Tooth Position Research Articles

Infraocclusion in the Primary and Permanent Dentition-A Narrative Review.

The gradual movement of a tooth away from the occlusal plane is called infraocclusion or reinclusion. Reincluded teeth are most often deciduous molars, and permanent teeth are less frequently affected. Depending on the level of the infraocclusion, the severity of the disorder is classified as mild, moderate, or severe. The etiology of the phenomenon is not fully known. Tooth submerging can lead to serious complications, such as abnormal position of adjacent teeth, displacement of the bud of the permanent successor, shortening of the dental arch, or developmental disturbances of alveolar process. Early diagnosis of the tooth infraocclusion and regular monitoring of its progression help to avoid serious permanent sequelae. The treatment of reinclusion often involves only observation. However, in some cases, the therapeutic procedure requires interdisciplinary treatment by specialists from various fields of dentistry. This study presents current methods of diagnosis and treatment of patients with submerged teeth.

The Use of Clear Aligners in Multi-Segmental Maxillary Surgery: A Case-Control Study in Cleft Lip and Palate and Skeletal Class III Patients.

Background: Maxillary hypoplasia and mandibular asymmetry may be corrected with orthognathic surgery after growth completion. For most stable results, some cases may require segmental Le Fort I osteotomies. Unfortunately, Invisalign's software (6.0 version) still has some inherent limitations in predicting outcomes for complex surgeries. This study explores the potential of aligners, particularly in multiple-piece maxillary osteotomies in both cleft and non-cleft patients. Method: Thirteen patients who underwent pre-surgical treatment with Invisalign were retrospectively matched in terms of diagnosis, surgical procedure, and orthodontic complexity with thirteen patients treated using fixed appliances. Virtual curves following the lower arch were employed to guide the correct pre-surgical positions of the upper teeth with a simple superimposition technique. The amount of impressions required in both groups to achieve satisfactory pre-surgical alignment of the segmented arches was compared. Results: one or no refinement phases were needed in the Invisalign group to reach an acceptable pre-surgical occlusion, while the amount of pre-surgical impressions needed to reach adequate coordination with fixed appliance treatment was slightly higher (p > 0.05). Conclusions: it appears that clear aligner could serve as an effective treatment for individuals necessitating segmental Le Fort I osteotomies when aided by the suggested simple superimposition approach.

Experimental study of symmetrical ferrofluid seals with single magnetic source and small clearance

To enhance the sealing pressure of normal ferrofluid seals with single magnetic source and small sealing clearance, a symmetrical ferrofluid seal (SFFS) was designed. The study utilizes a combination of finite element simulation and experiments to investigate the influence of crucial factors, including sealing clearance, number of pole teeth, step height, and pole teeth position, on the sealing pressure of SFFS. The findings indicate that the experimental sealing pressure values for SFFS closely match the theoretical sealing pressure values. The sealing pressure of the SFFS decreases as the sealing clearances and step height increase. It increases with an increase in the number of pole teeth.

Invisalign Lite: a cross-sectional investigation of orthodontist treatment-planning practices.

To survey treatment-planning practices of orthodontists related to the Invisalign Lite clear aligner appliance (Align Technology, San Jose, Calif). Patients satisfying inclusion and exclusion criteria and treated with Invisalign Lite were selected from a database containing more than 17,000 patients. Relevant data regarding treatment-planning practices were obtained from Align Technology's treatment-planning facility, ClinCheck, and evaluated. Most (n = 135; 79.9%) patients were female and had a median (interquartile range [IQR]) age of 30.5 (23.8, 43.1) years. The median (IQR) number of aligners for the sample was 23.0 (14, 28) for the maxilla and 24 (14, 28) for the mandible. Most (n = 122; 72.2%) patients required at least one additional series of aligners. More locations for interproximal reduction (IPR) were prescribed in the mandible (mean 1.91 [1.78]) than in the maxilla (1.03 [1.78]; P < .024) in the initial accepted plan of all patients. More teeth were prescribed composite resin (CR) attachments in the maxilla (P < .0001) in the initial accepted plan of all patients. Issues regarding tooth position protocols (n = 50; 53.3%) and requirement for additional IPR (n = 68; 45.3%) were reasons for treatment plan changes before acceptance of the initial treatment plan by orthodontists. More than 7 of 10 patients required at least one additional series of aligners after the initial series of Invisalign Lite aligners was completed. Prescription of IPR was more common in the mandible, and prescription of CR attachments was more common in the maxilla.

