Dental Arch Parameters Research Articles

Predictive modelling of freeway space utilising clinical history, normalised muscle activity, dental occlusion, and mandibular movement analysis

This study aimed to predict dental freeway space by examining the clinical history, habits, occlusal parameters, mandibular hard tissue movement, soft tissue motion, muscle activity, and temporomandibular joint function of 66 participants. Data collection involved video-based facial landmark tracking, mandibular electrognathography, surface electromyography of mandibular range of motion, freeway space, chewing tasks, phonetic expressions, joint vibration analysis, and 3D jaw scans of occlusion. This resulted in a dataset of 121 predictor features, with freeway space as the target variable. Six models were trained on synthetic data ranging from 500 to 25,000 observations, with 65 original observations reserved for testing: Linear Regression, Random Forest, CatBoost Regressor, XGBoost Regressor, Multilayer Perceptron Neural Network (MPNN), and TabNet. Explainable AI indicated that key predictors of freeway space included phonetics, resting temporalis muscle activity, mandibular muscle activity during clenching, body weight, mandibular hard tissue lateral displacements, and dental arch parameters. CatBoost excelled with a test error of 0.65 mm using 5000 synthetic data points, while a refined MPNN achieved the best performance with 25,000 synthetic data points and 121 unique predictors, yielding an absolute error of 0.43 mm on the 65 original observations.

Change in Dental Arch Parameters—Perimeter, Width and Length after Treatment with a Printed RME Appliance

One of the important parameters in orthodontics is the perimeter of the dental arch. Precise assessment is necessary in cases of maxillary constriction treated with a rapid maxillary expander (RME). The orthodontic software allows customization of the processes from diagnosis to manufacturing of the treatment device. The aim of the present study is to evaluate a relationship between the parameters of the dental arch—perimeter, width, and length—and to follow the changes during treatment. The study is based on the digital measurements of 3D models of 33 patients treated with a digitally planned and printed RME. In the results an increase of 3.99 mm in perimeter was achieved. The rest of the parameters were changed as follows: The width of the dental arch was increased in the premolar area by an average of 3.3 mm; in the area of the first molars, the increase was 4.41 mm; the length of the dental arch in the anterior segment was reduced by an average of 0.54 mm; and the whole length by 0.52 mm. Correlation between the studied variables was described by linear equations. In conclusion, rapid maxillary expansion is a reliable method for gaining predictable space in the dental arch.

Evaluation of First Molar Buccolingual Angulations and Dental Arch Parameters in Adolescents with Bilateral Posterior Crossbite.

This study aimed to compare the maxillary and mandibular transverse dental arch widths and buccolingual inclinations of the molar teeth in patients with and without bilateral posterior crossbite (BPC) divided into different age groups. The study included dental models from 120 patients (age: 12-18 years), including 60 with BPC (32 boys and 28 girls) and 60 without BPC (controls; 30 boys and 30 girls), who were divided into three age groups (12-14, 14-16, and 16-18 years). The centroid and lingual transverse arch widths, dental arch perimeters, dental arch depths, and buccolingual angulation of the molar teeth in the maxillary and mandibular regions were evaluated using scanned three-dimensional dental models. Dental arch parameters and buccolingual molar angulation did not significantly differ between the different age groups in either the patients with BPC or the controls (p>0.05). However, several dental arch width parameters differed significantly between sexes in both groups, with higher values in boys than in girls (p<0.05). The difference in the upper and lower molar buccolingual angulation between patients with BPC and controls was greater at the age of 16-18 years than the age of 12-14 years (p<0.05). Patients with BPC have smaller maxillary dental arch widths and larger mandibular intermolar widths than those without BPC. The difference in the molar buccolingual angulation between them increases with advancing age.

Three-dimensional relationship between the degree of bilateral impacted mandibular third molars angulation and the mandibular dental arch parameters: a cross-sectional comparative study.

