Stability of fiducial cephalometric landmarks of growing Class II malocclusion patients: a three-dimensional retrospective study.

OBJECTIVES: To evaluate three-dimensionally (3D) the stability of Nasion (Na), Sella (S), Basion (Ba), Porion (Po), and Orbitale (Or) in different age groups of growing Class II malocclusion patients and, additionally, to assess rotational changes of the S-Na and Ba-Na lines and the Frankfurt Horizontal Plane (FHP). MATERIALS AND METHODS: Cone-beam computed tomography studies of 67 Class II division 1 malocclusion patients, acquired at baseline (T0) and 1 year later (T1), were retrospectively assessed. Anterior cranial fossa was used for volumetric superimposition. Subjects were grouped according to their age at T0: group 1 (G1) (8-10 years), G2 (11-13 years), and G3 (14-17 years). Quantitative assessments of the 3D linear displacements (Euclidean distance) in the position of Na, S, Ba, Po, and Or were performed. Displacement in the X, Y, and Z projections and the rotation of S-Na, Na-Ba, and FHP were also quantified. RESULTS: All cephalometric landmarks showed 3D displacement (P = .001) in the three age groups. Orbitale remained stable in the vertical and sagittal dimension from 8 to 17 years (P > .05). S-Na, Na-Ba, and the FHP showed statistically significant angular rotation (P < .05) in younger patients (G1), while in older individuals (G2 and G3) they were stable (P > .05). CONCLUSIONS: Na, S, Ba, and Po showed vertical and sagittal positional changes relative to the anterior cranial fossa during the growth of Class II individuals. After age 11, S-Na, Na-Ba, and FHP did not show rotation and, thus, are valid parameters for angular cephalometric analysis in Class II growing patients.

Association between arch perimeter management and the occurrence of mandibular second molar eruption disturbances.

OBJECTIVES: To investigate the association between the management of mandibular arch perimeter during development of the dentition and its effects on second permanent molar (M2) eruption. MATERIALS AND METHODS: Seven electronic databases were searched without restrictions up to June 2020. Assessment was performed using the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool for non-randomized clinical trials (non-RCT). Odds ratio (OR) with 95% confidence intervals was calculated from random-effects meta-analyses. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to assess the certainty of the evidence. RESULTS: Five non-RCTs, with serious to moderate risk of bias, were included. A low certainty of evidence indicated that individuals undergoing mandibular arch perimeter management by controlling the position of the first molar had a high prevalence of M2 eruption difficulties. The odds of eruption disorders was 7.5 times higher (OR: 7.57, [3.72, 15.41], P < .001) in treated individuals. Subgroup analysis revealed that appliances that increased the arch perimeter lead to a greater chance of eruption disorders compared to appliances that only maintained the perimeter. The predictive factors for the M2 eruption difficulty were its previous mesioangulation in relation to the first molar (>24°) and the treatment time (>2 years). CONCLUSIONS: Mandibular arch perimeter management during development of the dentition leads to an increase in the occurrence of M2 eruption difficulties. The identification of possible risk factors as well as the choice of the appropriate appliance type and the monitoring of these individuals seems to be essential to avoid undesirable effects with this therapy.

Do adjunctive interventions in patients undergoing rapid maxillary expansion increase the treatment effectiveness?