Complementary description of three species of the subgenus Anthoseius De Leon (Acari: Phytoseiidae) from India

Taxonomy of the subgenus Anthoseius De Leon (Acari: Phytoseiidae) has become challenging and often causing confusions among taxonomists. We here provide complementary descriptions of three species, T. (A.) bengalensis Karmakar et al., T. (A.) bulbosis Karmakar et al., and T. (A.) serrulatus Ehara, based on the specimens collected from Karnataka, India. During the identification of our specimens, we observed several important morphological differences between the new specimens and the original descriptions of the first two species. The morphological differences include number of dorsal solenostomes (absence or presence of gd5), position of preanal pores, chelicera dentition including position of teeth, shape of calyx of spermatheca, and leg chaetotaxy including number of setae on genu II, number of macrosetae and shape of ventral setae. Since these characters are crucial for phytoseiid taxonomy, we decided to examine the type specimens of these two species. Our examination on their holotypes confirmed that the morphological characters mentioned above are different than those reported in their original descriptions, but identical to the complementary descriptions provided here. In addition, T. (A.) serrulatus has not been recognized by several acarologists and repeatedly described under different names. We proposed five new and three suspected synonymies for this species. Lastly, we also provided the first description of males of T. (A.) bengalensis.

Effects of clear aligners on the vertical position of the molar teeth and the vertical and sagittal relationships of the face: a preliminary retrospective before-after clinical trial

IntroductionDespite the popularity of clear aligners, their predictability has not been assessed adequately. Moreover, no study has investigated their effects on numerous dentomaxillary variables. Therefore, this study was conducted for the first time, assessing several new or controversial items. The aim of the study was to evaluate the effects of clear aligners on the vertical position of the molar teeth and the vertical and sagittal relationships of the face.MethodsThis preliminary retrospective before-after non-randomized clinical trial was performed on 168 observations of 84 patients (33.60±9.28 years, 54 females) treated with 0.75mm Invisalign appliances. Pretreatment and posttreatment values were measured for: mandibular plane angle, occlusal plane angle, Y-Axis, ANB, facial angle, lower anterior facial height, overbite, and the distances of the molars from the palate and mandibular plane were measured. The alterations in parameters caused by treatment (delta values) were calculated for each measurement. Effects of treatment and some parameters on delta values were analyzed statistically (α=0.05).ResultsMean±SD of ΔMP-FH, ΔOP-FH, ΔY-Axis, ΔLAFH, ΔNPog-FH, ΔANB, ΔOverbite, ΔSNB, Δ6-PP, Δ7-PP, Δ6-MP, and Δ7-MP were respectively 0.11±1.61, 0.80±1.56, 0.15±1.18, 0.07±0.91, -0.22±1.25, 0.03±0.62, 0.04±1.15, -0.06±1.14, -0.36±0.94, -0.32±1.14, 0.19±0.96, 0.18±1.10. Only the alterations in OP-FH, 6-PP, and 7-PP were significant (P≤0.011). Age, sex, treatment duration, or pretreatment mandibular plane angle were not correlated with any delta values. However, the pretreatment occlusal plane angle was negatively correlated with ΔOP-FH and ΔY-Axis. Crowding was correlated negatively with ΔOP-FH and ΔY-Axis and positively with ΔNPog-FH. Overjet was negatively correlated with ΔANB and ΔOverbite (P≤0.035).ConclusionsInvisalign intruded first/second maxillary molars and increased the occlusal plane angle. Age, sex, and treatment duration were not correlated with post-treatment anatomic alterations.