The purpose of this study was to three-dimensionally evaluate the relationship between the degree of bilateral impacted mandibular third molar (IM3M) angulation and the mandibular dental arch parameters in normal skeletal and dental malocclusion patients. In this retrospective cross-sectional comparative study, 120 adult subjects' cone-beam computed tomography (CBCT) images were three-dimensionally analyzed. The sample included 120 adults aged 20-30years, with a gender distribution of 51 male and 69 female participants. The sample was divided into 100 adults with bilateral IM3M (study group) and 20 adults with normal bilateral erupted M3M (control group). The study group was sub-divided into three groups according to the degree of IM3M buccolingual angulation (BL°): group A, < 12° on the center of the ridge (N = 30), group B, 12-24° off-center of the ridge (N = 40), group C, > 24° off-center of the ridge (N = 30). The study group was also sub-divided into two groups according to IM3M mesiodistal angulation (MD°): group 1 from 10 to 45° (N = 36), group 2 > 45° (N = 64). Comparison within and between groups was performed using one-way ANOVA followed by Tukey's post hoc test. The correlation between IM3M, BL, and MD angulation and the mandibular arch parameter was calculated using Pearson's correlation coefficient. Statistically significant differences (P < 0.001) were found between the IM3M BL° and anterior teeth inclination, arch length (AL), and inter-second molar width (inter 2nd MW) as well as between the IM3M MD° with anterior crowding and the arch length (P < 0.001). A significant positive correlation was found between IM3M BL° and anterior teeth inclination and between IM3M MD° and anterior teeth crowding and inter 2nd MW. A significant negative correlation was observed between IM3M BL° and inter 1st MW and 2nd MW. The degree of buccolingual and mesiodistal angulation of the impacted mandibular third molars was related with mandibular dentoalveolar changes. Increased buccolingual angulation is generally associated with increased anterior teeth inclination and decreased 1st and 2nd inter-molar width. The increase in mesiodistal angulations was generally related with increased anterior teeth crowding and 2nd inter-molar width. Assessment of the relationship between the impacted mandibular third molars and the degree of arch discrepancy, and the position of mandibular incisors in the three planes of space might help in the decision-making process for the extraction of the impacted third molars in adult patients.

Gender determination using dental arch characteristics among a south Indian pediatric population: A morphometric study

Aim: To establish the normative data of dental arch characteristics and use them to determine the gender among a pediatric population of south India. Methods: Three hundred children aged 3 to 5 years were selected. The intra oral examination of each child was carried-out using a sterile disposable mouth mirror and a CPI probe. To receive maximum illumination, the oral examination was done in adequate natural daylight seating the child in upright positioning on a chair. Following, the molar and canine relationship was recorded. The investigators prepared the maxillary and mandibular impression of teeth and their dental casts. The intercanine width, intermolar width, dental arch form, arch length and arch perimeter was measured. The descriptive analysis of all the explanatory and outcome parameters was done using frequency and proportions for categorical variables, whereas in Mean &amp; SD for continuous variables. To compare the selected dental arch parameters between genders, Independent Student t-test Chi-Square test were used. P≤0.05 was set as the level of significance. Results: The mesial step molar relationship and Class I canine relationship were found be more common among males compared to females, however it was not statistically significant (p&lt;0.26). Although, the ovoid arch form was commonly seen especially among males followed by square and tapered, it was not statistically significant (p=0.14). The intercanine width, intermolar width, arch length and arch perimeter was greater in males than females. (p&lt;0.001) Conclusions: Sexual dimorphism was observed among the studied dental arch parameters. Dental arch dimensions like intercanine width of the maxillary arch, intermolar width, and arch perimeter of both maxillary and mandibular arches showed to be an indicator for gender determination with an accuracy of 100%. Keywords: Dental Arch; Primary Teeth, Sexual Dimorphism

Maxillary Expansion: A Comparison of Damon Self-Ligating Bracket Therapy with MARPE and PAOO.

