Changes In Arch Dimensions Research Articles

Digital nasoalveolar molding through presurgical orthopedics in newborns/infants with cleft lip and palate: A comprehensive review and case study.

This study aims to provide a comprehensive review and case study about the advantages and disadvantages of the application of digital technologies in presurgical orthopedics in newborns/infants with cleft lip and palate (CLCP). Positive changes in the nasal anatomy, maxillary arch, and cleft width could be achieved. Three representative cases of newborns/infants with CLCP were managed using the presurgical newborn/infant orthopedics (PSIO) approach. The patients were diagnosed and treated. Detailed descriptions of the impression procedures and PSIO appliance construction and placement were provided for each case. Case 1 utilized traditional impression techniques, Case 2 employed a semi-digitalized approach with intraoral digital scanning, and Case 3 utilized a completely digitalized method for appliance construction. Positive changes in maxillary arch dimensions and cleft width reduction were observed in all cases. The management of CLCP in newborns and infants poses a complex challenge with profound implications. The PSIO approach not only facilitates reconstructive surgery but also enhances overall quality of life. Digital tools, like specialized optical scanners and 3D printing, revolutionize the PSIO process, making it more efficient and patient-friendly. Clinical benefits include improved facial morphology, esthetics, feeding, speech, and optimized future surgical results. Despite ongoing efficacy debates, global adoption as the initial surgical approach underscores its value. The integration of digital technologies offers new hope for patients and families, promising a brighter future for those affected by this congenital condition.

Effect of orthodontic premolar extraction on maxillary teeth angulation and arch dimensions in adolescent patients: A 3-D digital model analysis.

Therapeutic orthodontic premolar extraction is a common orthodontic treatment, yet the extent of its impact on the upper dental arch dimensions and teeth angulations is still under exploration. Hypothesis: We postulated that the therapeutic extraction of orthodontic premolars significantly alters the orientation of teeth and the dimensions of the dental arch. Objective: This study assessed the impact of therapeutic orthodontic premolar extraction on dental arch dimensions and tooth angulations. We conducted a retrospective cohort study involving 30 patients who underwent bilateral upper premolar extraction and fixed appliance treatment. Pre and post-treatment dental casts were scanned, and changes in tooth angulations and arch dimensions were evaluated using 3D digital maxillary models. Statistical analyses encompassed the application of paired samples t-test. Significant post-treatment changes were observed, including distal tipping in anterior teeth, minor mesial tipping in first molars, and a reduction in torque for central incisors and canines. Dental arch dimensions were also influenced, with increased width and depth between the canines and decreased width between the second premolars while inter-molar width and overall arch depth significantly reduced post-treatment. Therapeutic orthodontic premolar extraction significantly affects dental arch dimensions and tooth angulations. These findings have implications for treatment planning and predicting changes associated with orthodontic treatments involving premolar extraction. Key words:3D digital models - orthodontic premolar extraction - teeth angulation - dental arch dimensions.

The Influence of Dental Arch Dimensional Changes on Pharyngeal Airway After Extraction Treatment In Class II Division 1 Malocclusions

The Influence of Dental Arch Dimensional Changes on Pharyngeal Airway After Extraction Treatment In Class II Division 1 Malocclusions

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.

Efficacy of lower arch leveling, lower incisors’ root resorption, and pain associated with the correction of curve of Spee using different orthodontic archwires: a randomized clinical trial

