Intermolar Width Research Articles

Maxillary arch width and buccal corridor changes with Damon and conventional brackets: A retrospective analysis.

To evaluate the effect of Damon self-ligating and conventional bracket systems on buccal corridor widths and areas. A retrospective sample of consecutively treated patients using either conventional (CG, n = 45) or Damon self-ligating (SL, n = 39) brackets was analyzed to determine any differences in buccal corridor widths and areas both within and between groups. Pretreatment and posttreatment frontal photographs were transferred to Photoshop CC, standardized using intercanthal width, and linear and area measurements were performed with tools in Photoshop CC. Ratios were then calculated for statistical analysis. Relationships between arch widths and buccal corridors were also examined. There were no significant differences in the posttreatment intercanine or intermolar widths either within or between the CG and SL groups. There were no significant differences in any buccal corridor width or area measurement either within or between the CG and SL groups. There were strong correlations with the intercanine width and the corresponding buccal corridor smile width measurements. There was an inverse correlation with the buccal corridor area in relation to the canine and the total smile width. It is likely that posttreatment increases in arch width can be seen in patients treated with either a conventional bracket system or the Damon system. It is highly unlikely that there is any significant difference in buccal corridor width or area in patients treated with the Damon self-ligating system or a conventional bracket system.

Predictors of long-term stability of maxillary dental arch dimensions in patients treated with a transpalatal arch followed by fixed appliances.

BackgroundThe aim of this retrospective study was to identify which dental and/or cephalometric variables were predictors of long-term maxillary dental arch stability in patients treated with a transpalatal arch (TPA) during the mixed dentition phase followed by full fixed appliances in the permanent dentition.MethodsThirty-six patients, treated with TPA followed up by full fixed appliances, were divided into stable and relapse groups based on the long-term presence or not of relapse. Intercuspid, interpremolar and intermolar widths, arch length and perimeter, crowding, and upper incisor proclination were evaluated before treatment (T0), post-TPA treatment (T1), post-fixed appliance treatment (T2), and a minimum of 3 years after full fixed appliances’ removal (T3). A binary logistic regression was performed thereafter to evaluate the impact of the dental arch and cephalometric measurements at T1 and the changes between T0 and T1 as predictive variables for relapse at T3.ResultsThe proposed model explained 42.7 % of the variance in treatment stability and correctly classified 72.2 % of the sample. Of the seven predictive variables, only upper anterior crowding (p = 0.029) was statistically significant. For every millimeter of decreased crowding at T1 (after TPA treatment/before starting the fixed orthodontic treatment), there was an increase of 3.57 times in the odds of having stability.ConclusionsThe best predictor of relapse was maxillary crowding before treatment. The odds of relapse increase by 3.6 times for every millimeter of crowding at baseline.

Assessment of Artificial Teeth Setup Device: A Three-Dimensional Model Analysis.

This study assessed the use of the commercial artificial teeth setup device Staub Cranial System (Neu-Ulm) in Asian subjects. Fourteen completely dentate Thai volunteers were randomly recruited. Study casts (control group) and duplicated casts (experimental group) of all subjects were prepared. Artificial teeth were replaced on duplicated casts according to the manual. Computed tomography scans of all casts were performed. Intercanine width, intermolar width, incisocervical length, and occlusal plane were investigated. The length of the natural mandibular left central incisor was smaller than the reconstructed one. The reconstructed occlusal plane was more parallel to the hamular-incisive papilla plane than that of the control group.

Evaluation of mandibular transverse widths in patients affected by unilateral and bilateral cleft lip and palate using cone beam computed tomography

To evaluate the mandibular dental, alveolar, and skeletal transversal widths in patients affected by unilateral (UCLP) and bilateral (BCLP) cleft lip and palate and to compare the findings with a well-matched normal occlusion sample using cone beam computed tomography images. The study sample consisted of 75 patients divided into three groups: the UCLP (29 patients; mean age: 15.40 ± 3.22 years), BCLP (18 patients; mean age: 15.54 ± 3.72 years), and normal occlusion (28 patients; mean age: 15.82 ± 2.11 years) groups. Mandibular dental (intercanine and -molar), alveolar (intercanine and -molar), and skeletal (bigonial width) transversal measurements were performed three-dimensionally and analyzed using the one-way variance analysis and post hoc Tukey tests. Patients affected by UCLP and BCLP had statistically significantly lower intercanine alveolar widths (P < .05 and P < .001, respectively) and larger intermolar (P < .001 and P < .05, respectively) and intermolar alveolar widths (P < .001) compared with the normal occlusion group. Furthermore, the patients affected by UCLP and BCLP had similar mandibular dental, alveolar, and skeletal transversal widths (P > .05). The UCLP and BCLP groups showed statistically significantly smaller values for intercanine alveolar widths and larger values for intermolar dental and alveolar widths compared with the normal occlusion group. This shows the importance of using individualized archwires according to the pretreatment arch widths of the patients affected by UCLP and/or BCLP.

