Molar Bands Research Articles

Space management using Transpalatal arch in mixed dentition phase: A case report

Introduction: The early exfoliation of primary molars during the mixed dentition phase often results in disruptions to the normal development of occlusion. An alternative option for space management in the maxillary arch besides the commonly used Nance palatal holding appliance is the transpalatal arch which allows some amount of space regaining. Case report: A 9 year old female reported with a complaint of missing tooth in the upper right back tooth region since 2 years. On examination, there was premature loss of the right primary maxillary first molar causing space deficiency in the arch form. A treatment plan was made for space regaining and distalization with transpalatal arch custom made with 0.9mm stainless steel wires and soldered to the molar bands. The treatment spanned for 10 months with the eruption of the permanent successor in correct arch form. Conclusion: Although the use of transpalatal arch is limited in pediatric dentistry, it can be used for correcting minor space discrepancies of the maxillary arch. More number of cases need to be studied for extending the use of the appliance in interceptive orthodontics.

Analysis of changes and correlation in condyle-fossa relationship after maxillary skeletal expansion.

To investigate the changes in condyle-glenoid fossa relationship after maxillary skeletal expansion (MSE) and to verify the correlation between the condyle positional changes and expansion effect. In this study, 20 patients (mean age 21.1 ± 5.7 years, 8 male, 12 female) with maxillary transverse deficiency (MTD) were treated with the MSE appliance, which contained molar bands and a expander with four micro-implants. The CBCT images were taken before expansion (T0), after expansion (T1) and after 6 months of maintenance (T2). The posterior TMJ space (PS), superior TMJ space (SS), anterior TMJ space, coronal lateral TMJ space (CLS), coronal medial TMJ space (CMS), condyle axis angle, maxillary basal bone width (BWM), inter-molars width, nasal bone width, molar inclination and molar palatal cusp height (U6H) were measured using Dolphin Imaging. At T1, compared with T0, the PS and SS significantly increased by 0.41 mm (P = .008) and 0.3 mm (P = .007). But only the SS significantly increased by 0.21 mm (P = .025) at T2. There was a significant difference of 0.37 mm (left-right, P = .014) between the left and right SS at T0, but no significant difference at T1 and T2. The increased BMW showed weak positive correlations with the change of PS (P = .015) and CMS (P = .031), and the decreased U6H showed weak negative correlations with the change of PS (P = .015) and CLS (P = .031) at T1. The use of MSE led to an increase in the SS and PS, which were weakly correlated with BWM and U6H. But this effect in the TMJ space gradually diminished after 6 months of maintenance, and the symmetry of the condyle-fossa relationship was preserved.

Metal Artifact Reduction by Using MARS System of a CBCT Unit with Different Components of Fixed Orthodontic Appliances: An In vitro CBCT Analysis

Introduction During Cone beam computed tomography (CBCT) imaging in the head and neck region of patients who are undergoing fixed orthodontic treatment, the different components of fixed orthodontic appliances can produce various metal artifacts which may degrade the diagnostic image quality in the region of interest. Therefore, the metal artifact reduction software (MARS) system can be used in most CBCT units to reduce the amount of artifacts generated from various fixed orthodontic appliance components including skeletal anchorage devices. Aims and Objectives The main purpose of this study was to quantitatively evaluate the effectiveness of MARS system of a CBCT unit in reducing the amount of artifacts generated by various fixed orthodontic appliance components during CBCT imaging. Materials and Methods Four dental arch shaped phantoms that were fabricated along with different fixed orthodontic appliance components (metal bracket, molar band, transpalatal arch, mini-implant) underwent CBCT scanning without and with the MARS setting option. After using the MARS system of a CBCT unit, the reduction in the amount of artifacts that were generated by various fixed orthodontic appliance component was calculated by using Google Colab software that utilized Python code and OpenCV system to generate a binary mask image. The resulting mask image highlights the areas where artifacts are detected, allowing for further analysis or visual inspection. The contours found within the mask image represent the boundaries of the artifact regions. Results After calculating the percentage decrease in artifact area for each component of fixed orthodontic appliance, one-way analysis of variance (ANOVA) test was performed to compare the percentage decrease in artifact area for each component of fixed orthodontic appliances. *P-values are calculated using one-way analysis of variance ( p < 0.05). The percentage decrease in artifact area for different components of fixed orthodontic appliance ranged from 39.67% to 48.58%. The stainless steel bracket showed the significant artifact area reduction with a mean percentage decrease of 48.58% as compared to other components. Conclusion The effect of MARS system in reducing the amount of metal artifacts generated varied according to the component type of fixed orthodontic appliance and, MARS system was more efficient for stainless steel brackets as compared to other components. CBCT imaging of head and neck region can be carried out without taking off the orthodontic appliances by applying MARS system which can significantly decrease the artifact area.

