Interpremolar Widths Research Articles

Predicting the Risk of Maxillary Canine Impaction Based on Maxillary Measurements Using Supervised Machine Learning.

To predict palatally impacted maxillary canines based on maxilla measurements through supervised machine learning techniques. The maxilla images from 138 patients were analysed to investigate intermolar width, interpremolar width, interpterygoid width, maxillary length, maxillary width, nasal cavity width and nostril width, obtained through cone beam computed tomography scans. The predictive models were built using the following machine learning algorithms: Adaboost Classifier, Decision Tree, Gradient Boosting Classifier, K-Nearest Neighbours (KNN), Logistic Regression, Multilayer Perceptron Classifier (MLP), Random Forest Classifier and Support Vector Machine (SVM). A 5-fold cross-validation approach was employed to validate each model. Metrics such as area under the curve (AUC), accuracy, recall, precision and F1 Score were calculated for each model, and ROC curves were constructed. The predictive model included four variables (two dental and two skeletal measurements). The interpterygoid width and nostril width showed the largest effect sizes. The Gradient Boosting Classifier algorithm exhibited the best metrics, with AUC values ranging from 0.91 [CI95% = 0.74-0.98] for test data to 0.89 [CI95% = 0.86-0.94] for crossvalidation. The nostril width variable demonstrated the highest importance across all tested algorithms. The use of maxillary measurements, through supervised machine learning techniques, is a promising method for predicting palatally impacted maxillary canines. Among the models evaluated, both the Gradient Boosting Classifier and the Random Forest Classifier demonstrated the best performance metrics, with accuracy and AUC values exceeding 0.8, indicating strong predictive capability.

Sex determination through maxillary dental arch and skeletal base measurements using machine learning

BackgroundCranial, facial, nasal, and maxillary widths have been shown to be significantly affected by the individual’s sex. The present study aims to use measurements of dental arch and maxillary skeletal base to determine sex, employing supervised machine learning.Materials and methodsMaxillary and mandibular tomographic examinations from 100 patients were analyzed to investigate the inter-premolar width, inter-molar width, maxillary width, inter-pterygoid width, nasal cavity width, nostril width, and maxillary length, obtained through Cone Beam Computed Tomography scans. The following machine learning algorithms were used to build the predictive models: Logistic Regression, Gradient Boosting Classifier, K-Nearest Neighbors (KNN), Support Vector Machine (SVM), Multi-Layer Perceptron Classifier (MLP), Decision Tree, and Random Forest Classifier. A 10-fold cross-validation approach was adopted to validate each model. Metrics such as area under the curve (AUC), accuracy, recall, precision, and F1 Score were calculated for each model, and Receiver Operating Characteristic (ROC) curves were constructed.ResultsUnivariate analysis showed statistical significance (p < 0.10) for all skeletal and dental variables. Nostril width showed greater importance in two models, while Inter-molar width stood out among dental measurements. The models achieved accuracy values ranging from 0.75 to 0.85 on the test data. Logistic Regression, Random Forest, Decision Tree, and SVM models had the highest AUC values, with SVM showing the smallest disparity between cross-validation and test data for accuracy metrics.ConclusionTransverse dental arch and maxillary skeletal base measurements exhibited strong predictive capability, achieving high accuracy with machine learning methods. Among the evaluated models, the SVM algorithm exhibited the best performance. This indicates potential usefulness in forensic sex determination.

Dental and Alveolar Arch Widths in Normal Occlusion and Class II Division 1 Malocclusion

This study was to evaluate and compare dental arch and alveolar widths of patients with Class II division one malocclusion with group of untreated normal occlusion subjects. This study was performed using measurement on dental casts of 30 normal occlusion and 30 Class II division 1 malocclusion of Iraqi sample aged 15-22 years. T-test was applied for comparing the groups , the finding of this study indicated that maxillary interpremolar width, maxillary canine, maxillary premolar and maxillary first molar and mandibular premolar and molar alveolar widths were found significantly narrower in the Class II division 1 group when compared with the normal occlusion sample (P&lt;.001). The maxillary and mandibular intermolar and mandibular intercanine alveolar widths were statistically significantly larger in the Class II division 1 group ( P&lt;.01) . Maxillary molar teeth in subjects with Class II division 1 malocclusion tend to incline to the buccal to compensate the insufficient alveolar base therefore rapid maxillary expansion rather than slow maxillary expansion should be considered during treat ment of Class II division 1 patients. The results of our study sugg ested that transverse discrepancy in Class II division one maloccl usion originated from upper posterior teeth and maxillary alveolar base.