ObjectivesTo compare between 3 archwires (AWs) for leveling curve of Spee (COS) in terms of efficacy of reduction, external apical root resorption (EARR), pain experienced, and the lower arch dimensional changes during COS leveling.Trial designRandomized clinical trial.SettingJordan University of Science and Technology Postgraduate dental clinics.Material and methodsFifty-three subjects with COS > 5 mm were included in this study. The subjects were randomly divided into three groups based on the AW used: group 1, 0.017 × 0.025-inch stainless-steel (SS) AW; group 2, 0.019 × 0.025-inch SS AW; and group 3, 0.021 × 0.025-inch β-titanium (TMA) AW. The intervention was randomly allocated using the permuted random block size of 3 with a 1:1:1 allocation ratio. In the three groups, a 5-mm depth reverse COS was placed in the AWs. The following time points were defined for COS assessment: T1, before interventional leveling AW placement; and T2–T7, 1–6 months after interventional leveling AW placement. Records consisted of dental study models and periapical (PA) radiographs. Pain scores were recorded using visual analogue scale. Patients were followed up on a monthly basis until COS < 1.5 mm.Main outcome measuresCOS depth reduction, lower incisors’ EARR, pain scores, and arch dimensional changes.ResultsAn overall reduction of 3.82 mm, 4.47 mm, and 3.85 mm of the depth of COS was achieved in groups 1, 2, and 3, respectively. The mean differences of 0.65 mm between groups 1 and 2 and 0.62 mm between groups 2 and 3 were significant at P < 0.05. Lower incisors’ EARR during leveling COS ranged from 0.68 to 0.72 mm, from 0.63 to 0.82 mm, and from 0.53 to 0.88 mm in groups 1, 2, and 3, respectively (P > 0.05). Higher pain scores were reported by group 2 subjects during the first 24 h. Arch length and width increased significantly in groups 2 and 3 (P < 0.05). In all groups, COS leveling was achieved by lower incisor intrusion and proclination and lower molar extrusion.ConclusionsAll investigated AWs were effective in leveling COS with minimal lower incisors’ EARR (< 1 mm). COS was leveled by lower incisors’ intrusion and proclination and lower molar extrusion. Pain scores were the highest in group 2 during the first 24 h.Clinical relevanceThe 3 investigated leveling AWs were effective for the leveling COS and at the same time safe on the roots of the lower anterior teeth.

MANDIBULAR ARCH CHANGES FOLLOWING EXPANSION WITH SCHWARZ APPLIANCE IN GROWING PATIENTS – A SYSTEMATIC REVIEW.

Aim and Objectives&#x0D; The aim of this review is to systematically evaluate and assess the available evidence on arch dimensional changes in the mandible following expansion using Schwarz Appliance in growing patients.&#x0D; Materials and Methods &#x0D; The protocol for the review was registered with the PROSPERO database. A systematic search was done on the following scientific databases PubMed, Cochrane Central, LILACS and Google Scholar to identify articles of relevance published until April 2021. Articles that satisfied the inclusion criteria were included in the review. The review was performed based on the PRISMA guidelines. MINORS tool was used to evaluate the Risk of Bias and quality of evidence of the included studies.&#x0D; Results &#x0D; 243 trials were identified after implementing the search strategy. After eliminating duplicates 196 trials remained. After screening the titles and abstracts for the eligibility criteria, 190 trials were eliminated from further review. Full text was sought for the remaining six articles and one study was eliminated after review of the full text. Four the included studies showed low Risk of Bias in their methodologies and one study showed a low risk of Bias in its methodology. Qualitative analysis was performed on the remaining five trials. The studies significant increase in the Intermolar, intercanine, interpremolar and arch perimeter and also observed significant up righting of the permanent mandibular first molar.&#x0D; Conclusion&#x0D; Arch dimensional changes in the mandible of growing patients after expansion using Schwarz Appliance are dento-alveolar in nature. No skeletal Expansion is seen.