OBJECTIVES: To evaluate the clinical effectiveness of adjunctive interventions in individuals undergoing rapid maxillary expansion (RME). MATERIALS AND METHODS: MEDLINE, Web of Science, Cochrane, Scopus, LILACS, and Google Scholar were searched without restrictions up to June 2020. Trials involving participants undergoing orthopedic or surgical RME, along with adjunctive interventions, were included. Risk-of-bias assessments were performed using the Cochrane tool for randomized trials-2. The certainty level of evidence was assessed through the Grading of Recommendations Assessment, Development and Evaluation tool. RESULTS: Six randomized clinical trials, with low to high risk of bias, were included. Low certainty of the evidence suggested that low-level laser facilitated opening of the midpalatal suture during the active phase of RME. Likewise, moderate certainty demonstrated that low-level laser accelerated the healing process of the suture during the retention phase. The clinical impact of this outcome, that is, stability and retention time, was not evaluated. Very low evidence indicated that osteoperforations along the midpalatal suture increased maxillary transverse skeletal gains in young adults undergoing RME. Low evidence suggested that platelet-rich plasma therapy did not minimize the vertical and thickness bone loss after RME in the short term. CONCLUSIONS: Based on currently available information, the use of low-level laser associated with maxillary expansion seems to provide a more efficient suture opening and bone healing. Limited evidence suggests that osteoperforations improve the skeletal effects of RME in non-growing individuals. There are no adjunctive interventions capable of reducing the periodontal side effects of RME.

Unusual case of prolonged breastfeeding in an orthodontic patient: clinical and psychosocial implications / Amamentação prolongada em paciente ortodôntico: implicações clínicas e psicossociais

Case report: This article presents the case of an 11-year-old patient who sought orthodontic treatment, complaining of crooked teeth. In anamnesis, an emotional and physical dependence was reported regarding the act of breastfeeding. Considerations on the diagnosis, psychological implications, and clinical approach in this rare case were addressed. An orthodontic treatment and myofunctional therapy were performed to resolve the occlusal and functional aspects of the patient. Psychological therapy for the child and her mother was required to handle emotional sequelae. Conclusion: Multidisciplinary treatment was prescribed. Dentists should be aware of this need in cases of patients with special characteristics for treatment beyond oral problems. In orthodontics, this may be the difference between effective treatment outcomes or not.

Relato de caso: Este artigo apresenta o caso de uma paciente de 11 anos que procurou tratamento ortodôntico com queixa de "dentes tortos". Na anamnese, foi relatada dependência emocional e física da criança em relação ao ato de amamentar. Considerações sobre diagnóstico, implicações psicológicas, abordagem clínica neste raro caso foram abordadas. Foi realizado tratamento ortodôntico e terapia miofuncional para resolução dos aspectos oclusais e funcionais do paciente. Um acompanhamento psicológico para crianças e sua mãe foi necessária para abordar sequelas emocionais inerentes. Conclusão: Um tratamento multiprofissional foi instituído e o dentista deve estar atento a essa necessidade nos casos de pacientes com características especiais, visando uma abordagem além dos problemas bucais. Na Ortodontia, essa pode ser a diferença entre os resultados eficazes do tratamento ou não.

Influence of heritability on occlusal traits: a systematic review of studies in twins.

BACKGROUND: The aim of this systematic review was to identify, evaluate, and provide a current literature about the influence of heritability on the determination of occlusal traits. MATERIALS AND METHODS: MEDLINE, SCOPUS, Web of Science, LILACS, and Google Scholar were searched without restrictions up to March 2020. Studies with twin method were considered and the risk of bias assessment was performed using quality of genetic association studies checklist (Q-Genie). The coefficient of heritability (h2), model-fitting approaches, and coefficient correlation were used to estimate the genetic/environmental influence on occlusal traits. The GRADE tool was used to assess the quality of the evidence. RESULTS: Ten studies met the eligibility criteria. Three studies presented good quality, five moderate quality, and two poor quality. Most studies have found that the intra-arch traits, mainly the maxillary arch morphology, such as width (h2 16-100%), length (h2 42-100%), and shape (h2 42-90%), and the crowding, mainly for mandibular arch (h2 35-81%), are under potential heritability influence. The traits concerning the inter-arch relationship, as overjet, overbite, posterior crossbite, and sagittal molar relation, seem not to be genetically determined. The certainty of the evidence was graded as low for all outcomes. CONCLUSIONS: Although weak, the available evidence show that the heritability factors are determinant for the intra-arch traits, namely, arch morphology and crowding. Possibly due they are functionally related, the occlusal traits concerning the maxillary and mandibular relationship seem to have environmental factors as determinants. In this scenario, early preventive approaches can offer a more effective and efficient orthodontic treatment.

