Craniomandibular transverse tomographic evaluation after anterior open bite orthodontic treatment with miniplates anchorage.

BACKGROUND: Skeletal anterior open bite (SAOB) represents one of the most complex and challenging malocclusions in orthodontics. Orthodontic treatment supported by miniplates enable to reduce the need for orthognathic surgery. Transverse dimension may be affected by intrusion biomechanics. This study aims to assess transverse bone alterations in patients with SAOB who underwent orthodontic treatment with absolute anchorage using four miniplates. METHODS: A total of 32 patients of both sexes, with an average age of 33.8 years, diagnosed with SAOB and treated orthodontically with four miniplates (one in each hemiarch), were selected for this study. Tomographic examinations were performed before (T1) and after (T2) orthodontic treatment. Linear measurements (width of the maxillary base, maxillary alveolar, maxillary root, maxillary dental cusp, mandibular alveolar) and angular measurements (maxillary intermolar angle) were assessed in these images. The Shapiro-Wilks normality tests were applied to verify data distribution, and the paired t-test was used to compare the initial and final measures obtained. RESULTS: Among the evaluated parameters, the maxillary alveolar width, maxillary dental cusp width, mandibular alveolar cusp width, and intermolar angle showed statistically significant differences between T1 and T2 (p < 0.05). However, maxillary base and maxillary root widths showed no significant difference (p > 0.05). CONCLUSIONS: Intrusion and distalization with miniplates in SAOB therapy may lead to significant expansive changes, due to molars cusps width and buccal inclination increase restricted at the alveolar level.

Effects of polymethyl methacrylate-based bone cement graft for treating excessive gingival display and its dimensional facial changes: 12-Month clinical study.

Objective: to present a 12-month follow-up with photographic and tomographic analyses of the effect of polymethyl methacrylate-based bone cement graft (PMMA) in gingival exposure (GE) in patients with excessive gingival display (EGD). Methods: Twelve patients with EGD were included. The PMMA was surgically placed. A frontal and lateral photograph protocol was performed at baseline (T0), 3 (T3), 6 (T6), and 12 months (T12) post-operatively. Soft tissue cone-beam computed tomography (ST-CBCT) was performed at T0 and T12. Measures included GE, length of the lip vermilion (LLV), lip shape (LS), nose width (NW), filter width (FW), nasolabial angle (NAS) while smiling, and nasolabial angle at rest (NAR). The height, thickness, and volume of the cement graft were also measured in the ST-CBCT. The comparisons were performed by Kruskal-Wallis test at 5 % of significance (p < 0.05). Results: The height, thickness, and volume of the PMMA were respectively 12.84 ± 1.59 mm, 3.83 ± 0.53, and 1532.02 ± 532.52 mm3. PMMA significantly decreased GE from 8.33 ± 1.25 mm (T0) to 6.60 ± 0.93 mm (T12) (p < 0.01). NAR was 98.34 ± 9.28° at T0 and increased to 105.13 ± 7.33° at T12; however, the angle value was not statistically different (p = 0.08). LLV, LS, NW, FW, and NAS did not exhibit statistical differences between the baseline and follow-up periods. Conclusions: PMMA significantly decreased GE in a 12-month follow-up without influencing adjacent soft tissue anatomical structures.

Dental and periodontal dimensions stability after esthetic clinical crown lengthening surgery: a 12-month clinical study.

