Insertion Of Appliance Research Articles

Elastic Chain Premaxillary Retraction Appliance Does Not Increase Inter-Canthal Dimension in Patients with Bilateral Cleft Lip and Palate.

To determine if the elastic chain premaxillary retraction (ECPR) appliance increases inter-medial and inter-lateral canthal dimension in patients with bilateral complete cleft lip and palate (BCLP). Retrospective cohort study. Specialized tertiary care facility. 126 patients with BCLP; 75 had ECPR, 51 had no pre-surgical manipulation. Three-dimensional facial photographs were obtained prior to insertion of appliance (T0), post-appliance therapy prior to appliance removal/labial repair (T1), and several months after labial repair (T2) for a longitudinal ECPR group, and were obtained after age 4 years (T3) for a non-longitudinal ECPR group and for the non-ECPR group. Inter-medial and inter-lateral canthal dimension (en-en, ex-ex) was determined for all groups/time-points. Measurements were compared between groups and to norms. The mean en-en and ex-ex was 32.6 ± 3.2 mm and 84.4 ± 6.3 mm for the ECPR group and 33.5 ± 3.1 mm and 86.7 ± 7.2 mm for the non-ECPR group at T3. Inter-medial and inter-lateral canthal dimensions were significantly greater than normal (P < .05) in both groups; there was no significant difference between groups (P > .05). The mean en-en and ex-ex for the Longitudinal ECPR group was 27.5 ± 2.4 mm and 66.7 ± 3.7 mm at T0, 29.6 ± 2.4 mm and 70.4 ± 2.9 mm at T1, and 29.2 ± 2.3 mm and 72.3 ± 3.8 mm at T2. en-en and ex-ex increased significantly from T0-T1 (P < .05), decreased at T2 (P > .05) and was significantly larger than normal at all time-points (P < .05). Inter-medial and inter-lateral canthal dimension increased after ECPR but returned to baseline growth trajectory. These dimensions were above normal at all time-points. There was no difference between those that did and did not have dentofacial orthopedic manipulation.

Clinical parameters and inflammatory biomarkers among patients with multibracket appliances: a prospective clinical trial

BackgroundAim of the presented study was to investigate changes in clinical parameters and active matrix metalloproteinase-8 (aMMP-8) levels in gingival crevicular fluid of patients before and during treatment with multibrackets appliances.MethodsFifty-five adolescents scheduled for the treatment were included. Clinical parameters and subgingival samples were obtained at six time points: 1 week before appliance insertion (T0), 3 (T1), 6 (T2) weeks, 3 (T3), 6 (T4) months, and 1 year (T5) after that. Gingival index and plaque index were assessed to evaluated changes on the clinical status. Subgingival samples were collected to analyze changes in aMMP-8.ResultsScores for gingival and plaque index increased after bracket insertion. The gingival index increased from T2 (p < 0.05) until T5 (p < 0.0001). Plaque index also increased, reaching its maximum peak at T3 (p < 0.05). Moreover, an increase of aMMP-8 levels (p < 0.05) was noted. There was no significant between upper and lower jaws.ConclusionsTreatment with multibracket appliances in adolescents favors dental plaque accumulation and may transitionally increase gingival and plaque index and aMMP-8 levels leading to gingival inflammation, even 1 year after therapy began.Trial registrationThis study was approved by the Ethics Committee of the dental medical association Rheiland-Pfalz, Germany (process no. 837.340.12 (8441-F)), and followed the guidelines of Good Clinical Practices.

Testing the effect of functional orthopedic appliance Simões network 6 (SN6) through surface electromyography on rest mandibular position – a pilot study

The maintenance of the lower level of muscle contraction is fundamental for the development and health of the stomatognathic system (SS). Malocclusion leads to unbalance muscle activity, since Class II treatment is not the most prevalent malocclusion in the general population but is the more frequent to search for treatment in dental offices and the most prevalent skeletal component in the class II malocclusion is the retrognathia this pilot investigation aims to study the effect of rest electric activity of bilateral anterior temporal, masseter and suprahyoid muscle in individuals undergoing class II treatment with functional orthopedic appliance Simões Network 6 (SN6). Surface electromyography recordings of bilateral anterior temporal, masseter and suprahyoid muscle in rest position was obtained before and 8 minutes after the functional appliance insertion in mouth. Results showed improvement of electric muscle activity in rest position and balance of bilateral muscle electric activity in all muscle. Based on the preliminary results it can be conclude that jaw functional orthopedics (JFO) provides alteration of the resting records in the mandibular rest position of the studied muscles, indicating relaxation of the muscles studied and a more symmetrical electric activity. Further studies are necessary for a better understanding of the effects of functional orthopedic appliances in the electric activity of stomatognathic muscle in the mandibular rest position.