FABRICATION OF MAYNE’S SPACE MAINTAINER FOR PREMATURE LOSS OF DECIDUOUS TEETH

Background: Premature loss for deciduous teeth is defined as the teeth that fall out before approaching the time of eruption of their replacement permanent teeth regardless of the reason for the loss of the teeth. The premature loss of deciduous teeth can cause the teeth next to the edentulous area to shift and lose arch space causing permanent teeth to grow abnormally. Prevention can be done by using Mayne's space maintainer so that the negative impact of premature loss does not occur. Purpose: Report the fabrication of Mayne's space maintainer in premature loss case. Case analysis: The laboratory accepted a working model with a case of premature loss in tooth 74 and was asked to make the Mayne's space maintainer. Result: This appliance consists of a molar band attached to tooth 75 with a 0.9 mm loop that is soldered on the buccal of the molar band. Conclusion: It is concluded that fabrication of Mayne's space maintainer in the case of premature loss of tooth 74 includes the preparation of a working model, adjustment of the molar band on tooth 75, making the loop, followed by soldering the loop to the molar band, finally the finishing and polishing.

Effects of delayed appointments in fixed orthodontic patients due to lockdown during the COVID-19 pandemic

ObjectivesTo determine the frequency of orthodontic emergencies and their impact on the treatment progress caused by delayed appointments due to the lockdown during the COVID-19 pandemic. Materials and methodsTwo hundred thirty-eight patients undergoing fixed orthodontic treatment participated in this cross-sectional study. A pre-structured questionnaire was divided into six parts (Part A-C comprised of orthodontic emergencies and Part D-F comprised of various adverse effects and impacts on treatment progress). Two specialist orthodontists performed clinical examinations to complete the questionnaire. The final data were expressed as frequency and percentage. ResultsMaximum number of patients reported four months after lockdown. Nearly half of the patients reported debonding of at least one of the brackets. Loosening of molar bands and debonding of second molar tubes were observed in 12.6% and 18.9% of patients, respectively. Ligation method failures were reported in 41.2% of the patients. Patients fitted with transpalatal arch/lingual arch skeletal anchorage showed a failure rate of 26.1% and 10%, respectively. Almost 29% of the patient complained of discomfort due to distal wire impingement. Undesired tooth movements were seen in almost 25% of patients. Alignment, space closure, and settling of occlusion were affected in 47.6%, 17.4%, and 35.7% of patients, respectively. ConclusionsThis study helps to determine various types of adverse effects that can occur due to delayed appointments. The study's outcomes suggest that clinicians should be prepared to deal with future pandemics or other causes that might lead to delayed appointments.

Can Velopharyngeal MRI be Used in Individuals with Orthodontic Devices?