Digital assessment of supracrestal tissue attachment and its correlation with dentogingival components.

The aim of this study is to measure, in vivo, the supracrestal tissue attachment dimensions (STADs) by means of a noninvasive digital method and to investigate the association between STADs and gingival thickness (GT), tooth position, tooth length, tooth width, keratinized tissue width (KTW), buccal bone thickness (BBT), and bone crest (BC) level. Nineteen periodontally healthy subjects who previously received full mouth periodontal charting, cone beam computed tomography, and intraoral scan for the purpose of implant planning were included in the study. A digital imaging software was used for the superimposition of Digital Imaging and Communications in Medicine and stereolithography files, along with hard and soft tissue measurements. Pearson's correlation and ANOVA statistical analyses were used to investigate potential trends between STADs and other dentogingival components. A total of 203 teeth were assessed, with an average STADs of 2.05mm (±0.99mm). STADs were larger in mandibular than maxillary teeth (p-value <0.001) and decreased from anterior to posterior teeth. STADs exhibited an inverse relationship with BBTs and GTs (p-value <0.001) and the KTW (p-value=0.05). Positive correlations were found between GT and BBT (p-value <0.001), whereas both were negatively correlated with the distance between the cementoenamel junction and BC (p-values 0.019 and 0.006, respectively) and positively correlated with KTW (p-value <0.001). This study highlighted the dynamic nature of STA relative to tooth position. Additionally, it explored the intricate relationships of STADs with various dentogingival components. To the best of the authors' knowledge, this study represents the first application of CBCTs, intraoral scans, and clinical probe depths for noninvasive supracrestal tissue attachment measurements. This study advocates for a personalized assessment of supracrestal attachments, incorporating tooth position and other dentogingival components. The study emphasizes the importance for practitioners to consider the specific patient gingival phenotypes during restorative or surgical planning to avoid adverse outcomes.

Comparative study on the results of orthodontic diagnostics by using algorithms generated by Artificial Intelligence and simple algorithms.

Artificial intelligence (AI) is computer-generated intelligence, as opposed to the natural intelligence of humans and some animals. Kaplan and Haenlein define AI as "the ability of a system to correctly interpret external data, to learn from such data and use what it has learned to achieve specific goals and tasks through a flexible adaptation". The term "artificial intelligence" is used colloquially to describe machines that mimic the "cognitive" functions that people associate with other human minds. One of the areas where technological advances have brought significant changes is orthodontics, especially in terms of diagnosis and orthodontic prediction.The aim of this study is to conduct a comparative analysis between the results obtained by using the complete algorithms that define Artificial Intelligence and the simple algorithms of classical medical software, used in the detection of the position and shape of teeth in various orthodontic anomalies. A group of 45 patients with maxillary-dento anomalies Angle Class I (DDM with crowding and deviation of the superior inter-incisive line) was studied. Two types of algorithms were used in the study group: modern type I algorithms and simple algorithms used in classical software to detect the position of the frontal teeth. Through the symmetrical points of the face the facial axes were determined, and after the detection of the contour of each tooth the incisional curve was calculated. The median line was analyzed against the vertical axis of the face, and the incisional curve towards the horizontal axis. The study shows that AI algorithms offer an increased level of tooth position detection, compared to traditional softwares. Complex algorithms, specific to Artificial Intelligence, showed superior detection, and more stability in the analysis. Technological evolution and the development of machine learning capabilities have opened new perspectives in guiding orthodontic treatments through artificial intelligence (AI).

