A comparison of treatment results of adult deep-bite cases treated with lingual and labial fixed appliances

ObjectivesTo compare the cephalometric treatment results of adult deep-bite cases after labial and lingual fixed orthodontic treatment.Materials and MethodsA total of 102 patients underwent lingual orthodontic treatment and complete records were evaluated. The following inclusion criteria were used: patients who had Angle Class I or mild Class II malocclusion; comprehensive orthodontic treatment that did not include intrusion mechanics or any extractions; patients with an initial overbite of more than 3.7 mm. Thirteen patients met the inclusion criteria. These cases were matched with the same number of patients according to age with a labial orthodontic treatment group. Pre- and post-treatment cephalometric radiographs were evaluated. Independent t test or Fisher exact tests were performed to assess the differences between the groups.ResultsProclination of the upper incisors was higher in the labial group. Incisor mandibular plane angle (IMPA) showed an increase of 1.2° in the lingual group and 9.7° in the labial group. Lower incisor edge was approximately in a stable sagittal position in the lingual group but significant lower incisor proclination was seen in the labial group. The lower incisors were intruded (-1 mm) in the lingual group but lower incisors were minimally extruded (0.3 mm) in the labial group. No significant difference was found in the movements of upper and lower molars for both groups.ConclusionsThe nature of lower incisor movement involved less protrusion in lingual orthodontics than the labial treatment. Lingual orthodontic treatment is a better option in adult cases where intrusion of lower incisors without labial tipping is desired.     

Bone tissue amount related to upper incisors inclination

Objective: To evaluate the amount of buccal and lingual supporting bone tissue of 60 upper central incisors and the relationship with their inclination.Materials and Methods:Thirty healthy adult patients with no previous orthodontic treatment were evaluated using cone-beam computed tomography. Cross-sectional views were analyzed to check the amount of the bone tissue on the cervical (cervical buccal thickness/CBT; lingual/CLT), middle (middle buccal thickness/MBT; lingual/MLT), and apical regions (apical buccal thickness/ABT; lingual/ALT). The Pearson correlation, linear regression, and analysis of variance tests were used (P < .05).Results:The values of ABT of both teeth (11, right upper central incisor; 21, left upper central incisor) were significantly increased with the increase in the angle between the axis of the upper central incisor and the palatal plane (1/PP) (tooth 11 P  =  .034; tooth 21 P  =  .009), yet without a strong linear correlation. At the buccal and lingual surfaces, the mean apical supporting bone tissue was significantly greater than the other areas, and the middle region significantly greater than the cervical (P < .001).Conclusions:For both surfaces (buccal and lingual), the amount of bone tissue in the apical region was significantly higher than the middle and cervical regions, and the middle region was significantly higher than the cervical region. In relation to the upper central incisor''s inclination, the higher the 1/PP the higher was ABT. However, the coefficient values for both teeth were low.     

Short-Term Influence of Lingual Orthodontic Therapy on Microbial Parameters and Periodontal Status: A Preliminary Study

Objective:To perform a preliminary study of the short-term effect of fixed, customized lingual orthodontic appliances on periodontal and microbial parameters.Materials and Methods:The sample comprised 20 subjects (6 males and 14 females) with a mean age of 22.3 years ± 8.6 years. Before (T₀) and 4 weeks after placement (T₁) of custom-made lingual appliances on the lower teeth only, plaque index (PI), probing pocket depth (PPD), and bleeding on probing (BOP) were measured. A 16S rRNA-based polymerase chain reaction (PCR) method was used to detect Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) in the crevicular fluid. To compare periodontal parameters on bonded lingual (testing) and unbonded palatal (control) and labial (control) sites between T₀ and T₁, the Wilcoxon test was applied.Results:On the lingual aspects of bonded teeth, a significant increase of BOP (T₀: 23.4 ± 22.5%; T₁: 46.2 ± 23.5%; P  = .001) and PI (T₀: 0.3 ± 0.3; T₁: 1.0 ± 0.7; P  =  .001) was observed, but no significant changes for PPD (T₀: 2.1 ± 0.4 mm; T₁: 2.2 ± 0.3 mm; P  =  .286) were found. On control sites, no significant changes were recorded for any periodontal parameter. Aa was found in 25% of the patients at baseline (5 subjects) and in 35% of the patients at T₁ (2 additional positive subjects), whereas Pg was found in 5% of the cohort at T₀ and at T₁ (same patient).Conclusions:Even in the short term, insertion of fixed lingual appliances induced a worsening of periodontal parameters restricted to bonded lingual sites.     

