Does orthodontic treatment using clear aligners and fixed appliances affect periodontal status differently?

DESIGN: Systematic review and meta-analysis of clinical trials, and prospective or retrospective cohort. The protocol of the study was registered in advance on PROSPERO. DATA SOURCES: An electronic search in MEDLINE (PubMed), Web of Science, Scopus, and The Cochrane Library was conducted by two independent authors up to September 2022. Additionally, OpenGrey and www.greylit.org were searched for gray literature, whereas ClinicalTrials.gov was searched for detecting any relevant unpublished data. STUDY SELECTION: The review question was defined in PICOS format as follows: population (P), patients undergoing orthodontic therapy; intervention (I), orthodontic therapy with clear aligner (CA); comparison (C), orthodontic therapy with fixed appliances (FA); outcome (O), periodontal health status and development of gingival recession; studies (S), randomized clinical trials (RCTs), controlled clinical trials, and retrospective or prospective cohort studies. Cross-sectional studies, case series, case reports, studies without a control group, and studies with less than 2 months follow-up were excluded. DATA ANALYSIS: Periodontal health status was assessed as a primary outcome and it was measured in terms of pocket probing depth (PPD), gingival index (GI), plaque index (PI) and bleeding on probing (BoP). Gingival recession (GR) was assessed as secondary outcome, and was measured as the development or progression of GR, shown by the apical migration of the gingival margin occurring between pre- and post-orthodontic treatment. Each periodontal index was assessed in three-time points; short-term (2-3 months from baseline), mid-term (6-9 months from baseline), and long-term (12 months or more from baseline). A descriptive analysis of included articles was performed. Pairwise meta-analyses were conducted to compare outcomes assessed in FA and CA groups and were only performed when studies reported similar periodontal indices at similar follow-ups. RESULTS: 12 studies (3 RCTs, 8 prospective cohort studies, 1 retrospective cohort study) were included in the qualitative synthesis, of which, 8 studies were included in the quantitative synthesis (meta-analysis). A total of 612 patients (321 treated with buccal FA and 291 with CA) were assessed. Results from meta-analyses favored CA in regards to PI, demonstrating a significant difference in the mid-term follow-up (number of studies = 4, standardized mean difference [SMD] = -0.99, 95% confidence interval [CI] = -1.94 to -0.03, I2 = 99%, P = 0.04). There was a tendency to report better GI values with CA, specifically in long-term (number of studies = 2, SMD = -0.46 [95% CI, -1.03 to 0.11], I2 = 96%, P = 0.11). However, no statistical significance between the two treatment modalities was shown for any follow-up intervals (P > 0.05). As for PPD, the long-term follow-up showed statistical significance favoring CA (SMD = -0.93 [95% CI, -1.06 to 0.7], P < 0.0001), whereas short- and mid-term follow-ups did not show significant differences between FA and CA. Overall, patients treated with CA showed better values of BoP and less GR when compared to patients treated with FA. CONCLUSIONS: Available evidence is still not enough to conclude the superiority of clear aligner therapy in terms of periodontal status during orthodontic treatment compared to fixed appliances.

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

DESIGN: 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). CASE SELECTION: 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). DATA ANALYSIS: 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 the Friedman test and followed by post-hoc tests with Bonferroni correction. RESULTS: 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. CONCLUSIONS: 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.

Does using mobile applications and social media-based interventions induce beneficial behavioral changes among orthodontic patients?