To evaluate the influence of common pediatric orthodontic appliances on velopharyngeal (VP) MRI and to compare MR image sequences to determine if sequence parameters impact the visibility of key VP structures commonly assessed in clinical VP MRI. Participants undergoing orthodontic treatment completed a VP MRI study. Level of distortion caused by orthodontic devices on 8 anatomical sites of interest and using variable MRI sequences was evaluated. Single institution. Nineteen participants undergoing orthodontic treatment. Level of distortion caused by metal artifacts and MR sequence used. The results of this study demonstrate that appliances such as hyrax palatal expanders and braces with stainless steel brackets are acceptable for a VP MRI, while class II corrector springs are not recommended. The HASTE MRI sequence with 2D imaging techniques should be utilized if the child has orthodontic devices, while FSE and 3D imaging techniques are not recommended. The presence of wire spring coils and molar bands are likely to not to interfere with the MRI evaluation. Findings from this study suggest that the presence of orthodontic appliances does not hinder visualization of all velopharyngeal structures during an MRI. Therefore, careful consideration must be made prior to disqualifying or recommending patients for VP MRI.

Immediate retrieval of an accidentally ingested tube pre-welded molar band from stomach – A case report

Accidental ingestion or aspiration of dental foreign bodies is a life-threatening medical emergency. Orthodontic materials such as brackets, bands, wire segments, and appliances are the second most common of foreign bodies to be ingested. Immediate retrieval from the stomach before the object passes the duodenal sweep is recommended. This article reports a case of retrieval of accidentally ingested tube pre-welded molar band within 45 min of ingestion, using endoscopy.

Comparison of the Bone-Anchored Pendulum Appliance and the Bone-Anchored Intraoral Bodily Molar Distalizer: An Original Research.

With the advent of mini-implants, Class II correction has become routine. The study's goal was to compare the "Bone-Anchored Pendulum Appliance (BAPA)" to the "Bone-Anchored Intraoral Bodily Molar Distalizer (BAIBMD)" in terms of clinical efficacy. Five boys and five girls were among the 10 patients in this split-mouth trial who had to have their molars distalized. On one side, BAPA Construction, and on the other, BAIBMD was piloted. A titanium mini-screw was used to secure both appliances to the bone since this was a spilled-mouth technique. The first molar bands to apply 200 g of force were used for both devices, as with all the other components that were similar for both appliances. For both sides, the nature, duration, and rate of tooth movement were compared. Using the Wilcoxon signed-rank test, descriptive statistics for several parameters were examined. Distalization was accomplished on both sides with clinical success. The rate of distalization did not show any significant variation. Less time was needed for distalization with BAPA, as evidenced by the statistically substantial variances in treatment duration between the two groups. Molar tipping was noticed in BAPA, and it was statistically significant. While the pace of distalization was equal for both appliances, BAIBMD required more time than BAPA but resulted in a distal tooth movement that was mostly translatory in nature.

Comparative Evaluation of Antibacterial Activity of Chlorhexidine, Povidone Iodine and Glutaraldehyde for Disinfection of Orthodontic Appliances - An In-Vitro Study

Introduction: Orthodontist must take precautionary measures to protect patients from cross-infection by contaminated materials received from the manufacturers. To minimize the incidence of cross-infection prior to bonding an invitro study was done to assess the antibacterial activity of chlorhexidine, povidone iodine and glutaraldehyde. Aim: To compare the antibacterial activity of 2% chlorhexidine, 5% povidone iodine and 2% glutaraldehyde on orthodontic materials prior to bonding. Materials and methods: A total of 36 samples were included in this study. The main group consists of 3 disinfectants and one control group (n =4). Group -1(Chlorhexidine gluconate), Group - 2 (Povidone Iodine), Group - 3 (Glutaraldehyde) and Group - 4 (Control group –untreated). Each group consists of 3 subgroups of the tested samples namely group A (brackets), group B (archwires) and group C - molar bands (n=9). which were contaminated by 3 bacterial species streptococcus, staphylococcus, lactobacillus and the number of colonies were counted before disinfection. The contaminated samples were subjected to disinfection with 2% chlorhexidine for 5 minutes 2% glutaraldehyde and 5% Povidone Iodine for 10 minutes. 20µl of sample of the disinfected samples were incubated and the number of colonies were counted after disinfection. Results: There were no colonies formed when 5% Povidone iodine was used to disinfect archwires and molarbands in few tested samples. 2% glutaraldehyde and 2% chlorhexidine were not effective against lactobacillus species. Povidone iodine was effective when compared to glutaraldehyde and chlorhexidine gluconate and effective against all the three species namely Streptococcus, Staphylococcus and Lactobacilli species. The obtained p-value is < 0.001 which is statistically significant when all groups were compared overall. Conclusion: Disinfection with 5% povidone iodine was most effective when compared with 2% chlorhexidine and 2% glutaraldehyde.