Striving for Perfection: How Stable Is Orthodontic Treatment When Excellent Outcomes Are Achieved? A 9-Year Post-Treatment Retrospective Study.

(1) Aims: The main objective of this retrospective study was to assess the long-term stability of difficult orthodontic treatments treated to an excellent result and to correlate stability to possible prognostic factors. Secondary objectives were to observe the changes in retention protocol over time and to assess Oral Health-related Quality of Life (OHRQoL) after a long-term post-treatment follow-up. (2) Methods: Cases presented for final examination by orthodontic postgraduate students were retrospectively screened for eligibility. Eligible patients were recalled for a post-treatment recall appointment (T2), consisting of a clinical examination and intraoral scan, and were asked to complete the Oral Health Impact Profile-14 (OHIP-14-DK). Gender, age at treatment commencement (T0), treatment modality and duration, and retention protocol were extracted from the records. At T2, the duration of the retention period was recorded, and retainers in place were clinically compared to the original retention protocol. The following variables were assessed on the sets of models at T0, T1 (end of treatment), and T2: arch length and width, overjet and overbite, Dental Aesthetic Index (DAI), Peer Assessment Rating score (PAR), and Little's Irregularity Index (LII). Multiple regression models were conducted. (3) Results: Eighty-five subjects attended T2. The mean post-treatment follow-up was 9.4 years +/- 2.4. In the upper arch, at T1, 74 patients had a combination of fixed and removable retainers, while at T2, 55 had a fixed retainer only. In the lower arch, at T1, 67 patients had a fixed retainer only, with this number increasing to 76 at T2. From T0 to T1, the PAR score improved by 96.1%, with the improvement remaining at 77.5% at T2. The stability of lower inter-canine and upper inter-premolar widths was significantly correlated with the extent of changes during treatment. The presence of a lower fixed retainer at T2 and a low LII at T1 were prognostic factors for stability. The mean weighted total OHIP-14 score at T2 was very low (1.6 ± 2.4 points). (4) Conclusions: In a sample with an initial high-severity malocclusion and treated to an excellent outcome, long-term stability was very good. Good stability can be retained when a lower fixed retainer is present at T2 and when a low LII is achieved at T1.

Treatment effects after maxillary expansion using invisalign first system vs. acrylic splint expander in mixed dentition: a prospective cohort study

BackgroundInvisalign First System (First) is a new type of orthodontic appliance for maxillary arch expansion in mixed dentition children. Till now, few studies have evaluated the expansion effects of First versus other appliances. What’s more, most studies of arch expansion did not include a natural group to rule out growth effects. This prospective cohort study aimed to evaluate the dental and dentoalveolar effects using First or acrylic splint rapid maxillary expander (RME) in adolescents excluding growth factors.Materials and methodsAfter screening by strict inclusion criteria and propensity score matching (PSM), fifty-one patients were included: First group (n = 17), RME group (n = 17), and natural growth (NG) group (n = 17). Nine indicators including dental arch width, dentoalveolar arch width, and inclination of the molars were measured on digital dental casts at baseline (T0) and six-month follow-up (T1). Paired t-tests were used for intra-group results, and two-sample independent t-tests were used for inter-group comparisons.ResultsThere was no significant increase in all indicators within six months in the NG group (p > 0.05). In the First group and RME group, all width indicators were significantly increased after treatment (p < 0.05). The RME group exhibited greater expansion than the First group in intercanine width, first interpremolar width, second interdeciduous molar width, first intermolar width, arch perimeter, intercanine dentoalveolar width, intermolar dentoalveolar width, and inclination of the molars (p < 0.05). Whereas, there was no significant difference in arch depth between the two treated groups.ConclusionsBoth First and RME can expand the maxillary arch in mixed dentition. In case of mild to moderate maxillary transverse deficiency (MTD), Invisalign First System could be a reasonable option. RME shows significant better efficiency of dental arch expansion than First, recommended for patients with severe MTD.Trial registrationThis prospective study was registered on ClinicalTrials.gov (01/02/2022, registration number: ChiCTR2200056220). The trial was approved by the Ethical Committee of the Hunan Xiangya Stomatological Hospital Central South University (20,200,088), and informed consent was obtained from all subjects and their legal guardian(s).