DESIGN: Systematic review and meta-analysis of randomized controlled trials (RCTs) and controlled clinical trials (CCTs). The protocol of the study was registered on the International Prospective Register of Systematic Reviews (PROSPERO: CRD42019157298). DATA SOURCES: Seven electronic databases (MEDLINE, Web of Science Core Collection, Unpublished Clinical Trials accessed through clinicaltrials.gov, Embase, LILACS, ProQuest Database, The Cochrane Library) were searched. Additionally, the reference lists of the included studies were hand searched. STUDY SELECTION: Clinical trials (RCT and CCT) that assessed the impact of the interventional use of mobile applications and social media among orthodontic patients were included. The review question was defined in PICO format as follows: population (P) = patients (no age restriction) undergoing orthodontic treatment using fixed, removable, or functional appliances, or patients in the retention phase that are wearing fixed or removable retainers; intervention (I) = mobile applications and social media-based interventions; comparison (C) = control group that did not receive any adjunctive intervention; outcome (O) = behavior changes in orthodontic patients after receipt of the intervention. Two authors independently conducted literature search from inception up to March 2021. DATA ANALYSIS: Social media-based interventions and mobile applications (or bespoke) were used in the form of reminders (WhatsApp reminders) and provision of information including YouTube videos and Instagram posts. Primary outcomes included adherence to wearing appliances or adjuncts, oral hygiene levels, oral health-related behaviors, periodontal outcomes, appointment attendance, knowledge, and related iatrogenic effects. Treatment-related experiences and patient-reported outcomes were assessed as secondary outcomes. RESULTS: 16 studies (14 RCTs and 2 CCTs) were included in the qualitative synthesis, of which only 7 studies were included in the quantitative synthesis (meta-analysis). Results from meta-analyses showed that the intervention was favored in relation to gingival index (GI) (number of studies = 4, standardized mean difference [SMD] = -0.81, 95% confidence interval [CI] = -1.35 to -0.28, P = 0.00, certainty of evidence = very low), plaque index (PI) (number of studies = 7, SMD = -0.91 [95% CI, -1.64 to -0.19], P = 0.01, certainty of evidence = very low), and bleeding index (BI) (number of studies = 4, SMD = -0.22 [95% CI, -0.50 to 0.05], P = 0.11, certainty of evidence = high). Sensitivity analysis was performed (including additional 3 studies for GI and 5 studies for PI), which also favored the intervention in relation to GI (number of studies = 7, SMD = -0.60 [95% CI, -1.01 to -0.18], P = 0.00, certainty of evidence = very low), and PI (number of studies = 12, SMD = -0.67 [95% CI, -1.14 to -0.19], P = 0.01, certainty of evidence = very low). CONCLUSIONS: Limited evidence supports beneficial behavior change among orthodontic patients when using mobile applications or social media-based interventions.

Genetics of three-dimensional tooth inclination and angulation in orthodontic patients with Class I Occlusion: A cross-sectional study.

PURPOSE: This cross-sectional study aimed to utilize quantitative polymerase chain reaction (qPCR) to investigate the influence of genetic variance over teeth inclination and angulation in orthodontic patients with Class I occlusion. MATERIALS AND METHODS: DNA was extracted from adolescent patients seeking orthodontic treatment in a single institution (from July 2018 to April 2020), who had CBCTs taken as part of initial standardized records. Patients had permanent dentition, Class I skeletal and dental classifications, with normal vertical and transverse skeletal dimensions, normal incisors inclination, no to mild crowding or spacing. qPCR was performed using genetic markers for candidate genes EPB41, TGFß3, GHR and PAX9. Three-dimensional teeth inclinations (TI) and angulations (TA) were evaluated using Invivo6 software and correlated with genotypes. Reliability of TI and TA was assessed using intraclass correlation coefficients (ICC). Mixed models and multiple linear regression analyses were used to assess the association between each single nucleotide polymorphisms (SNP) with tooth inclination (TI) and with tooth angulation (TA). The results were evaluated at the significance level of P<0.05. RESULTS: Twenty four adolescent patients with mean age of 13.4±2.4 years were included in the study. ICC showed adequate intra-examiner reliability for TI and TA (0.806

Supernumerary tooth autotransplantation to replace missing maxillary central incisor using three-dimensional replica: A 6-year follow-up.

INTRODUCTION: Tooth autotransplantation is a viable surgical treatment option for patients with missing permanent teeth. Premolars are generally used for autotransplantation but often require extensive modifications. This case report evaluates the use of supernumerary tooth as an alternative option for premolar autotransplantation. This report shows successful supernumerary tooth autotransplantation with 6-year follow-up. METHODS: A 13-year-old male with non-contributory medical history was referred for a missing maxillary left central incisor (#9) and presence of a supernumerary tooth. The clinical and radiographic examination revealed presence of supernumerary tooth with similar dimensions to a central incisor. The treatment plan included autotransplantation of the supernumerary tooth to replace the missing central incisor (short-term) and future implant replacement of the autotransplanted tooth when jaw growth ceases (long-term). The patient and parents consented to treatment. A 3-D tooth replica was constructed based on CBCT analyses. Site #9 was prepared using split ridge technique to create a socket to house the 3-D replica. Upon achieving proper socket form, the supernumerary tooth was extracted and autotransplanted in the prepared socket. The supernumerary tooth was splinted, and the bite opened posteriorly using composite to eliminate any occlusal interferences. RESULTS: The patient was followed up clinically and radiographically. The autotransplanted supernumerary tooth integrated well within the newly created socket and remained functional at the 6-year follow-up. CONCLUSIONS: The current case presents successful management of supernumerary tooth autotransplantation with 6-year follow-up. The results show stable periodontium with satisfactory functional and aesthetic results.

