Intermolar Width Research Articles

The assessment of rapid palatal expansion using a remote monitoring software

ObjectiveDental Monitoring (DM) is a software system that allows orthodontists to remotely monitor a patient's treatment. This study evaluated the accuracy of DM software in assessing the achievement of treatment goals in patients undergoing rapid palatal expansion treatment and patient acceptance of DM. MethodsConsecutively treated patients undergoing rapid palatal expansion were invited to participate. Participants were trained to capture intraoral photos/videos using the DM app. Maxillary intermolar width (mm) and posterior crossbite correction measured by DM were compared with digital models and intraoral measurements. Patient acceptance of the DM app was evaluated with a survey. ResultsOf the 30 patients enrolled, 20 patients completed the study. DM accurately assessed the correction of posterior crossbite. There was no significant difference in intermolar width measurements obtained with DM, digital model, or intraoral examination. Overall, 71% of the participants found the DM app “easy” to work with and 43% of the patients preferred DM over a clinical visit. ConclusionIn-person evaluation of maxillary expansion with a Hyrax expander can be replaced with remote monitoring using the DM software, yet challenges associated with digital imaging hinder the use of this remote evaluation for some patients.

Management of the dentoalveolar effects of tongue hypertrophy in patients with Duchenne muscular dystrophy: A pilot study

Subjects affected by Duchenne muscular dystrophy (DMD) develop severe malocclusions with the progression of the disease, due to changes in orofacial musculature and function, including tongue hypertrophy. We aimed to evaluate the benefits of maintaining mandibular interarch width with the help of a simple fixed orthodontic appliance. Three adolescent DMD boys were selected consecutively to receive a passive rigid mandibular lingual arch, and followed for 4–5 years. An untreated age-matched control group was chosen and followed for a similar period. Study casts were obtained at baseline and after follow-up. Outcomes measured were overjet, overbite, maxillary and mandibular intermolar widths, mandibular arch depth, molar relationships, and the presence of lateral crossbites and anterior or lateral openbites. Changes in measurements obtained between the two time points were compared in each age-matched pair. There was a clinically important increase in the mandibular intermolar width in the non-treated children ranging from 2.5 mm to 9 mm, but not in those treated. Malocclusions generally deteriorated in untreated children while they remained stable in treated children. The use of a rigid mandibular lingual arch in boys with DMD can help slow down the rapid deterioration of the developing malocclusions that accompanies the progression of the disease.

Association between snoring and deciduous dental development and soft tissue profile in 3-year-old children

The aim was to study the association between snoring and development of occlusion, maxillary dental arch, and soft tissue profile in children with newly completed deciduous dentition. Thirty-two (18 female, 14 male) parent-reported snorers (snoring ≥3 nights/week) and 19 (14 female, 6 male) nonsnorers were recruited. Breathing preference (nose or mouth) was assessed at the mean age of 27months by otorhinolaryngologist. At the mean age of 33months, an orthodontic examination was performed, including sagittal relationship of second deciduous molars, overjet, overbite, and occurrence of crowding and lateral crossbite. Bite index was obtained to measure maxillary dental arch dimensions (intercanine and intermolar width, arch length). A profile photograph was obtained to measure facial convexity. No significant differences were found between nonsnorers and snorers in any of the studied occlusal characteristics or in measurements of maxillary dental arch dimensions. Snorers were found to have a more convex profile than nonsnorers. Occurrence of mouth breathing was more common among snorers. Parent-reported snoring (≥3 nights/week) does not seem to be associated with an adverse effect on the early development of deciduous dentition, but snoring children seem to have more convex profile than nonsnorers. Snoring is a mild sign of sleep-disordered breathing, and in the present study its short time lapse may not have had adequate functional impact on occlusion.

Evaluation of Growth and Development of Late Mixed Dentition Upper Dental Arch with Normal Occlusion Using 3-Dimensional Digital Models.