What is the impact of miniscrew-assisted rapid palatal expansion on the midfacial soft tissues? A prospective three-dimensional stereophotogrammetry study

ObjectivesTo evaluate the midfacial soft tissue changes of the face in patients treated with miniscrew-assisted rapid palatal expansion (MARPE).Materials and methods3D facial images and intra-oral scans (IOS) were obtained before expansion (T0), immediately after completion of expansion (T1), and 1 year after expansion (T2). The 3D images were superimposed and two 3D distance maps were generated to measure the midfacial soft tissue changes: immediate effects between timepoints T0 and T1 and overall effects between T0 and T2. Changes of the alar width were also measured and dental expansion was measured as the interpremolar width (IPW) on IOS.ResultsTwenty-nine patients (22 women, 7 men, mean age 25.9 years) were enrolled. The soft tissue in the regions of the nose, left of philtrum, right of philtrum, and upper lip tubercle demonstrated a statistically significant anterior movement of 0.30 mm, 0.93 mm, 0.74 mm, and 0.81 mm, respectively (p < 0.01) immediately after expansion (T0–T1). These changes persisted as an overall effect (T0–T2). The alar width initially increased by 1.59 mm, and then decreased by 0.08 mm after 1 year, but this effect was not significant. The IPW increased by 4.58 mm and remained stable 1 year later. There was no significant correlation between the increase in IPW and alar width (r = 0.35, p = 0.06).ConclusionsOur findings indicate that MARPE results in significant but small changes of the soft tissue in the peri-oral and nasal regions. However, the clinical importance of these findings is limited.Clinical relevanceMARPE is an effective treatment modality to expand the maxilla, incurring only minimal and clinically insignificant changes to the midfacial soft tissues.

Maxillary Arch Dimensions in Children with Unilateral Cleft Lip and Palate Receiving Alveolar Bone Grafting.

To analyse the maxillary arch dimensions of children aged 9 and 12 with unilateral cleft lip and palate (UCLP) who received orthodontic treatment and secondary alveolar bone grafting. This retrospective cohort study was performed on 30 patients with UCLP. All patients were treated at the Cleft Lip and Palate Centre, which is part of the University Medical Centre Amsterdam and Academic Centre for Dentistry Amsterdam, the Netherlands. Children with non-syndromic UCLP who received pre- and postsurgical orthodontics combined with secondary alveolar bone grafting between the ages of 9 and 12 years were included. Maxillary arch dimensions were assessed on 60 digitised dental casts with measurements of the intermolar widths, interpremolar widths, arch perimeters, arch lengths, arch widths, and palatal depths. The results of a paired-samples t-test revealed a statistically significant increase (P < .05) in intermolar width 1, intermolar width 3, interpremolar width 1, arch perimeter, and arch width between the ages of 9 (T0) and 12 (T1). Intermolar width 2 and the palatal depth decreased statistically significantly between T0 and T1. Analysis of maxillary arch dimensions of children with UCLP indicates significant changes between 9 and 12 years of age. This suggests that orthodontic treatment and secondary alveolar bone grafting can be effective in improving maxillary arch dimensions. However, there is a need for collaborative research and data collection in order to provide sensible and evidence-based care to patients with cleft lip and palate.

Evaluation of Maxillary Transverse Arch Dimensions Following Leveling and Alignment with Different Archwire-Bracket Combinations During Fixed Appliance Treatment - A Retrospective Study

Background- Arch expansion is one of the non- extraction methods of gaining space. This study aims to assess and compare the arch expansion achieved during initial leveling and alignment with three different bracket-archwire combinations.&#x0D; Material and Methods- This was a retrospective study done in a university setup. From the available patient information archives, records of 30 subjects based on their advocated bracket system were identified and categorized into three groups. Their pre-treatment (T0) and post aligning (T2) 3D model maxillary scans were superimposed according to the reference points marked on the third palatal rugae using an OrthoAnalyzer software(3 shape version 19.0) to assess the changes in Intercanine width (ICW), Inter-premolar width (IPW) and Intermolar width (IMW) and arch length. For the recorded data, descriptive statistics, One-way ANOVA and Tukey HSD post hoc were analyzed using SPSS software. &#x0D; Results- Except for the Damon group that showed considerable increase in the intermolar and premolar dimensions, other groups had no statistically significant differences in terms of Intercanine width, Interpremolar width, and Intermolar width and Arch length.&#x0D; Conclusion- Changes in the transverse dimension were noticed among all the three groups with maximum in the Damon bracket and Damon archwire combination. Although the difference in expansion between groups showed no statistically significant difference, it was appreciated clinically in relieving dental crowding.