Effects of long-term use of the lower lingual arch from 8.5 years to 13.2 years

To investigate the effects of long-term use of the lower lingual arch (LLA) on the sagittal and vertical positions of the permanent lower incisors and first molars. The sample consisted of 98 patients who were treated with an LLA (LLA group) and 39 patients who were treated without an LLA (no-LLA group). The positional changes of the lower incisors and first molars were analyzed after performing mandibular structural superimpositions on lateral cephalometric radiographs taken before treatment (T1) and at the end of LLA therapy (T2). The mean ages at T1 and T2 were 8.5 years and 13.2 years, respectively. Study casts were analyzed to quantify arch dimensional changes. Mesial movement of the lower molar cusp was similar between the LLA and no-LLA groups, but the vertical position was slightly greater at T2 in the LLA group. In the LLA group, there was a molar tip-back effect, and the lower incisors were proclined 4.2° more than in the no-LLA group. Arch perimeter decreased 3.6 ± 2.6 mm without an LLA and 0.97 ± 3.7 mm with an LLA. Intercanine and intermolar widths both increased about 1 mm more with an LLA (P < .0001). The LLA does not seem to restrict mesial movement and vertical eruption of the lower incisors and molars in the long term. The LLA effectively preserves the arch perimeter at the expense of a slight lower incisor proclination.

Is there any difference between conventional, passive and active self-ligating brackets? A systematic review and network meta-analysis

To test the null hypothesis that there was no difference in treatment efficiency between therapies undertaken with conventional (CBs), passive self-ligating (PSLBs) or active self-ligating (ASLBs) brackets. An electronic search was performed in 3 data bases (Pubmed, Web of Science, Cochrane Library) from their origin up to January 2019. Additional references were hand searched. Search was strictly restricted to randomized controlled trials (RCTs) and split-mouth design studies (SMDs). RCTs and SMDs were initially processed separately and subsequently combined in a network meta-analysis. The following variables were evaluated: treatment duration, number of visits, occlusal outcomes, alignment rate, transverse arch dimensional changes, incisor position modification, rate of space closure, anchorage loss, bond failure, root resorption, perception of discomfort during the initial phase of alignment, time to ligate in or to untie an archwire, periodontal variables, quality of life. On 229 papers, 30 RCTs and 9 SMDs were finally included in this study. Out of 85 comparisons, 16 only revealed statistically significant differences. It was quicker to untie and ligate an 0.014 NiTi arch from/in 6 ASLBs anterior ceramic brackets compared to 6 ceramic CBs. It was also more painful to insert and remove an 0.019×0.025 SS wire in/from PSLB's brackets compared to CB's attachments. Compared to conventional brackets, there was less maxillary incisor proclination with PSLBs in non-extraction cases. Moreover, there was less bleeding on probing 4-5 weeks after bonding with PSLBs compared to CBs brackets. The only significant difference between ASLBs and PSLBs was that alignment was 10 days faster with active self-ligating braces compared with passive self-ligating braces even if treatment duration between ASLBs and PSLBs was not significantly different. The network meta-analysis revealed that IMPA was greater in extractions cases with CBs compared with both ASLBs (+2,5°) and PSLBs (+1,6°). The vast majority of the studied variables did not show any significant differences between the three types of brackets. The most significant findings were that it was quicker to insert and remove archwires from ASLBs compared to CBs, and it was more painful to insert and remove an 0.019×0.025" stainless steel wire in/from PSLBs compared to CBs. The major difference between ASLBs and PSLBs was that alignment was 10 days faster with active self-ligating braces compared with passive self-ligating braces even if treatment duration between ASLBs and PSLBs was not significantly different. Most of the claims put forward by the suppliers were not substantiated by our network meta-analysis.

Upper arch dimensional changes with clear aligners in the early mixed dentition : Aprospective study.