Impaction of mandibular third molars after orthodontic treatment by the edgewise method: a retrospective study.

This study aimed to determine the incidence of mandibular third molar (M3) impaction after orthodontic treatment by edgewise appliances, and identify possible determinant factors of M3 impaction. A retrospective cohort study was conducted with 1154 patients. Complete orthodontic records were analyzed pretreatment and posttreatment, considering the following variables: type of Angle malocclusion, treatment with or without extraction of first premolars, overbite, stage of dentition, M3 prior angulation and duration of orthodontic treatment. Impaction was determined after radiographic evidence of total closure of the root apex. The chi-square test and Poisson regression (p < 0.05) were used for statistical analysis with a hierarchical approach. Rate ratios (RR) and 95% confidence intervals (CI) were calculated. Mandibular M3 impaction incidence was 17%. Overbite equal to or greater than 4 mm (RR = 1.23, 95%CI: 1.11-1.26, p < 0.001), prior mesial angulation of M3 (RR = 0.59, 95%CI: 0.52-0.68, p < 0.001), non-extraction of first premolars (RR=1.06, 95%CI: 1.01-1.12, P=0.019) and orthodontic treatment time equal to or less than three years (RR = 0.94. 95%CI: 0.90-0.99, p < 0.014) were significantly associated with impacted M3. There was no correlation between the type of Angle malocclusion and the risk of impaction. In conclusion, the incidence of mandibular M3 impaction was considered low. The main pretreatment factors directly involved in impaction were mesioangulation of M3 and overbite equal to or greater than 4 mm. Orthodontic treatment with extraction of first premolars and treatment time greater than 3 years reduce the risk of impaction.

Incremental or maximal mandibular advancement in the treatment of class II malocclusion through functional appliances: A systematic review with meta-analysis.

To systematically review the effects of functional appliances (FA) using incremental vs maximal mandibular advancement regarding cephalometric measurements in class II malocclusion individuals and to assess patient-centred-outcomes. Six electronic databases were searched without restrictions up to April 2020. We included randomized and non-randomized controlled trials using identical FA. Trials involving participants who used adjunct appliances, inter-maxillary elastics, who received surgical treatment or that recruited individuals with cleft lip/palate or craniofacial deformity/syndrome were excluded. Risks of bias assessments were performed using the Cochrane risk of bias tool-2 and ROBINS-I tools. Mean differences (MD) with their 95% confidence intervals were calculated from random-effects meta-analyses. The GRADE tool was used to assess the certainty of the evidence. Six studies were included. Low to very low certainty of evidence indicated that incremental mandibular advancement resulted in greater gains in mandibular length (MD = 0.89 [0.38, 1.34], P = .0005), anterior mandibular displacement (MD = 0.73 [0.40, 1.06], P < .0001) and SNB angle (MD = 0.44 [0.02, 0.85], P = .04). No significant differences were found for maxillary, dento-alveolar and upper airway outcomes between construction bite protocols (P > .05). Study design and appliance-related factors influenced the results of the subgroup analyses. Existing evidence is inadequate to assess patient-related response and long-term outcome could not be assessed. Currently, there are a heterogeneous number of studies with low quality and methodological issues can lead to biases that strongly limit an evidence-based conclusion. Weak evidence suggests gains in mandibular skeletal parameters in the short term using FA with incremental mandibular advancement. Randomized trials evaluating key topics such as patient-centred outcomes need to be conducted to guide clinical management. PROSPERO (CRD42019147436).

Effects of lip bumper therapy on the mandibular arch dimensions of children and adolescents: A systematic review.