Genetic influence on the curves of occlusion in children seeking orthodontic treatment.

OBJECTIVE: To examine the proportion of variability in the Curve of Wilson (COW) and the Curve of Spee (COS) that is explained by genetic factors in siblings seeking orthodontic treatment. MATERIALS AND METHODS: Pre-treatment cone-beam computed tomography (CBCT) of 148 sibling patients were selected. The sample consisted of 79 females and 69 males with a mean age of 12 years 7 months. The COS was measured by creating a tangent line from the distobuccal cusp of the mandibular first molars and the highest incisal tip of the mandibular incisors. Measurements were taken from that tangent line to the deepest point on the premolars and canines. The COW was measured using the molar axis line to the perpendicular to WALA (Will Andrews Lawrence Andrews) points' axis line. RESULTS: The results indicate that these occlusal curves are generally moderate to highly heritable. Heritability of COW-maxilla was 78.3%, heritability of COW-mandible was 43.2% and heritability of COS was 100% (P-value<0.05). CONCLUSIONS: Most of the developmental variability in the curves of occlusion comes from genetic differences, with very little contribution from environmental factors. Therefore, siblings tend to show similar occlusal curves.

Evaluating interactions of airway changes during growth with orthodontic treatment.

OBJECTIVE: The aim of this study was to longitudinally evaluate changes in the pharyngeal airway volume in adolescents treated with fixed orthodontic appliances compared to matched untreated adolescents and to assess its impact on airflow resistance. MATERIALS AND METHODS: The sample consisted of 16 adolescents (mean start age of 11 years 3 months) who had started and completed treatment at the orthodontic department of the University of Detroit Mercy School of Dental Medicine. This group was compared to a control that consisted of 16 adolescents (mean start age 12 years) who had two CBCTs with no treatment in between for the purpose of regular orthodontic evaluation. Differences in airway volume, length, minimum cross-sectional area, and the average cross-sectional area were calculated. RESULTS: The results indicated that the airway volume increased by 39% and was a statistically significant change (P<0.05). Regarding the influence on airflow resistance, the change in cross sectional area was significant in the group treated with fixed orthodontic appliances (P<0.03). CONCLUSION: Adolescents treated with fixed orthodontic appliances do experience an increase in airway volume, as well as a decrease in airway resistance to airflow compared to that in normal growth.

The heritability of alveolar bone thickness in siblings seeking orthodontic treatment.

INTRODUCTION: The purpose of this study was to calculate heritability estimates of alveolar bone thickness around maxillary and mandibular incisors. METHODS: The sample consisted of cone-beam computed tomography scans of 69 groups of siblings. The scans were analyzed, and Invivo5 software was used to measure the labial and lingual bone thickness. The central point of the root was identified as the point of rotation in order to construct the point of intersection with the outer bone surface. The linear distance was measured from this constructed point to the root apex. The general linear method was then used to calculate the heritability of alveolar bone thickness. RESULTS: Heritability of alveolar bone thickness was, on average, 58.0% for maxillary incisors and 50.3% for mandibular incisors. These estimates indicate a moderate to high heritability of alveolar bone thickness with an overall average heritability of 54.1%. CONCLUSIONS: Genetic factors were found to play significant roles in determining bone thickness around these teeth. The genetic effect on alveolar bone thickness around incisors is moderate to high.

Heritability of the pharyngeal airway volume and dimensions as assessed from siblings with overt malocclusions.