Speech performance and oral impairments with lingual and labial orthodontic appliances in the first stage of fixed treatment: A randomized controlled trial

Objectives:To compare (1) speech performance based on an auditive analysis and sonagraphy and (2) levels of oral impairment between fixed lingual and labial orthodontic appliances.Materials and Methods:Thirty-four patients with Class I division 1 malocclusion and moderate crowding of upper teeth were distributed randomly into two groups. Seventeen patients in group A (mean age: 20.6 years; standard deviation [SD]: 2.9 years) were treated with fixed lingual appliances (Stealth®, AO, Sheboygan, Wisc), whereas 17 patients in group B (mean age: 21.8 years; SD: 3.3 years) were treated with conventional fixed labial appliances. Speech performance was tested using spectrographic analysis of fricative /s/ sound before, immediately after (T1), 1 month after, and 3 months after bracket placement. The levels of oral impairment were assessed using standardized questionnaires.Results:A significant deterioration in articulation was recorded at all assessment times in group A but only at T1 in group B. Significant intergroup differences were recorded at all assessment times (P < .001). Speech difficulties were significantly higher in the lingual brackets group after 1 month of bracket placement (P < .001). Soft tissue irritation and chewing difficulty were significantly higher in the lingual appliance group after 24 hours of bracket placement (P < .001).Conclusions:The lingual appliance is more problematic than the labial one in terms of speech articulation. Although patients with both appliances suffered from different degrees of oral impairment, patients with lingual appliances had more untoward effects, particularly during the first month of treatment.     

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

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

Parents' preferences regarding appearance and attire of orthodontists

Objective:To evaluate parents'' preferences regarding the appearance and attire of orthodontists.Materials and Methods:Parents attending their child''s first orthodontic appointment were asked to choose from among sets of photographs of potential orthodontic providers. Selected factors were varied within the sets, including sex and age of the provider as well as attire (casual, formal, white coat, or scrubs), hairstyle (loose or tied back for women, facial hair or clean shaven for men), and presence of a nametag.Results:A total of 77 parents participated. There were significant differences in choice of provider in terms of the provider''s sex (P < .0001), age (P  =  .0013), dress (P < .0001), hair (P < .0001), and nametag (P  =  .0065). There were no significant differences in preference attributable to parent characteristics (P > .05).Conclusion:Parents of orthodontic patients demonstrated clear preferences for choosing a provider related to factors that are not within the control of the practitioner (sex and age) as well as factors that can be changed by the practitioner (attire, hairstyle, and wearing a nametag).     

Evaluation of alveolar bone support around incisors in patients with unilateral cleft lip,alveolus, and palate in late mixed dentition using cone beam computed tomography

Objectives:To evaluate alveolar bone support around cleft-adjacent maxillary central incisors (U1) in patients with unilateral cleft lip, alveolus and palate (UCLAP) in the late mixed dentition and to investigate the correlation between the alveolar bone thickness (ABT) and tooth inclination.Materials and Methods:Cone beam computed tomography scans of 45 subjects with UCLAP (29 boys, 16 girls; mean age = 10.74 ± 1.08 years) were assessed. The distance between the cementoenamel junction (CEJ) and alveolar bone crest (AC), and the ABTs at 3 mm, 6 mm, and the apex were measured on the labial, lingual and distal surfaces of U1. The cleft and normal sides were compared using a paired t-test and Pearson''s χ² test. Pearson''s correlation was used to explore the association between the ABT and tooth inclination of cleft-adjacent U1 in the labiolingual and mesiodistal dimensions.Results:The CEJ-AC distances were significantly greater in cleft-adjacent U1 (P < .01), with more bone height reduction observed labially and distally (P < .001). The labial, lingual, and apico-distal ABTs were decreased on the cleft side (P < .01). A positive correlation was found between the apico-labial ABT and the labiolingual inclination (r = 0.568, P < .01).Conclusions:Patients with UCLAP have reduced alveolar bone support around the cleft-adjacent U1, and the apico-labial ABT tends to decrease with increasing lingual tooth inclination; however, the correlation was weak.     