Purpose The aim of this study was to investigate arch parameters and dentoalveolar changes from pretreatment to posttreatment by comparing the Miniscrew Assisted Rapid Palatal Expansion (MARPE), Periodontally Accelerated Osteogenic Orthodontics (PAOO), and Damon self-ligating bracket therapies. Materials and Methods Seventy-nine patients underwent maxillary expansion followed by or in conjunction with Damon (n = 23), PAOO (n = 28), and MARPE (n = 28) therapies. Nine maxillary dental arch parameters were compared at pretreatment, posttreatment as well as, increments of treatment change. Measurements were made on STL study casts using 3Shape Ortho Analyzer 3D scanner software. Results All groups showed significant posterior width increase in the molar area. The mean increase in inter-molar distance was more than 8X greater in MARPE group compared to Damon and more than 4X greater compared to PAOO. MARPE showed significantly greater increments of change in inter-molar width and palatal vault area Conclusions All groups showed a significant width increase in the canine and molar area. MARPE showed the greatest increase in inter-molar width, followed by PAOO and Damon. MARPE was the only group to show a significant increase in palatal vault area.

VARIANT ANATOMY OF TRANSITIONAL OCCLUSION DENTAL ARCH AT OPTIMAL OCCLUSAL RELATIONSHIPS

Through the transitional bite period, the variability of the dental arch shape and size is due to the replacement of milk teeth with permanent ones, which feature different odontometric values. The aim of this study was to identify the main linear and angular parameters of dental arches, in view of the trusive position of the incisors with optimal functional occlusion. A stratified study was involved 76 children ages 8–12 years old, who were divided into three groups (protrusive, retrusive and mesotrusive dental arches). An analysis of cone-beam computed tomograms and plaster models of jaws was carried out, which was preceded by obtaining informed consents according to the Ethics Committee requirements. The study revealed certain features of the variant anatomy of transitional occlusion dental arch. The calculated factors allowed identifying the proportionality of the dental arch parameters to odontometric indicators. During that, the dental-diagonal factor (the ratio of the dental arch length to the incisor-molar diagonals) for the upper jaw was 1.06±0.01, for the lower arch being equal to 1.09±0.01, in all types of dental arches, which is a fact to be used in clinical orthography to predict the location of the dental arch incisor (central) point in case of shape anomalies, specifically in the anterior part. The angular parameters of the diagnostic dental pentagon will allow simulating the geometric and graphical construction of arches through the transitional occlusion period.

Assessment of Dental Arch Parameters in Turkish Twins.

The aim of this study is to investigate the relative contributions of genetic and environmental factors to variations in dental dimensions in a sample of Turkish twins, and to estimate heritability using dental casts. The study samples were selected from the twin children between 3-15 years old who referred for their first dental examination. Fifty nine monozygotic and one hundred and forty three dizygotic twin pairs were examined in the study. The alginate impression material used to create the plaster model of maxilla and mandible. Anterior arch width, posterior arch width, arch length and arch circumference were measured on models prepared from measurements taken for both maxilla and mandible with digital caliper. The similarities and differences of the measurements were compared between pairs of twins and zygocytes. Morever, the effects of bad oral habits, bruxism, a result of psychosocial factors on measurements were examined. Statistical analysis was performed using Paired T Test, Wilcoxon Test and Mann Whitney U test. A total of 404 dental models of 118 (29.2%) monozygotic and 286 (70.8%) dizygotic twins were evaluated. There was no statistical difference between sibling pairs in both monozygotic and dizygotic twins. The measurement similarity between twin siblings differed according to zygosity in all measurements (p<0.05). It has been observed that the finger sucking and mouth breathing affect the dental arch measurements (p<0.05). These results indicate that the differences in dental arch dimensions between monozygotic twin pairs are less than the difference between dizygotic twin pairs.

Clinical types of hard palatal vault in people with various gnathic dental arches within physiologically optimal norm