Assessing the immediate impact of Twin-block appliance insertion on adolescents' sleep using a wearable device.

This prospective clinical study aimed to evaluate the immediate impact of Twin-block appliance insertion on the sleep of adolescents using a wearable device. A total of 24 girls, aged 11-13 years, with Class II division 1 molar relationship, skeletal class 2 malocclusion (ANB ≥5) and overjet measuring ≥5 mm were selected. Exclusion criteria included a history of previous orthodontic treatment, systemic disease, irregular sleep pattern, obstructive sleep apnea, medical history of breathing disorders, or concurrent use of medications. Participants wore a wearable device to measure sleep parameters, including deep sleep, light sleep, minutes awake during sleep, wake-up times, bedtimes and total sleep times. The participants wore the device for 10 days prior to Twin-block insertion and sleep data were collected for another 10 days after insertion. Following the insertion of the Twin-block appliance, there was a highly statistically significant shift in bedtime and wake-up time to later hours (P < .001). All participants experienced a highly significant delay in bedtime compared to the recommended 10 pm time (P < .001). Additionally, there was a significant increase in the duration of light sleep (P < .05). However, the effect on deep sleep, minutes awake during sleep and sleep duration was not statistically significant. None of the sleep parameters tested showed statistically significant changes between the first 5 days after Twin-block insertion with the subsequent 5 days. The immediate insertion of the Twin-block appliance disrupts sleep onset, wake-up time and light sleep during the specified period of 10 days.

Effects of Fixed Orthodontic Appliance with Antihypertensive Drugs on the Body Weight of Experimental Rats

Background: This study aims to investigate the effect of fixed orthodontic appliances and/or antihypertensive drugs on the weight of experimental rats. Materials and Methods: Thir-ty-six male Wistar albino rats were subjected to a split-mouth design study, in which an orthodontic appliance was inserted in one side to move the first molar mesially for 2 weeks while the other side acted as a control to tooth movement. The rats were allocated into three groups: group A (n = 12), without any pharmacological treatment; group B (n = 12), subcu-taneous injection of bisoprolol fumarate (5 mg/kg) daily; and group C (n = 12), subcutaneous injection of valsartan (10 mg/kg) daily. A fixed orthodontic appliance with a closing coil spring delivering 50 gm of force was used to move the first molar mesially while the incisors served as an anchor unit. The weight of the rats was measured on days 1 (the day of appli-ance insertion), 7, and 14. Results: No significant (P &gt; 0.05) difference in the body weight of rats was found among the three groups at each time point; however, significant (P &lt; 0.05) weight loss was noted after the first and second week of the experiment in all study groups. Conclusion: The body weight loss of rats following the insertion of a fixed orthodontic ap-pliance could be related to the effects of the appliance rather than the administered antihy-pertensive drugs.

Effect of prematurely primary front teeth loss with anterior esthetic fixed appliance on fricative production in Arabic-speaking children

BackgroundPrimary teeth affect the life quality regarding chewing, speech production, esthetics, and psychological well-being. Young children usually lose their primary maxillary incisors due to trauma or care and that leads to fault production of alveolar and dental fricatives. Fixed esthetic appliance replacing the lost primary front teeth were inserted and fricative sounds /s/,/s/,/∫ /,/z/and /z/ were tested before and after insertion of the fixed appliance through different time intervals.ResultsImprovement of fricative sound production occurred after fixed appliance insertion the /s/ sound, followed by /s/ sound showed immediate improvement while the /∫ / sound was the least to be improved even after 1 month duration. Both sounds /z/ and /z/ sound showed distortion immediately.ConclusionPremature loss of primary incisors in young children has a significant impact on speech production.