Reliability of digital orthodontic setups.

To evaluate the reliability of digital orthodontic setup technology by comparing it with manual setups and models cast at the end of orthodontic treatment. Initial models, manual setups, and final models of 20 patients were used. The initial and final models, as well as the manual setups, were scanned using a 3Shape R-700 scanner, while the digital setups were fabricated based on the initial models using 3Shape OrthoAnalyzer software. Evaluation of the models based on the manual setup, digital setup, and final models of each patient was performed using the following linear measurements: intercanine widths, intermolar widths, and length of the upper and lower dental arches. The results disclosed that none of the measures assessed through the manual setup, digital setup, and final models showed statistically significant differences (P > .05). Based on these findings, it can be inferred that digital setups are as effective and accurate as manual setups and constitute a tool for diagnosing and treatment planning that can be reliably reproduced in orthodontic treatments.

Comparative study of reproducibility and accuracy in measuring mesiodistal tooth sizes using three different methods: 2D digital, 3D CBCT, and 3D CBCT segmented

To develop a 3D cone-beam computed tomography (CBCT) method (CBCT method) for determining tooth sizes and arch dimensions and to compare the accuracy and reproducibility of that method with those of a previously described 3D segmented CBCT method (CBCT seg. method) and a 2D digital method. Plaster study models and CBCT images were available for 34 patients. For the first method, the plaster study casts were digitalized and measured using the 2D digital method. For the second method, CBCT seg. method, the CBCT images were sent in DICOM format to InVivoDental® Company for segmentation and conversion into three-dimensional images of the models. For the third method, CBCT method, axial cuts were performed on the CBCT images, and tooth sizes and arch dimensions were measured using Anatomage® software. Significant differences were found between the tooth size measurements obtained with the 3D CBCT method and the 2D digital method, but not for the intercanine width, intermolar width, and arch length. There were no significant differences between the measurements obtained with the CBCT seg. method and the 2D digital method. A 3D CBCT method has been developed. It presented good accuracy for the intercanine width, intermolar width, and arch length, but not for the mesiodistal tooth sizes. Model segmentation will be necessary for measurements of tooth size.

Does a true knowledge of dental crowding affect orthodontic treatment decisions?

To assess whether a true knowledge of crowding alters treatment decisions compared with estimates of crowding. Thirty-six orthodontists were asked to estimate crowding using visualization on eight mandibular arch study models and to indicate possible extraction choices. For each model, the intermolar widths, intercanine widths, and clinical scenarios were identical, but the true crowding varied from 0.2 to 8.4mm as to a lesser extent did the curve of Spee. Eleven orthodontists repeated the visualization exercise after 2 weeks to assess reliability. All 36 of the orthodontists were asked to repeat the treatment planning exercise on the same models, but this time was provided with the true amount of crowding in each case. When the 36 orthodontists used direct visualization of the models to assess crowding, the range of their estimates of crowding increased as the crowding increased. As might be expected, they also tended to move towards extraction treatments as the crowding increased (P = 0.013, odds ratio = 3). Although the reliability of the repeat estimates of crowding were moderate, the mean estimates were greater than the true crowding for each model. When orthodontists were presented with the true amount of crowding, rather than their estimate of crowding, it had a significant effect on the decision to extract, with fewer orthodontists recommending extractions. The principal limitation of this study is that it was a laboratory-based study and utilized just the mandibular arch model for estimation and treatment planning. Direct visualization may overestimate the amount of crowding present. When the true amount of crowding is known, it can lead to more consistent treatment planning, with the decision to extract fewer teeth in the borderline cases. A formal space analysis is likely to assist with treatment planning.

Association of breastfeeding and three-dimensional dental arch relationships in primary dentition.