The study is based on an analysis of conebeam computed tomograms and biometric examination of jaw cast models obtained from 68 people aged 21–35 with permanent teeth physiological occlusion. The findings were used to identify the relationship between the morphometric values (height, depth) of the palatal vault, and the linear parameters (length, width) of dental arches. In patients with mesognathic dental arches, the palatal vault index, taken as a ratio between the palate height to the alveolar part width, was 41.14 ± 2.87%, whereas the width indicators exceeded (by 2.43 times on average) the hard palate vault depth parameters. People with dolichognathic dental arches had the value of the palatal vault index reaching 51.75 ± 2.57%, while the width indicators exceeded the depth parameters of the hard palate vault by 1.93 times on average. In patients with brachygnathic dental arches, the palatal vault index was 28.29 ± 2.62%, with the width indicators exceeding the depth parameters by 3.53 times on average. There is evidence showing that mesognathic dental arches have mesopalatal (proportional) palatal vault matching them, while in case of dolichognathic dental arches, the match is dolichopalatal (high and narrow) type of vault. As for brachygnathic dental arches, then the match is brachypalatal, i.e. a low and wide vault. The obtained data can be used in clinical orthodontics, orthopedic dentistry, as well as maxillofacial surgery to assess the hard palate parameters, to diagnose palatal vault pathologies, and to select respective treatment approaches in view of the dental arches shape and size anomalies.

Dental Arch Parameters and Goslon Scores in Mixed Dentition of Egyptian Children with Surgically Repaired Unilateral Cleft Lip and Palate

Introduction: Various forms of malocclusion are usually encountered in non-syndromic cleft lip and palate, mostly affecting maxillary dental arch. Objective: To assess the dental arch parameters in surgically treated unilateral cleft lip and palate Egyptian children with mixed dentition and compare them with those of comparable healthy non-cleft children. Material and Methods: Comparative cross-sectional study design was used. Twenty-six non-syndromic children with repaired unilateral cleft lip and palate (UCLP), aged 6-9 years, were compared to twenty-six healthy non-cleft children (control group) recruited from Faculty of Dentistry, Alexandria University. Both groups were divided into two age groups; 6-7 years and 8-9 years. For each subject, dental arch parameters were measured using dental study models. Results: Mean maxillary arch depth and inter-canine arch width were significantly smaller in UCLP children than in non-cleft children in the age groups 6-7 and 8-9 years. Mean inter-molar arch width was not significantly narrower in UCLP children than in non-cleft children. Mean mandibular arch dimensions of UCLP children did not differ significantly from those of non-cleft children. The mean Goslon Yardstick score was 3. Conclusion: Children with UCLP, aged 6-9 year old, had significant reduction in mean maxillary arch dimensions compared to healthy matching non-cleft children except for inter-molar arch width which showed no significant reduction. The average dental arch relationship in surgically-repaired UCLP children was fair according to Goslon Yardstick index.

Assessment of Dental Arch Parameters in Turkish Twins.

The aim of this study is to investigate the relative contributions of genetic and environmental factors to variations in dental dimensions in a sample of Turkish twins, and to estimate heritability using dental casts. The study samples were selected from the twin children between 3-15 years old who referred for their first dental examination. Fifty nine monozygotic and one hundred and forty three dizygotic twin pairs were examined in the study. The alginate impression material used to create the plaster model of maxilla and mandible. Anterior arch width, posterior arch width, arch length and arch circumference were measured on models prepared from measurements taken for both maxilla and mandible with digital caliper. The similarities and differences of the measurements were compared between pairs of twins and zygocytes. Morever, the effects of bad oral habits, bruxism, a result of psychosocial factors on measurements were examined. Statistical analysis was performed using Paired T Test, Wilcoxon Test and Mann Whitney U test. A total of 404 dental models of 118 (29.2%) monozygotic and 286 (70.8%) dizygotic twins were evaluated. There was no statistical difference between sibling pairs in both monozygotic and dizygotic twins. The measurement similarity between twin siblings differed according to zygosity in all measurements (p<0.05). It has been observed that the finger sucking and mouth breathing affect the dental arch measurements (p<0.05). These results indicate that the differences in dental arch dimensions between monozygotic twin pairs are less than the difference between dizygotic twin pairs.