OBJECTIVES: To evaluate the stability of periodontal tissues 3 (T3), 6 (T6), and 12 (T12) months after esthetic crown lengthening (ACL) and the possible correlations between changes in those structures. MATERIALS AND METHODS: Twenty individuals were evaluated through clinical assessment, photography, and tomography. Measurements included gingival margin (GM), clinical crown length (CCL), interdental papilla height (PH) and width (PW), gingival thickness (GT), bone thickness (BT), probing depth (PD), distance between alveolar crest and GM, distance between alveolar crest and cementoenamel junction. Nonparametric and correlation statistics were performed (p < 0.05). RESULTS: CCL at T0 was 7.42 ± 0.70 mm and increased to 9.48 ± 0.49 mm immediately after ACL, but it decreased to 8.93 ± 0.65 mm at T12. PD decreased 0.60 mm from T0 to T6, and it increased 0.39 mm from T6 to T12. BT decreased 0.20 mm, while GT increased 0.29 mm from T0 to T12. Both PW and PH showed enlargement in T12. A positive moderate correlation was found between CCL/T0 and CCL/T12, GT/T0 and AC-GM/T12, BT/T0 and GT/T12. A few negative moderate correlations were PD/T0 and CCL/T12, PD/T0 and PH/T0, PD/T0 and BT/T12. CONCLUSIONS: ACL procedure was effective. Although some rebound occurred, that was not clinically important. PD tended to reestablish its original length, partially due to a migration of GM during the healing period. Besides, a thickening of supracrestal soft tissues was observed. CLINICAL RELEVANCE: The present study centers on the factors influencing the stability of periodontal tissues after esthetic crown lengthening, underscoring the procedure's influence on esthetics and biology and the need for careful treatment planning.

Periradicular repair after single- and two-visit root canal treatments using ultrasonic irrigant activation and calcium hydroxide dressing of teeth with apical periodontitis: study protocol for randomized controlled trials.

BACKGROUND: In certain clinical situations, root canal treatment in teeth with apical periodontitis is performed in multiple visits, with the use of intracanal dressing between visits, aiming to reduce microorganisms and their by-products of the root canal system prior to filling. However, in recent years, discussions have been growing about the real need for the use of intracanal dressing in these cases. The use of ultrasonic activation of the auxiliary chemical substance has increased the potential for decontamination promoted during the chemomechanical preparation of the root canal. Thus, this study is designed to explore whether the use of intracanal dressing between visits during endodontic treatment favors periradicular repair in teeth with apical periodontitis. METHODS: This is a randomized, prospective, double-blinded, controlled clinical trial designed to evaluate 3 distinct clinical approaches used during endodontic therapy: group 1-root canal treatment in a single visit (RCT-SV); group 2-root canal treatment in two visits with intracanal dressing (RCT-TVWD); and group 3-root canal treatment in two visits without intracanal dressing (RCT-TVWOD). A total of 150 adult patients aged 18 to 60, with at least one tooth diagnosed with asymptomatic apical periodontitis and periradicular lesion (confirmed with a cone beam computed tomography (CBCT)), will be randomized and will undergo one of the types of clinical approaches during endodontic therapy. Patients' postoperative pain levels will also be recorded in periods of 24, 48, and 72 h and 7 days. Subsequently, clinical findings and long-term follow-up evaluations, with periradicular repair, will be performed at 6 and 12 months by intraoral periapical radiograph (IOPAR) and CBCT at the 24-month follow-up. DISCUSSION: This study will evaluate the periradicular repair of mandibular molar teeth with apical periodontitis, providing information about the efficacy, benefits, and safety of performing the endodontic treatment in a single and two visits, with and without the use of calcium hydroxide dressing. All endodontic therapy procedures will be performed under a dental operating microscope and using ultrasonic activation of auxiliary chemical substances. These results may contribute to changes in the clinical approaches adopted during endodontic therapy of teeth with apical periodontitis and reveal the potential of complementary approaches that aim to enhance the decontamination of the root canal system during the preparation stage. TRIAL REGISTRATION: ClinicalTrials.gov NCT05256667. Registered on 24 February 2022.

Finite element analysis of a newly designed miniplate for orthodontic anchorage in the maxillary anterior region.