BackgroundThe benefits of breastfeeding on oral health are still inconclusive, especially the association on occlusion. This study aimed to investigate the association of breastfeeding and the development of primary dentition.MethodsA cross-sectional study was conducted with 851 Asian children aged 2–5 years old in Hong Kong. Questionnaires were completed by the parents to collect information on breastfeeding and the non-nutritive sucking habits. The children’s dental arch relationships were examined in the sagittal, vertical, and transverse dimensions by an experienced examiner.ResultsChildren who experienced pure breastfeeding for more than 6 months had a lower chance of developing a class II incisal relationship (P < 0.05) or an increased overjet (P < 0.05), and had wider intercanine (P < 0.05) and intermolar widths (P < 0.05). Vertically, no association on the extent of overbite or openbite was found (P >0.05).ConclusionsPure breastfeeding for more than 6 months is positively associated with primary dental arch development in the anterior sagittal dental segment and on the horizontal arch width in primary dentition. Therefore, pure breastfeeding for more than 6 months is recommended, as it is associated with lower chance of the development of abnormal dental relationships. The results will be valuable for education and promotion of maternal breastfeeding.Electronic supplementary materialThe online version of this article (doi:10.1186/s12903-015-0010-1) contains supplementary material, which is available to authorized users.

Quad-helix appliances may be more successful than removable expansion plates at correcting posterior crossbites.

The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) Medline, Embase, the US National Institutes of Health Trials Register and the World Health Organisation (WHO) Clinical Trials Registry Platform were searched with no restrictions. Randomised controlled trials (RCTs) of orthodontic treatment for posterior crossbites in children and adults were considered. Study selection, data abstraction and risk of bias assessment were carried out independently by two reviewers. Dichotomous data were summarised with risk ratios (RR) and 95% confidence intervals (CIs) and continuous data with mean differences (MD) with 95% CIs. Meta-analyses were conducted when comparisons and outcomes were sufficiently similar. Fifteen studies were included; seven were at high risk of bias, two at low risk and six at unclear risk. Nine studies compared fixed appliances with mid-palatal expansion but no difference between appliances was reported. Low quality evidence from two studies with 96 participants found that fixed quad-helix appliances may be 20% more likely to correct crossbites than removable expansion plates (RR 1.20; 95% CI 1.04 to 1.37), and quad-helix appliances may achieve 1.15 mm more molar expansion than expansion plates (MD 1.15 mm; 95% CI 0.40 to 1.90;). Very limited evidence showed that both fixed quad-helix appliances and removable expansion plates were superior to composite onlays in terms of crossbite correction, molar and canine expansion. There is a very small body of low to moderate quality evidence to suggest that the quad-helix appliance may be more successful than removable expansion plates at correcting posterior crossbites and expanding the inter-molar width for children with early mixed dentition (aged eight to 10 years). The remaining evidence we found was of very low quality and was insufficient to allow the conclusion that any one intervention is better than another for any of the outcomes in this review.

Rapid maxillary expansion on the permanent teeth versus the deciduous teeth: Comparison of skeletal and dentoalveolar effects by volumetric tomography

BackgroundThe aim of this study was to evaluate skeletal and dentoalveolar effects of rapid maxillary expansion (RME) on the permanent and deciduous teeth by means of volumetric tomography. MethodsThe sample included 12 patients with transverse maxillary hypoplasia (6 treated with RME on the permanent first molars, 6 treated with RME on the deciduous second molars) in the mixed-dentition phase. Beginning and postexpansion cone beam computed tomography images were compared for analysis of the skeletal and dentoalveolar effects of the two devices. ResultsRME treatment significantly increased the palatal volume in both groups (by 10.78% with RME on the permanent teeth vs. by 9.89% with RME on the deciduous teeth). Intermolar width increased for both skeletal and dental measurements. First upper molar tipping was greater on the first permanent molars when RME was anchored on the deciduous teeth than when anchored on the permanent teeth (4.02° vs 2.13°). Decompensation of the lower molars was greater in patients treated with RME on the permanent teeth than on the deciduous teeth (4.58° vs. 1.71°). ConclusionsRME treatment significantly increased palatal volume. RME anchored on the permanent teeth determined greater dental intermolar width variation and a significant difference in decompensation of the lower molars. RME anchored on the deciduous teeth was more effective in increasing skeletal intermolar width and inclination of the first molars.