CASE REPORT: ORAL MANIFESTATIONS OF YOUNG PATIENT SUFFERING FROM BOTH THALASSEMIA MAJOR AND HEPATITIS B

<h3>Introduction</h3> Thalassemia is a hereditary hemolytic anemia characterized by the inability of erythroblasts to produce the beta-chain of the hemoglobin structure. Patients with thalassemia acquire hepatitis most often from viruses contracted from blood transfusions especially in developing countries like Pakistan. This case reports the distinct oral manifestations in a young patient with thalassemia major and hepatitis B. <h3>Case Report</h3> An 8-year-old male patient visited Jinnah Sindh Dental Outpatient Department with the complaint of bleeding gums. According to the history, the patient was suffering from beta-thalassemia congenitally. Both parents were normal (carrier). He had 5 siblings of which 4 were phenotypically healthy (carriers). A 12-year-old sister had died because of beta-thalassemia. The patient had undergone regular blood transfusion from the age of 5 years. The patient was diagnosed with hepatitis 2 months ago, possibly due to contaminated blood transfusion. <h3>Clinical Findings</h3> The clinical examination showed that the patient was poorly built and undernourished with short stature. The prominent dental arch parameters evident were the characteristic appearance known as "chipmunk face" (caused by hyperplasia of bone marrow in the maxilla that exceeds the mandible). Frontal and parietal bossing with depressed nasal bridge were present. <h3>Oral Findings</h3> Intraoral examination demonstrated class II malocclusion along with maxillary protrusion. Other findings included overcrowding of mandibular anteriors, proclined upper anterior teeth, generalized yellowish discolored teeth, mild generalized diastema, and localized periodontitis affecting the lower anteriors. Multiple decayed teeth with heavy deposition of calculus and plaque on teeth with dark stains were also seen.

Orthodontic treatment strategy in patients with dental arch asymmetry in the diagonal direction taking into account craniofacial morphology

Based on the results of morphological studies of the craniofacial complex, biometrics of plaster models of the jaws of 76 young people (18-25 years old) with asymmetry of dental arches, an algorithm was developed for modeling the predicted sizes of dental arches with their asymmetry in the diagonal direction. The methodological approach is based on the use of individual cephalometric indicators (diagonal and transverse face size), morphometric parameters of dental arches (incisor-molar diagonal, transverse intermolar arch size, dental arch depth) and stable correction factors for assessing the conformity (inconsistency) of real and predicted biometric data. Further stages of modeling the predicted sizes of dental arches with their asymmetry in the diagonal direction include the construction of incisor-molar and incisor-canine triangles, taking into account the anthropometric parameters of the maxillofacial region. The use of a diagnostically significant method in the clinic of orthodontics makes it possible to establish the topography of key teeth (canines, second molars) in the dental arch, taking into account the individual characteristics of the patient’s craniofacial complex. The implementation of the obtained results in clinical dentistry in patients with asymmetry of dental arches in the diagonal direction is advisable to substantiate the methods (extraction, without extraction) of complex treatment in order to achieve a functional balance of occlusal relationships, as well as optimal balance of morphological, functional and aesthetic characteristics.

Accuracy of predicting the upper arch expansion using the ClinCheck software

BACKGROUND: Among the anomalies of the dentoalveolar system, narrowing of the upper dental arches in a permanent bite occurs in 57% of the cases examined. Aligners are a preferable method for correcting the position of the teeth and expanding dental arches. Planning and modeling treatment outcomes when using clear aligners are essential parts, since it is the quantitative assessment of treatment outcomes that improves clinical practice. The ClinCheck software allows making an almost fully automated design and manufacturing of Invisalign.&#x0D; AIM: This study aimed to assess the accuracy of predicting the expansion of the upper arch using the ClinCheck software.&#x0D; MATERIAL AND METHODS: A prospective clinical study included 19 patients with dentoalveolar anomalies whose dental arch parameters were measured before and after treatment with Invisalign Full and Invisalign Teen. Evaluation of the accuracy of predicted expansion using ClinCheck was carried out by comparing the simulated parameters and actual outcomes. To assess the achieved results, individual tooth from the original ClinCheck model was superimposed on the digital model from the post-treatment scan. For the studied parameters, the arithmetic mean was calculated, and significant differences were established at a significance level of p 0.05.&#x0D; RESULTS: As regards treatment result, patients showed a significant expansion of the upper dental arch in the premolar and molar region as well as protrusion of the incisors. Data showed a high accuracy of prediction using ClinCheck, since no significant differences were found between the mean values obtained as a result of treatment and those predicted using ClinCheck.&#x0D; CONCLUSIONS: 1) Invisalign technology is effective in widening the upper arch. Following treatment, patients showed significant differences in the width for the first premolars at 4.030.24 mm, for the second premolars at 3.610.25 mm, for the first molars at 2.110.31 (p 0.05), as well as clinically significant incisor protrusion of 6.531.41 (p 0.05). 2) Differences between the mean values obtained following treatment and simulated in the ClinCheck program were as follows: expansion along the canines, 0.050.11 mm (p 0.05); expansion along the first premolars, 0.040.23 mm (p 0.05); expansion along the second premolars, 0.0030.14 mm (p 0.05); expansion along the first molars, 0.0020.13 mm (p 0.05), and incisor protrusion, 0.120.92 (p 0.05).