Effect of Magnetic Resonance Imaging at 1.5 T and 3 T on Temperature and Bond Strength of Orthodontic Bands with Welded Tubes: An In Vitro Study.

Magnetic resonance imaging (MRI) is a widely used diagnostic technique. Patients wearing orthodontic devices are often requested to remove their appliances before an MRI exam, even when the exam involves anatomical areas far from the head, in order to prevent the heating and detachment of the appliances. The present report aims to evaluate changes in temperature and adhesive forces of molar bands after MRI at two different strength outputs. Sixty stainless steel molar bands were bonded on permanent human upper molars using two different cements: Unitek Multi-Cure Glass Ionomer Band Cement (3M Unitek, Monrovia, CA, USA) and Transbond Plus Light Cure Band Adhesive (3M Unitek). Appliances were subjected to MRI with two different strengths (1.5 Tesla and 3 Tesla). Tubes and band temperature was measured before and after MRI. Subsequently, the shear bond strength (SBS) test was calculated. Data underwent statistical analysis (p < 0.05). After MRI, molar bands exhibited significant heating, even though not clinically relevant, with a temperature increase ranging between 0.48 °C and 1.25 °C (p < 0.05). SBS did not show significant differences (p > 0.05). The present study suggests that, under MRI, the molar bands tested are safe; therefore, their removal could be not recommended for non-head and neck MRI exams. Removal would be necessary just in artifact risk areas.

Antimicrobial properties of glass-ionomer cement incorporated with zinc oxide nanoparticles against mutans streptococci and lactobacilli under orthodontic bands: An in vivo split-mouth study

Background: The aim of this study was to assess the effect of incorporation of zinc oxide nanoparticles (ZnO-NPs) to glass-ionomer cement (GIC) (Fuji II SC, GC Corp., Tokyo, Japan) on subgingival accumulation of mutans streptococci and lactobacilli under orthodontic bands.Materials and Methods: In order to conduct this in vivo split-mouth study, 20 patients aged between 7 and 10 years who required lingual holding arch on their mandibular first molars were divided into two groups. In one group, Fuji II SC GIC was used for cementation of the right molar band, and the same cement containing 2 wt% ZnO-NPs was used for the left one. The opposite was performed for the second group while the operator was blinded to the cement types. Subgingival microbial sampling was performed 16 weeks after cementation of lingual arch. Mutans streptococci and lactobacilli colony counts were compared. Paired t-test was used to compare the two cement groups. Data were analyzed using SPSS version 21, and P ≤ 0.05 was considered statistically significant.Results: The mean colony counts of mutans streptococci, lactobacilli, and total bacterial count in Fuji II SC containing ZnO-NPs were significantly lower than the corresponding values in plain Fuji II SC group.Conclusion: Incorporation of ZnO-NPs into GIC reveals antimicrobial features against mutans streptococci and lactobacilli under orthodontic bands.

Camouflage Treatment of Skeletal Anterior Open Bite with Tongue Training

The aim of this case report was to present an adult patient who suffered from poor occlusal function and poor aesthetic appearance due to skeletal anterior open bite. After orthodontic treatment, she was satisfied with improvements of mastication and esthetics. A case of 20-year-old female with skeletal Class II jaw relationship, mandible retrognathism and anterior open bite without signs and symptoms of temporomandibular disorder. Intraoral examination showed premature contact over bilateral posterior teeth and the forward resting position of tongue. Our treatment plan was orthodontic camouflage with extraction of all first premolars and tongue training. As forward resting position of tongue was noted, a tongue crib soldered on molar bands was used and the patient was instructed with tongue exercises. Normal overbite and overjet were achieved within four years of treatment. Her profile became more harmony after correction of anterior open bite. Although the stability of occlusion relies on the position of tongue, the current masticatory and facial profile provide a better quality of life. Orthodontic treatment of skeletal anterior open bite should be very careful. Appropriate diagnosis, differentiation of etiology and proper selection of mechanics must be verified before initiating treatment.