INTRODUCTION: The aim of this systematic review was to identify, evaluate, and provide a synthesis of the available literature on the effects of lip bumper (LB) therapy on the mandibular dental arch of children and adolescents. METHODS: MEDLINE, Scopus, Web of Science, Cochrane Library, and Lilacs were systematically searched without restrictions up to May 2019. Risk-of-bias assessment was performed using Cochrane's tool for randomized controlled trials (RCTs) and the Risk of Bias in Nonrandomized Studies of Interventions tool for non-RCTs. The Grading of Recommendations, Assessment, Development and Evaluation tool was used to assess the quality of the evidence. RESULTS: After examination of the full texts, 6 studies were included. One RCT presented unclear risk of bias, and 5 non-RCTs presented serious to moderate risk of bias. LB therapy resulted in a buccal inclination of the incisors, distalization of the permanent first molars, and distal inclination of the permanent first molars, which increased perimeter and arch length. An increase in the arch width with greater gain in the interpremolar and/or deciduous molar distance and less gain in intercanine and intermolar distances was also reported. LB therapy increased the risk of second molar impaction with inclination >30° and the risk of ectopic eruption when treatment time was >2 years. The level of the evidence was graded as very low for variable arch length and second molar eruption disturbances. All other outcomes were graded as having low level of evidence. CONCLUSIONS: Owing to the low level of certainty identified, the conclusions should be considered cautiously. Increase in arch perimeter and width was attributed to the proclination of the incisors, buccalization of the deciduous molar and premolar areas, and distal inclination of the molars. However, there was an increased chance of impaction and ectopic eruption of permanent second molar after treatment with LB.

Systematic review of biological therapy to accelerate orthodontic tooth movement in animals: Translational approach.

OBJECTIVES: To systematically review and evaluate what is known regarding contemporary biological therapy capable of accelerating orthodontic tooth movement (OTM) in animal model. MATERIALS AND METHODS: MedLine, Scopus, Web of Science and OpenGrey were searched without restrictions until June 2019. Following study retrieval and selection, relevant data was extracted using a standardized table. Risk of bias (RoB) assessment was performed using the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) tool. RESULTS: Fifty-one animal studies were included. Two biological therapies were identified as capable of accelerating the OTM: chemical methods (49 studies) and gene therapy (2 studies). The main substances that increased the OTM rate were cytokines (13 studies), followed by growth factors (6 studies) and hormones (5 studies). Most studies were assessed to be at unclear or high RoB. The application protocols, measurement and reporting of outcomes varied widely and methodologies were not adequately reported. CONCLUSIONS: Although biological therapies to accelerate OTM have been widely tested and effective in preclinical studies, the validity of the evidence is flawed to support translational of these results. There is a need for well-designed experimental studies to translate these methods for clinical field.

Impaction of mandibular third molars after orthodontic treatment by the edgewise method: a retrospective study

Abstract This study aimed to determine the incidence of mandibular third molar (M3) impaction after orthodontic treatment by edgewise appliances, and identify possible determinant factors of M3 impaction. A retrospective cohort study was conducted with 1154 patients. Complete orthodontic records were analyzed pretreatment and posttreatment, considering the following variables: type of Angle malocclusion, treatment with or without extraction of first premolars, overbite, stage of dentition, M3 prior angulation and duration of orthodontic treatment. Impaction was determined after radiographic evidence of total closure of the root apex. The chi-square test and Poisson regression (p < 0.05) were used for statistical analysis with a hierarchical approach. Rate ratios (RR) and 95% confidence intervals (CI) were calculated. Mandibular M3 impaction incidence was 17%. Overbite equal to or greater than 4 mm (RR = 1.23, 95%CI: 1.11-1.26, p < 0.001), prior mesial angulation of M3 (RR = 0.59, 95%CI: 0.52-0.68, p < 0.001), non-extraction of first premolars (RR=1.06, 95%CI: 1.01-1.12, P=0.019) and orthodontic treatment time equal to or less than three years (RR = 0.94. 95%CI: 0.90-0.99, p < 0.014) were significantly associated with impacted M3. There was no correlation between the type of Angle malocclusion and the risk of impaction. In conclusion, the incidence of mandibular M3 impaction was considered low. The main pretreatment factors directly involved in impaction were mesioangulation of M3 and overbite equal to or greater than 4 mm. Orthodontic treatment with extraction of first premolars and treatment time greater than 3 years reduce the risk of impaction.