Comparative evaluation of efficacy of two Class II correctors in treatment of skeletal Class II malocclusion: A multicenter randomized controlled trial

BackgroundThis article aims to compare clinical efficacy of newly introduced PowerScope 2 appliance with Forsus FRD in the treatment of Skeletal Class II malocclusion. MethodsThis randomized controlled trial studied 40 patients at two centers (20 patients at each center, divided into two groups of 10 patients each as Group 1: Forsus FRD and Group 2: PowerScope 2 appliance. The skeletal, dental, soft tissue, and airway changes were noted at T0 (pretreatment), T1 (preappliance therapy), and T2 (postappliance therapy). Acoustic Pharyngometry (Eccovision® Acoustic Pharyngometer) was done to ascertain changes in mean airway volume and area with both modalities noninvasively. Treatment duration and chairside time in appliance installation and removal were noted. Patient comfort was compared using a customized questionnaire survey. ResultsA significant change was observed in skeletal, dental, soft tissue, and airway parameters after treatment with both modalities (p-value <0.05 for all) with no significant intergroup difference (p-value >0.05). Chairside time spent in appliance insertion was significantly lower with PowerScope 2 appliance (10.33 min) as compared to the Forsus FRD appliance (18.28 min) (p-value <0.05). Visual Analogue Scale scores for parameters such as problems in mastication, problems in speech, and problems in oral hygiene maintenance were significantly lower with PowerScope 2 appliance as compared to the Forsus FRD appliance (p-value <0.05). ConclusionsAlthough both modalities are effective in the management of Class II malocclusion, the PowerScope 2 appliance scores better in terms of lesser chairside time in appliance installation and better patient comfort.

Do patient-reported outcomes of miniscrew-supported maxillary expansion in adolescent patients differ between slow and rapid activation protocol?

Single-center randomized clinical trial with two parallel arms. The protocol of the study was approved by the institutional review board (IRB) of the Faculty of Dentistry, Alexandria University (IRB: 00010556-IORG: 0008839) and registered in Clinicaltrials.gov (identifier number: NCT04225637). Before the trial commencement, parents/legal guardians signed informed consents. The study complied with the CONSORT (Consolidated Standards of Reporting Trials). 30 adolescent patients aged between 12 to 16 years with transversely deficient maxilla requiring skeletal maxillary expansion were recruited to be included in the study. Patients received miniscrew-supported Penn expanders and they were randomly allocated (ratio 1:1) into two groups based on the activation protocol; slow maxillary expansion (SME = turn every other day) or rapid maxillary expansion (RME = 2 turn/day). The patient-reported outcome measures were the following: pain, headache, pressure, dizziness, speech, chewing and swallowing difficulties, swallowing difficulty. The participants rated the reported outcomes using numeric rating scale (NRS) at 4 time points: t1 = before appliance insertion, t2 = after first activation, t3 = after 1 week of activation, and t4 = after last activation. Patients were advised not to use analgesics, and to contact their provider in case of severe pain. Descriptive measures and patient-reported outcomes at various time points were calculated. Comparisons between the two groups at each time point were assessed using Mann-Whitney U-test. Comparisons of time points in each group were assessed using theFriedman test and followed by post-hoc tests with Bonferroni correction. 6 patients were not included in the analysis for different reasons, allowing a total of 24 patients (12 patients in each group) to be analyzed. Mean ages of the patients in the SME and RME group were 14.30 ± 1.37 and 15.07 ± 1.59, respectively. Median scores were in the bottom quartiles of NRS for all reported outcomes. RME group reported significantly higher scores for all measured variables, with exception of headache and dizziness, which showed no statistical difference between the two group. Mild to moderate discomfort and functional limitation is anticipated with the activation of miniscrew-anchored Penn expanders. Slow activation protocol provided a better overall patient experience when compared to a rapid activation protocol.

The effect of anterior esthetic fixed appliance of prematurely lost primary incisors on sound production and speech intelligibility