Comparative evaluation of the retention of two different preformed molar bands: An in vitro study

: The purpose of giving space maintainer in primary dentition is to prevent the migration of adjacent teeth, thus holding space in dental arch for succedaneous tooth to erupt. Molar band is the fundamental component of space maintainer. The retention of band to the tooth surface is important to ensure fixed appliance therapy. Several methods have been described to improve the mechanical retentive surfaces of bands including sandblasting, burs, etc. Sandblasting of the metal surfaces improves the retention by roughening, thereby increasing the surface area and improving the potential for degree of mechanical attachment.: The aim of the study was to evaluate and compare the forces require to deband preformed pre- sandblasted and preformed in-office sandblasted molar band and to determine which type is successful to ensure superior band retention.: Twenty sound permanent molars were selected and equally divided into two groups. In group I, pre sandblasted molar bands were cemented onto the molar teeth and in group II, in-office sandblasted molar bands were cemented onto the molar teeth using ReLyX U200 as luting cement in both. The cemented samples were tested for their resistance to dislodgement on Instron Universal testing machine in tensile mode.: The result showed that the debanding forces required to remove the pre-sandblasted bands were higher as compared to in-office sandblasted molar bands.: Pre-sandblasted bands resulted in greater degree of surface roughness by providing a stronger bond between the band and the tooth as compared to in-office sandblasted bands.

White Spots Prevalence and Tooth Brush Habits during Orthodontic Treatment.

White spots (WS) are one of the most undesirable side effects in patients undergoing orthodontic therapy and are usually located around bracket bases and even detected under the molar bands. The aim of the present cross-sectional study was to evaluate the WS lesion during orthodontic therapy and the correlation between WS and oral hygiene habits. Patients requiring orthodontic treatment with a fixed appliance were screened for the inclusion/exclusion criteria, and 74 subjects were finally enrolled. Each patient received three examinations: at T0, the day of the application of the fixed appliance; at T1, three months later; and at T2, six months after treatment start. After calculating descriptive statistics, differences between groups were evaluated with an independent sample t-test. The first type error was set as p ≤ 0.01. The observed prevalence of WS lesions was 59.5% on T1 and 60.8% on T2. The most affected teeth result to be upper molars, lower left first molar, upper right central incisor and upper left lateral incisor, upper right canine, upper left first premolar, and lower right first molar. A higher frequency of daily tooth brushing was accompanied by a lower prevalence of WS. No significant effect of sex was observed.

A to Z Steps of In-person Screening, Treatment, and Caring Procedure in Orthodontic Clinics During COVID-19 Pandemic: A Rapid Mini-review

Background: A novel coronavirus emerged from Wuhan, China, in December 2019. Dental healthcare providers are at the highest risk of exposure since the primary source of the virus is saliva, and dentists are the front-line personnel working with the oral cavity. Since orthodontic treatment is a long-term procedure for children and teenagers, and because of the critical gap in preparing a specific guideline on orthodontic treatment procedures, orthodontic practitioners have faced numerous complicated issues in this regard. This mini-review aimed to summarize the facts that the orthodontic settings should be aware of the dental difficulties during COVID-19 with a particular focus on orthodontic treatment. Methods: In this short review, electronic databases of Medline, Scopus, Web of Science, and Google Scholar were searched for relevant articles and guidelines from January 2019 to March 2021 using the following key terms: “COVID-19,” “SARS-CoV-2,” “Pandemic,” “Orthodontics,” and “Orthodontists.” Results: Gathering recommendations of experts and several guidelines led to the following crucial steps in orthodontic procedures: screening through a telehealth questionnaire; admitting just patients into the dental center; ventilating the waiting room; measuring the temperature of patients’ bodies; disinfecting the dental unit and instruments after each visit; using personal protective equipment; washing hands; minimizing the use of high-speed handpieces to reduce the aerosol generation; and sterilization of archwires, orthodontic markers, photographic retractors, molar bands, burs, miniscrews, and unit waterline with proper methods. Conclusions: All dentists should be up-to-date on cross-transmission of SARS-CoV-2 and follow the international infection control protocols as well as national/provincial/local guidelines and apply them to the regional settings after generalization and matching with the condition.