Quantitative Light-induced Fluorescence-Digital as an oral hygiene evaluation tool to assess plaque accumulation and enamel demineralization in orthodontics

Objective:To assess the use of Quantitative Light-induced Fluorescence-Digital as an oral hygiene evaluation tool during orthodontic treatment.Materials and Methods:In this prospective, randomized clinical trial, 33 patients undergoing fixed orthodontic appliance treatment were randomly allocated to receive oral hygiene reinforcement at four consecutive appointments using either white light (WL) or Quantitative Light-induced Fluorescence-Digital (QLF) images, taken with a device, as visual aids. Oral hygiene was recorded assessing the QLF images for demineralization, by fluorescence loss (ΔF), and plaque coverage (ΔR30). A debriefing questionnaire ascertained patient perspectives.Results:There were no significant differences in demineralization (P  =  .56) or plaque accumulation (P  =  .82) between the WL and QLF groups from T0 to T4. There was no significant reduction in demineralization, ΔF, in the WL, or the QLF group from T0–T4 (P > .05); however, there was a significant reduction in ΔR30 plaque scores (P < .05). All the participants found being shown the images helpful, with 100% of the QLF group reflecting that it would be useful to have oral hygiene reinforcement for the full duration of treatment compared with 81% of the WL group (OR 2.3; P < .05).Conclusions:Quantitative Light-induced Fluorescence-Digital can be used to detect and monitor demineralization and plaque during orthodontics. Oral hygiene reinforcement at consecutive appointments using WL or QLF images as visual aids is effective in reducing plaque coverage. In terms of clinical benefits, QLF and WL images are of similar effectiveness; however, patients preferred the QLF images.     

Desire for orthodontic treatment and associated factors among adolescents in southern Brazil

Objective:To estimate the prevalence of the desire for orthodontic treatment and investigate associated factors among adolescents in southern Brazil.Materials and Methods:A cross-sectional study was carried out with 704 adolescents aged 12 and 13 years at municipal public schools in the city of Balneário Camboriú (southern Brazil). The adolescents answered a previously tested questionnaire addressing satisfaction with their dental appearance, speech function, chewing function, and the desire for orthodontic treatment. The parents/guardians answered a questionnaire addressing satisfaction with their child''s dental appearance and socioeconomic variables. A trained and calibrated orthodontist collected clinical data on malocclusion using the Dental Aesthetic Index (DAI). Statistical analysis was performed using multivariate Poisson regression with robust variance.Results:The prevalence of the desire for orthodontic treatment was 69.6% (490/704). In the adjusted analysis, the outcome was significantly more prevalent among girls (P < .001), those with difficulty chewing (P  =  .026), those dissatisfied with their dental appearance (P < .001), and those with greater malocclusion severity (P < .001). The following orthodontic characteristics were associated with the desire for orthodontic treatment in the multivariate model: diastema in anterior segment (P < .001), anterior maxillary irregularity (P < .001), maxillary overjet ≥6 mm (P < .001), and mandibular overjet (P  =  .047).Conclusions:The desire for orthodontic treatment among 12- and 13-year-old adolescents is influenced by gender, dissatisfaction with one''s dental appearance, difficulty chewing, malocclusion severity, and orthodontic characteristics. These findings should be considered together with normative indications regarding the need for orthodontic treatment in adolescents.     