A scanning electron microscopy investigation of the precision of three orthodontic bracket slot systems

ObjectiveOne of the most imprortant factors in achieving ideal teeth positions is the precision of the slot dimensions of orthodontic brackets into the archwires are inserted.This study aimed to assess the accuracy of the dimensions of orthodontic bracket slots and molar buccal tube apertures and to compare them with the specifications provided by the manufacturers.MethodA total of sixty brackets and ten molar buccal tubes with varying slot heights were examined using a scanning electron microscope from the mesial side. The dimensions and morphology of these bracket slots and buccal tubes apertures were assessed using the AutoCAD Software. A one-sample t-test was conducted to compare the measurements with the values provided by the manufacturer.ResultsThe findings of the present study indicated that the height of the measured bracket slots and buccal tube apertures dimensions were significantly larger than the actual dimensions and exhibiting divergent walls. On the other hand, the depth of the brackets slots showed significantly smaller values than the actual one.ConclusionA need for careful consideration when selecting a commercially accessible brand for everyday use is essential as certain materials may not meet acceptable standards.

Exceptionally rapid tooth development and ontogenetic changes in the feeding apparatus of the Komodo dragon.

Dental developmental and replacement patterns in extinct amniotes have attracted a lot of attention. Notable among these are Paleozoic predatory synapsids, but also Mesozoic theropod dinosaurs, well known for having true ziphodonty, strongly serrated carinae with dentine cores within an enamel cap. The Komodo dragon, Varanus komodoensis, is the only extant terrestrial vertebrate to exhibit true ziphodonty, making it an ideal model organism for gaining new insights into the life history and feeding behaviours of theropod dinosaurs and early synapsids. We undertook a comparative dental histological analysis of this extant apex predator in combination with computed tomography of intact skulls. This study allowed us to reconstruct the dental morphology, ontogeny, and replacement patterns in the largest living lizard with known feeding behaviour, and apply our findings to extinct taxa where the behaviour is largely unknown. We discovered through computed tomography that V. komodoensis maintains up to five replacement teeth per tooth position, while histological analysis showed an exceptionally rapid formation of new teeth, every 40 days. Additionally, a dramatic ontogenetic shift in the dental morphology of V. komodoensis was also discovered, likely related to changes in feeding preferences and habitat. The juveniles have fewer dental specializations, lack true ziphodonty, are arboreal and feed mostly on insects, whereas the adults have strongly developed ziphodonty and are terrestrial apex predators with defleshing feeding behaviour. In addition, we found evidence that the ziphodont teeth of V. komodoensis have true ampullae (interdental folds for strengthening the serrations), similar to those found only in theropod dinosaurs. Comparisons with other species of Varanus and successive outgroup taxa reveal a complex pattern of dental features and adaptations, including the evolution of snake-like tongue flicking used for foraging for prey. However, only the Komodo dragon exhibits this remarkable set of dental innovations and specializations among squamates.

A New Versatile Tool for Accurate Bracket Positioning—An In Vitro Study

Aim To evaluate and compare the accuracy of bracket positioning in the incisogingival and mesiodistal aspects with the MBT gauge and new multipurpose bracket positioning tool. Materials and Methods Bracket positioning of maxillary anterior teeth ( n=30) was assessed on the typhodont model. The UNC-15 (University of North Carolina) probe was modified as an MBP tool. Five different malocclusions: (a) Class II Division 1 ( n=6); (b) Class II Division 2 ( n=6); (c) Class I with mesially inclined maxillary anterior teeth ( n=6); (d) Class I with crowding in maxillary anterior teeth-3 mm ( n=6); (e) Class I with different vertical heights of maxillary anterior teeth ( n=6). The measurements of the study were divided into three groups; Group A: Central Incisor, Group B: Lateral Incisor, and Group Canine, based on positioning with MBT Gauge and MBP tool. The measurements on each tooth were recorded using vernier calliper, on the basis of which the discrepancy in vertical and axial bracket positioning was assessed. Results The comparative evaluation of the MBT gauge and MBP Tool showed statistically insignificant differences between all the groups (p&gt;0.05). The mean standard deviation with the MBT gauge was 0.5-0.7 mm, whereas with the MBP tool was only 0.05- 0.3 mm only; suggesting clinical relevance and acuity during bracket positioning. Conclusion The MBP tool is relatively accurate and comparable to the MBT gauge as the horizontal and vertical arm of the MBP tool facilitates proper visualization by coinciding with the long axis of the tooth on the typhodont model leading to augmented precision.