OBJECTIVE: To quantify the relative contributions of genetic and environmental factors to airway volume and dimensions in orthodontic patients. MATERIALS AND METHODS: One hundred and twenty-five siblings from 57 families were selected. Cone beam computed tomography scans were taken as part of the orthodontic records and the Dolphin3D © imaging software was used to determine airway volume and dimensions. SOLAR program was implemented to calculate heritability. RESULTS: The heritability of the airway volume was negligible but increased significantly from 5% to 72% (95% confidence interval was 27% to 100%) when anterior-posterior (AP) dimension was controlled in the calculating model. CONCLUSION: The capacity to maintain, rather than having proper AP dimension of the airway, seems to be the most critical mark of a proper airway volume.

Heritability of teeth angulation and inclination in patients with overt malocclusion.

PURPOSE: To use 3-dimensional cone beam computed tomography (CBCT) images obtained on patients before treatment with dental malocclusion to calculate the heritability estimates of full-tooth angulation and inclination. A heritability estimate is a number between zero and one indicating the percentage of genetic factors involved in determining the phenotypic variation observed. METHOD: CBCT images of 111 patients (51 sibships) were analysed measuring both tooth angulation and inclination using the Anatomage Invivo5 software for central incisor to second molar. The long axis of each tooth was defined and traced as the cusp tip of the most mesiobuccal cusp to 6mm coronal to the apex of the mesiobuccal root. SPSS statistical software was used to analyse the data and calculate the heritability estimates for each tooth type in the maxilla and in the mandible regardless of the side. RESULTS: Teeth inclination showed higher heritability estimates than tooth angulation. Furthermore, maxillary teeth showed higher heritability estimates than mandibular teeth and anterior teeth showed higher heritability than posterior teeth. CONCLUSION: Genetic effect was more evident on tooth inclination than tooth angulation, on anterior teeth more than posterior teeth, and on maxillary teeth more than mandibular teeth.

Comparison of early treatment outcomes rendered in three different types of malocclusions.

OBJECTIVE: To evaluate the outcome of early treatment in Class I, II, and III malocclusions based on the reduction of weighted Peer Assessment Rating (PAR) scores. MATERIALS AND METHODS: Two hundred thirty subjects (female = 105; male = 125) selected from 400 cases were divided into three groups based on their malocclusions (Class I, II, and III). The PAR index was evaluated prior to early treatment (T0), at the end of phase I (T1), and after completion of phase II therapy (T2). The reliability of overall PAR scores was assessed by Bland-Altman plot and intraclass correlation coefficient. The starting age, total weighted PAR scores and their changes after phase I and II treatments, treatment time, and the percentage of correction in the three different malocclusions were assessed by repeated-measures analysis of variance with post hoc analysis. The level of significance was set at P < .05. RESULTS: More than 30% reduction of the weighted PAR scores and less than 10 points of the remaining weighted PAR scores were observed in all malocclusion groups at T1. The Class III group had the highest percentage of correction during phase I treatment. CONCLUSIONS: Early treatment effectively reduced the complexity of Class I, II, and III malocclusions and accounted for 57%, 64%, and 76% of the total correction, respectively, after phase I treatment, as indicated by an overall reduction in weighted PAR scores. The Class III group responded most favorably to early treatment followed by the Class II group.

Changes in the oropharyngeal airway of Class II patients treated with the mandibular anterior repositioning appliance.

OBJECTIVE: To evaluate the effects of functional appliance treatment on the oropharyngeal airway volume, airway dimensions, and anteroposterior hyoid bone position of growing Class II patients. MATERIALS AND METHODS: Twenty Class II white patients (mean age, 11.7 ± 1.75 years) treated with the MARA followed by fixed appliances were matched to an untreated control sample by cervical vertebrae maturation stage at pretreatment (T1) and posttreatment (T2) time points. Cone beam computed tomography scans were taken at T1 and T2. Dolphin3D imaging software was used to determine oropharyngeal airway volume, dimensions, and anteroposterior hyoid bone position. RESULTS: Multivariate ANOVA was used to evaluate changes between T1 and T2. Oropharyngeal airway volume, airway dimensions, and A-P position of the hyoid bone increased significantly with functional appliance treatment. SNA and ANB decreased significantly in the experimental group (P ≤ .05). Changes in SNB and Sn-GoGn failed to reach statistical significance. CONCLUSIONS: Functional appliance therapy increases oropharyngeal airway volume, airway dimensions, and anteroposterior hyoid bone position in growing patients.

