Moderate Crowding Research Articles

ARCH DEVELOPMENT FOR MODERATE CROWDING USING SELF LIGATING BRACKETS: A CASE REPORT

The use of self ligating bracket system is gaining popularity because of its effectiveness in treating patients with moderate crowding using a non extraction therapy. The author report a case of 14 year 3 months old female who presented to the orthodontic clinic with moderate upper and lower anterior crowding, proclination of upper anterior and increased overjet and overbite. It was decided to treat the case with non extraction orthodontic therapy using self ligating bracket system. Following 28 months of treatment time, there was a favorable outcome in the profile of the patient. The patient presented with Class I molar and canines relationships bilaterally with normal overjet and overbite after the conclusion of the treatment. The present case study demonstrates that self ligating bracket system could be feasible choice in treating moderate to severe crowding cases without extraction therapy.

Dentoalveolar effects of nonextraction orthodontic treatment of moderate crowding: A comparison of conventional, active self-ligating, and passive self-ligating bracket systems

ObjectiveThe purpose of this study was to compare patterns of dentoalveolar changes that take place after nonextraction treatment of Class I malocclusions with moderate crowding using conventional (CON), active self-ligating (ASL), and passive self-ligating (PSL) bracket systems. Material and MethodsThree cast and nine cephalometric variables on 39 patients were evaluated and compared before treatment (T0), at end of treatment (T1), and ≥6 months in retention (T2). The pattern of change over time points was visualized and defined as the profile formed on a graph of the measurement over time. Differences in patterns between the groups were visualized as nonparallel profiles, and detected statistically using time*group interaction terms that were included in multivariable analyses of variance. Post hoc Tukey test was used to compare estimated means between all possible paired time points within each system. ResultsPatterns of change did not differ significantly for cephalometric variables, most of the arch widths (AW), the maxillary arch perimeter (AP) (P = 0.1404), or maxillary arch depth (AD) (P = 0.2601), but did differ for the mandibular AP (P = 0.0145) and AD (P = 0.0224). ConclusionsAlthough there were no significant differences between CON and PSL in the patterns of changes for any of the variables studied, ASL showed some differences from either CON or PSL. All three groups showed statistically significant increases in AWs of maxillary or mandibular premolars. Although ASL seemed to have controlled the mandibular incisors better, the results need to be interpreted with caution, as the clinical significance of the differences seen could be limited under certain circumstances.

Dental arch changes in postretention in Class II division 1 extraction cases.

The purpose of this study is to evaluate the postretention stability of the dental arches in Class II division 1 patients treated with four bicuspid extractions and the edgewise technique. A digital caliper was used to analyze the dental casts from 29 Class II division 1 malocclusion patients with skeletal type II (14 males, 15 females; ages ranging from 10.2-18.0 years), treated with four bicuspid extractions and the edgewise technique. Intercanine width, intermolar width, arch length, irregularity index, overjet and overbite were evaluated at three times: pretreatment (T1), posttreatment (T2) and postretention (T3) (mean: 4.15 years). Student's t-tests were used to compare the pretreatment-posttreatment, posttreatment-postretention and pretreatment-postretention. Significance was determined at P<0.05. The results of the study are listed as: (1) The upper and lower intercanine widths significantly increased (P<0.05) between T1-T2 and decreased between T2-T3. However, no significant changes were observed between T1-T3; (2) The upper and lower intermolar widths significantly decreased (P<0.05) between T1-T2, between T2-T3 and between T1-T3, except for the upper intermolar width between T2-T3 which showed no significant change; (3) The upper and lower arch lengths significantly decreased (P<0.05) at posttreatment and postretention due to the closure of extraction spaces. Both the upper and lower arch lengths significantly decreased between T1-T2, T2-T3, and T1-T3, except for the upper arch length between T2-T3, which showed no significant change; (4) The irregularity index was significantly improved after treatment. However, there was a slight increase in incisor irregularity at postretention. At postretention, 75.86% of the patients had mild crowding, 20.68% had moderate crowding, 3.48% had severe crowding; (5) The overjet and overbite significantly decreased (P<0.05) between T1-T2 and increased between T2-T3. The changes in the dental arches were small at postretention with a tendency to return towards their original position. The overall stability of Class II division 1 extraction cases is relatively good.