Comparison of personality traits,attitude toward orthodontic treatment,and pain perception and experience before and after orthodontic treatment

Objective:To compare personality traits, attitude toward orthodontic treatment, and pain perception and experience before and after orthodontic treatment.Materials and Methods:One hundred subjects (50 male and 50 female) were included in this study. The mean (SD) age was 17.5 (2.05) years at T1 and 19.15 (2.32) years at T2. The instruments for data collection were questionnaires that included assessment of patients'' personality traits, attitudes toward orthodontic treatment, and pain perception/experience. Subjects completed the questionnaires at two different times: before orthodontic treatment (T1) and after fixed orthodontic treatment (T2). Subjects were treated by fixed orthodontic appliances for an average (SD) period of 18.64 (0.35) months. Paired sample t-test and chi-square test were used to detect any differences.Results:Significant changes in personality traits were detected after orthodontic treatment irrespective of gender. Neuroticism, openness, agreeableness, and conscientiousness scores were improved (P < .001). A positive attitude toward orthodontic treatment was reported at T1 (4.31 [±1.26]) and improved at T2 (3.98 [±1.16]) irrespective of gender (P < .05). The average (SD) expected pain score (T1) was 4.73 (1.88) and the average (SD) experienced pain score (T2) was 4.63 (1.58). Significant difference in the expected and experienced pain scores was not detected (P  =  .11).Conclusions:Personality traits and attitude toward orthodontic treatment improved after orthodontic treatment. Reported actual pain experience during orthodontic treatment was similar to that expected before treatment.     

Patient attitudes toward retention and perceptions of treatment success

Objective:To discern patients'' opinions regarding responsibility for orthodontic retention and to determine whether patient attitudes toward retention are related to perceptions of treatment success.Materials and Methods:Questionnaires regarding orthodontic retention were distributed to first-year undergraduate college students (n  =  158), first-year dental students (n  =  183), and retention patients at orthodontic offices (n  =  214). Items included treatment satisfaction, perceived responsibility for retention, type of retainer prescribed, reasons for discontinuing use of retainers, and relapse experienced.Results:Four hundred twenty-eight of 555 participants indicated that they had received orthodontic treatment. Most indicated they were either “satisfied” or “very satisfied” with their teeth, both at the end of treatment (96%) and currently (84%). There was a strong relationship between the perception of stability of tooth position and current satisfaction level (P < .0001). Most individuals (88%) indicated that they themselves were responsible for maintaining the alignment and fit of their teeth. Those who indicated that someone else was responsible were nearly twice as likely to be dissatisfied with their teeth (P  =  .0496). Patients who had been prescribed clear, invisible retainers were significantly more likely to be “very satisfied” currently (50%) compared to those with Hawley (35%) or permanently bonded (36%) retainers (P  =  .0002). Patients with Hawley retainers were significantly less likely to be wearing them currently as prescribed (45%) than those with invisible (65%) or bonded (68%) retainers (P < .0001).Conclusions:Satisfaction with orthodontic results after treatment is related to patient perceptions of responsibility for retention and perceived stability of tooth position. Patients should play a contributory role in formulating orthodontic retention plans.     

Quality of orthodontic treatment performed by orthodontists and general dentists: A blind comparative evaluation

Objective:To perform a blind comparative evaluation of the quality of orthodontic treatment provided by orthodontists and general dentists.Materials and Methods:Sixty cases of orthodontic treatment were evaluated—30 treated by specialists in orthodontics and 30 treated by general dentists with no specialization course. Orthodontists were selected randomly by lots, in a population of 1596 professionals, and recordings were performed based on the guideline established by the Objective Grading System proposed by the American Board of Orthodontics. Each participant was asked to present a case considered representative of the best outcome among the cases treated, regardless of the type or initial severity of the malocclusion. Statistical analysis involved the chi-square, Wilcoxon, and Mann-Whitney tests. The level of significance was set at P  =  .05 for the statistical tests.Results:The results showed that 29 orthodontists (96.7%) presented cases considered satisfactory and would be approved on the qualification exam, whereas only 15 dentists (50%) had cases considered satisfactory. Moreover, treatment time was significantly shorter among the orthodontists (P  =  .022), and the posttreatment comparison revealed that orthodontists achieved better outcomes considering all the variables studied.Conclusions:Orthodontists spend less time on treatment and achieve better quality outcomes than cases treated by general dentists who have not undergone a specialization course in orthodontics.     