Objective The purpose of this study was to observe the three-dimensional growth and development of the maxillary arch in 10-year-olds with normal occlusion during the late mixed dentition stage. Methods Forty-four 10-year-old students (22 males and 22 females) who had normal occlusion during late mixed dentition were selected from an elementary school in Beijing, China. Once per year for three consecutive years, a dental cast was obtained from each subject, and the cast was scanned with a 3D digital scanner (R700 3D). The three-dimensional measurements of the maxillary dental arch and the inclination of the bilateral maxillary first molars were obtained from the digital model. Results The upper anterior arch length (UAAL), upper total arch length (UTAL), upper inter primary or permanent canine width (UICW), upper intermolar width (UIMW), and upper dental arch length (UDAL) increased by 0.959 mm, 0.583 mm, 0.955 mm, 1.462 mm, and 2.46 mm, respectively, over the two years (P < 0.001). UR6BL and UL6BL decreased by 4.416° and 7.133°, respectively, over the two years (P < 0.001). The values of the UICW and UIMW were 1.67 mm and 1.86 mm, respectively, larger in males than in females at 12 years old (P < 0.01). The change in the UTAL was 0.431 mm greater in males than in females over the 2 years (P < 0.05). Conclusion The UAAL, UTAL, UICW, UIMW, and UDAL in 10- to 12-year-olds with normal occlusion increased with age. The buccolingual inclination of the bilateral maxillary first molars inclined to the palatal side with age. The UICW and UIMW were larger in males than in females at 12 years old. The male UTAL increased more than the female UTAL over the 2 years.

Vacuum-formed retainer versus bonded retainer for dental stabilization in the mandible-a randomized controlled trial. Part I: retentive capacity 6 and 18 months after orthodontic treatment.

Evidence concerning the most appropriate retention strategy after orthodontic treatment is still inconclusive. This trial compares the retentive capacity of vacuum-formed Essix C-retainers (VFR) and bonded cuspid-to-cuspid retainers (CTC) in the mandible 6 and 18 months after orthodontic treatment. A single-centre two-arm parallel-group randomized controlled trial. This study included 104 adolescent patients, computer-generated randomized with sequentially numbered, opaque, and sealed envelopes into two groups and stratified by gender (52 females and 52 males). The patients were treated with fixed appliances with and without tooth extractions in both jaws and were ready for debond. In the intervention arm, patients received a VFR (n = 52); in the active comparator arm, patients received a CTC (n = 52). Dental casts were obtained at debond (T1), after 6 months (T2), and after 18 months (T3). The casts were digitized. The retentive capacity was evaluated on digital three-dimensional models using Little's Irregularity Index (LII), overbite, overjet, arch length, and intermolar and intercanine width. Baseline values were similar for both groups. Statistically significant increases were noted in LII and overbite, mainly between T1 and T2, but also between T1 and T3 in the VFR group (LII = 0.52 mm, P < 0.001, overbite = 0.51 mm, P < 0.001) and in the CTC group (LII = 0.45 mm P < 0.001, overbite = 0.36 mm, P < 0.001). There were no significant differences between groups. Overjet showed small variations during the observation periods but was overall stable within and between groups after 18 months. Arch length decreased slightly in both groups after 6 and 18 months. Intermolar and intercanine widths remained stable after debond. Patients, operator, and outcome assessor could not be blinded due to the study design. VFR and CTC have the same retention capacity in the mandible after 6 and 18 months. Relapse mainly occurs during the first 6 months of retention, but the post-treatment changes are generally small. Shorter VFRs in the mandible do not cause negative vertical effects. Part-time wear regimen is not associated with increased relapse. NCT03070444.