Crowding correction through extraction of a lower incisor

ABSTRACT Tooth-bone discrepancy, or crowding in the lower arch, is traditionally corrected by removing first or second premolars; the extraction of a lower incisor is an uncommon approach but presents another treatment alternative. Treatment goal: to present the case report of a patient who was given this alternative treatment. The patient had 15 years 4 months of age. The intraoral analysis revealed a normodivergent skeletal class I with bilateral molar class I, bilateral canine class I, decreased overbite, and increased overjet. She had lower moderate and mild upper crowding as well as a habit of digital suction. Treatment time was one year and four months.

A Retrospective Study to Evaluate the Intra-Arch Dimensional Changes in Moderate Crowding Cases Treated Non Extraction with a Passive Self-Ligation Appliance.

Background: Non-extraction treatment protocols are better accepted by patients as well as clinicians. Among the techniques and mechanics with the potential to facilitate non-extraction treatment includes headgears, fixed sagittal correctors, transverse expansion screws and self-ligating systems. Objectives: To evaluate the intra-arch dimensional changes in moderate crowding cases, treated non-extraction with a passive self-ligating (Damon 3MX) appliance using digitized models and lateral cephalograms. Methods: A total of 20 patients (age group of 15 - 18 years) who had undergone non extraction orthodontic treatment with the Damon 3MX appliance were selected. All the pre-treatment and post-treatment dental stone models of maxillary and mandibular arches were scanned using 3D digital scanner (Maestro 3D, Greatlakes, USA) and were converted into digital models. Various parameters undertaken were measured digitally on the computer in millimetres. Cephalometric tracings of pre and post treatment cephalograms were performed using digital cephalometrics (Nemo Ceph, version 6.0, Spain). Statistical analysis was performed using t-test. Results: More transverse expansion was observed in the region of 1st and 2nd premolars as compared to the inter-canine and inter molar region in maxillary and mandibular arch. However a decrease in arch depth was observed in maxillary arch but arch depth of mandibular arch was found to be increased. There was significant increase in anterior proclination in both maxillary and mandibular arches. Conclusions: Passive self-ligating system causes a significant increase in transverse width in both maxillary and mandibular dental arches.

Osteogenic Accelerated OrthodonticsTM for treatment of a Skeletal Class II patient with moderate crowding

Osteogenic Accelerated OrthodonticsTM for treatment of a Skeletal Class II patient with moderate crowding

Effectiveness of bovine-derived xenograft versus bioactive glass with periodontally accelerated osteogenic orthodontics in adults: a randomized, controlled clinical trial.

BackgroundPeriodontally accelerated osteogenic orthodontics (PAOO) combines periodontal therapy with orthodontic therapy, which minimises treatment time. This study compared the effectiveness of a bovine-derived xenograft with that of bioactive glass when combined with PAOO for the treatment of adult patients with moderate crowding of the teeth.MethodsIn this prospective, single-masked clinical trial, 33 orthodontic patients (20 women, 13 men; mean age 21.2 ± 1.43 [18 − 27] years), were randomly allocated to one of three groups. Group 1 underwent a modified corticotomy technique on the labial side only, whereas group 2 was treated with the same technique combined with PAOO using a bovine-derived xenograft and group 3 was treated in the same way but combining PAOO with bioactive glass. The total treatment duration was recorded from the start of active orthodontic treatment, immediately after corticotomy, and at the time of debonding. Probing depth was evaluated clinically and bone density and root length were evaluated radiographically on the day of surgery (baseline, T1), post-treatment at debonding (T2), and 9 months post-treatment (T3).ResultsThe duration of orthodontic treatment was markedly reduced to an average of 11.4 ± 0.14 weeks in all groups. All probing depths were < 3 mm, the interdental papillae were well preserved, there was no loss of tooth vitality, and there was no evidence of significant apical root resorption at any time interval. All groups showed a decrease in mean bone density at T2 followed by an increase at T3. The net percentage change that occurred between baseline and 9 months post-treatment was significantly different between the three groups. Groups 2 and 3, where grafts were incorporated, demonstrated a statistically significant greater increase in bone density than group 1 at T3.ConclusionCombination of orthodontic treatment and periodontal surgery is an effective treatment for adult patients that decreases the duration of active treatment and reduces the risk of root resorption. Use of a bovine-derived xenograft with modified corticotomy provided superior benefits in terms of increased bone density than did the use of bioactive glass.Trial registrationThe study was retrospectively registered at ClinicalTrials.gov under Clinical Trial Registration Number: NCT02796911.