AimsThis work aimed to compare the sound production and speech pattern in children with prematurely extracted anterior teeth after prosthetic rehabilitation with fixed functional space maintainer.Settings and designThe study was conducted as a clinical trial. The clinical part was carried out at Pediatric Dentistry Department, Faculty of Dentistry, Tanta University and speech evaluation and assessment was done in Phoniatric Unit, ENT Department, Faculty of Medicine, Tanta University.Patients and methodsTwenty-five children of both sexes aged from 3 to 6 years old were included in the study. The selected children were in need for extraction of maxillary primary incisors or had already got extracted and treated by anterior esthetic fixed appliance. Children attended for speech and language evaluation at before appliance delivery, immediately after appliance insertion, 7 days after appliance insertion, 14 days after appliance insertion and 1 month after appliance insertion. And they were evaluated by articulation test, speech intelligibility test, and spectrographic parameters.Statistical analysis usedAll test statistics were performed using the SPSS software statistical package and the significance was set at P value less than or equal to 0.05.ResultsThere were statistically significant differences between follow up periods for/S/,/S/, and/Z/sounds but no statistically significant difference for/z/and/∫/sounds. The mean shimmer in dB, the mean absolute Jitter and the mean noise to harmonic ratio for the sounds were diminished after adaptation of the appliance. Also, high significant differences were found between 1 month after appliance insertion and all different follow up periods. No difference with immediately after appliance insertion.ConclusionsReplacement of prematurely lost primary incisors with fixed prosthetic appliances will assist in the proper development and intelligibility of speech. Also, in accurate consonants sounds production as/s/,/s/,/z/,/∫/(alveolar fricatives), and/z/(dental fricatives).

Patient-reported outcomes of slow vs rapid miniscrew-supported maxillary expansion in adolescents: secondary outcomes of a randomized clinical trial.

To compare patient-reported experience between a Penn expander activated every other day vs twice daily. A total of 30 patients aged 12-16 years with transverse maxillary deficiency were recruited from the outpatient clinic, Faculty of Dentistry, Alexandria University (February 2019-December 2020). They were randomly allocated to two groups using block randomization (block size of six) and an allocation ratio of 1:1, which was concealed using opaque, sealed, sequentially numbered envelopes. Both groups received Penn expanders anchored by four palatal miniscrews. The slow maxillary expansion (SME) group activated the appliance once every other day. The rapid maxillary expansion (RME) group activated the appliance twice daily. Outcome measures were pain, pressure, headache, dizziness, speech difficulty, chewing difficulty, and swallowing difficulty scores rated by the participants on an 11-point numeric rating scale (NRS) at the following four time points: before appliance insertion (t1), after first activation (t2), after 1 week of activation (t3), and after last activation (t4). Data of 24 patients in the SME group (n = 12, mean age = 14.30 ± 1.37 years) and RME group (n = 12, mean age = 15.07 ± 1.59 years) were analyzed. Median scores for all outcomes were in the bottom quartiles of the NRS. No difference was found between the two groups at t1 or t2. Significantly higher scores for all variables, except dizziness and headache, were reported in the RME group at t4. Activation of miniscrew-supported expanders resulted in mild to moderate discomfort and functional limitation. Slow activation resulted in a better overall patient experience compared with rapid activation.

Fixed Orthodontic Treatment Increases Cariogenicity and Virulence Gene Expression in Dental Biofilm.

Background: Dental caries commonly occurs during orthodontic treatment because fixed appliances can impede effective oral hygiene practices. This study investigated the effects of fixed orthodontic treatment on dental biofilm maturity and virulence gene (gtfB, ldh, brpA, spaP, luxS, and gbpB) expression. Methods: Dental biofilms and virulence gene expression were determined in 24 orthodontic patients before and after treatment of ≥6 months. A three-tone disclosing gel was used to stain dental biofilm and assess its maturity by its color change—pink (new dental biofilm), purple (mature dental biofilm), and light blue (cariogenic dental biofilm). Gene expression levels were determined using real-time PCR. Results: After fixed orthodontic appliance insertion, the percentage of new dental biofilm decreased, whereas that of cariogenic dental biofilm significantly increased (p < 0.05). There was no significant difference in the percentage of mature dental biofilm (p > 0.05). Fixed orthodontic appliances increased gtfB, ldh, brpA, and gbpB gene expression above 1.5-fold in dental biofilm. In contrast, there was no change in spaP or luxS gene expression after treatment. Conclusions: Fixed orthodontic appliance insertion induced ecological changes and cariogenic virulence gene expression in dental biofilm.

Effects of anterior bite planes fabricated from acrylic resin and thermoplastic material on masticatory muscle responses and maximum bite force in children with a deep bite: A 6-month randomised controlled trial.