Relationship between soft tissue dimensions and tomographic radial root position classification system for immediate implant installation.

The aim of this study was to evaluate the relationship between soft tissue dimensions and radial root position (RRP) classification for immediate implant placement on maxillary anterior teeth. Maxillary anterior teeth (n = 420) were analyzed in the radial plane of cone beam computed tomography (CBCT) scans. Each tooth was classified according to its RRP: class I, (IA, IB); class II (IIA, IIB) class III; class IV, and class V. Soft tissue thickness at different landmarks, supracrestal soft tissue height, and crestal bone thickness were measured in CBCT. Keratinized tissue width was clinically measured. Gingival phenotype (thick or thin) was evaluated by transparency of the periodontal probe and at the landmark 2mm from the gingival margin in CBCT. Class I tooth position accounted for 31.7%, class II for 45%, class III for 13.3%, class IV for 0.5%, and class V for 9.5%. The gingival phenotype was associated with RRP (χ2 test, p < 0.05). Soft tissue dimensions were significantly different over RRP classes (ANOVA and Tukey tests, p < 0.05). Types IA and IIA presented both thick soft and hard tissues. When planning immediate implants in the anterior maxilla, soft tissue dimensions evaluation should be incorporated into RRP classification to increase the accuracy and predictability of treatment outcomes.

Periodontitis was associated with mesial concavity of the maxillary first premolar: a cross-sectional study

The association between the anatomical features of teeth and the pathogenesis of periodontitis is well-documented. This study aimed to evaluate the influence of the mesial concavity of the maxillary first premolar on periodontal clinical indices and alveolar bone resorption rates. Employing a cross-sectional design, in 226 patients with periodontitis, we used cone beam computed tomography(CBCT) to examine the mesial concavity and alveolar bone resorption of 343 maxillary first premolar. Periodontal clinical indicators recorded by periodontal probing in the mesial of the maxillary first premolar in patients with periodontitis. Our findings indicate that the presence of mesial concavity at the cemento-enamel junction of the maxillary first premolar was not significantly influenced by either tooth position or patient sex (p > 0.05). Nonetheless, the mesial concavity at the cemento-enamel junction of the maxillary first premolar was found to exacerbate alveolar bone resorption and the inflammatory condition (p < 0.05). We infer that the mesial concavity at the cemento-enamel junction of the maxillary first premolar may contribute to localized alveolar bone loss and accelerate the progression of periodontal disease.

Use of 3D printing models for donor tooth extraction in autotransplantation cases

ObjectiveTo clarify whether the 3D printing model has auxiliary functions in toto extraction of donor tooth in autotransplantation cases.MethodsTwo hundred and sixty patients who would have operation of ATT were divided into two groups. In group 1, determination of the tooth extraction in toto was predicted only according to the clinical and imaging examination. In group 2, the prediction was performed according to the clinical and imaging examination as well as the 3D model of donor tooth pre-extraction. A prespctive clinical study was designed on intra-group comparison between the predicted and actual donor teeth situation when extraction in cases of ATT. The consistent rate for the predicted results and the actual results were compared with the two groups.ResultsA remarkable difference was observed between the predicted results and the actual results of tooth positions and root numbers in group without model (p < 0,05). The consistency rate of the model group (94.62%) was significantly higher than that of non 3D model group (86.15%) (p = 0.034).ConclusionThe 3D printing model for the donor tooth is helpful for dentists to predict the accuracy of toto extraction of donor teeth in autotransplantation cases.

Correlation between Tooth Position Parameters and Apical Fenestration: A Cone-Beam Computed Tomography Study.