Influence of tonsillar grade on the dental arch measurements

The role of the palatine tonsils in the development of dental intra-arch and interarch abnormalities is often brought up in the literature, but it remains controversial. Data on the probable relationship between enlarged tonsils and the occurrence of orthodontic abnormalities are subjective. The purpose of this study was to seek an association between the space occupied by the palatine tonsils and the dental arch measurements. A cross-sectional study was performed on a group of children subdivided into 5 groups according to the standardized tonsillar hypertrophy grading scale. Dental arch measurements were recorded for each child. Data were analyzed with software. Comparisons of qualitative variables according to tonsillar grade were made using the chi-square test. The strength of the association between tonsillar grade and qualitative variables was evaluated with a phi coefficient (φ). The strength of the association between tonsillar grade and quantitative variables was assessed by the Spearman' rank correlation coefficient (rho). The significance threshold was set at P = 0.05. The maxillary dental arch depth was significantly and positively correlated to grade. The maxillary intercanine, interpremolar, and intermolar widths were significantly and negatively correlated to grade. Grade 4 was strongly associated with molar Class II malocclusions, and posterior crossbite with functional lateral deviation of the mandible. Early evaluation of the size of the palatine tonsils would help to prevent orthodontic abnormalities caused by upper airway obstruction. Thus, patients could be spared late, more aggressive treatments that are less efficient than treatments during childhood.

Evaluation of arch form between Vietnamese and North American Caucasians using 3-dimensional virtual models.

The purpose of this study was to investigate the three-dimensional (3D) morphologic differences in the mandibular arch of Vietnamese and North American White subjects. The sample included 113 Vietnamese subjects (41 Class I, 37 Class II and 35 Class III) and 96 White subjects (29 Class I, 30 Class II and 37 Class III). The samples were regrouped according to arch form types (tapered, ovoid, and square) to compare the frequency distribution of the three arch forms between ethnic groups in each angle classification. The facial axis point of each tooth was digitized on 3D virtual models. Four linear and two ratio variables were measured. In comparing arch dimensions, the intercanine and intermolar widths were wider in Vietnamese than in Whites (p < 0.001, p = 0.042, respectively). In the White group, there was even frequency distribution of the three arch forms. However, in the Vietnamese group, the square arch form was the most frequent followed by tapered and ovoid arch forms. The arch forms of Whites were narrower than Vietnamese. In North American Whites, the distribution of the arch form types showed similar frequency. In Vietnamese, the square arch form was more frequent.

Dental arch changes associated with rapid maxillary expansion: A retrospective model analysis study.

Introduction:Transverse deficiency of the maxilla is a common clinical problem in orthodontics and dentofacial orthopedics. Transverse maxillary deficiency, isolated or associated with other dentofacial deformities, results in esthetic and functional impairment giving rise to several clinical manifestations such as asymmetrical facial growth, positional and functional mandibular deviations, altered dentofacial esthetics, adverse periodontal responses, unstable dental tipping, and other functional problems. Orthopedic maxillary expansion is the preferred treatment approach to increase the maxillary transverse dimension in young patients by splitting of the mid palatal suture. This orthopedic procedure has lately been subject of renewed interest in orthodontic treatment mechanics because of its potential for increasing arch perimeter to alleviate crowding in the maxillary arch without adversely affecting facial profile. Hence, the present investigation was conducted to establish a correlation between transverse expansion and changes in the arch perimeter, arch width and arch length.Methods:For this purpose, 10 subjects (five males, five females) were selected who had been treated by rapid maxillary expansion (RME) using hyrax rapid palatal expander followed by fixed mechanotherapy (PEA). Pretreatment (T1), postexpansion (T2), and posttreatment (T3) dental models were compared for dental changes brought about by RME treatment and its stability at the end of fixed mechanotherapy. After model measurements were made, the changes between T1–T2, T2–T3 and T1–T3 were determined for each patient. The mean difference between T1–T2, T2–T3 and T1–T3 were compared to assess the effects of RME on dental arch measurements. Results are expressed as mean ± standard deviation and are compared by repeated measures analysis of variance followed by a post-hoc test. Arch perimeter changes are correlated with changes in arch widths at the canine, premolar and molar regions.Results:The intercanine arch width increased by 2.9 mm, inter first premolar width increased by 3.2 mm, inter second premolar width increased by 4.6 mm, intermolar width increased by 4.4 mm, arch perimeter increased by 3.2 mm, arch length decreased by 1.8 mm from pretreatment to posttreatment. There is a strong positive correlation of arch perimeter with intercanine width (r2 = 0.99), interpremolar width (r2 = 0.99) and intermolar width (r2 = 0.98), indicating that there is a significant increase in arch perimeter with increase in arch width at the canine, premolars and molar regions.Conclusion:Findings of this study demonstrate that there was a significant increase in the intercanine, inter first premolar, inter second premolar intermolar arch width and arch perimeter from pretreatment to postexpansion, which was stable at the end of fixed mechanotherapy (PEA). There was a nonsignificant decrease in arch length from pretreatment to postexpansion that further decreased nonsignificantly from postexpansion to posttreatment.