Accuracy of predicting the upper arch expansion using the ClinCheck software

BACKGROUND: Among the anomalies of the dentoalveolar system, narrowing of the upper dental arches in a permanent bite occurs in 57% of the cases examined. Aligners are a preferable method for correcting the position of the teeth and expanding dental arches. Planning and modeling treatment outcomes when using clear aligners are essential parts, since it is the quantitative assessment of treatment outcomes that improves clinical practice. The ClinCheck software allows making an almost fully automated design and manufacturing of Invisalign.&#x0D; AIM: This study aimed to assess the accuracy of predicting the expansion of the upper arch using the ClinCheck software.&#x0D; MATERIAL AND METHODS: A prospective clinical study included 19 patients with dentoalveolar anomalies whose dental arch parameters were measured before and after treatment with Invisalign Full and Invisalign Teen. Evaluation of the accuracy of predicted expansion using ClinCheck was carried out by comparing the simulated parameters and actual outcomes. To assess the achieved results, individual tooth from the original ClinCheck model was superimposed on the digital model from the post-treatment scan. For the studied parameters, the arithmetic mean was calculated, and significant differences were established at a significance level of p 0.05.&#x0D; RESULTS: As regards treatment result, patients showed a significant expansion of the upper dental arch in the premolar and molar region as well as protrusion of the incisors. Data showed a high accuracy of prediction using ClinCheck, since no significant differences were found between the mean values obtained as a result of treatment and those predicted using ClinCheck.&#x0D; CONCLUSIONS: 1) Invisalign technology is effective in widening the upper arch. Following treatment, patients showed significant differences in the width for the first premolars at 4.030.24 mm, for the second premolars at 3.610.25 mm, for the first molars at 2.110.31 (p 0.05), as well as clinically significant incisor protrusion of 6.531.41 (p 0.05). 2) Differences between the mean values obtained following treatment and simulated in the ClinCheck program were as follows: expansion along the canines, 0.050.11 mm (p 0.05); expansion along the first premolars, 0.040.23 mm (p 0.05); expansion along the second premolars, 0.0030.14 mm (p 0.05); expansion along the first molars, 0.0020.13 mm (p 0.05), and incisor protrusion, 0.120.92 (p 0.05).

REGRESSION MODELS OF INDIVIDUAL LINEAR DIMENSIONS NECESSARY FOR CONSTRUCTING THE CORRECT FORM OF DENTAL ARCH IN YOUNG WOMEN WITH A WIDE FACE, DEPENDING ON THE FEATURES OF ODONTOMETRIC AND CEPHALOMETRIC INDICATORS

The purpose of the study: build and analyze the regression models of computed tomographic parameters necessary to determine the correct shape of dental arches, depending on the odontological and cephalometric parameters for girls with normal occlusion close to orthognathic occlusion and a wide type of face.&#x0D; Materials and methods: for 20 girls with normal occlusion close to the orthognathic bite and with a wide face type, in the license package "Statistica 6.0" developed regression models of linear sizes necessary for constructing the correct shape of dental arches, depending on odontometric and cephalometric indicators.&#x0D; Results: thus, in girls with normal occlusion close to orthognathic occlusion, having a wide type of face, all 18 possible reliable regression models (with a coefficient of determination from 0.620 to 0.973) of the reproduction of individual computed tomographic characteristics of the dental arches of upper and lower dental jaws depending on odonto- and cephalometric parameters were developed and analyzed.&#x0D; Conclusions: the results obtained indicate the need to take into account the type of face when calculating the parameters of dental arches.