Tooth Size and Arch Widths in Crowded Class I Malocclusion

Objective: To examine the extent to which maxillary arch width and tooth size contributes to dental crowding.&#x0D; Methods: A cross-sectional study was conducted for six months after approval of synopsis by ERC of KMDC with 96 patients at department of orthodontics, Karachi Medical and Dental College, Karachi, Paki- stan. Patients with age 13-21 years with maligned teeth, over-crowding, presence of all fully erupted per- manent teeth and all angle classes were included, whereas patients with history of orthodontic treatment, presence of fractured restorations/crowns with tooth anomalies such as number, size, form and position as confirmed on clinical examination and craniofacial anomalies/syndromes were excluded. Maxillary crowding was calculated as the millimetre difference between arch perimeter and the sum of tooth widths of both second premolars. Arch perimeter was measured from the mesial aspect of the permanent first molar to its antimere with a brass wire. Intermolar arch width was calculated as distance from the central fossa of permanent maxillary first molar to its antimere. Data was analysed using SPSS 23.0. Prior to analysis assumptions were tested; an independent sample t-test was used to compare differences in crowded maxillary arch widths and spearman correlation was used to determine relationship between variables.&#x0D; Results: Significant differences were obtained in anterior (t(63) = -2.547, p=0.047) and posterior tooth size (t(63)= -2.218, p=0.030) in patients with mild, moderate and severe maxillary crowded arches and an in-verse weak correlation was obtained against maxillary crowding and maxillary arch widths (r=-0.054) and maxillary crowding and anterior tooth (r= -0.201) and posterior tooth size (r= -0.353).&#x0D; Conclusion: An inverse significant relation was found between crowding and tooth sizes &amp; significantly different tooth sizes were observed in patients with mild, moderate and severe maxillary crowding.

Is there a relationship between dental crowding and the size of the maxillary or mandibular apical base?

To determine whether apical base size is related to dental crowding. Digital scans of dental casts were taken of 75 untreated Class I adults to measure maxillary and mandibular tooth size, dental arch perimeters, intermolar widths, and intercanine widths. Cone beam computed tomography (CBCT) images were used to measure the apical base of the maxilla and mandible, including the total cross-sectional area, five basal arch perimeters and five basal arch widths. Principal components factor analyses were performed to evaluate the relationships between the apical base size and tooth-size-arch-length discrepancies (TSALD). The dental arch and maxillary apical base measures were significantly larger in males than females. There were only limited sex differences in mandibular apical base size. The dental arch measurements were smaller in subjects with greater upper and lower TSALD. Maxillary and mandibular apical base dimensions were positively interrelated. Low-to-moderate correlations were found between the size of the maxillary apical base and TSALD. The size of the mandibular apical base was not related to upper or lower TSALD. Tooth size showed little to no relationship with TSALD. Although maxillary apical base size is related to maxillary and mandibular crowding in subjects with Class I malocclusion, mandibular apical base size is not.

Optimization of clinically applied orthodontic archwire electrothermal treatment conditions by heat tint and mechanical properties: An experimental study

Electric resistance heat treatment procedures are performed by most orthodontists; however, the effects of electrothermal treatment on the mechanical properties, surface morphology, phase transition, colour and arch width of stainless steel archwires remain controversial and are worthy of investigation. Stainless steel archwires (0.017×0.025 and 0.019×0.025 inches) were heat-treated using a spot-welder machine at a power setting of 3 for 5, 10, 15 or 20s and were then cooled in air. After the heat treatment, we analysed the surface morphology of the samples by scanning electron microscopy (SEM) and the flexural modulus with a universal testing machine. The changes in phase and the austenite content after heat treatment were determined by X-ray diffraction (XRD). The changes in the colour of the sample were analysed by a digital single-lens reflex (DSLR) camera, and the arch width changes were measured with Vernier calippers. The flexural modulus and austenite content of the orthodontic stainless steel archwires increased after heat treatment (P<0.05). The colour changed from silver to yellow-brown-blue. Heat treatment of the stainless steel wires increased the inter-canine and inter-molar widths only when the amount of heat received was low. Heat treatment of stainless steel orthodontic archwires using an electric resistance device is an effective and convenient method to improve their flexural modulus. The colour of the wire surface after heat treatment can help determine the heating conditions, and the maximum flexural modulus of the stainless steel wires was obtained when the colour changed to brownish yellow.

Twenty-year follow-up of functional treatment with a bionator appliance: A retrospective dental cast analysis.