One goal of orthodontic treatment in mixed dentition is to expand the maxillary arch to allow proper tooth alignment and acorrection of sagittal and vertical malocclusions. However, for most treatment protocols, expected outcome is not really clear to allow for astandardization of phaseI orthodontic treatments. This lack of information makes it difficult for clinicians to predict tooth movements, including transverse expansion efficacy with Invisalign® (Align Technology, Santa Clara, CA, USA) in children. Therefore, the aim of the present study was to evaluate the transverse maxillary arch development with the Invisalign First System® in growing subjects. The study group included 23subjects (9females, 14males, mean age 9.4 ± 1.2years). Patients were treated nonextraction with Invisalign First System® clear aligners with no auxiliaries other than Invisalign® attachments. Transverse interdental widths were measured only in the upper arch on each model at the start (T1) and at the end (T2) of treatment. Apaired t‑test was chosen to compare T2-T1 changes. The level of significance was set at 5%. The greatest increase of maxillary width was detected at the level of the upper first deciduous molars (+3.7 ± 1.4 mm; P < 0.001), followed by the level of the second deciduous molars (+3.4 ± 1.6 mm; P < 0.001) and by the deciduous canine (+2.6 ± 2.0 mm; P < 0.001). Upper first molars showed agreater expansion in the intermolar mesial width (+3.2 ± 1.2 mm; P < 0.001) than in the intermolar distal (+1.7 ± 1.2 mm; P < 0.001) and transpalatal width (+1.2 ± 1.2 mm; P < 0.01). The Invisalign First System® can be considered effective in growing patients who require maxillary arch development. The greatest net increase was detected at the level of upper first deciduous molars, whereas the upper first molars showed agreater expansion in the intermolar mesial width due to arotation that occurs around its palatal root.

The verisimilitude of damon brackets versus damon archwires– The real hero

: The Damon passive self-ligating system introduced broad archwires and a passive clip with posterior expansion and with minimal tipping of the teeth. To evaluate and compare the effectiveness of Damon brackets and Damon arch wires in maxillary arch dimensional changes with that of conventional brackets and conventional archwires. A total of 20 patients were selected for the study and randomly divided into 4 Groups with 5 patients in each group. Records (Study models) were taken before starting the treatment (T0) and at the end of leveling and alignment (T1) for all the 20 subjects. Pre-treatment (T0) and at the end of leveling and alignment (T1) study models were assessed for inter canine width, inter first premolar width and inter first molar width. There was statistically significant increase in maxillary arch width in Damon system and conventional bracket with Damon archwires when compared to conventional bracket system and Damon brackets with conventional archwires. The use of conventional or self-ligating brackets does not seem to be an important predictor of change in maxillary arch width in non-extraction patients. The amount of increase in arch width was due to Damon archwires and not because of Damon brackets.

Comparison of Changes in Incisors Inclination and Dental Arch Dimensions in Damon and MBT Systems Using Dolphin Software

Background: There is great controversy regarding the effect of MBT and Damon bracket systems on dental arch dimensions and incisor position. Objectives: We aimed to study the effects of two different brackets (MBT and Damon) on dental arch dimensions and incisors position after orthodontic treatment. Methods: In this retrospective study, the records of 20 patients who underwent orthodontic treatment with MBT or Damon bracket systems were studied. All patients had class I skeletal and dental malocclusion and were treated without extraction. The patients were treated either with Damon or MBT bracket systems (n = 10). Lateral cephalograms were traced using the Dolphin software to determine the position of incisors. In addition, transverse dimensions of dental arches were measured on occlusal photographs. Fishers’ exact test, independent-test, Man-Whitney, paired t-test, and Wilcoxon were used for statistical analysis. P &lt; 0.05 was set as significant. Results: There was no significant difference between the two groups regarding age, sex, and initial values of the variables studied. U1-Apog (mm), upper inter-canine, lower inter-second premolar distance showed a significant difference before and after treatment in the Damon system. However, no significant difference was observed between initial and post-treatment values in the MBT group. L1-Apog (°), IMPA (°), maxillary inter-first and second premolars, inter-canine, and mandibular inter-canine distance was higher in the Damon system after treatment compared to MBT. Changes of the upper and lower transverse dimensions of the dental arches and the incisor positional did not reveal a notable difference in the Damon and MBT systems (P &gt; 0.05). Conclusions: There was no significant difference regarding changes in dental arches and incisor positions between the Damon and MBT systems.