Quantitative Analysis of Biofilm Formation On Labial and Lingual Bracket Surfaces

ObjectivesTo evaluate and compare the biofilm formation between labial and lingual orthodontic brackets.Materials and MethodsTwenty patients with a mean age of 24 ± 8.8 who had received labial or lingual orthodontic treatment were enrolled in the study. Biofilm formation on 80 brackets was analyzed quantitatively with the Rutherford backscattering detection method. Five micrographs were obtained per bracket with views from the vestibule/lingual, mesial, distal, gingival, and occlusal aspects. Quantitative analysis was carried out with surface analysis software (ImageJ 1.48). Data were analyzed by Mann-Whitney U and Kruskal-Wallis tests (α = 0.05).ResultsTotal biofilm formation was 41.56% (min 29.43% to max 48.76%) on lingual brackets and 26.52% (min 21.61% to max 32.71%) on labial brackets. Differences between the two groups were found to be significant. No difference was observed in intraoral location. The biofilm accumulation was mostly located on gingival, mesial, and distal surfaces for both groups.ConclusionsThe biofilm accumulation on lingual orthodontic therapy was found to be more than labial orthodontic therapy.     

Lingual orthodontic treatment: A YouTube™ video analysis

Objectives:The aim of this study was to examine the quality of information offered for patients seeking information on lingual orthodontic treatment.Materials and Methods:YouTube™ was searched for videos about lingual orthodontic treatment using the key word “lingual braces” from the Google Trends application. One hundred and four videos were selected to be analyzed from the first 120 results. The video content was evaluated using a 10-point score, which was used for classifying low- and high-content video groups. The video information and quality index (VIQI) was applied to determine the quality of the videos. The Mann-Whitney U-test, Chi-square test, and logistic regression analysis were used, and the Pearson correlation coefficient was calculated for statistical evaluations.Results:We classified 32 videos as high-content and 72 as low-content. Most videos were uploaded by laypeople (58.7%, n = 61). Definition of lingual braces and psychological impact were the most commonly discussed topics (51.0%), followed by speech performance (47.1%), pain (44.2%), tongue soreness (37.5%), and biomechanics (14.4%). Compared to the low-content group, the high-content video group had a significantly higher mean number of views (19,867.41 vs 6720.08, P = .002) and more “likes” (135.88 vs 13.01, P < .001), “dislikes” (4.34 vs 0.81, P < .001), and “comments” (26.28 vs 5.31, P = .002). There was no difference in the total VIQI score between the groups (P = .009).Conclusions:The content of YouTube™ videos for lingual orthodontics was generally incomplete. Most videos mentioned psychological effects, but few videos discussed the biomechanics or procedure. Orthodontists should be aware of the information available on YouTube™.     

Comparative study of root resorption of maxillary incisors in patients treated with lingual and buccal orthodontics

Objective:To compare the magnitude of external apical root resorption (EARR) of maxillary incisors in patients with mild to moderate anterior crowding, treated with lingual and conventional (labial) orthodontics.Materials and Methods:The sample comprised 40 patients divided into two groups: lingual (20 patients) and conventional buccal brackets (20 patients). Patient ages ranged from 11 to 45 years, and the study included 12 men and 28 women. Apical root resorption was measured from periapical radiographs obtained at the beginning of treatment (T1) and at the end of the leveling phase (T2). Periapical radiographs were scanned and transferred to the CorelDraw X7 image-processing program, in which measurements of root lengths were performed. For intragroup and intergroup comparisons between the T1 and T2 phases, paired and independent t-tests, respectively, were used at 5% significance.Results:There was significant apical root resorption for all teeth evaluated; the magnitude of the EARR (T2−T1) ranged from −0.35 mm to −0.63 mm in the lingual group, and from −0.66 mm to −0.85 mm in the conventional group. Although there was an intergroup variation in the magnitude of EARR observed, no statistically significant differences were found. Neither group presented any teeth with resorption ≥1 mm.Conclusions:The magnitude of apical root resorption in maxillary incisors in patients with anterior crowding was similar regardless of orthodontic technique, lingual or conventional. Both techniques resulting in an apical rounding considered clinically insignificant.     

