Removable Orthodontic Appliances Research Articles

Valutazione elettromiografica ed elettrognatografica del trattamento ortodontico-chirurgico

Objectives Electromyography and electrognatography are very useful to assess neuromuscular function in the diagnosis and treatment of patients during orthodontic surgical treatment. The aim of this work is to evaluate both neuromuscular function and mandibular movements in 70 patients undergoing orthodontic surgical treatment. Material and methods During the orthodontic surgical treatment all patients were submitted to usual clinical and radiographic exams and to periodical electromyographic and electrokinesiographic evaluations. The test group consisted of 70 patients (27 men and 43 women) at the end of growth. Electromiography and kinesiography were performed at the time of diagnosis, at the beginning of orthodontic therapy, periodically during orthodontic treatment before surgery, the day before surgery, during the intermaxillary block, at the removal of the fixation, during orthodontic treatment after surgery, at the removal of orthodontic appliance and the during follow up. The instruments used in this research were a Freely electromiograph and a K6-I EMG electromiograph and electrognatograph. The anterior temporal and the masseter muscles were tested. The control group consisted of adult patients with skeletal class I, with no temporomandibular disorders and no previous orthodontic or surgical-orthodontic treatments. Mandibular movements were assessed by a Myotronics K6-1 kinesiograph. The results were statistically analyzed by t test and ANOVA test. Results At the beginning of treatment the patients of the test group showed a malocclusion-compensating balance. During orthodontic treatment before surgery electromyographic and electrognathographic values started to worsen and continued to worsen until surgery. They improved during orthodontic treatment after surgery. After removing orthodontic appliances, electromyographic values improved and reached optimal values. Recover of mandibular movements was also satisfying even if it took a longer time than muscular rehabilitation. At the end of the treatment maximum mandibular opening was still smaller than before treatment. Conclusions This study confirms that functional rehabilitation of patients during orthodontic-surgical treatment is timely and good. Functional evaluation is important to reduce as much as possible a faulty neuromuscular activity that may cause a relapse; it also helps clinicians to control treatment and results.

Settling of the Occlusion Following Orthodontic Treatment may not Improve Functional Occlusion

Changes in functional occlusion during the postorthodontic retention period: a prospective longitudinal clinical study. Morton S, Pancherz H. Am J Orthod Dentofacial Orthop 2009;135(3):310-5. Gregory King DMD, DrMedSci In orthodontic patients treated to a satisfactory static occlusion with a fixed appliance, how does functional occlusion change following orthodontic appliance removal and during retention? Information not available Cohort study Level 2: Limited-quality, patient-oriented evidence Not applicable.

In vivo remineralization of artificial enamel carious lesions using a mineral-enriched mouthrinse and a fluoride dentifrice: A polarized light microscopic comparative evaluation

Remineralization process is accelerated by the presence of fluoride ions in the oral environment, but this mechanism of caries reversal will be further enhanced if the concentration of calcium, phosphate and fluoride ions is supersaturated with respect to that of oral fluids. This in vivo study was carried out to evaluate and compare the remineralizing efficacy of a urea-based mineral-enriched mouthrinse and a fluoridated dentifrice using an in vivo intraoral appliance model and polarized light microscopic evaluation technique. The specimens were prepared from sound teeth and artificial caries was produced using an artificial caries medium in vitro and enamel specimens were inserted in removable orthodontic appliances that were to be worn by 14 children of 10-15 years of age. They were divided into three groups - nonfluoridated dentifrice, fluoridated dentifrice and mineral-enriched mouthrinse groups. After the 6-month experimental period, during which the enamel specimens inserted in the intraoral appliance were subjected to one of the agents (either fluoride, nonfluoride dentifrice or mouthrinse) in vivo, the specimens were retrieved from the patients and were evaluated using the polarized light microscopic technique. On analysis, mineral gain occurred in all groups, viz. nonfluoride dentifrice group, fluoride dentifrice and mineral-enriched mouthrinse group. However, it was found to be complete in the mouthrinse group, i.e. both at the surface and at the subsurface (67%), while in the fluoridated dentifrice group, 43% of the samples showed mineral gain in both zones. In the nonfluoridated dentifrice group also, remineralization occurred but was limited either to the surface or the subsurface zone. Urea-based mineral-enriched mouthrinse was shown to be more efficacious in the process of remineralization of artificial carious lesions.