Are self-ligating brackets more efficient than conventional brackets ? A meta-analysis of randomized controlled and split-mouth trials

The aim of this systematic review and meta-analysis was to compare self-ligating brackets (SLBs) considered as a whole to conventional brackets (CBs). An electronic search was performed in three databases (PubMed, MEDLINE via Web of Science, Cochrane Library) from their origin up to June 2017. Additional articles were hand searched from January 2006 to June 2017. This meta-analysis was restricted to randomized controlled trials (RCTs) and split mouth design studies (SMDs). No distinction was made between active and passive SLBs. The following variables were investigated: treatment duration, number of visits, alignment rate, rate of space closure, perception of discomfort during the initial phase of treatment, pain experience during wire insertion or removal, bond failure rate, time to ligate in or to untie an archwire, periodontal indices, occlusal outcomes, transverse arch dimensional changes and root resorption. 25 RCTs and 9 SMDs were finally selected. It was more painful to insert or remove a 0.019× 0.025 SS archwire in/from SLBs. It was significantly quicker to insert or remove an archwire from SLBs. There was less bleeding on probing with SLBs 4 or 5 weeks after bonding. All other variables did not exhibit any significant difference between SLBs and CBs. Out of the 31 comparisons between self-ligating and conventional brackets, 9 only revealed statistically significant differences. This meta-analysis contradicts most of the promotional statements put forward by the distributors.

Structural changes in foot and arch dimensions in the third trimester of pregnancy

PurposeThe goal of the study was to investigate changes in foot anatomical characteristics in the last trimester of pregnancy.MethodsTwenty pregnant women (mean age: 30.8 years) from a local clinic were recruited. Body mass, foot length and width, longitudinal arch height, and several angular variables quantifying plantar and arch structure were measured. A foot imprint was obtained with a digital podoscope (CQ Elektronik System, Poland) at the beginning and end of the third trimester of pregnancy.ResultsBody mass was significantly greater at the end of the last trimester. Increases were also observed in the SztriterGodunow index in both feet (&lt;i&gt;p&lt;/i&gt; &lt; 0.007), although foot length and width increased only in the left foot. Among the angular characteristics, the only significant changes involved an increase in the talocalcaneal angle (&lt;i&gt;p&lt;/i&gt; &lt; 0.007) and a decrease in the 1st metatarsophalangeal angle in the right foot (&lt;i&gt;p&lt;/i&gt; &lt; 0.04).ConclusionsSignificant changes in plantar and arch structure were observed in the final trimester of pregnancy, primarily involving a transverse expansion of the left foot and alteration in the angular characteristics of the right foot. The results of the research show anthropometric changes in feet of women in the last trimester of pregnancy. They indicate the foot parts in which the greatest changes occur and what the direction of these changes is. This will allow to create a preventive foot corrective exercise program for pregnant women.

Anterior tooth alignment and arch dimensions changes: 37-year follow-up in patients treated with and without premolar extraction

The objective of this research was to evaluate the anterior tooth alignment and dental arch dimension changes after orthodontic treatments with and without premolar extractions in the long-term. Fifty-seven patients with Class I and Class II malocclusion were divided into 2 groups. Group 1 included 16 patients treated with nonextraction therapy, with mean initial (T1), final (T2), and long-term follow-up (T3) ages of 13.20years, 15.07years, and 50.32years, respectively. The mean treatment (T2-T1) and long-term follow-up (T3-T2) times were 1.86years and 35.25years, respectively. Group 2 included 41 patients treated with extraction of 4 first premolars, with T1, T2, and T3 ages of 13.31years, 15.63years, and 53.60years, respectively. The mean treatment and long-term follow-up times were 2.32years and 37.96years, respectively. The mean retention time was 2.26years for both groups. The dental casts were obtained and digitized at T1, T2, and T3 stages. The following measurements were obtained: Little irregularity index, arch length, perimeter, and intercanine, interpremolar, and intermolar widths. Intragroup and intergroup comparisons were performed with repeated measures analysis of variance and t tests, respectively. Anterior tooth irregularity index increased at T3 in both groups. In addition, all arch dimensions, except the intercanine width, were significantly smaller in the extraction group at T3. Both groups showed similar arch dimension changes at T3, except for the mandibular arch perimeter. The percentage of mandibular anterior tooth alignment change was significantly greater in the nonextraction than in the extraction group. There was no difference in the changes of anterior alignment and transverse arch dimensions in patients treated with and without premolar extraction at T3, but the percentage of mandibular anterior tooth alignment changes was higher in the nonextraction than in the extraction patients at T3. The mandibular arch perimeter showed more of a decrease at T3 in extraction patients.