Anterior bite planes are bite-raising appliances used for deep bite correction. However, muscle responses to anterior bite planes of different harnesses may vary. To prospectively evaluate masticatory muscle activity, muscle balance and maximum bite force (MBF) responses to anterior bite planes fabricated from acrylic resin (ABP) or bi-laminate thermoplastic (TBP) over 6months in children with a deep bite. Sixty-six children were randomly assigned to the ABP, TBP or untreated control groups. Masticatory muscle activity, activity index (AC) and percentage overlapping coefficient (POC) were assessed by surface electromyography; MBF, using a custom-made bite force sensor. Data were collected before, immediately after appliance insertion and after 2 weeks and 1, 3 and 6months of treatment. Within- and between-group differences were analysed using the one-way ANOVA/Kruskal-Wallis and Mann-Whitney U tests (α=.05); Friedman's tests were used to assess within-group differences over time (α=.08). At rest, no dependent variables changed throughout the study. At maximum clenching, masticatory muscle activity immediately dropped significantly but returned to baseline values and was equal to the control group at 1-3months. The ABP group had significantly lower masseter activity and AC than the TBP group after insertion. Neither POC nor MBF were significantly different within or between groups. Masticatory muscle activity reduced after anterior bite plane insertion but returned to baseline after 1-3months. Masseter activity decreased significantly more in the ABP group than TBP group. Neither appliance significantly affected POC or MBF. Thai Clinical Trial Registry (TCTR20210330002).

Effect of Khat Chewing on Gingival Health of Patients with Fixed Orthodontic Appliances: A Controlled-Clinical Trial

This clinical trial aimed to evaluate the effect of Khat chewing on the gingival health of patients with fixed orthodontic appliances (FOAs) by measuring some periodontal parameters before and during 6-time intervals of orthodontic therapy. It also aimed to evaluate this effect regarding gender. The study included 39 Yemeni orthodontic patients with a mean age of 25.7±4.5; divided into two groups, a control (non-chewers) with a mean age of 25.81±4.3 and an experimental (chewers) group with a mean age of 25.61±4.8. An examination sheet was used for data collection, including the patient’s personal information, oral health status, and three periodontal parameters: plaque index (PI), gingival index (GI), and pocket depth (PD). These data measurements were analyzed using SPSS v.24. The study showed an increase in mean plaque, gingival, and pocket depth indices at all-time visits after the appliance insertion compared to all patients’ pre-treatment status. It indicates that Khat chewing harms all periodontal parameters during the orthodontic treatment period. Mean PI, GI and PD were lower in female patients than male patients after the appliance insertion. The khat chewing process mechanically removes the dental plaque, decreasing PI and GI, while PD was worse in Khat chewers than non-chewers. Finally, it is recommended that chewing Khat should be avoided during orthodontic therapy.

Effect of Removeable Orthodontic Appliance on Oral PH, Candida Albicans, Candida Dubliniensis, and Streptococcus Mutans Count

Removable orthodontic appliances (ROAs) are popular devices to move or retain teeth during or after orthodontic treatments providing a good environment for adhesion and colonization of pathogenic and non-pathogenic organisms. The aim of the present study was to explore the presence and variability of oral PH, levels of Candida Albicans, Candida Dubliniensis, and Streptococcus (S.Mutans) in children before and during the treatment with ROAs. In this clinical trial study, a total of 160 patients aged 8–12 years old in both genders were enrolled from a larger sample of patients who were clinically confirmed to obtain ROAs. They were randomly divided into three groups; 1- PH Group (n=51), 2- Candida Group (n=51), and 3- S.Mutans Group (n=58). Patients were assessed prior (T0) and again one month later (T1) following appliance insertion. The oral cavity was sampled for PH level, Candida species and bacterial species by culture. Paired t-Test and ANOVA were applied for statistical analysis. The level of significance was assumed to be P ≤ 0.05 for all tests. In Group 1, PH values decreased from 6.89±0.5 in T0 to 6.55±0.7 in T1 (0.5% decrease) with statistically significant difference (P=0.002). In group 2, total Candida count at dorsal tongue was more than hard palate. Also, the difference (5.1±6 increase) was significant between the mean Candida count in T0 and T1 (P=0.001). Although the C.Albicans count was more than C.Dubliniensis, the difference was not significant. In group 3, S.mutans showed a significant difference between the two subgroups of case and control (P&lt;0.005). ROAs change the balance to decrease the values as well as increase the proliferation/colonization of Candida specimen and S.mutans. This implicated the importance of paying special attention to oral hygiene in orthodontic patients to prevent oral disease and the aggravation of systemic disease in immunocompromised conditions.