The Differences between Dentist’s and Non-Dentist’s Perceptions on Facial Attractiveness

Orthodontics plays an important role in an individual's appearance. An individual's appearance can affect the perception of others which can vary greatly depending on their education background, profession and social life. Objective: To determine if there are differences between dentist’s and non-dentist’s perceptions of facial attractiveness with various types of malocclusions particularly in Indonesian population. Methods: A cross sectional study was conducted on 80 dentists and 80 non-dentists aged 23-49 years old. The differences between dentist’s and non-dentist’s perceptions were assessed by giving scores on ten photographs for each gender that have been digitally manipulated and showing normal occlusion and nine types of malocclusion. Perceptions of facial attractiveness were measured by visual analogue scale (VAS, range: 0-10). Mann Whitney test was used to analyze the differences. Results: Normal occlusion is the most attractive condition for dentists and non-dentists. There are significant differences between dentist’s and non-dentist’s perceptions of facial attractiveness showing normal occlusion, increased overjet, increased overbite, reduced overjet, reduced overbite, mild crowding, open bite, and reversed overjet malocclusions (p 0.05). Conclusion: Regarding the facial attractiveness, dentist’s and non-dentist’s perceptions are significantly different for most malocclusion types. However there is an agreement that severe and moderate crowding are the most disturbing malocclusion that have a considerable effect on facial attractivenes.

Crowding severity associated with dental mass

Crowding has been classified as one of various types of malocclusions, which are identified as the third most prevalent oral disease. It is of great importance in orthodontics to know the mesiodistal length of teeth because it is an determining factor in the diagnosis of space discrepancies of the jaws. Objective: To determine if there is more dental mass associated with an increase in the severity of crowding. Material and methods: A sample of 120 study models with no previous orthodontic treatment was formed. It was divided into 3 groups: 40 with mild crowding, 40 with moderate crowding and 40 with severe crowding. Mesiodistal dental widths were measured in both arches from the right first molar to the left first molar. The information was tabulated in a Microsoft Excel sheet and statistics were performed in StatCalc version 8.1.3 program. Descriptive statistics were calculated and ANOVA tests were performed. Results: The average age was 16 years. In the maxilla, in the severe crowding cases, average tooth mass was 101.34 mm and in the mandible, 93.50 mm. In moderate crowding cases, in the upper dental arch, the average tooth mass was 98.30 mm and in the lower arch, 90.15 mm. In arches with mild crowding an average tooth mass of 95.06 mm was found in the maxilla and of 87.10 mm in the mandbile. When comparing the groups with severe crowding, statistically significant differences in the maxilla and mandible were found. Conclusions: As the crowding severity increases, there is more tooth mass in patients.

Compensation due to lower first molar absence by means of traditional unilateral mesialization of the posterior segment