Effect Of Joint Surface Treatment On The Flexural Strength Of Repaired Auto-Polymerized Acrylic Resin.

Objective: Repair of acrylic part of removable orthodontic appliance involves, joining two parts of fractured appliance with acrylic. The study was designed to evaluate the effect of joint surface treatment on the fl exural strength of repaired auto-polymerized acrylic resin. Materials and Methods: 100 rectangular specimens were fabricated of clear auto-polymerized acrylic resin. Specimens were divided into fi ve groups (n=20) coded A to E. The Group A was intact specimens, used as a control. Other specimens were sectioned in the middle to simulate fracture. Group B had no joint surface treatment. In the remaining three groups, joint surface was treated with abrasive air blasting, methymethacrylate and acetone respectively. Specimens were repaired with pink auto-polymerized acrylic resin. The fl exural strength of the specimens was measured using a three - point bending test. The data was statistically analyzed using student’s t-test at p<.05. Results: Statistically signifi cant differences were found between the control and all repair groups. Within Repair groups, there were statistically signifi cant differences between untreated joint surface group and joint surface treated groups. There was no statistically signifi cant difference among joint surface treated groups. Conclusion: Mechanical joint surface treatment by abrasive air blasting or application of methylmethacrylate or acetone resulted in a signifi cant improvement in the fl exural strength of repaired auto-polymerized acrylic resin. However none of the repair method used in this study could produce comparable fl exural strength, as of intact auto-polymerized acrylic resin.

Did you know? A question and answer dialogue for the orofacial myologist

This article addresses selected concepts and procedures related to orofacial myology in a question and answer format. Topics include tongue-tip placement for swallowing; a masseter-contraction swallow; temporary anchorage devices utilized in orthodontic treatment; relapse following orthodontic treatment; some advantages and disadvantages of fixed and removable orthodontic appliances; the extraction of teeth in orthodontic treatment; posterior and anterior crossbite considerations; and the importance of recasting the emphasis and focus of myofunctional therapy to orofacial rest posture therapy. In addition, this article promotes projects that orofacial myologists and orthodontists can mutually undertake to assist in advancing the data base regarding orofacial myofunctional disorders, thereby serving to enhance the reputation and value of orofacial myofunctional therapy within the dental profession.

In situ and in vitro comparison of laser fluorescence with visual inspection in detecting occlusal caries lesions

The aim of this study was to compare the in situ and in vitro performances of a laser fluorescence (LF) device (DIAGNOdent 2095) with visual inspection for the detection of occlusal caries in permanent teeth. Sixty-four sites were selected, and visual inspection and LF assessments were carried out, in vitro, three times by two independent examiners, with a 1-week interval between evaluations. Afterwards, the occlusal surfaces were mounted on the palatal portion of removable acrylic orthodontic appliances and placed in six volunteers. Assessments were repeated and validated by histological analysis of the tooth sections under a stereomicroscope. For both examiners, the highest intra-examiner values were observed for the visual inspection when in vitro and in situ evaluations were compared. The inter-examiner reproducibility varied from 0.61 to 0.64, except for the in vitro assessment using LF, which presented a lower value (0.43). The methods showed high specificity at the D(1) threshold (considering enamel and dentin caries as disease). In vitro evaluations showed the highest values of sensitivity for both methods when compared to the in situ evaluations at D(1) and D(2) (considering only dentinal caries as the disease) thresholds. For both methods, the results of sensitivity (at D(1) and D(2)) and accuracy (at D(1)) showed significant differences between in vitro and in situ conditions. However, the sensitivity (at D(1) and D(2)), specificity and accuracy (both at D(1)) of the methods were not significantly different when the same condition was considered. It can be concluded that visual inspection and LF showed better performance in vitro than in situ.