To investigate changes in dental arch configuration, relationship, and malocclusion directly after Class II malocclusion treatment with a Balters bionator modified by Ascher as well as 20 years after treatment. Orthodontic dental cast analysis of 18 patients with skeletal Class II treated with a bionator without any additional fixed therapy was performed with a digital caliper at three stages: before (T0), after (T1) and 20 years after (T2) treatment. Arch perimeter and depth, intermolar and intercanine distance, overjet, overbite, sagittal molar and canine relationship, mandibular incisor irregularity (Little's index), and malocclusion (PAR index) were assessed. During treatment (T0-T1), upper arch perimeter significantly increased with a significant decrease in the upper and lower arch perimeter long-term (T1-T2), whereas corresponding arch depths changed only slightly in both periods. Transverse intermolar width increased significantly during treatment, remaining almost constant from T1 to T2. Lower intercanine distance remained fairly unchanged during treatment, but decreased significantly during follow-up. Lower incisor irregularity improved slightly during treatment but increased significantly long-term. After treatment, sagittal molar relationships on both sides were improved, overjet and overbite reduced; these significant changes remained stable long-term. The peer assessment rating (PAR) index was significantly lower after treatment and increased insignificantly during follow-up. 20 years after bionator treatment without additional fixed appliances, the improved sagittal relationship and the reduced overjet and PAR index remained fairly stable. Long-term changes are most likely due to physiological aging processes and are not associated with bionator treatment.

Comparison of transverse maxillary dental arch width changes with self-ligating and conventional brackets in patients requiring premolar extraction – A randomised clinical trial

The purpose of this study was to evaluate, the change in the transverse maxillary arch dimensions, in patients requiring all first premolar extractions when using Active and Passive Self-ligating brackets, and comparing them with Conventional brackets. This study was a non-blinded randomised clinical trial, which consisted of 42 patients (21 males and 21 females) within the age group of 16-25 years, having bimaxillary protrusion. They were divided into three groups with 14 patients each. In Group 1-Conventional brackets (3M Unitek), in Group 2-Passive Self-ligation brackets: Smart Clip (3M Unitek), and in Group 3-Active Self-ligation brackets: Empower AO (American Orthodontics) were bonded. All brackets had MBT prescription and 0.02" slot size. Dental study models were taken before the start of treatment and after six months of retraction. Inter-canine and intermolar widths were measured in all the three groups in the above mentioned stages. As compared to Conventional brackets, Self-ligating brackets (Passive and Active) showed greater increase in the transverse arch widths. Furthermore, between Passive and Active Self-ligating brackets, Passive Self-ligating brackets-Smart Clip (Group 2) showed a greater increment in the transverse arch dimensions, with an increase of 4.89mm in the inter-canine width and 3.4mm in intermolar width. Significant difference was found between Self-ligating brackets and the Conventional bracket system regarding maxillary arch width dimensional changes. Passive Self-ligating brackets-Smart Clip (Group 2) showed the highest and inter-molar width increase.

Three-dimensional morphological analysis of the palate of mouth-breathing children in mixed dentition

To study the effects of mouth-breathing on maxillary arch development by comparing the palatal morphology of mouth- and nose-breathing children in mixed dentition. Children in mixed dentition were enrolled and categorized into mouth-breathing (test group) and nose-breathing groups (control group) according to their breathing patterns. Children's plaster models were scanned with 3D laser scanner, and the 3D data were reconstructed and measured using Minics 15.0 and Geomagic 12.0 software. Measurement data (inter-molar width, palatal height, palatal volume, and palatal surface area) of the two groups were compared, and the correlation among the four measurement items was analyzed. The participants were 73 children (37 in test group and 36 in control group) with a mean age of (8.63±0.78) years old. The test group had significantly smaller inter-molar width, palatal volume, and palatal surface area but significantly higher palatal height than the control group (P<0.05). Inter-molar width and palatal volume were positively correlated with the palatal surface area in the test group (P<0.05). Inter-molar width and palatal height were positively correlated with the palatal surface area in the control group (P<0.01). Mouth-breathing children have significantly reduced inter-molar width, palatal volume, and surface, and substantially increased palatal height, leading to different developmental patterns of the palatal morphology.

Skeletal and dental effects of surgically assisted rapid palatal expansion: a systematic review of randomized controlled trials.