This study aimed to assess the relationship between apical fenestration-a defect in the alveolar bone involving the root apex-and tooth position in all tooth groups, excluding the third molars, utilizing cone-beam computed tomography (CBCT) images. A total of 800 CBCT scans (400 maxillary and 400 mandibular) from patients undergoing various treatments were examined by a single professional (radiologist and endodontist). Statistical analyses, including the chi-square test or Fisher's exact test, were conducted using R software 2.7.3 (R Foundation, Vienna, Austria). Results indicated a significant association (p ≤ 0.05) between apical fenestration and tooth position. In the upper teeth, apical fenestrations were notably present in the mesio-buccal (17.17%) and disto-buccal (11.07%) roots of the first molars. Conversely, apical fenestrations in the lower teeth were relatively less frequent. The study revealed a negative correlation between apical fenestration and mesial inclination, rotation, and extrusion in the upper teeth. However, a positive correlation was observed between apical fenestration and lingual inclination in the upper teeth. In conclusion, this study illuminates the distribution of apical fenestration and its correlation with tooth positions, offering insights into factors influencing this defect in dental anatomy. The findings enhance our understanding of nuanced relationships between tooth position and apical fenestration in the upper and lower dental arches.

A Method for Determining the Formation Position of Comb Tooth of Kerr Micro-Ring

A Method for Determining the Formation Position of Comb Tooth of Kerr Micro-Ring

Does the sagittal root position of maxillary anterior teeth affect the decision making on immediate implants in the anterior maxilla? A CBCT-based study.

Immediate implant placement in the maxillary esthetic zone is a challenging and demanding task. To achieve favorable results, proper case selection and treatment planning are necessary. Variables like the sagittal root position (SRP) and the labial bone thickness (LBT) of maxillary anterior teeth are of paramount importance for predictable outcomes. The aim of the present study was to evaluate the SRP and LBT of maxillary anterior teeth in the context of immediate implant placement by using cone-beam computed tomography (CBCT) in a sample of the Pakistani population. A cross-sectional study was conducted using the CBCT scans of patients. The SRP of each tooth (maxillary canine to canine) was evaluated in the sagittal section of a CBCT scan according to the classification by Kan et al. The LBT of each tooth was measured perpendicularly to the long axis of tooth at 3 sites: at the alveolar crest (P1); 2 mm from the alveolar crest (P2); and 4 mm from the alveolar crest (P3). Descriptive statistics were reported for SRP and LBT. The χ2 test was employed to assess any association between the variables. Class I SRP was the most prevalent (n = 196, 81.7%), while Class III was the least frequent (n = 1, 0.4%). The association between the tooth type and SRP was statistically non-significant (p = 0.510). In the evaluated sample of the Pakistani population, the most frequent type of the SRP of maxillary anterior teeth was Class I, which is most favorable for immediate implant placement. Furthermore, the labial bone in the maxillary esthetic zone was found to be mostly thin - LBT was within the range of 0.5-0.9 mm - which makes immediate implant placement in the anterior maxilla a challenge. The results of the present study could serve as a guide for clinicians in terms of appropriate patient selection for immediate implant placement in the maxillary esthetic zone.

CBCT vs panoramic radiography in assessment of impacted upper canine and root resorption of the adjacent teeth: A systematic review and meta-analysis.