Comparison of alignment efficacy and arch dimensions changes with superelastic-, heat-activated-, and seven stranded coaxial nickel-titanium archwires during fixed orthodontic treatment – A double-blind randomized clinical trial

Objectives: The objectives of this study were to compare the alignment efficacy, changes in arch dimensions, and pain experience with three different nickel-titanium (NiTi) archwires. Material and Methods: Forty-five subjects were subjected to indirect bonding in the mandibular arch, and allocated to three groups using block randomization; Group 1 (0.014” Superelastic NiTi), Group 2 (0.014” 27° Copper NiTi), and Group 3 (0.016” seven stranded coaxial NiTi archwire). The mandibular study models were retrieved periodically at 4-week intervals for 12 weeks, which were blinded to measure the change in Little’s irregularity index (LII) and dental arch dimensions. Pain and discomfort were recorded with visual analog scale at five different time intervals, namely, immediately after bonding (0) and at 1-, 4-, 8-, and 12-h for initial 7 days. Repeated analysis of variance, Wilcoxon Signed-Rank test, post hoc Bonferroni test, and Friedman’s test was applied for the comparison and was used for data analysis. Results: A significant reduction of LII score and increase inarch length, intercanine, interpremolar, and intermolar width (P ≤ 0.001) were observed after 12 weeks among all groups. However, intergroup comparison showed significant mean changes only for intercanine width (Group 1 versus 3) and interpremolar width (Groups 1 and 3; Groups 2 and 3). All other variables were found to be insignificant at all-time intervals when compared among each group. The increase in pain score was maximum with Group 1and least with Group 3. Conclusion: All archwires were found to be effective in reducing the LII score. Nevertheless, Group 3 archwire could achieve reduction of LII to zero in 14% of subjects than Groups 1 and 2.

Predictability of Maxillary Dentoalveolar Expansion Using Clear Aligners in Different Types of Crossbites

The aim of this study was to determine the efficacy and predictability of maxillary dentoalveolar expansion clear aligners in unilateral, bilateral, and single-tooth types of crossbite. This prospective analytical study enrolled adults with dentoalveolar posterior crossbite. Orthoanalyzer™ 1.7 software was used to analyze stl files of digital models before treatment (T1), predicted post-treatment outcome (T2), and observed outcome (T3). Changes in intercanine width, first and second interpremolar widths, and intermolar width were compared using a mixed ANOVA model for repeated measures (α = 0.05). The study included 46 patients aged 20–60 years, 15 with unilateral, 15 bilateral, and 16 single-tooth crossbite. In all crossbite groups, expansion was largest at the second premolar level (unilateral: 2.54 mm; bilateral:, 4.86 mm; single-tooth: 3.41 mm) (ANOVA p &lt; 0.001) and smallest at the canine level. Expansion predictability was 90% at the first premolar level in the single-tooth crossbite group, 86% at the second premolar level in the bilateral crossbite group, and 79% at the second premolar level in the unilateral crossbite group. No significant difference was found between the predicted and observed expansion in any crossbite group. Dentoalveolar expansion using differential anchorage techniques with clear aligners is highly predictable, although the treatment plan should consider overcorrection of the expansion movement to achieve the planned outcome.