Surgically assisted rapid maxillary expansion (SARME) is a surgical technique developed to correct transverse discrepancies in skeletally mature patients. However, there is limited evidence concerning the immediate skeletal and dental changes obtained only due to SARME. The aim of the present systematic review is to investigate the immediate skeletal and dental effects of SARME in adult patients with transverse maxillary hypoplasia. An electronic search of the literature in MEDLINE, The Cochrane Library, Lilacs and Scopus databases was performed. Only randomized controlled trials (RCTs) studies investigating the skeletal and dental effects of SARME procedures in adult patients were included. The included studies received a methodological quality scoring according to the revised Cochrane risk-of-bias tool for randomized trials. The quality of evidence was assessed by means of the Grading Recommendation Assessment, Development and Evaluation (GRADE) system. For each included study and for each analysed parameter, the difference in means and 95 per cent confidence interval was calculated between baseline and immediate post-expansion. A meta-analysis of original outcome data, if possible, was conducted. Nine articles were selected. The methodological quality ratings indicated that one study was at low risk of bias, seven presented some concerns and only one was at high risk of bias. In all the included studies, the SARME procedure resulted in a significant expansion of the maxillary transverse dimension. The meta-analysis compared skeletal and dental inter-molar width before and after treatment: the mean difference was of 3.3 mm (2.8-3.9) and 7.0 mm (6.1-7.8), respectively (P-value less than 0.001). The quality of evidence was low-moderate. SARME is effective in obtaining a significant expansion of the maxillary transverse dimension. However, the immediate SARME effect is mainly a molar expansion rather than a pure bone transverse widening of the maxilla. The review protocol was registered at PROSPERO database with the registration number CRD42018117967.

Association between maxillary transverse discrepancy and occurrence of potentially impacted maxillary canines in mixed dentition patients

The aim of this study was to determine the association between transverse maxillary discrepancy and occurrence of potentially impacted maxillary canines in mixed dentition patients. This cross-sectional analytical study was conducted on 85 Pakistani subjects (32 males and 53 females) aged between 8 to 13 years, having good quality orthopantomographs and dental casts. Maxillary transverse discrepancy was assessed by subtracting the mandibular intermolar width from the maxillary intermolar width on dental cast. Maxillary lateral incisors and canines were traced from orthopantomographs, and canines were placed into sector classification. Chi-square test was used to determine the difference in the occurrence of potentially impacted maxillary canines between patients with maxillary transverse discrepancy and patients without maxillary transverse discrepancy. There was no significant difference seen in the occurrence of impacted maxillary canines in patients with and without maxillary transverse discrepancy in mixed dentition patients. Patients with maxillary transverse discrepancy may not be at a higher risk of palatal canine impaction. Radiological presence of canine in sector II, III and IV, pose a higher risk of canine impaction.

Comparison of Two Retention Appliances with Respect to Clinical Effectiveness.

The aim of this study was to compare the clinical effectiveness of Essix and Hawley retainers during the retention period. A total of 30 subjects whose fixed orthodontic treatment results were evaluated according to the American Board of Orthodontics Phase III Objective Grading system were included in this study. After the removal of orthodontic attachments, the study participants were equally divided into two retention protocols: upper-lower Essix and upper-lower Hawley. The subjects were instructed to wear their retainers full time for 6 months, except during meals, and during nights only for 6 months. The clinical effectiveness of the retainers was evaluated according to the overjet, overbite, maxillary, and mandibular intercanine widths, intermolar widths, arch lengths, irregularity indexes, and lateral cephalometric measurements. All dental model and lateral cephalometric measurements were performed by the same investigator during three periods: pre-treatment, post-treatment, and post-retention. The overjet, overbite, maxillary, and mandibular intercanine widths; intermolar widths; and arch lengths and lateral cephalometric measurements were not statistically significantly different between the groups and identified time periods. Although the maxillary and mandibular irregularity indexes increased from the post-treatment to post-retention periods, the difference was not statistically significant. Pre-treatment, post-treatment, and post-retention lateral cephalometric measurements were not statistically significantly different between and within the groups. According to the results of a repeated-measures analysis of variance with two factors, and although an increase was found in the maxillary and mandibular irregularity indexes, the clinical effectiveness of Essix and Hawley retainers was found to be similar during the retention period.