The IC may cause reabsorption of adjacent teeth; therefore detailed assessment of its position would enhance decision-making in the clinical workflow. The objective was to compare cone-beam computed tomography (CBCT) and panoramic radiography (PR) in assessing the position of the impacted upper canine (IC) and root resorption of adjacent teeth. Pubmed, EMBASE, Science Direct, Web of Science, and SCOPUS databases were searched for studies published before August 2023. Studies that evaluated IC by using both imaging methods were included. For statistical analysis, the Comprehensive Meta-Analysis software (Biostat; Englewood, NJ) was used, p≤0.05. A total of 17 articles were included, with 877 patients (average age of 17.6 years) and 1,115 ICs. The most frequent mesio-distal location of the IC was in sectors 3 and 4. The meta-analysis was performed with eleven studies. CBCT was more accurate in determining the labio-palatal position compared with PR (p<0.001) (CI 95%; 60% in labial position, 0.254-0.542, OR:0.398; 56% in palatal position, 0.350-0.533, OR:0.441; 78% in mid-alveolus position, 0.188-0.234, OR:0.221). For IC angulation to the midline, CBCT showing a smaller and more accurate angle than PR (p<0.001) (CI 95%, 18.008-33.686). IC angulation to the occlusal plane and lateral incisor, there was smaller angle in PR compared to CBCT (p<0.001) (CI 95%, 51.292-65.934; CI 95%, 30.011-55.954). With PR, fewer cases of root resorption of teeth adjacent to the IC were visualized compared with CBCT (86% less) (p<0.001) (CI 95%, 0.089-0.186; OR value: 0.138; n=1049). CBCT showed statistically significant differences compared to PR in the assessment of IC position and root resorption of adjacent teeth. CBCT provided clinically relevant information that may contribute to diagnosing and planning IC treatment when PR was not sufficient. Key words:Canine teeth, tooth, impacted, panoramic radiography, Cone-beam computed tomography, systematic review, meta-analysis.

Accelerated Orthodontic Treatment Using Photobiomodulation: A Randomized Clinical Trial.

Orthodontic treatment (OT) aims to align and correct teeth positions. However, conventional treatment methods often require a considerable amount of time. Photobiomodulation (PBM) has emerged as a potential solution to OT. The study included 60 patients, divided equally into two groups: the PBM group and the control group. Patients in the PBM group received light therapy sessions applied directly to the OT area during each visit. Both groups underwent regular orthodontic adjustments. Treatment duration, changes in tooth alignment, and patient discomfort were evaluated. Statistical analysis was performed to compare the outcomes between the groups. The results of the study indicated that the PBM group experienced a statistically significant reduction in treatment duration compared to the control group. Moreover, there were noticeable improvements in tooth alignment in both groups. Patients in the PBM group reported minimal discomfort during the treatment process. These findings suggest that PBM has the potential to expedite OT without compromising its effectiveness. In conclusion, this randomized clinical trial demonstrates that PBM can be an effective approach to accelerate OT. The technique led to a significant reduction in treatment duration and was well-tolerated by patients.

Clinical possibilities of applying the method of photostatic biometrics of plaster models of jaws

The development of modern methods of biometrics is an urgent task of clinical dentistry. Aim. To determine the clinical possibilities of applying the method of photostatic biometrics of plaster models of jaws.&#x0D; Material and methods. A retrospective study was conducted on 46 pairs of plaster jaw models with physiological occlusion. Biometrics of jaw models from plaster was carried out according to generally accepted methods. The method of photostatic biometrics of jaw models is based on photographing models with a ruler for the convenience of subsequent scaling. The photo was marked with landmarks and reference lines in various directions.&#x0D; Results. The depth of the dental arch, or molar sagittal of the upper arch, when measured on the models was (44.16 ± 1.14) mm, and in the photo – (47.31 ± 1.29) (p ˂ 0.05). On the lower jaw, the dimensions were (44.86 ± 1.05) mm and (40.46 ± 1.2) mm, respectively (p ˂ 0.05). The differences in the size of the arc depth are explained by the complexity of the biometrics of plaster models and the determination of the landmark (conditional transversal) using a conventional caliper and ruler. Rotation angles of the second molars averaged (15.01 ± 0.21) degrees on the upper jaw and (12.49 ± 0.18) degrees on the lower arch. The first upper molars were rotated at (19.96 ± 0.22) degrees, and the lower ones were slightly smaller (17.52 ± 0.16) degrees.&#x0D; Conclusion. Thus, the method of photostatic biometrics of plaster models of jaws can be used as an additional study designed to assess the position of key teeth and interstitial point when superimposed on the model of various geometric shapes and the template of the individualized dental arch and allows you to determine the angles of rotation of the teeth.