This case was designed to compensate for the absence of the lower first molar by means of traditional mesialization of the posterior segment thus restoring the lost function and aesthetics. Mesial movement of the lower second and third molars was performed, while controlling the incisor position, when losing anchorage is required. Mesialization of the posterior segment is important to solve problems involving the absence of the fi rst molar since this procedure prevents tilting of adjacent teeth towards the edentulous space, extrusion of the antagonist, or periodontal problems, all of which induce a lack of support, stimulation and hygiene. The case reports a male patient of 31 years of age with a non-contributory medical history, who wished to «improve my crooked teeth». Clinical and radiographic analysis revealed an apparently symmetrical, dolichocephalic, hyperdivergent, skeletal class II due to maxillary protrusion. Intraorally, he presented a non-assessable molar class on the right side and a class I on the left; a non-assessable right and left canine class due to disocclusion and moderate crowding in upper and lower arch. Orthodontic treatment consisted in upper and lower first premolar extractions; anchorage and 0.022” Roth fixed appliances alignment and leveling was performed with the following archwire sequence: 0.014”-0.018” NiTi. For space closure, a 0.017” x 0.025” SS double keyhole loop archwire with Suzuki ligature was used. The segments were anchored for mesialization of teeth #47- 48, using bilateral class II elastics; second order bends were done for tooth #47 to parallelize the roots and short up and down elastics were placed for better intercuspation. Satisfactory facial, dental, aesthetic and functional results were obtained. In the retention phase, an upper and lower circumferential retainer were used.

Anomalous, non-Gaussian tracer diffusion in crowded two-dimensional environments

A topic of intense current investigation pursues the question of how the highly crowded environment of biological cells affects the dynamic properties of passively diffusing particles. Motivated by recent experiments we report results of extensive simulations of the motion of a finite sized tracer particle in a heterogeneously crowded environment made up of quenched distributions of monodisperse crowders of varying sizes in finite circular two-dimensional domains. For given spatial distributions of monodisperse crowders we demonstrate how anomalous diffusion with strongly non-Gaussian features arises in this model system. We investigate both biologically relevant situations of particles released either at the surface of an inner domain or at the outer boundary, exhibiting distinctly different features of the observed anomalous diffusion for heterogeneous distributions of crowders. Specifically we reveal an asymmetric spreading of tracers even at moderate crowding. In addition to the mean squared displacement (MSD) and local diffusion exponent we investigate the magnitude and the amplitude scatter of the time averaged MSD of individual tracer trajectories, the non-Gaussianity parameter, and the van Hove correlation function. We also quantify how the average tracer diffusivity varies with the position in the domain with a heterogeneous radial distribution of crowders and examine the behaviour of the survival probability and the dynamics of the tracer survival probability. Inter alia, the systems we investigate are related to the passive transport of lipid molecules and proteins in two-dimensional crowded membranes or the motion in colloidal solutions or emulsions in effectively two-dimensional geometries, as well as inside supercrowded, surface adhered cells.

Classification and operation in the treatment of maxillary retrusion of adult patients with cleft lip and palate

To classify the patients with cleft lip and palate who need orthognathic surgery and to propose the corresponding operations. From January 2005 to May 2015, 121 patients with cleft lip and palate diagnosed as maxillary retrusion were treated by orthognathic surgery. Inclusion criteriar: (1) male aged over 16, female aged over 14; (2) diagnosed as non-syndromic cleft lip and palate without systemic disease and other genetic diseases; (3) without previous orthodontic and orthognathic treatment; (4) having no other craniofacial malformation. Maxillary features and repaired types were recorded. 93 patients were included and divided into two categories depended on the dental crowding. Class I: the teeth quantity and bone quantity is coordinated, space analysis ≤ 4 mm (mild dental crowding). The forward distance of maxillary less than 6 mm was defined as Class I a (36 cases) more than 6 mm as Class I b (28 cases). Class II: the teeth quantity and bone quantity is not coordinated, space analysis > 4 mm ( moderate or severe dental crowding). After the simulation of distraction osteogenesis, the anterior crossbite was corrected defined as Class II a (23 cases), not corrected defined as Class II b (6 cases). Class I a were corrected by conventional orthognathic surgery. While Class I b were corrected by Le Fort I maxillary advancement using distraction osteogenesis. Class II a were repaired just by anterior maxillary distraction. While Class II b need to combine conventional orthognathic surgery with anterior maxillary distraction. All the patients were satisfied with the treatment effect. The patients of cleft lip and palate with maxillary retrusion who need orthognathic surgery can be classified as the method mentioned above, and then choose the appropriate operations.