The dental arch dimensions in Vietnamese children at 7 years of age, and their variation by gender and ethnicity

PurposeDental arch dimensions are important not only in dentistry (e.g. orthodontists and prosthodontists, and forensic odontology), but also other medical fields, biology, biometrics, painting or sculpture. This study aimed to determine these dimensions in Vietnamese children and compare these measurements across four ethnic groups and genders. MethodsA cross-sectional study was conducted on 3204 Vietnamese children at 7 years of age from four major ethnic groups in Vietnam (Kinh, Tay, Thai and Muong). ResultsThe means variables in study subjects were 33.72 ± 2.16 mm for upper inter-canine width (UCW); 52.74 ± 2.55 mm for upper inter-molar width (UMW); 8.69 ± 1.79 mm for upper anterior length (UAL); 29.59 ± 1.97 mm for upper posterior length (UPL); 26.94 ± 2.49 mm for lower inter-canine width (LCW); 45.89 ± 2.59 mm for lower inter-molar width (LMW); 5.04 ± 1.53 mm for lower anterior length (LAL); and 26.22 ± 2.07 mm for lower posterior length (LPL). The UCM, UMW, and LMW of Muong were significantly wider in males, but narrower in females compared with other ethnic groups. The Kinh, Tay and Thai groups had no significant differences between genders in all dimensions, but these sizes were significantly larger in males than females of Muong group. ConclusionsThis study presents the means of dental arch dimensions in 7 year-old Vietnamese children, and there is no statistical differences in these dimensions between genders of almost studied groups, except Muong group. Ethnic differences are observed only in UCW, UMW and LMW of Muong vs other groups. Furthermore, Vietnamese children have dental arch width similar to the African and Caucasian.

Recombinant Human Bone Morphogenic Protein-2 Combined With Autogenous Bone Graft for Reconstruction of Alveolar Cleft

Recombinant human bone morphogenic proteins (rhBMPs) have been introduced for reconstruction of alveolar defects. The volume of the bone formed at the cleft region may be related to rhBMP-2 dose. Greater side effects have been reported with increased doses of rhBMP-2. The aim of the present study was to assess the bone at the cleft area using low dose of rhBMP-2 combined with autogenous bone graft for reconstruction of the alveolar cleft. Patients with unilateral cleft lip and palate between the 11 to 14 years old were enrolled. After palatal expansion, autogenous graft was placed at the side of cleft in the control group (n = 6). In the BMP group, the rhBMP-2 was injected into the autogenous bone graft at the defect site (n = 5). Cone beam computed tomography (CBCT) images were taken of all patients immediately and 3 months after graft surgery to compare the density, thickness, and height of the bone graft between the 2 groups. Intermolar and interpremolar widths were also measured. The authors found less diminish of density and height of the bone graft 3 months postsurgery in patients with autogenous bone graft combined with rhBMP-2. However, significant difference in the relapse tendency of transverse dimension of the arch or thickness of the bone graft was not observed between the 2 groups. Thus, low dose rhBMP-2 combined with autogenous bone graft can be promising to reach predictable results after alveolar reconstruction in cleft lip and palate patients.

3D-CT assessment of mandibular widths in young subjects with different underlying vertical facial patterns

AimThis study was undertaken to evaluate the relationships among dental arch widths, mandibular bone widths, and masseter muscle dimensions in growing children with different underlying vertical facial patterns using three-dimensional computed tomography (3D-CT). MethodFifty-eight young subjects (32 male and 26 female) with a mean age of 13.27 (±1.59) years had undergone cranial CT examinations as part of medical diagnosis. 3D-CT images were reconstructed for the assessment of various mandibular dental and bone widths in relation to the vertical facial pattern and masseter muscle dimensions. ResultsThe cross-sectional area and volume of the masseter muscle, mandibular plane angle, total posterior face height and lower posterior face height were significantly different among the vertical pattern groups. There were a number of significant positive and negative correlations among the muscular dimensions and the dental and bone widths with the different vertical patterns. ConclusionsDolichofacials are likely to have relatively smaller masseter cross-sectional areas and volumes than brachyfacials, and vice versa. There is likely to be a close association between mandibular intermolar width and the corresponding widths at the apical and lower border levels. There is not likely to be the same association between the intercanine width and the corresponding lower border width. Brachyfacials are likely to have a greater width of buccal cancellous bone through which the canines can potentially be expanded laterally.