Archwire ligation techniques, microbial colonization, and periodontal status in orthodontically treated patients.

Fixed or removable orthodontic appliances impede the maintenance of oral hygiene and result in plaque accumulation. Plaque retention surrounding orthodontic appliances leads to enamel demineralization caused by organic acids produced by bacteria in the dental plaque. Many studies have evaluated the effects of fixed orthodontic appliances on microbial flora and periodontal status, but only a few have evaluated the method of ligation as an additional factor. The aim of this study was to determine the changes in microbial flora and periodontal status after orthodontic bonding and to determine whether two different archwire ligation techniques affect these changes. A total of 21 orthodontic patients scheduled for fixed orthodontic treatment were selected for this split-mouth study. Two commonly used auxiliaries (elastomeric rings and ligature wires) for tying archwires were tested. Microbial and periodontal records were obtained before bonding (T0), one week later (T1), and five weeks after bonding (T2). Paired t-test and Wilcoxon signed rank test were used to compare the groups statistically. Although, teeth ligated with elastomeric rings exhibited slightly greater numbers of microorganisms than teeth ligated with steel ligature wires, the differences were not statistically significant and could be ignored. The two archwire ligation techniques showed no significant differences in the gingival index, bonded bracket plaque index, or pocket depths of the bonded teeth. However, teeth ligated with elastomeric rings were more prone to bleeding. Therefore, elastomeric ring use is not recommended in patients with poor oral hygiene.

What Can Be Achieved with Removable Orthodontic Appliances?

How effective is a therapy which relies solely on removable orthodontic appliances? A group of 276 consecutive patients, whose mean age was 9.50 years, diagnosed with various types of malocclusion, whose records were complete, and who were treated solely with removable appliances. Measurement of the PAR Index of the pre- and post-treatment study casts, standard statistical analyses, calculation of the correlation coefficients, and method error. The mean pre-treatment PAR score was 19.5, the mean post-treatment PAR score 5.9. In the PAR nomogram, 79% of the patients were classified as "improved", and 16% as "greatly improved". In contrast, 5% had to be classified as "worse/no different". The overall situation improved by a mean of 14 PAR points, corresponding to a mean improvement of 68%. Using the PAR Index as a standard, removable appliances can be used successfully to correct malocclusions, providing the indication is correct and the clinician's expertise in this field of the speciality is very high.

Microsensor technology to help monitor removable appliance wear

Retention is routinely prescribed after orthodontic treatment to prevent relapse. Orthodontists often notice a discrepancy between what a patient reports about retainer wear and what a clinical examination shows. In these cases, is the patient misreporting wear, or is the retainer at fault? Scientific Compliance (Atlanta, Ga) has invented, patented, and produced the Smart Retainer environmental microsensor that can be easily incorporated into many types of removable orthodontic appliances to monitor compliance. The technology behind the Smart Retainer environmental microsensor is possible because of recent reductions in electronic component sizes and power requirements. A proprietary USB-powered Smart Reader uses wireless technology to download information about actual usage from the Smart Retainer. The information is decrypted and analyzed, and can be shown to the patient in easy-to-understand charts. The orthodontist can use this information to discuss actual retainer usage vs prescribed retainer usage with the patient or parent and make data-driven recommendations about future retention.

Iatrogenic effects of removable orthodontic appliances

Undesirable effects that occur during orthodontie treatment can be attributed to a lack of understanding of physics involved and individual variations in biologie response. A proper insight into the biomechanical principles underlying orthodontic applianee therapy is indispensable for executing efficient orthodontic treatment. While designing, one of the aspects that is frequently neglected is the direction of force applied (vector) on the teeth by active components. Knowledge of vectors would help a dentist decide the placement of active components and thereby foresee the results obtainable. Through these case reports it is emphasized that every step of removable appliance therapy should be carefully monitored by an experienced clinician himself and if iatrogenics arise, then its recognition and rectification is mandatory