Changes in mandibular incisor position and arch form resulting from Invisalign correction of the crowded dentition treated nonextraction.

To investigate changes in mandibular incisor position resulting from Invisalign correction of the crowded dentition without extraction. A retrospective chart review was completed on 61 adult White patients. Patients were categorized into three groups based on the value of pretreatment crowding of the lower dentition: 20 mild (2.0-3.9 mm), 22 moderate (4.0-5.9 mm), and 19 severe (>6.0 mm). Cephalometric radiographs were measured to determine lower incisor changes. Interproximal reduction and changes in arch width were also measured. Statistical evaluation of T0 and T1 values using paired t-tests and analysis of covariance were applied to evaluate mean value changes. Lower incisor position and angulation changes were statistically significant in the severe crowding group. There were no statistically significant differences in lower incisor position between the mild and moderate crowding groups. There was a statistically significant increase in buccal expansion in each of the three groups. Invisalign(®) treatment can successfully resolve mandibular arch crowding using a combination of buccal arch expansion, interproximal reduction, and lower incisor proclination. When there is <6 mm of crowding, lower incisor position remained relatively stable. The lower incisors proclined and protruded in the more severely crowded dentitions (>6 mm).

Does the decision to extract influence the development of gingival recessions?

Mandibular anterior crowding can be treated by expanding the dental arch or by extracting teeth, usually premolars. The aim of this study was to assess long-term outcomes of extraction versus non-extraction therapies in terms of gingival recession. Fifty consecutive patients were selected, including 26 non-extraction and 24 extraction cases. All had been treated with fixed appliances because of well-defined comparable moderate crowding and Angle Class I malocclusion. Patient age was documented before treatment, upon debonding, and during retention, thus, allowing the calculation of the duration of active treatment and retention. The records available for these three points in time included casts and cephalograms. The casts were used to quantify mandibular anterior crowding and the associated clinical crown lengths. Based on the cephalograms, a number of symphyseal variables were measured. Data analysis included descriptive statistics, correlation tests, and multiple regressions. For accurate comparison of the extraction and non-extraction treatment groups, we required and verified that no significant intergroup differences were present with regard to initial crowding, duration of retention, and age at final record-taking. Both groups revealed increases in crown length, which fell short of statistical significance but were twice as large for canines than for incisors. The treatment decisions to extract premolars did result in significantly different topographic positions of the lower incisors, but they made no difference in the recession outcomes. None of the variables in our regression analysis was found to predict gingival recession. Findings of gingival recession in patients having undergone orthodontic treatment do not seem to be related to extraction/non-extraction treatment decisions.

Cone beam computed tomography evaluation of distance from cementoenamel junction to alveolar crest before and after nonextraction orthodontic treatment.

To evaluate the distance between the cementoenamel junction and the alveolar bone crest before and after orthodontic treatment using cone beam computed tomography (CBCT). The sample comprised 30 patients with Angle Class I malocclusion and mild to moderate crowding. The study database comprised dental CBCT scans obtained before and after orthodontic treatment. The distance between the cementoenamel junction to the bone crest of the buccal (n = 720) and lingual (n = 720) surfaces was measured in 24 teeth for each patient using a specific software tool (Xoran version 3.1.62). The Wilcoxon test was used for statistical analysis, and the level of significance was set at P < .05. The distance between the cementoenamel junction and the bone crest increased in 822 (57%) of the 1440 surfaces after orthodontic treatment. The buccal surface of the lower central incisors had the greatest frequency of increased distance (75%), and the lingual surface of lateral incisors had the lowest (40%). The distance between the cementoenamel junction and the alveolar bone crest was greater than 2 mm (alveolar bone dehiscence) in 162 (11%) of the 1440 surfaces before orthodontic treatment and in 279 (19%) after treatment. The distance from the cementoenamel junction to the bone crest changed after orthodontic treatment; the distance was greater than 2 mm in 11% of the surfaces before treatment and in 19% after treatment.