Comparison between Class II Division 1 and 2 Malocclusions and Normal Occlusion regarding Tooth Size Discrepancy and Arch Dimensions using Digital Models

The orthodontists grant a considerable importance to dental arch dimensions to attain more stability of the dentition and better esthetics. The aim of this study was to measure tooth size disharmony and dental arch dimensions in both divisions of class II malocclusion and compare them to Normal occlusion as a control group using three dimensional digital models obtained from 3Shape E1 laser scanner (3Shape, Copenhagen, Denmark). This work was performed on 120 dental casts randomly selected from the records of patients (age range 16- 22 years) attending the Department of Orthodontics, Faculty of Dentistry, Mansoura University. Various parameters were measured including anterior and overall Bolton ratios, maxillary and mandibular intercanine, interfirst premolar and intermolar widths, maxillary and mandibular arch depth, palatal depth, depth of curve of Spee, overjet and overbite. Mean and standard deviation were calculated. One-way ANOVA was used to detect possible differences between groups. The findings indicate that Class II division 1 malocclusion showed significantly greater maxillary arch depth, palatal depth, mandibular intercanine, interpremolar and intermolar widths and larger overjet amount in comparison with Class II division 2, while revealed significantly higher values of maxillary arch depth, mandibular intermolar width, curve of Spee, overjet and overbite than Normal Class I. On the other hand Class II division 2 malocclusion had significantly greater overall Bolton ratio, maxillary intermolar width, curve of spee depth and overbite than Class II division 1, while it showed deeper curve of Spee and larger amount of overjet and overbite compared to Normal Class I. The results of the current study can help the clinicians in treatment planning and provide guidance for proper selection of arch wires to obtain post-treatment stability.

Accuracy of a smartphone-based orthodontic treatment-monitoring application: A pilot study.

To investigate the reliability and accuracy of a monitoring system in patients undergoing orthodontic treatment with a rapid maxillary expander. Specifically, the amount of tooth movement calculated by the software was compared with the actual measurements taken on plaster models obtained during an in-office visit. Patients took intraoral video scans using the monitoring software's smartphone application (Dental Monitoring, Paris, France), immediately followed by impressions for plaster models. Intercanine and intermolar width measurements were calculated by the software and compared with those made on the plaster models. Data were analyzed using two one-sided t-tests for equivalence with equivalence bounds of ±0.5 mm. The significance level was set at .05. Thirty sets of measurements were compared. The intercanine and intermolar measurement differences were on average 0.17 mm and -0.02 mm, respectively, and were deemed equivalent. The monitoring software seems to provide an accurate assessment of linear tooth movements.

Three-dimensional evaluation of rapid maxillary expansion anchored to primary molars: direct effects on maxillary arch and spontaneous mandibular response.

The purpose of this study was to evaluate the effects of rapid maxillary expansion (RME) on maxillary and mandibular arch in the mixed dentition. Forty-four consecutive patients with transverse maxillary deficiency were recruited. Test group: 21 patients (10 male, 11 female; 7.4 ± 1.2 years) who underwent RME (Haas type) therapy banded on the primary second molars. 17 patients (10 male, 7 female; 7.3 ± 1.1 years old) who did not receive any orthodontic treatment. Dental casts obtained pre-treatment and after appliance removal (11 months) were processed by means of a three-dimensional scanner (3Shape D250 laser, DK). Digital landmarks were traced using the VAM software (Canfield Scientific Inc., Fairfield-NJ, USA). Arch Length, interdental width and torque differences were measured before and after the removal of the appliance. The t-test (P<0.05) for paired data was applied to evaluate the measurements values before and after treatment. The linear regression model was employed to assess the correlations between treatment effects. The efficacy of the RME was confirmed both on maxillary and mandibular arch. Mandibular intermolar width (+2.02 mm) together with primary intermolar (+1.39 mm), intercanine width (+0.95mm) and torque variations significantly increased. The untreated control group showed no significant statistical differences between T0 and T1. The linear regression between maxillary and mandibular data showed correlations between the torque of the teeth 16/46 and 65/85 (P<0.05). RME anchored on primary molars is an effective treatment option to correct tranverse maxillary deficiencies. All the measurements increased significantly confirming the indirect effect of RME on the mandibular arch.