DENTAL ARCH DIMENSIONS AND FORMS IN THE NIGER DELTA REGION OF NIGERIA

This scrutiny assessed the dental arch dimensions and arch forms in a Niger Deltan population from Nigeria. The enquiry identified variations in tooth arch size. The inquiry compared the influence of gender on the dental parameters. This cross-sectional survey was done between February, 2021 and March, 2022. This study is a biometric analysis of dental casts of 206 subjects (104 males and 102 females) recruited from Teem Dental Clinic, Ekpan, Delta State, Nigeria. The dental arch sizes were determined. The proportions detailed are arch length, arch width, and arch form. The data were analyzed via the Statistical Package for the Social Sciences, version 22.0. Dental arch proportions (inter-canine width, inter-premolar width, inter-molar width and arch length) were lesser in females than in males. The Chucks arch form was considered in this scrutiny and the outcome was as follows: Tapered (49.5%), Ovoid (36.4%) and Square (14.1%). The dominant arch form was tapered, and the least common was square. Males mostly portrayed greater dental arch proportions than females.

Assessment of sexual dimorphism in Maharashtrian young adults using maxillary intercanine, interpremolar, and intermolar widths: A morphometric study.

Sexual dimorphism practically involves differences in size and appearance of the same species which does not involve the difference in sexual organs. A significant variation also occurs with the tooth size, shape, etc., which plays a critical role in sex determination. Forensic investigations are used in defining the number of missing people whose skeletal remains are unknown. Depending on the available bones and their state, a variety of methods with varying degrees of reliability are available for identifying unknown remains. Fifty male and 50 female patients in the age group 20-30 years were randomly selected after taking a detailed history. All maxillary impressions were made with alginate and poured into a dental stone. These casts were measured for intercanine width, interpremolar width, and intermolar width using a digital vernier caliper, and findings were correlated with sexual dimorphism. Intercanine width between the tips of right and left maxillary canine was measured in males and females at 36.08 ± 2.04 mm (Range: 30.05-41.64 mm) and in females, the mean intercanine width was 34.31 ± 1.75 mm (Range: 28.35-39.01 mm), respectively. Interpremolar width between the distal pits of right and left first premolars was measured in males and females at 38.97 ± 2.10 mm (Range: 33.94-45.21 mm) and in females, the mean interpremolar width was 36.92 ± 1.87 mm (Range: 31.34 mm), respectively. Intermolar width between the central fossae of right and left first molars was measured in males and females at 50.43 ± 2.25 mm (Range: 44.16-56.84 mm) and in females, the mean intermolar width was 47.90 ± 2.06 mm (Range: 42.66-54.63 mm), respectively. In males, the mean value of the combination of intercanine, interpremolar, and intermolar widths was 125.47 ± 5.61 mm (Range: 108.15-141.86 mm) and in females, it was 119.12 ± 5.05 mm (Range: 103.25-134.36 mm). Mean values of all combinations were larger in males than in females. Thereby, maxillary arch widths contribute to accuracy in determining the gender of the individual.

Correlation of Arch Width and Vertical Facial Morphology in Untreated Adults at a Tertiary Care Centre: A Cross-sectional Study

Introduction: The vertical dimension of a face is crucial in determining facial aesthetics and harmony. It is important for the orthodontist to understand the relationship between dental arch width and facial morphology for correct diagnosis and proper treatment plan. Aim: To determine the relationship between the vertical face pattern, dental arch width and also, to compare arch widths among both untreated female and male adults. Materials and Methods: This quantitative cross-sectional study was conducted in the Department of Orthodontics and Dentofacial Orthopaedics, at Sharad Pawar Dental College, Sawangi, Wardha, Maharashtra, India. The duration of the study was 1 month, from June 2019 to July 2019. Dental casts and lateral cephalograms were collected from 50 untreated adults (25 males and 25 females), aged between 18 to 30 years, who had minimal spacing, crowding and no crossbite. On every patient’s cephalogram, the angle between the plane of the mandible to the cranial base anterior Sella Nasion (SN) angle was calculated. Intercanine, intermolar, and interpremolar widths were measured on dental casts. Females and males arch width were compared. The significance of the differences was assessed using Student’s t-test, one-way Analysis of Variance (ANOVA) test and regression analysis. Results: The mean age of male study participants in the study was 24.44±5.04 years, whereas, mean age of females was 24.88±3.08 years. There were 25 males and 25 females of 18-30 years with mean age of 24 and 25 years, respectively. Arch widths of males were found to be significantly greater than, those of females (p&lt;0.05) and it was observed that, interarch width decreased significantly as the Sella Nasion-Mandibular Plane (SN-MP) angle increased. Regression analyses of male subjects revealed a significant positive relationship between the SN-MP angle. Whereas, the SN-MP angle and width of maxillary first premolar’s buccal cusp tip and the width of the second premolar (most buccal and buccal cusp tip), was found to have a strong correlation in female subjects. Conclusion: It was found that, the width of the dental arch is related to vertical face morphology and gender. During orthodontic therapy, it is recommended to use individualised archwires based on each individual’s pretreatment arch shape and width.