Ingestion of orthodontic appliances: A literature review.

Ingestion is the entry of a substance into the human organism, which occurs by taking it through the mouth into the gastrointestinal tract. One of the adverse events that may happen during the course of an orthodontic treatment is the ingestion of orthodontic appliances. The present review aims to investigate the literature regarding the ingestion of orthodontic appliances. An electronic search was carried out in order to identify case reports of ingestion of foreign objects related to orthodontic treatment in PubMed, Scopus, and Web of Science until July 2019.Nineteen articles were retrieved. In these articles, ingestion had occurred inadvertently, due to patients’ or orthodontists’ errors. Some of the most commonly ingested appliances were molar bands, segments of wire, and expansion keys. It is likely that patients with a specific medical background are more prone to ingestion of orthodontic appliances. Special precautions need be taken in order to avoid such incidents. These precautions are analyzed in three categories: general, those related to fixed appliances, and those related to removable appliances.

The effect of different mouth washes on metallic ions release from silver-soldered and laser-welded orthodontic attachments. A comparative in vitro study

To compare the effect of different mouth washes on metallic ions release from silver-soldered and laser-welded orthodontic attachments. In this comparative in vitro study, 32 samples of molar bands without attachments were used. Sixteen samples were silver soldered to stainless steel (SS) wire and 16 samples were laser welded using laser welding device to SS wire. Each group samples were divided into four test groups and submerged in solution containing sodium fluoride (NaF), NaF + alcohol (NaF + alcohol), Chlorhexidine (CHX), and artificial saliva (AS). Samples were shaken for 24 h with an agitation rate of 60 rpm. One sample from each group was selected to study the morphologic changes on their surfaces through scanning electron microscopy (SEM), and remaining samples were studied for metal ions released and dissolved in the solutions using spectrometry. The metal ions release values of two different attachment methods in three different mouth washes and AS group were compared using the unpaired t-test. A two-way analysis of variance was used to identify the significant differences between the two types of orthodontic attachments immersed in four different types of solutions. P < 0.05 was defined to be set significant for all tests. Level of metal ions released from the samples of silver soldering was higher than from laser welding. The lowest amounts of metal ions were released in CHX while highest in NaF + alcohol. The SEM images were in accordance with these findings. Laser welding should be preferred over silver soldering for the construction of orthodontic appliances. CHX containing mouthwashes such as Hexidine can be prescribed for the patients undergoing orthodontic treatment. More in vivo experiments will determine whether the levels of dissolved nickel ions can reach the toxic or sub-toxic concentrations or not.

Prevalence of Caries Secondary to the Orthodontic Treatment in Patients Visiting a Private Dental Hospital-A Retrospective Study

Introduction: Orthodontic treatment involving fixed appliance is a long term process. This treatment has a maximum risk of development of caries as proper oral hygiene maintenance would not be noticed. This increases the number of streptococcus mutans and lactobacillus which would form a biofilm. The armamentarium used in this treatment like molar band, brackets etc. are plaque stagnant areas, which over a period of time leads to caries, gingivitis etc. Thus, proper oral hygiene should be maintained by patients.&#x0D; Aim: The main objective of the study is to assess the prevalence of caries secondary to the orthodontic treatment in patients visiting a private dental hospital.&#x0D; Materials and Methods: A descriptive study which was performed under a university setting where all the patients reported to Private Dental college and hospital, Chennai. The data was collected by reviewing patients records and analysed the data of 140 patients who underwent orthodontic appliance treatment between May 2019- December 2020. The population size of the study was found to be n=80. Data was collected, tabulated, statistical analysis was done using SPSS- IBM.&#x0D; Results and Discussion: From the statistical analysis, it is observed that the total number of caries that could be seen after the orthodontic appliance treatment was more in males (58.23% ) when compared to females and the most commonly affected age is between 18-25 years with 49.37%. Moreover, the common tooth that affected were molars with 49.37%.&#x0D; Conclusion: Within the limitations of the current study, it is found that molars are the most commonly affected teeth and the age group which is affected the most is between 18-25 years. Thus, it is the imperative for dentists to provide preventive resin restorations, fluoride varnish and also proper instructions for maintenance of oral hygiene during the orthodontic treatment.