Mandibular arch dimensional changes subsequent to utilizing nickel-titanium and nickel – free orthodontic arch wires: A prospective clinical study

Mandibular arch dimensional changes subsequent to utilizing nickel-titanium and nickel – free orthodontic arch wires: A prospective clinical study

The Effect of First Permanent Tooth Eruption on Dental Arch Dimension

Background: Crowding is one of the most prevalent types of malocclusion as well as a major problem in clinical orthodontics. It is essential to know the cause of crowding in order to achieve a better treatment. Objectives: A longitudinal analysis of arch dimension changes in late primary and early mixed dentition periods in children was designed and investigated the effect of eruption of precedence on the arch size in the samples under study. Methods: This longitudinal study was carried out on 32 children aged 5.5 - 6.5 years who had no erupted permanent dentition. Impression was taken and the arch perimeter, depth and width as well as tooth size were measured by a digital calliper and a brass wire on casts. After eruption of the first permanent tooth, the second impression was taken; the above-mentioned parameters were measured on the second casts. Data were analysed by ANOVA test. Results: Four pattern of eruption of precedence were as follows: maxillary 1st molar, mandibular incisors, Mandibular 1st molars and simultaneous eruption of maxillary and mandibular 1st molars. With eruption of mandibular central incisors, inter canine width and overjet increased by 0.81 and 0.27 mm, respectively. The mandibular arch perimeter increased by 2.25 mm with simultaneous eruption of maxillary and mandibular permanent first molars. The maxillary arch perimeter increased by 1.25 mm and 1.50 mm with eruption of maxillary first molars and simultaneous eruption of maxillary permanent first molars, respectively. Conclusions: Eruption precedence had a significant effect on changing mandibular inter canine width, maxillary arch perimeter, mandibular arch perimeter and overjet.

Comparison of WALA ridge and dental arch dimensions changes after orthodontic treatment using a passive self-ligating system or conventional fixed appliance.

To compare changes in WALA ridge and mandibular dental arch dimensions in orthodontic patients treated with a passive self-ligating system and conventional appliances. Original paper. Orthodontic department at Inga University Center, Maringá, PR, Brazil. Pretreatment (T1) and posttreatment (T2) dental casts of 60 patients with Class I malocclusion treated with slight to moderate crowding that were divided into two groups. Group 1: 30 patients treated with a passive self-ligating system, at a mean initial age of 17.68 years and mean treatment time of 2.31 years. Group 2: 30 patients treated with conventional appliances, at a mean initial age of 19.23 years and mean treatment time of 2.56 years. Measurements were taken using a digital caliper directly on pre and posttreatment dental casts to evaluate the transversal dimension behavior of the mandibular dental arch and the WALA ridge width. Self-ligating group presented an increase in WALA ridge width and mandibular transversal dimensions significantly greater than the conventional group, with the exception of intermolar cusp tip distance and intercanine WALA ridge. There was no statistically significant difference between the groups. There was also observed a significantly greater increase of the transversal buccal axis dimensions in the premolar area when compared to the WALA ridge increase in both groups. Treatment with a passive self-ligating system resulted in a significantly greater increase of the WALA ridge width and mandibular arch dimensions when compared to conventional appliance.