Indication and technical application of stripping

Interproximal enamel reduction is a technique used for creating space in cases of mild or moderate crowding. There are several indications and contraindications determined by the tooth shape and the percentage of the caries index. The instruments used for the technique are diamond-coated metal strips, diamond discs and burs, each with advantages and disadvantages. Another way of interdental enamel reduction is using chemical products such as orthophosphoric acid. There are opposite impacts on the enamel surface and the periodontal tissues, based on the literature review.

Orthodontic management of a patient with canine displacement associated with an unusual impaction of central incisor. Case report

This case report describes the treatment of a nine-year-old female patient with a history of dental trauma at age five in the incisors area. She had an early mixed dentition, class I molar relationships and moderate crowding. The maxillary central incisor had not erupted, so we determined radiographically that it was impacted in a horizontal position toward the midline, the lateral incisor was inclined and the canine mesially displaced with an impaction tendency against the lateral incisor. Orthodontic treatment consisted of the placement of initial 4×2 orthodontic fixed appliances and space opening. The periodontal surgery was performed in two stages. In the first stage the central incisor was surgically exposed. Subsequently in the second stage, the maxillary right deciduous canine was extracted, then periodontal surgery was performed to expose the impacted permanent canine. Finally, we tractioned each tooth into its proper position.

Manejo ortodóncico de paciente con desplazamiento de canino asociado a una inusual impactación del incisivo superior. Reporte de caso

This case report describes the treatment of a nine-year-old female patient with a history of dental trauma at age five in the incisors area. She had an early mixed dentition, class I molar relationships and moderate crowding. The maxillary central incisor had not erupted, so we determined radiographically that it was impacted in a horizontal position toward the midline, the lateral incisor was inclined and the canine mesially displaced with an impaction tendency against the lateral incisor. Orthodontic treatment consisted of the placement of initial 4×2 orthodontic fixed appliances and space opening. The periodontal surgery was performed in 2-stages. In the first stage the central incisor was surgically exposed. Subsequently in the second stage, the maxillary right deciduous canine was extracted, then periodontal surgery was performed to expose the impacted permanent canine. Finally, we tractioned each tooth into its proper position.

Open bite treatment using clear aligners

A 35-year-old female patient with dentoalveolar open bite of 4 mm, molar Class I malocclusion, centered midlines, moderate crowding, and labial inclination of the lower incisor was treated with clear aligners to reduce protrusion and close the anterior open bite. The result showed that clear aligners were an effective method with which to correct this malocclusion. The treatment was complete after 18 months. The patient was satisfied with her new appearance and function.

Wait times in the emergency department for patients with mental illness

It has been suggested that patients with mental illness wait longer for care than other patients in the emergency department. We determined wait times for patients with and without mental health diagnoses during crowded and noncrowded periods in the emergency department. We conducted a population-based retrospective cohort analysis of adults seen in 155 emergency departments in Ontario between April 2007 and March 2009. We compared wait times and triage scores for patients with mental illness to those for all other patients who presented to the emergency department during the study period. The patients with mental illness (n = 51 381) received higher priority triage scores than other patients, regardless of crowding. The time to assessment by a physician was longer overall for patients with mental illness than for other patients (median 82, interquartile range [IQR] 41-147 min v. median 75 [IQR 36-140] min; p < 0.001). The median time from the decision to admit the patient to hospital to ward transfer was markedly shorter for patients with mental illness than for other patients (median 74 [IQR 15-215] min v. median 152 [IQR 45-605] min; p < 0.001). After adjustment for other variables, patients with mental illness waited 10 minutes longer to see a physician compared with other patients during noncrowded periods (95% confidence interval [CI] 8 to 11), but they waited significantly less time than other patients as crowding increased (mild crowding: -14 [95% CI -12 to -15] min; moderate crowding: -38 [95% CI -35 to -42] min; severe crowding: -48 [95% CI -39 to -56] min; p < 0.001). Patients with mental illness were triaged appropriately in Ontario's emergency departments. These patients waited less time than other patients to see a physician under crowded conditions and only slightly longer under noncrowded conditions.