A Simple Technique Using a Modified Nance Appliance as Anchorage for Maxillary Molar Distalization—Two Case Reports

Maxillary molar distalization to correct a dental Class II molar relationship and to create space to relieve crowding has been a long-lasting subject of debate in orthodontics. Generally, to distalize maxillary molars, an intra-arch distalization appliance is favored over an inter-arch appliance since it does not utilize mandibular dentition as an anchorage, so some unwanted side effects on mandibular incisors can be avoided. A variety of intra-arch appliances have been developed to distalize maxillary molars, such as the pendulum, Jones jig, first class appliance, distal jet, and modified C-palatal plate. Although they could achieve efficient molar distalization, the learning curve of proper appliance insertion and activation is relatively long. In addition, the appliances are not comfortable for the patients due to the bulky activation units, especially when the activation units are designed in the palatal area. The current manuscript describes a novel and effective maxillary intra-arch molar distalization appliance—a modified Nance appliance technique, which consists of: (1) palatally, a big acrylic button against the palatal rugae and connected to the premolars with wide mesh pads; (2) buccally, regular brackets on maxillary premolars and first molars with sectional round stainless steel archwires and open coil springs between the second premolar and first molar. Either bilateral or unilateral maxillary molar distalization can be achieved with this appliance, and the Class II elastics are not needed. It is simple to be fabricated, delivered, and activated, and it is comfortable for patients.

Adolescents’ perception of malocclusion, their motivations, and expectations concerning the orthodontic treatment. Is it all about attractiveness? A qualitative study

In addition to essential clinical parameters, orthodontic treatment outcomes should also consider patients' opinions and perceptions, which could be comprehensively clarified with a qualitative scientific approach. Considering that the information on younger patients' views is scarce, the objective of this study was to investigate how adolescent orthodontic patients perceive malocclusion, and their motivations and expectations concerning orthodontic corrective treatment. In this descriptive qualitative study, 12 adolescents aged 12 to 14 years and of both genders, covering a heterogeneous collection of malocclusions, were recruited from the waiting list of an Orthodontics Graduate Course. They were individually interviewed before the appliance insertion by an experienced researcher using an interview guide and photographic records to stimulate patients' self-perception of their oral condition. The interviews proceeded simultaneously with transcription analyses until saturation. After the transcription evaluation, the framework analysis technique was performed. Data derived from the transcription analyses were grouped into 3 major themes: perceptions concerning the concepts of normality and abnormality regarding oral health; self-perceptions regarding malocclusion and other discrepancies; and motivations for seeking orthodontic treatment and expectations related to the results. Attractiveness was exceptionally relevant among adolescent patients. Most interviewees seemed to focus their attention on esthetically upsetting dentofacial traits, which they expected to be corrected by orthodontic treatment. In addition to self-oriented appearance-driven motivations, parents, other health professionals, friends, and peers also influenced adolescents' perception of their need for treatment. The achievement of a normal dentofacial status seems to be closely attached to social and individual aspirations.

Oral Impacts of Aligners versus Fixed Self-Ligating Lingual Orthodontic Appliances

The aim of this prospective study was to compare a fixed lingual orthodontic appliance with a commonly used aligner system, focusing on oral impacts and speech disturbances, during the first 3 months of orthodontic treatment. Two groups of adults were evaluated: 21 treated with Invisalign® and 26 with In-Ovation L® lingual brackets. Health-related quality of life questionnaires were used to assess the oral impacts, and speech samples were collected for speech evaluation by professionals. The levels of pain and painkiller intake were similar, increasing on the first day, and decreasing at 3 months. Subtle injuries on the lip and cheeks were initially reported in the aligner group. Lingual patients experienced more discomfort in swallowing and opening the mouth, tongue injuries and food residues, even at 3 months. The consonants “s” and “z” were mainly affected in both groups immediately after appliance insertion, but more often in the aligner group. These speech disturbances recovered in the following 3 months. In conclusion, both groups reported disturbances in quality-of-life measures; however, patients wearing lingual appliances experienced more disturbances, which persisted after three months. Speech disturbances were slightly more pronounced in the aligner group and recovered after three months.

The Effects of Static Magnetic Field on Orthodontic Tooth Movement in Mice.