Causation of Oxidative Stress and Defense Response of a Yeast Cell Model after Treatment with Orthodontic Alloys Consisting of Metal Ions.

Misaligned teeth have a tremendous impact on oral and dental health, and the most efficient method of correcting the problem is orthodontic treatment with orthodontic appliances. The study was conducted to investigate the metal composition of selected orthodontic alloys, the release of metal ions, and the oxidative consequences that the metal ions may cause in the cell. Different sets of archwires, stainless steel brackets, and molar bands were incubated in artificial saliva for 90 days. The composition of each orthodontic material and quantification of the concentration of metal ions released were evaluated. Metal ion mixtures were prepared to determine the occurrence of oxidative stress, antioxidant enzyme defense system, and oxidative damage to proteins. The beta titanium alloy released the fewest metal ions and did not cause oxidative stress or protein damage. The metal ions from stainless steel and the cobalt-chromium alloy can cause oxidative stress and protein damage only at high concentrations. All metal ions from orthodontic alloys alter the activity of antioxidant enzymes in some way. The determined amounts of metal ions released from orthodontic appliances in a simulated oral environment are still below the maximum tolerated dose, and the concentrations of released metal ions are not capable of inducing oxidative stress, although some changes in antioxidant enzyme activity were observed at these concentrations.

Comparison of dentoskeletal and soft tissue changes between tooth-borne and tooth-bone-borne hybrid nonsurgical rapid maxillary expansions in adults: a retrospective observational study

BackgroundDespite the gradual increase in the use of rapid maxillary expansion (RME), specifically RME with the aid of skeletal anchorage in adults, there have been no reports comparing dentoskeletal and soft tissue changes between nonsurgical tooth-borne and tooth-bone-borne RMEs in adults. This study aimed to analyse differences in dentoskeletal and soft tissue changes between tooth-borne and tooth-bone-borne RMEs using a similar appliance design and the same expansion protocol in adult patients.MethodsTwenty-one patients with tooth-borne expansion (a conventional expansion screw with two premolars and two molar bands for dental anchorage [T-RME]) and the same number of patients with tooth-bone-borne hybrid expansion (a conventional expansion screw with two premolar and two molar bands for dental anchorage and four mini-implants in the palate for skeletal anchorage [H-RME]) were included. Dentoskeletal and soft tissue variables at pretreatment (T1) and after expansion (T2) were measured using posteroanterior and lateral cephalograms and frontal photographs. The sex distribution of the two groups was analysed using the chi-square test, and the change after RME in each group was evaluated using the Wilcoxon signed-rank test. Differences in pretreatment age, expansion duration, post-expansion duration, and dentoskeletal and soft tissue changes after RME between the two groups were determined using the Mann–Whitney U test.ResultsThere were no significant differences in the expansion protocol, pretreatment conditions, and sex distribution between the two groups. Despite similar degrees of dental expansion at the crown level between the two groups, H-RME induced increased skeletal and parallel expansion of the maxilla compared to T-RME. After expansion, H-RME demonstrated increased forward displacement of the maxilla without significant changes in the vertical dimension, while T-RME exhibited increased backward displacement of the mandible, increased vertical dimension, and decreased overbite. Both groups showed significant retroclination and extrusion of the maxillary incisors without significant intergroup differences. There were no significant soft tissue changes between the two groups.ConclusionThis study suggests that using skeletal anchorage in RME may induce increased skeletal and parallel expansion of the maxilla without significant effects on the vertical dimension.