisalign appliance: a retrospective analysis of predicted vs achieved outcomes.

To quantify the predicted occlusal contact outcomes compared with the clinically achieved occlusal contacts following treatment using the Invisalign aligner appliance. The occlusal contacts of 33 adult patients presenting with a Class I mild-to-moderate malocclusion (spacing <4 mm or crowding of <6 mm) and treated using the Invisalign appliance were measured at the initial, predicted, and achieved stages of treatment by the metrology software Geomagic Control X. Assessed measurements were related to individual teeth and anterior, posterior, and overall contacts. The mean (standard deviation) difference between the achieved occlusal contact was significantly less than that predicted for overall occlusal contact and posterior occlusal contact (P < .0025). The achieved posterior occlusal contact was also less than pretreatment initial posterior occlusal contact. There was no difference in anterior occlusal contact between the predicted and achieved outcomes (P > .05). The central and lateral incisors displayed no statistically significant difference between the predicted and achieved occlusal contact. The patients with prescribed overcorrection demonstrated a statistically significant difference in predicted occlusal contact compared with those with nonprescribed overcorrection (P ≤ .0025), but no statistically significant difference in achieved occlusal contact. Treatment by the Invisalign appliance in Class I mild-to-moderate malocclusion resulted in a decrease in posterior occlusal contact. Further research is required to account for the deficiencies between the predicted and achieved clinical outcome related to occlusal contact and to determine the corrective changes required in the treatment protocols.

A Novel 3D Volumetric Method of Analyzing Gingival Positional and Dimensional Alterations During Orthodontic Therapy: A Pilot Study.

The aim of the present study was to develop a 3D digital image-analysis method to quantitatively assess gingival changes after clear-aligner orthodontic therapy. Using teeth as fixed reference points, 3D image analysis tools have been used to quantify mucosal level changes after specific therapies. This technology has not been applied to orthodontic therapy, primarily because orthodontic tooth movement precludes using teeth as fixed reference points. Rather than superimposing the pre- and posttherapy volumes for the entire dentition, the methodology presented herein superimposed the pre- and post-therapy volumes for individual teeth. The lingual tooth surfaces, which remained unaltered, were used as fixed references. Intraoral scans taken before and after clear-aligner orthodontic therapy were imported for comparison. Volumes were created for each 3D image and were superimposed in a 3D image-analysis software that allowed quantitative measurements. The results demonstrated this technique's ability to measure very small changes in the apicocoronal position of the gingival zenith, as well as alterations of gingival margin thickness, following clear-aligner orthodontic therapy. The present 3D image-analysis method offers a useful tool for investigating the periodontal dimensional and positional changes that accompany orthodontic therapy.