Comparison of Changes in Dental Arch Dimensions in Cases Treated with Conventional Appliances and Self-Ligating Damon System

Proposition: The objective of this study was to compare changes in maxillary and mandibular dental arch dimensions in cases treated nonextraction with conventional appliances and self-ligating Damon System. Materials and Methods: initial (T1) and final (T2) dental casts of 45 patients with Class I malocclusion treated nonextraction, with slight to moderate crowding, divided into two groups. Group 1: 21 patients treated with self-ligating Damon appliances, at a mean initial age of 18.37 years and mean treatment time of 2.11 years. Group 2: 24 patients treated with conventional appliances, at a mean initial age of 19.50 years and mean treatment time of 1.99 years. The model analysis was performed; Little irregularity index was used to evaluate crowding and arch form was evaluated by measurements in maxillary and mandibular arches including intercanine, interpremolar (first and second premolars) and intermolar distances and arch length. The intragroup comparison was performed with dependent t or Wilcoxon tests and intergroup comparison, with independent t or Mann Whitney tests. Results: In intergroup comparison of treatment changes (T2-T1) the Damon group presented an increase in maxillary transversal dimensions significantly greater than the conventional group. The change in maxillary arch length did not show difference between the groups. Regarding the mandibular arch, the Damon group presented a significantly greater increase in intercanine and inter first premolars than the conventional group. In The mandibular arch length, the greater and significant increase was observed in the groups of patients treated with conventional appliances. Conclusions: The treatment with the Damon appliances resulted in a significantly greater increase of maxillary arch dimensions when compared to conventional appliances. Mandibular intercanine and interpremolar distances also presented greater increase in Damon than conventional appliances. The increase in mandibular arch length was greater in conventional than in Damon group.

Maturational changes of the normal occlusion: A 40-year follow-up.

In this study, we aimed to evaluate the changes in dental arch dimensions, tooth size, and incisor crowding in subjects with normal occlusion over a 40-year period. A sample of 82 white subjects with normal occlusion evaluated in adolescence and early adulthood was recruited for a third evaluation in their sixth decade of life. The final sample included dental casts of 22 subjects (12 men, 10 women) obtained at mean ages of 13.3, 17.8, and 60.9years. The following variables were measured on the digital casts: mesiodistal tooth size; clinical crown height; arch length, width, and perimeter; palatal depth; crowding; overjet; overbite; and curve of Spee. Interphase changes were evaluated using repeated measures analysis of variance, followed by Tukey tests (P<0.05). Increases of clinical crown height in the posterior teeth and incisor crowding were found. Decreases of mesiodistal tooth size, mandibular intercanine width, arch length, arch perimeter, overbite, and curve of Spee were observed. Palatal depth increased from 13 to 17years of age. No changes were observed for overjet. Subjects with normal occlusion had changes in tooth size and alignment, overbite, and arch dimensions from adolescence to late adulthood.

Evaluation of maxillary buccal alveolar bone before and after orthodontic alignment without extractions: A cone beam computed tomographic study.

To assess the changes in the maxillary buccal alveolar bone during alignment without extractions. Secondarily, to evaluate the changes in arch dimensions and buccolingual inclinations of teeth and to identify risk factors for bone loss. Twenty-two adolescents with crowded permanent dentitions were treated without extractions with Damon 3MX brackets. Cone beam computed tomographic scans were taken before treatment (T0) and after alignment (T1). Bone thickness (BT) and height from the cementoenamel junction to the alveolar crest (BH) were evaluated at the maxillary central incisors, second premolars, and buccal roots of first molars. Changes in all variables from T0 to T1 were assessed. Correlations between bone changes and initial bone thickness, initial arch widths, initial crowding, amount of expansion, amount of tipping, and amount of molar rotation were calculated. BT decreased and BH increased significantly for the incisors and mesiobuccal root of the first molars. Arch dimensions generally increased together with tipping. Bone loss was correlated with crowding and amount of expansion in the premolar region. Initially thinner BT was correlated with greater apical migration of bone for the incisors. Nonextraction alignment with self-ligating brackets led to arch expansion associated with tipping of teeth. Expansion related to alignment resulted in horizontal and vertical bone loss at the incisors and mesiobuccal root of the first molars. Thinner BTs and more severe crowding before treatment increased the risk for buccal bone loss.