Tongue Adaptation and Airway Changes in Two Different Bracket Systems: A Randomised Clinical Trial

Introduction: Orthodontics apart from correcting the malocclusions provide an invariably indirect effects on surrounding musculature and airway by means of creating room for proper tongue posture which helps in improvement of oropharyngeal airway dimensions along with dentoalveolar corrections which in this study was experimented with two different bracket systemsMBT and Damon self-ligating systems. Aim: To assess the adaptation of tongue and oropharyngeal airway changes following treatment with two different bracket systems. Materials and Methods: This randomised clinical trial was conducted in the Department of Orthodontics, Saveetha Dental College and Hospital, Chennai, Tamil Nadu, India, and included 20 participants and categorised into two groups: Group 1 and group 2 included participants who underwent orthodontic treatment with Damon appliance therapy with Damon Copper NiTi (CuNiTi) wires and MBT prescription with Damon CuNiTi wires. Lateral cephalogram and intraoral scanning was done at the start of orthodontic treatment (T0) and after one year (T1). Cephalometric and occlusal model assessment to determine the adaptation of tongue and Oropharyngeal Dimensions (OD) were determined (T0-T1) using the Facad® and 3-shape software. Independent t-tests and paired t-tests were done to compare T0 and T1 for both the groups were done using Statistical Package for the Social Sciences (SPSS) software. Results: Results of paired t-tests showed a statistically significant difference at the Interpremolar distance (IPM1) region of both groups 1 and 2 between T0 and T1 (p=0.034, p=0.011), Intercanine distance (IC) of group 2 upper (p=0.043) and IPM2 of both the groups in the upper arch (p=0.042, p=0.022). Cephalometric results showed a significant increase in all the assessed parameters within the groups between T0 and T1 (p&lt;0.05). Oropharyngeal space did not show any difference in both the systems however comparatively increased in group 1 than in group 2. Conclusion: Treatment with Damon and MBT prescriptions with Damon Cuniti wires showed significant alterations in adaptation of tongue and oropharyngeal space and also in bringing about arch expansion in maxilla and mandible with the greatest expansion noted for first premolar of both the groups and IC and Interpremolar (2nd premolar) width of the upper arch of both the groups.

Qualitative and quantitative three-dimensional evaluation of maxillary basal and dentoalveolar dimensions in patients with and without maxillary impacted canines

BackgroundThis study aimed to three-dimensionally evaluate the qualitative and quantitative maxillary basal, dentoalveolar, and dental dimensions in patients with unilateral or bilateral maxillary impacted canines relative to their normal peers.Materials and methodsThis is a retrospective comparative study. Cone-beam computed tomography images of one hundred and fifty adult patients were divided into three equal groups: unilateral, bilateral, and control groups. Each had 50 patients that were three-dimensionally analysed. The quantitative measurements involved three basal (molar basal width, premolar basal width, and arch depth), seven dentoalveolar (molar alveolar width, premolar alveolar width, inter-molar width, inter-premolar width, inter-canine width, arch length, and arch perimeter), and two dental (canine length and width) measurements. The qualitative measurements included four bone density areas (buccal, lingual, mesial, and distal) around the maxillary impacted canines.ResultDifferences between the three groups were statistically different for the quantitative measurements involving the two basal variables (molar basal width and premolar basal width) and all measured dentoalveolar variables; these were smaller in the unilateral and bilateral groups compared with the control group (p < 0.001). Unilateral and bilateral impacted canine groups showed significantly wider and shorter canines than the control group (p < 0.001). The qualitative measurements (the four bone density areas) around unilateral and bilateral impacted canine groups showed significantly greater density than the control group (p < 0.001). There was no significant qualitative or quantitative difference between the unilateral and bilateral impacted canines. The three groups had no significant variations in terms of arch depth.ConclusionMaxillary unilateral and bilateral canine impactions are associated with reduced basal and dentoalveolar dimensions as well as wider and shorter maxillary canines compared to normal peers. The quality of bone around unilateral and bilateral impacted maxillary canines is higher than in non-impacted cases. Unilateral and bilateral canine impactions have quite similar qualitative and quantitative parameters.