Aerosol hazards in orthodontic appliance removal

Aerosol hazards in orthodontic appliance removal

Comprehensive Treatment of Hypodontia in 6 Years Old Patient

Agenesis described as a certain developemntal disorder that is a lacking in the number of teeth present intraorally. Hypodontia is an agenesis with the absence of one or several teeth. In most of the population, the prevalence is 3,5 - 6,5% with 0,3-0,4% for a severe hypodontia (an absence of 6 teeth or more clinically). Agenesis affects permanent dentition more often than primary dentition, and the incidence of agenesis is greater in female than male patients. Agenesis might be a result of environmental and genetic factors. It is necessary to have a comprehensive treatment for a case of hypodontia, which involves restorative, orthodontic, a prosthetic treatment based on the children's growth and development. In the present case, a patient of 6 years and 5 months old girl was diagnosed with severe hypodontia. The treatment of choice included a removable orthodontic appliance for the upper jaw and a removable space maintainer for the lower jaw. The removable orthodontic appliance served as an interceptive orthodontic treatment to correct anterior crossbites, and the child will be referred to the orthodontist to treat a Class III skeletal malocclusion. The space maintainer was to be used until the patient's condition become favorable for a permanent fixed bridge or steel removable partial denture.

Influence of Removable Orthodontic Appliance on Oral Microbiological Status

Influence of Removable Orthodontic Appliance on Oral Microbiological Status

Activation time and material stiffness of sequential removable orthodontic appliances. Part 3: Premolar extraction patients

The purpose of this study was to describe the movement of teeth adjacent to premolar extraction spaces during space closure with aligner appliances and then fixed appliances. The sample included 24 subjects from a larger study investigating an aligner system. All subjects had at least 1 premolar extracted as part of treatment. Dental casts and panoramic radiographs were measured for tooth tipping adjacent to extraction spaces at 3 treatment points: T0, initial; T2, end of aligners; and T3, end of fixed appliances. Chart records were reviewed for information about time in treatment. Treatment with aligners resulted in significant tipping of the teeth adjacent to premolar extraction sites. When followed by fixed appliances, these teeth were significantly uprighted. Aligner treatment followed by treatment with fixed appliances took an average of 40 months. In premolar extraction patients treated with aligners, dental tipping occurs but can be corrected with fixed appliances. This dual modality treatment might require more time than treatment with fixed appliances alone.

Impacts on Daily Performances Related to Wearing Orthodontic Appliances

To assess the prevalence, intensity, and extent of the impacts on daily performances related to wearing different types of orthodontic appliances. A total of 1657 students, 15 to 16 years old, were randomly selected from those attending all secondary schools in Bauru, São Paulo, Brazil. Only those wearing orthodontic appliances at the time of the survey were included. Face-to-face structured interviews were done to collect information about impacts on quality of life related to wearing orthodontic appliances, using the Oral Impact on Daily Performances (OIDP). Adolescents were also clinically examined to assess the type of orthodontic appliance they were wearing. Comparisons, by type of orthodontic appliance and covariables, were performed using nonparametric statistical tests. Three hundred fifty-seven adolescents (36.1% boys and 63.9% girls) undergoing orthodontic treatment participated in the study. The prevalence of condition-specific impacts related to wearing orthodontic appliances was 22.7%. Among adolescents with impacts related to wearing orthodontic appliances, 35.8% reported impacts of severe or very severe intensity and 90.1% reported impacts on only one daily performance, commonly eating or speaking. The prevalence, but not the intensity or the extent, of condition-specific impacts differed by type of orthodontic appliance (P = .001). One in four Brazilian adolescents undergoing orthodontic treatment reported side effects, specific impacts on daily living, related to wearing orthodontic appliances. Such impacts were higher among adolescents wearing fixed rather than removable or a combination of fixed and removable orthodontic appliances. This information could help to inform patients about the frequency and intensity of sociodental impacts during the course of their treatment.