Three-dimensional evaluation of the holographic projection in digital dental model superimposition using HoloLens device.

To assess validity and reliability of palatal superimposition of holograms of 3D digital dental models using a customized software, (Ortho Mechanics Sequential Analyzer OMSA), installed on Microsoft HoloLens device as compared to the OMSA application running on a regular computer screen. The sample consisted of pre- and post-treatment digital maxillary dental models of 20 orthodontic cases (12.3±1.9years) treated by rapid maxillary expansion (two turns per day). For each case, the pre- and post-treatment digital models were superimposed using hand gestures for marking the dental models holograms in mixed reality using the Microsoft HoloLens. The same models were then superimposed using the conventional landmark-based method with OMSA software running on a regular computer screen. The same set of dental arch parameters was measured on the superimposed 3D data by the two software versions for comparison. Agreement in the superimposition outcomes among the two superimposition methods was assessed using Dahlberg error (DE), concordance correlation coefficients (CCCs) using two-way ANOVA mixed model for absolute agreement and Bland-Altman analysis. Repeatability was acceptable for all variables based on the high values of CCCs over 0.99 with a lower 95% confidence limit over 0.95 for any variable. The DE ranged from 0.14mm to 0.36mm. The absolute error did not exceed 0.5mm for any variable. Using the depth vision capabilities of the Microsoft HoloLens, 3D digital dental models can be reliably superimposed allowing virtual assessment of orthodontic treatment outcomes.

Intra-Oral 3D Scanning for the Digital Evaluation of Dental Arch Parameters

Intra-oral scanning technology has brought a completely new approach to examination methods in dentistry. In comparison to traditional plaster casts, it allows more precise digital analysis of dental arch components during the treatment of dental disorders. Data acquired can also be used for the creation of three-dimensional (3D) models using 3D printers. This paper describes a data acquisition system, the mathematical processing of resulting three-dimensional model, and the statistical analysis of selected parameters of the dental arch. The study aims at comparing the results achieved from 20 models of the same individual acquired by different specialists. The proposed methodology includes mathematical rotation of objects into the optimal plane defined by the teeth tops’ location to increase the accuracy of the resulting parameters. The mean evaluated distances between canines (3-3) and premolars (5-5) are 24.29 mm and 37.98 mm, respectively, for the lower dental arch. The proposed object rotation increased these distance by 0.9% and 1.4%, respectively, reducing the rotation error. Moreover, the variability of results decreased and the mean value of the coefficient of variation was lowered by 12%. Image registration was then used to evaluate changes of dental arch parameters. This paper presents the advantages of digital models for visualisation of the dental arch allowing its flexible rotation and evaluation of its parameters.

Changes in Maxillary Dental Arch Parameters Concomitant to Maxillary 1st Premolar Extraction in Orthodontic Treatment of Angle Class Ii Dental Malocclusion

Changes in Maxillary Dental Arch Parameters Concomitant to Maxillary 1st Premolar Extraction in Orthodontic Treatment of Angle Class Ii Dental Malocclusion

Mandibular dental arch parameters in Down's syndrome patients with Class I occlusion. (A comparative study)

This study is carried out to find the dental arch form for patients with Down's syndrome and to compare the lower dental arch parameters of those patients with the corresponding norms, and to gain a correlation between the upper and lower arches for the Down's syndrome patients from previous study. A total sample of 50 patients with Down's syndrome were examined with an age ranged 14-18 years, the lower dental arch parameters were compared with another group, control, on student of an intermediate school matching with the age and Angle's classification (Class I).Study models for the upper and lower arches were constructed, then dental arch measurements were carried out and evaluated. The results show that the lower arch parameters for the patients with Down's syndrome were significantly smaller mean values than the control group for both genders with the males had greater values in inter arch distance and length, with high correlation between the upper and lower jaws .The wide arch form is the dominated arch form while the flat is the least to appear. The conclusion of the study is that the growth pattern of dental arches in Down's syndrome patients proportionally reduced when compared with those of norms, with a symmetrical configuration. Hence all arch forms are presented with different distribution.