Stability of changes in mandibular intermolar and intercuspid distances following orthodontic treatment.

The aim of this study was to determine the pattern and amount of change exhibited in mandibular intercanine and intermolar width during treatment and assessing its stability1-3 years post-retention. The material consisted of 70 cases of which 20 cases were treated without extraction and 30 cases were treated with extraction, which were compared with 20 untreated cases which served as a control group. A series of three measurements were made for each case of the treated group: At the beginning of treatment, end of active treatment and 1-3 years post-retention; and for the control group: At 12, 15 and 18 years of age. The Wilcoxon signed ranks test was used to evaluate treatment changes in each group. The Kruskal-Wallis H test was used to compare the treatment changes between the 3 groups (α = 0.05). SPSS 16 software (SPSS Inc., Chicago, IL, USA) was used to evaluate the data. Mean changes of intercanine width for three groups was -0.5 mm for control group, -0.26 mm for non-extraction group and +0.18 mm for extraction group. Intermolar width of the extraction group decreased significantly during treatment. In contrast to the extraction group, the control and non-extraction groups both demonstrated an increase in mean intermolar width which was 0.66 mm and 0.91 mm respectively. It was concluded that although mean changes of intercanine and intermolar width were statistically significant but they were not perceptible clinically.

New classification of lingual arch form in normal occlusion using three dimensional virtual models.

ObjectiveThe purposes of this study were 1) to classify lingual dental arch form types based on the lingual bracket points and 2) to provide a new lingual arch form template based on this classification for clinical application through the analysis of three-dimensional virtual models of normal occlusion sample.MethodsMaxillary and mandibular casts of 115 young adults with normal occlusion were scanned in their occluded positions and lingual bracket points were digitized on the virtual models by using Rapidform 2006 software. Sixty-eight cases (dataset 1) were used in K-means cluster analysis to classify arch forms with intercanine, interpremolar and intermolar widths and width/depth ratios as determinants. The best-fit curves of the mean arch forms were generated. The remaining cases (dataset 2) were mapped into the obtained clusters and a multivariate test was performed to assess the differences between the clusters.ResultsFour-cluster classification demonstrated maximum intercluster distance. Wide, narrow, tapering, and ovoid types were described according to the intercanine and intermolar widths and their best-fit curves were depicted. No significant differences in arch depths existed among the clusters. Strong to moderate correlations were found between maxillary and mandibular arch widths.ConclusionsLingual arch forms have been classified into 4 types based on their anterior and posterior dimensions. A template of the 4 arch forms has been depicted. Three-dimensional analysis of the lingual bracket points provides more accurate identification of arch form and, consequently, archwire selection.

Mandibular changes during initial alignment with SmartClip self-ligating and conventional brackets: A single-center prospective randomized controlled clinical trial.

ObjectiveTo test the null hypothesis that SmartClip self-ligating brackets are more effective than conventional brackets for initial mandibular alignment and identify influential factors.MethodsFifty patients were randomly allocated to two equal treatment groups by using an online randomization program: self-ligating group (SmartClip brackets) and conventional group (Gemini brackets). The archwire sequence was standardized. Changes in anterior irregularity index, intercanine width, and intermolar width were assessed on plaster models at 8th and 16th weeks. Changes in incisor position and inclination were assessed on lateral cephalometric radiographs at 16 weeks. Intragroup and intergroup comparisons were performed with paired t-test and Student's t-test, respectively. Multiple linear regression was performed to identify variables affecting improvement in anterior ambiguity.ResultsData of 46 patients were analyzed; those missing an appointment (n = 2) or showing bracket breakage (n = 2) were excluded. Incisor inclination (p < 0.05), intercanine width (p < 0.05), and intermolar width (p > 0.05) increased at 8 and 16 weeks in both the groups; no significant intergroup differences were noted (p > 0.05). Initial anterior irregularity index and intercanine width change were significantly associated with improvement in anterior irregularity (p < 0.001).ConclusionsThe null hypothesis was rejected. Bracket type has little effect on improvement in anterior ambiguity during initial mandibular alignment.