Characterization of oral films formed in the presence of a CPP–ACP agent: An in situ study

Objectives The aim of this study was to compare the morphological appearance and the molecular composition of intraoral integuments formed in situ on germanium (Ge) crystals in the presence or absence of the commercially available casein-phosphopeptide–amorphous calcium phosphate (CPP–ACP) cream agent. Methods Six volunteers participated in the study. Impression of maxillary arch was taken for each patient, and a removable orthodontic appliance with a custom-made retainer was fabricated. Clean Ge crystals mounted in the retainers were placed intraorally for 30 min, 8, 24 h and 1-week period. The free sampling surface of another series of Ge crystals was treated with the commercial CPP–ACP agent (Tooth Mousse), mounted in the retainers and placed intraorally for the same period as above. The free exposed surfaces in oral cavity of the specimens in all subjects were examined as follows: (a) reflected light microscopy, (b) micro-MIR-FTIR spectroscopy and (c) scanning electron microscopy (SEM) plus energy-dispersive X-ray microanalysis analysis (XEDS). Results The light microscopic observations revealed that there was a delay in biofilm formation on Ge surfaces treated with agent in comparison to those ones without treatment. The micro-MIR-FTIR spectra from the surfaces with Tooth Mousse showed an increase in intensity and a left shift of PO 4 3− peak (1064 cm −1). Finally, the PO 4 3− peak at lower bands (564 cm −1) and the low-wave bands at 525–530 cm −1 increased at 1-week interval. The SEM revealed the dendritic development of microbes. The XEDS analysis showed a significant increase in Cl/O, K/O, K/Cl and a decrease in Ca/O and P/O ratios on the crystal Ge without surface treatment. On contrary, on the crystal Ge with surface treatment an increase in Ca/O, Ca/P and a decrease in K/Cl ratios were found. Conclusion The results show that the presence of CPP–ACP agent delays the biofilm formation and favored the nucleation and crystallization of calcium phosphates, possibly in apatitic form, in matured biofilms.

Effect of Removable Orthodontic Appliance on Taste and Flavor Perception – A Clinical Study

Removable orthodontic appliances are known to be the cause of various complaints related to oral handling of food and beverages, phonation and vocalization. To evaluate the complaint regarding appliance and its effect on taste and flavor perception, 100 volunteers were selected for the study. Two groups (I and II) of 50 children each were divided as study and control groups between the age group of 8- 13 years. Selected volunteers were given taste and flavor stimuli and were asked to score as per their perception in different testing sessions. The overall results revealed that volunteers from both study and control groups, irrespective of the use of removable orthodontic appliances showed marked variation in the estimation of the taste and flavor stimuli in different testing sessions. However, the results obtained were statistically not significant.

Concurrent validity of the COHIP

This study examined the relationship between children's perception of their OHRQOL and their perceptions of their dentofacial image, social anxiety, and self-concept as an assessment of the concurrent validity for the Child Oral Health Impact Profile (COHIP). A nonrandom, consecutive sample of children, ages nine to 14 years, was recruited for this observational validation study. Participants had been accepted for treatment in the University of North Carolina Graduate Orthodontic clinic. Data were collected after gathering initial orthodontic records and prior to delivery of any fixed or removable orthodontic appliances. Participants completed the COHIP and standardized dimension-specific questionnaires with known psychometric properties designed to assess self-concept, social anxiety, and perception of facial image. Child assent with caregiver consent was obtained prior to data collection. Pearson's correlations between each of the domains of the COHIP and the Dento-facial Image, the Social Anxiety Scale, and the self-concept domains of the Multidimensional Self Concept Scale (MSCS) were calculated. Criteria for support of concurrent validity was established based on directionality of expected relationships and strength of the observed correlation coefficient. Each correlation was assessed as meeting or not meeting the criteria. A one-tailed one sample Z-test was used to test the null hypothesis that 58% of the calculated correlations would meet the criteria (expected a priori) with an alterative that less than 58% would meet the criteria. The average age of the 52 subjects enrolled was 11.8; 40% were male; and 85% were Caucasian. The hypothesis that 58% of the calculated correlations defined a priori as expected relationships would meet the criteria was supported by the data (P = 0.63). The perception of dentofacial appearance was positively correlated (range = 0.39 to 0.45; with all of the COHIP domains except for the School domain. Overall, the COHIP domains, particularly Self-Image and Social Emotional subscales, were positively correlated (0.32-0.52) with the MSCS self-concept domain scores, except Family Self-Concept. The COHIP domains, particularly Functional Well-being and Social Emotional subscales, were negatively correlated (-0.76 to -0.33) with the three Social Anxiety subscales that include both fear of negative evaluation and social avoidance. The findings in this study lend support to the validity of the COHIP since 77% of the expected relationships between the domains of the COHIP and the domains of general, standardized dimension-specific instruments were observed. The decision to use condition-specific, dimension-specific, or general quality of life (QOL) measures is dependent on the purpose of the study. For investigations in children on the effect of dental treatments or in epidemiologic studies of an oral health outcome, the use of condition-specific QOL measures like the COHIP have the advantages of increased patient responsiveness since the assessment is focused on a specific condition, oral health, and increased sensitivity to treatment effects.