Evaluation of rapid versus slow maxillary expansion in early adolescent patients with skeletal maxillary constriction using cone-beam computed tomography: A short-term follow-up randomized controlled trial.

Maxillary expansion is one of the treatment options for the correction of the skeletal constriction of the upper jaw. However, evidence regarding the best treatment effects with the use of rapid vs. slow maxillary expansion in the early adolescence period (i.e., between the age of 12 and 16 years) is still lacking in the available literature. The aim of the present study was to investigate the effectiveness of rapid and slow maxillary expansion in treating posterior skeletal constriction, and to compare the 2 techniques in terms of skeletal and dentoalveolar changes by using cone-beam computed tomography (CBCT). The sample consisted of 34 patients (15 males and 19 females) suffering from posterior skeletal constriction. They were randomly allocated either to the rapid maxillary expansion (RME) group (17 patients aged 13.76 ±0.32 years) or to the slow maxillary expansion (SME) group (17 patients aged 14.02 ±0.28 years). The skeletal and dental landmarks, and changes in the posterior dimensions were examined using CBCT radiographs at the beginning of treatment (T1) and at the end of the observation period (T2). There were no significant differences between the 2 groups in terms of skeletal and dental changes except the amount of change in the inter-premolar width at the root apex, which was greater in the SME group (p = 0.007), as well as the amount of change in the skeletal palatal width in the molar region, which was also greater in the SME group (p = 0.008). Both maxillary expansion protocols were effective in treating posterior skeletal constriction. The average changes in the skeletal and dental widths were generally similar in both groups. Therefore, SME can be considered as an alternative to RME in patients with skeletal maxillary constriction in the early adolescence period.

A two-year comparative assessment of retention of arch width increases between modified vacuum-formed and Hawley retainers: a multi-center randomized clinical trial

ObjectivesTo compare the clinical effectiveness of Hawley retainers (HRs) and modified vacuum-formed retainers (mVFRs) with palatal coverage in maintaining transverse expansion throughout a 24-month retention period and to assess the subjects’ perception toward the retainers.Materials and methodsThe trial accomplished blinding only by the outcome assessor and data analyst. Data were collected from post-orthodontic treatment patients who met the inclusion criteria. Thirty-five subjects were randomly allocated using a centralized randomization technique into either mVFR (n = 18) or HR group (n = 17). Dental casts of subjects were evaluated at debond (T0), 3-month (T1), 6-month (T2), 12-month (T3), and 24-month retention (T4). The intercanine width (ICW), interpremolar width (IPMW), interfirst molar mesiobuccal cusp width (IFMW1), and interfirst molar distobuccal cusp width (IFMW2) were compared between groups over time using Mixed ANOVA. A pilot-tested and validated questionnaire consisting of six items were given at T4. Subjects were instructed to rate their retainer in terms of fitting, speech, appearance, oral hygiene, durability, and comfort on a 100-mm Visual Analogue Scale (VAS).ResultsNo statistically significant differences in arch width were found between the two groups at ICW (P = .83), IPMW (P = 0.63), IFMW1 (P = .22), and IFMW2 (P = .46) during the 24-month retention period. Also, no statistically significant differences were found between perception of both retainers in terms of fitting, speech, oral hygiene, durability, and comfort (P > .05) after 24-month wear. The appearance of mVFRs was rated significantly higher compared to HRs (P < .05).ConclusionsHR and mVFR have similar clinical effectiveness for retention of transverse expansion cases in a 24-month retention period. Both retainers were perceived to be equal in terms of fitting, speech, oral hygiene, durability, and comfort. Subjects in the mVFRs group found their retainers to be significantly more esthetic than those in HRs group.

Effectiveness of miniscrew assisted rapid palatal expansion using cone beam computed tomography: A systematic review and meta-analysis.