Sexual dimorphism in permanent maxillary and mandibular canines and intermolar arch width: Endemic study

Aims and Objectives: The purpose of this study was to investigate whether dimorphism of permanent mandibular and maxillary canine teeth as well as intercanine and intermolar distance plays a role in establishing sex identity. Materials and Methods: Four hundred volunteers comprising 200 males and 200 females, with age ranging from 18 to 50 years, were selected. The greatest mesiodistal width of the canine teeth and the distance between the tips of canines of both arches and intermolar arch width were measured using vernier caliper with 0.02 mm resolution. All data were tabulated and analysis done by t test. Results: The widths of the mandibular and maxillary right and left canine teeth were almost bilaterally symmetrical in females and males. The mean values for left and right mandibular and maxillary canine widths were less in females than in males and the differences were statistically significant. The mean values for mandibular and maxillary intercanine and intermolar distances were less in females than in males and the differences were statistically significant (P

Cone-beam computed tomography evaluation of Pont's index predictability for Malay population in orthodontics.

Introduction:In orthodontic treatment, three-dimensional (3D) dental casts has a significant role in diagnosis and treatment planning. The aim of this study was to evaluate Pont's index predictability in orthodontics.Materials and Methods:Premolar arch width, molar arch width and mesiodistal width of the maxillary incisors were measured three-dimensionally to assess shape of dental arches. The data source was cone beam computed tomography (CBCT) high volumetric data acquisitions from Malay ethnic background. Arch widths were measured and recorded from 53 subjects (32 male and 21 female with the mean age, 25.81), both the maxillary and mandibular arches, to obtain CBCT high volumetric data. All measurements were obtained through CBCT Planmeca Romexis TM Software 2.3.1.R (Helsinki, Finland).Results:Pont's formula overestimated the upper and lower interpremolar distance, with mean differences of 8.35 ± 3 mm and 12.02 ± 3.20 mm, respectively. Furthermore, the formula overestimated the upper and lower intermolar distance, with mean differences of 7.87 ± 3 mm and 16.14 ± 5.86 mm, respectively.Conclusions:The results indicate that Pont's index is not practical for use with the Malaysian population since the index overestimated interpremolar and intermolar widths. This raises questions whether the index is a true predictor of arch width measurements.

Analysis of the cephalometric skeletal and dental characteristics of adult patients with cleft lip and palate who received orthopedic, orthodontic and/or surgical treatment during their childhood and adolescence

Background: Cleft lip and palate is one the most common congenital malformations that affect human faces in all ethnic, economic level, and educational groups. It may cause speech and psychological problems. This study presents the skeletal and dental characteristics of cleft lip and palate patients treated with maxillary orthopedics, orthodontics and surgery during their infant and adolescence years. Method: A retrospective cephalometric analysis study was performed in 2013 using the Dolphin Imaging System of 26 lateral head fi lms and 26 posteroanterior X-rays of cleft lip and palate adult patients who received orthopedic, orthodontic and/or surgical treatment during their infancy and adolescence between 1969 and 1985. All X-rays were taken during 1995-2002. Result: Most of the subjects presented a mesofacial growth pattern, a skeletal Class III maxilomandibular relation, a large mandibular body length, an increase in the vertical growth of the maxilla, and an increase in the facial, maxillary, nasal, intermolar and intercanine width, with a normal Overjet and Overbite and retroclined upper incisors. Key words: Cleft lip and palate, cleft lip, cephalometric analysis, orthopedic treatment, orthodontic and surgical treatment in adulthood, Dolphin Imaging System.

An evaluation of the dentoskeletal effects of slow maxillary expansion from the mixed to the permanent dentition

Abstract Introduction The aim of this study was to evaluate the dentoskeletal effects of a modified slow maxillary expansion appliance (MSMEA) during the transition from the mixed to the permanent dentition. Methods Forty subjects presenting with posterior crossbites were divided into two groups. Twenty-three subjects were assigned to a treatment group (mean age: 9.45 years) and 17 subjects assigned to a control group (mean age: 9.25 years). An MSMEA with acrylic occlusal coverage limited to the palatal cusps was used to provide maxillary expansion. The mean slow expansion treatment period was 7.8 months, while the mean observation period continued for 14.8 months of a 22.6-month total study period. Results Substantial dental and skeletal effects were observed following treatment with the MSMEA. Most maxillary inter-molar and deciduous inter-second molar width increases were maintained in the permanent dentition (91% and 97%, respectively). Skeletal maxillary transverse dimensions, which increased by 2 mm after active expansion, were significantly greater (p&lt; 0.001) when compared with the controls. Conclusion The findings suggested that an MSMEA provided orthopaedic and dental effects as a result of posterior crossbite correction. The effects of the appliance seen during the mixed dentition were maintained in the permanent dentition.