Effect of pressure and polishing technique on surface roughness of cold cured acrylic resin

The smoothness of acrylic surface plays an important role in producing removable orthodontic appliances. Int this study, we examine the effect of pressure and polishing technique on surface roughness of cold cured acrylic resin. Forty eight samples were prepared and classified into two groups: acrylic resin polymerization with and without pressure. Each group was classified into four subgroups: being polished with abrasive stone, bur for acrylic, silicone polisher and without being polished as control group. Surface roughness was measured using surface roughness tester. The surface roughness of polymerized acrylic with and without pressure and polished with different technique was analyzed using One-Way ANOVA, continued by Dunnet test. T-test was done to know whether there was the effect of pressure on surface roughness after being polished using certain technique. The result showed that pressure and polishing technique affected surface roughness significantly (p = 0.001). On the group of polymerization with pressure, surface roughness resulted from polishing with bur of acrylic showed significant difference with silicone polisher, whereas on the group without pressure, polishing with bur of acrylic showed significant difference with abrasive stone. Of the three polishing techniques, there was significant difference of surface roughness of cold cured acrylic resin (t = 0.002). It is concluded that pressure and polishing technique affected the surface roughness of cold cured acrylic resin. Polishing technique using bur of acrylic, followed by abrasive paper, rotating felt cone and soft brush showed less surface roughness on the group of polymerization with or without pressure.

In-vivo evaluation of the bacterial contamination and disinfection of acrylic baseplates of removable orthodontic appliances

This randomized clinical trial assessed, by using microbial culture and scanning electron microscopy (SEM), the contamination by mutans streptococci (MS) colonies/biofilms on acrylic baseplates of removable orthodontic appliances and evaluated the efficacy of antimicrobial sprays (Periogard [Colgate-Palmolive Ind. Brasileira, Osasco, SP, Brazil], Cepacol [Merrell Lepetit Farmacêutica e Industrial Ltda, Santo Amaro, SP, Brazil], and sterile tap water [control]) on their disinfection. Seventeen children were randomly enrolled in a 3-stage changeover system with a 1-week interval between each stage. All solutions were used in all stages by a different group of children. The acrylic baseplates were worn full time except at meals. At the end of each week of the trial, the baseplates were submitted to a randomized disinfection protocol and were sent for microbiologic analysis. New baseplates were constructed, and the same sequence of procedures was repeated 2 more times. Acrylic baseplates representing each test solution were examined by SEM. The Friedman test assessed differences at the 5% significance level among the solutions for MS biofilm formation on acrylic surface. Cepacol and Periogard reduced the formation of MS colonies/biofilms, and both solutions differed statistically from sterile tap water (P <.001). However, Periogard was significantly more effective against MS than Cepacol (P <.001). When MS colonies/biofilms were detected on acrylic surfaces under stereomicroscopy, this was confirmed with SEM. Acrylic baseplates of removable orthodontic appliances worn by children were contaminated by MS colonies/biofilms in all cases after 1 week. Although Cepacol had better results than sterile tap water, spraying with Periogard showed significantly greater efficacy in reducing MS colonies/biofilms on acrylic surfaces.