Dentoskeletal changes following mini-implant molar intrusion in anterior open bite patients

Objective:To evaluate skeletal and dental changes after intrusion of the maxillary molars in subjects with anterior open bite.Materials and Methods:This retrospective cephalometric study evaluated skeletal and dental changes resulting from the use of maxillary orthodontic mini-implants in 31 consecutively treated patients. Radiographs were taken at the start and end of maxillary molar intrusion to evaluate the associated changes. Statistical analysis was performed using a one-sample t-test.Results:The mean treatment observation time was 1.31 years (SD  =  2.03). The maxillary first molars (P  =  0.0026) and second molars (P  =  0.039) were intruded. However, the mandibular first molars (P  =  0.0004) and second molars (P  =  0.003) erupted in adolescent patients. Both the maxillary and mandibular first molars inclined distally (P  =  0.025 and P  =  0.044, respectively). The mandibular plane angle decreased (P  =  0.036), lower facial height decreased (P  =  0.002), and the occlusal plane angle increased (P  =  0.009). The overbite increased (P < .0001). The ANB angle decreased (P < .0001). Mandibular dental and skeletal changes were more apparent in adolescents, while adults tended toward maxillary changes.Conclusions:Vertical traction from orthodontic mini-implants reduces the maxillary posterior dentoalveolar height, thereby assisting orthodontic closure of anterior open bite. However, simultaneous eruption or extrusion of the mandibular molars should be controlled. Adolescent patients tend to demonstrate more favorable effects of mandibular autorotation than do adults.     

Debris,Roughness and Friction of Stainless Steel Archwires Following Clinical Use

Objective:To investigate the degree of debris, roughness, and friction of stainless steel orthodontic archwires before and after clinical use.Materials and Methods:For eight individuals, two sets of three brackets (n  =  16) each were bonded from the first molar to the first premolar. A passive segment of 0.019- × 0.025-inch stainless steel archwire was inserted into the brackets and tied by elastomeric ligature. Debris level (via scanning electron microscopy), roughness, and frictional force were evaluated as-received and after 8 weeks of intraoral exposure. Mann-Whitney, Wilcoxon signed-rank, and Spearman correlation tests were used for statistical analysis at the .05 level of significance.Results:There were significant increases in the level of debris (P  =  .0004), roughness of orthodontic wires (P  =  .002), and friction (P  =  .0001) after intraoral exposure. Significant positive correlations (P < .05) were observed between these three variables.Conclusion:Stainless steel rectangular wires, when exposed to the intraoral environment for 8 weeks, showed a significant increase in the degree of debris and surface roughness, causing an increase in friction between the wire and bracket during the mechanics of sliding.     

Activation and installation of orthodontic appliances temporarily impairs mastication:: A systematic review with meta-analysis