Inheritance of susceptibility to root resorption associated with orthodontic force in mice.

INTRODUCTION: External apical root resorption (EARR) is an unwanted sequelae of orthodontic treatment. Genetic factors account for approximately 64% of the EARR variation in humans. Inbred mice offer a model to control the environmental factors and genetic heterogeneity that complicate human genetic studies. Genetically distinct inbred mice and their offspring (F1s) were analyzed to examine the mode of inheritance and the influence of parental sex on the susceptibility to root resorption associated with orthodontic force (RRAOF). METHODS: RRAOF was determined histologically for male and female mice of the A/J, DBA/2J, and BALB/cJ strains, and the A/JxDBA/2J and A/JxBALB/cJ crosses (10 males and 10 females/reciprocal cross). RRAOF was induced by tipping the maxillary first molar mesially for 9 days. RESULTS: Sex differences were observed only among the mice of the BALB/cJ strain. Two patterns of inheritance were observed; F1s from the A/JxBALB/cJ cross were resistant, suggesting that the A/J have dominant resistance alleles. On the other hand, F1s from the A/JxDBA/2J cross showed RRAOF intermediate between their parental mice, suggesting a polygenic trait. CONCLUSIONS: These results provide evidence of a traceable and polygenetic component affecting RRAOF in mice.

Root resorption associated with orthodontic force in inbred mice: genetic contributions.

Root resorption (RR) is an unwanted sequela of orthodontic treatment. Despite rigorous investigation, no single factor or group of factors that directly causes RR has been identified. The purpose of this study was to examine the effect of the genotype on susceptibility or resistance to develop RR secondary to orthodontic force. Nine-week-old male mice from eight inbred strains were used and randomly distributed into control (C) or treatment (T) groups as follows: A/J (C = 9,T = 9), C57BL/6J (C = 7,T = 8), C3H/HeJ (C = 8,T = 6), BALB/cJ (C = 8,T = 6), 129P3/J (C = 6,T = 8), DBA/2J (C = 8,T = 9), SJL/J (C = 8,T = 10), and AKR/J (C = 9,T = 8). Each of the treated mice received an orthodontic appliance to tip the maxillary left first molar mesially for 9 days. Histological sections of the tooth were used to determine RR and tartrate resistant acid phosphatase (TRAP) activity. The Wilcoxon ranked-sum non-parametric test was used to evaluate differences between the groups. The results showed that the DBA/2J, BALB/cJ, and 129P3/J inbred mouse strains are highly susceptible to RR, whereas A/J, C57BL/6J and SJL/J mice are much more resistant. The variation in the severity of RR associated with orthodontic force among different inbred strains of mice when age, gender, food, housing, and orthodontic force magnitude/duration are controlled support the hypothesis that susceptibility or resistance to RR associated with orthodontic force is a genetically influenced trait.

Genetic predisposition to external apical root resorption.

External apical root resorption (EARR) can be an undesirable sequela of orthodontic treatment. Previous studies have suggested that EARR has a substantial genetic component. Linkage and association were examined between polymorphisms of the interleukin IL-1 (IL-1A and IL-1B) genes and EARR in 35 white American families. Buccal swab cells were collected for DNA isolation and analysis. The EARR in the maxillary central incisors, the mandibular central incisors, and the mesial and distal roots of the mandibular first molar were analyzed separately and together by using both linkage and association methods of analysis. Highly significant (P =.0003) evidence of linkage disequilibrium of IL-1B polymorphism with the clinical manifestation of EARR was obtained. The analysis indicates that the IL-1B polymorphism accounts for 15% of the total variation of maxillary incisor EARR. Persons homozygous for the IL-1B allele 1 have a 5.6 fold (95% CI 1.9-21.2) increased risk of EARR greater than 2 mm as compared with those who are not homozygous for the IL-1 beta allele 1. Data indicate that allele 1 at the IL-1B gene, known to decrease the production of IL-1 cytokine in vivo, significantly increases the risk of EARR. These findings are consistent with an interpretation of EARR as a complex condition influenced by many factors, with the IL-1B gene contributing an important predisposition to this common problem. Defining genetic contributions to EARR is an important factor in understanding the contribution of environmental factors, such as habits and therapeutic biomechanics.