ObjectiveThis study aims to examine the effectiveness of miniscrew assisted rapid palatal expansion (MARPE) treatment in late adolescents and adult patients using cone-beam computed tomography (CBCT).MethodsLiterature search was conducted in five electronic databases (PubMed, Embase, Scopus, Web of Science, and Cochrane Library) based on the PICOS keyword design focusing on MARPE. Out of the 18 CBCT screened outcomes, only nine parameters were sufficient for the quantitative meta-analysis. The parameters were classified into three main groups 1) skeletal changes, 2) alveolar change, and 3) dental changes. Heterogeneity test, estimation of pooled means, publication bias, sensitivity analysis and risk of bias assessment were also performed.ResultsUpon database searching, only 14 full-text articles were qualified from the 364 obtained results. Heterogeneity test indicated the use of the random-effects model. The pooled mean estimate were as follows 1) Skeletal expansion zygomatic width, 2.39 mm; nasal width, 2.68 mm; jugular width, 3.12 mm; and midpalatal suture at the posterior nasal spine and anterior nasal spine, 3.34 mm and 4.56 mm, respectively; 2) Alveolar molar width expansion, 4.80 mm; and 3) Dental expansion inter-canine width, 3.96 mm; inter-premolar width, 4.99 mm and inter-molar width, 5.99 mm. The percentage of expansion demonstrated a skeletal expansion (PNS) of 55.76%, alveolar molar width expansion of 24.37% and dental expansion of 19.87%.ConclusionsIn the coronal view, the skeletal and dental expansion created by MARPE was of the pyramidal pattern. MARPE could successfully expand the constricted maxilla in late adolescents and adult patients.

Comparison between Digital Casts and Cone Beam Computed Tomography for Measuring Maxillary Transverse Dimensions in Patients with Impacted Canines.

Cone beam computed tomography (CBTCT) scans (n = 45) and digital dental casts (n = 45) were both used to measure the maxillary transverse dimensions in patients with impacted maxillary canines. The objectives were to explore the associations of these dimensions with the impaction and patient characteristics, and to compare the measurements between these techniques. The maxillary width was measured on scans and casts at the Walaridge, and the intermolar width and interpremolar width levels were measured at the first and second premolars (measured from the buccal grooves and the palatal cuspids, and the palatal and lingual amelocemental junctions). Two examiners independently compared the measurements between the control quadrants (without impaction) and the case quadrants (with impaction) in patients with unilateral impactions, and between the unilateral and bilateral impaction groups. The interclass correlation coefficient (ICC) was calculated to assess the interexaminer reliability and paired or independent Student’s t-tests and ANOVAs were used for comparisons. The ICCs were 0.887 and 0.919, globally, for the measurements on the CBCT scans and casts, respectively, which indicates the excellent interexaminer reliability. On the CBCT scans, statistically significant differences were found between the case and control quadrants in the transverse measurements at the lingual level on the upper first molars, and at the WALA ridge level on the upper second premolars (p < 0.05) in the unilateral impaction group. Significant differences were found between the case quadrants in the unilateral versus the bilateral groups at the WALA ridge on the second premolars in casts (p < 0.05), and at the lingual point on the first molars on the CBCT scans (p < 0.05). No statistically significant differences in the transverse measurements were observed between the impacted buccal and palatal canines on either the casts or CBCT scans. To the best of our knowledge, this is the first study to compare the transverse measurements between digital models and CBCT scans.

One-year comparative assessment of retention of arch width increases between modified vacuum-formed and Hawley retainers.

To compare the clinical effectiveness of Hawley retainers (HRs) and modified vacuum-formed retainers (mVFRs) with palatal coverage in maintaining transverse expansion during a 12-month retention period. Data were collected from postorthodontic treatment patients who met the inclusion criteria. A total of 35 patients were randomly allocated using a centralized randomization technique into either mVFR (n = 18) or HR group (n = 17). The outcome assessor and data analyst were blinded to the retention method. Dental casts of patients were evaluated at debond, 3 months, 6 months, and 12 months of retention. Intercanine width (ICW), interpremolar width (IPMW), interfirst molar mesiobuccal cusp width 1 (IFMW1), and interfirst molar distobuccal cusp width 2 (IFMW2) were compared between groups over time using mixed analysis of variance. No statistically significant differences were found between the two groups for ICW (P = .76), IPMW (P = .63), IFMW1 (P = .16), and IFMW2 (P = .40) during the 12-month retention period. The null hypothesis could not be rejected. HR and mVFR had similar clinical effectiveness in the retention of transverse expansion cases during a 12-month retention period.