ObjectivesTo investigate the masticatory (masticatory performance, bite force, swallowing threshold, muscle activity, and questionnaires) and nutritional (nutrient intake) impacts of the activation and/or installation of different orthodontic appliances (fixed labial, lingual appliances, and clear aligners).Materials and MethodsSix electronic databases and gray literature were searched (up to May 2021) for relevant studies evaluating mastication and nutrition after activation/installation of orthodontic appliances. This review followed PRISMA guidelines and was registered at PROSPERO (CRD42020199510). The risk of bias (RoB 2 and ROBINS-I) and evidence quality Grading of Recommendations Assessment, Development, and Evaluation were analyzed.ResultsOf 4226 recorded and screened, 15 studies were finally included. Masticatory performance (standardized mean difference [SMD]: 1.069; 95% coefficient interval [CI]: 0.619 to 1.518) and bite force (SMD: -2.542; 95% CI: −4.867 to −0.217) reduced in the first 24 to 48 hours of fixed labial appliance installation/activation, but they were both normalized after 30 days (P > .05). The swallowing threshold remained constant (P > .05). Nutritional intake was rarely reported but showed copper (P = .002) and manganese (P = .016) reductions, with higher calorie and fat intake (P < .05). Lingual appliances impacted chewing more than labial, and clear aligner wearers reported fewer chewing problems (P < .001). Low to very low levels of evidence were found.ConclusionsBased on low to very low levels of evidence, mastication was reduced during the first 24 to 48 hours of fixed labial appliance activation/installation, but it was transitory (up to 30 days). Due to insufficient data, the nutritional impact of orthodontic appliances was not conclusive.     

Another way of looking at treatment stability

Objective:To determine the contribution of normal physiological changes to the overall manifestation of a relapse after orthodontic treatment. We analyzed long-term changes in the dentition of patients with Class I malocclusions after orthodontic treatment compared with a representative group with untreated Class I malocclusions.Materials and Methods:Study participants (n  =  66; mean age, 12 years at treatment initiation) were treated for Class I malocclusions. Dental changes were evaluated at 2, 5, 10, and 15 years after treatment. Control participants (n  =  79) had untreated Class I malocclusions (n  =  53 evaluated at ages 12 and 22 years; n  =  26 evaluated at ages 19 and 39 years). Dental changes were evaluated with the Peer Assessment Rating (PAR) index.Results:In untreated and treated groups, PAR scores increased over time with gender-specific changes. In the untreated groups, the PAR score significantly increased in male participants between the ages of 12 and 22 years (P  =  .04) and in female participants between the ages of 19 and 39 years (P  =  .001). In the treated group, early posttreatment changes were primarily related to the initial treatment response. Later changes in the PAR score could be attributed to physiological changes, with the same gender-specific changes as those observed in the untreated group.Conclusions:The pattern of physiological changes in dentition for participants between the ages of 12 and 39 was different between sexes. Females showed more relapse than males between 10 and 15 years posttreatment. This distinction should be considered when evaluating long-term orthodontic treatment responses.     

The treatment timing of labial inversely impacted maxillary central incisors: A prospective study

Objective:To determine the timing of treatment for the labial inversely impacted maxillary central incisors.Methods:Twenty-eight patients (mean age, 8.2 years) with labial inversely impacted maxillary central incisors were divided into early-treated and later-treated groups according to their dental age. All of the patients were treated with a combination of surgery and orthodontic traction using the Guide rod appliance. Cone-beam computed tomography images were taken immediately after treatment for assessing the root morphology, root length, and alveolar bone loss. Sagittal slices were evaluated at the widest labial-lingual width of the tooth in the axial view. All variables were evaluated by Simplant 13.0 software (Materialise Dental NV, Leuven, Belgium).Results:The rank sum test indicated that the root length of two groups showed a statistically significant difference between the impacted and homonym tooth, with a shorter length in the impacted tooth (P < .05). The D-value (difference of root length between the impacted and homonym tooth) and alveolar bone loss on the labial side of the impacted incisor are significantly less in the early-treated groups when compared with the later-treated groups (P < .05). Spearman rank correlation analysis showed a statistically positive association between the treatment timing and D-value (r  =  .623, P < .05). The chi-square test for morphology of root apex indicated that the incidence of the root-apex-directed labial side is significantly higher in the later-treated groups when compared with the early-treated groups.Conclusion:The labial inversely impacted maxillary central incisors should be treated early to promote root development by achieving a better morphology of root apex, thus reducing the risk of alveolar bone loss on the labial side.