The application of static magnetic field (SMF) has been considered an effective and noninvasive method to accelerate orthodontic tooth movement. The objective of this study was to explore the effects of SMF on orthodontic tooth movement in mice. A total of 105 Balb/c mice (body mass: 25-30 g) were divided into experimental group (SMF + force, 48), control group (force only, 48), and blank group (neither SMF nor force, 9). After the placement of orthodontic appliances, the experimental group was exposed to the SMF environment generated by Neodymium-iron-boron (NdFeB) magnets with anintensity of 20-204 mT. At 1, 3, 7, 14, 21, and 28 days after appliance insertion, eight animals in both experimental and control groups were sacrificed and the left maxillae were dissected to measure the distance of tooth movement, respectively. Meanwhile, the width of periodontal ligament (PDL), length of hyalinized zone, and the number of osteoclasts were evaluated by hematoxylin-eosin and tartrate-resistant acid phosphatase staining. We finally found that the experimental group demonstrated an enhanced rate and greater cumulative amount of tooth movement than the control group (0.2887 ± 0.0041 mm vs. 0.2114 ± 0.0089 mm, P < 0.05). On Days 7, 14, and 28, the experimental group also displayed a significantly greater width of PDL. Earlier formation and removal of the hyalinized zone, and significantly more osteoclasts were observed in the experimental group as well. The results suggested that SMF may be a promising nonsurgical intervention to accelerate orthodontic tooth movement. © 2021 Bioelectromagnetics Society.

Treatment effects of "PowerScope" fixed functional appliance - a clinical study.

To study the skeletal, dental effects and evaluate the soft tissue changes with PowerScope-fixed functional appliance in class II malocclusion. This clinical study was carried out where a total of 10 growing (CVMS 3 and 4) Class II Division 1 malocclusion patients, indicated for treatment with fixed functional appliance were allocated based on specific inclusion criteria. PowerScope (American Orthodontics) was used as the fixed functional appliance. Skeletal, dental and soft tissue effects of the appliance with various angular and linear parameters on a digital lateral cephalogram were evaluated for all 10 participants. Records were collected before the insertion of PowerScope appliance (T0) and after 5 months, during the appliance removal (T1). All participants were treated with 0.018"×0.025" MBT (3M Unitek) prescription. Statistical analysis was performed using a paired t-test to compare individual mean changes for each treatment category. Statistically significant changes were seen in skeletal parameters such as forward positioning of the mandible with an increase in SNB angle and N perpendicular-Pogonion distance, the class II jaw base relationship improved with reduction in ANB angle and Wits appraisal. Significant changes were observed in dental parameters such as forward positioning of mandibular incisors, maxillary molar distalization and intrusion with reduction in overbite and overjet respectively. In the soft tissue, a significant improvement in facial profile was seen due to an increase in labiomental angle. The results of this study have shown that statistically significant changes in skeletal, dental and soft tissue parameters.

Investigation and comparison of patient experiences with removable functional appliances.

To compare patients' experiences with the Invisalign Teen with Mandibular Advancement® (ITMA) and Twin Block (TB) appliances, both initially and after several months of wear. Sixty-eight patients completed an anonymous survey after at least 2 months of wearing ITMA or TB. Forty-five patients treated with ITMA (18 boys, 27 girls, mean age 13.6 years, SD ± 1.54) and 23 patients treated with TB (13 boys, 10 girls, mean age 10.60 years, SD ± 1.92) were included. More patients using the TB found their appliance to be visually intimidating as compared with patients using the ITMA (21.7% vs 8.9%). TB was more noticeable than the ITMA (69.6% vs 25%). Appliance insertion was more difficult for TB patients (21.8% vs 4.44% for ITMA). After several months, there were more reports of tooth soreness and lip/cheek soreness in the ITMA group. TB patients were more embarrassed even after several months (14.3% vs 0% for ITMA). More TB patients required extra appointments for breakage (50% vs 22.2% for ITMA). Speech, drooling, and jaw and lip/cheek soreness worsened initially for both groups but improved over time. There were no differences between the groups regarding visible facial changes, satisfaction with treatment experience, or time to acclimatize to the appliance. TB and ITMA patients shared similar experiences for most of the parameters measured, but there were significant differences between the groups regarding appliance wear and management, discomfort, and function.