INTRODUCTION: Multiple force vector applications may be indicated when an arch segment or en masse intrusion is needed. This finite element method study aimed to evaluate the total deform the stress yielded in the bone and the miniplate when forces with different directions and magnitudes were applied. METHODS: First, the prototyped skull model was fabricated on the basis of computed tomography (CT) scans. On this model, the miniplate was fixed, and orthodontic appliances were attached. Then, a 3-dimensional finite element model was constructed by reproducing the characteristics of the physical model. Seven situations were investigated, which diverged in the point of force application, the direction and the number of force vectors, and the force magnitudes. RESULTS: When the force was applied at 1 point, similar behavior could be observed concerning the deformation and the stress in the miniplate, the maxilla, and the screw holes. Most deformation and stress appeared in the transmucosal arm below the step bend and at the force application point. The angled vectors (-45° and 30°) presented smaller values concerning the vertical vectors. Similar or better performances could be observed when the forces were simultaneously applied at the 2 points. CONCLUSIONS: The newly designed miniplate showed similar or improved performances when multiple vectors were applied at the 2 points simultaneously compared with the force applied at 1 point. This newly designed miniplate may present improved performance in a clinical situation when multiple forces are demanded.

Aesthetic perception of smile in long face pattern patients who underwent maxillary impaction with miniplates or orthognathic surgery.

INTRODUCTION: The gummy smile is perceived in 10% of the population aged 20 to 30 years old, and it causes an aesthetic imbalance in the smile. This study investigated the existence of differences in the aesthetic perception of the smile after correcting the gummy smile using two different techniques: orthognathic surgery for maxillary impaction and miniplate-aided orthodontic impaction. METHODS: Photographs of 16 Long Face Pattern female patients were evaluated by 56 oral and maxillofacial surgeons, 56 orthodontists, and 56 laypeople before and after the treatment with one of the two techniques. These photographs were standardized using the Photoshop program, randomly organized, and then presented to the evaluators via the Google Meeting® application in the PowerPoint® program. To evaluate the attractiveness of the smile, the Visual Analogue Scale (VAS) was used. To analyze the intra and inter-examiner concordances, Spearman's correlation and Kendall's concordance tests were used, respectively. For intergroup comparison, the Friedman test was used, with a 5% significance level. RESULTS: For all three groups of evaluators, the post-treatment evaluation results were superior to the results before the treatment: surgeons and orthodontists assigned higher scores for surgical cases and laypeople for orthodontic cases. CONCLUSION: From a clinical point of view, there was no difference between the results of both techniques with regard to the aesthetic perception of smiles. A gingival exposure ranging from zero to two millimeters was considered the most aesthetic for all evaluators.

Effect of orthodontic maxillary posterior en masse intrusion anchored with miniplates on maxillary sinuses volume. Retrospective CBCT study.

OBJECTIVE: To evaluate, by means of cone beam computed tomography (CBCT), the volume change of maxillary sinuses in patients that underwent orthodontic maxillary posterior en masse intrusion anchored with miniplates. MATERIALS AND METHODS: The sample consisted of pretreatment (T1) and posttreatment (T2) CBCT scans obtained from 14 patients (4 male and 10 female), with a mean age of 32.4 years, that underwent orthodontic maxillary posterior en masse intrusion anchored with miniplates in the zygomatic crest. The mean treatment duration was 20 months and the mean intrusion movement was 2.4 mm. Maxillary sinus volume was measured by means of the software ITK SNAP (version 3.8.0) in T1 and T2 CBCT scans. The changes in sinuses volume were calculated by T1-T2 values. Data were analyzed statistically with Wilcoxon test at 5% of level of significance and the method error was analyzed with Wilcoxon test, intraclass correlation and Dahlberg's formula. RESULTS: The mean difference (T1-T2) was -242.85 mm³ (p = 0.396) for the right sinus and -32.5 mm³ (p = 0.875) for the left sinus. A slight increase in the volume of the sinuses was shown although these results were not statistically significant. CONCLUSION: The orthodontic maxillary posterior en masse intrusion anchored with miniplates did not influence significantly the maxillary sinus volume.

Histomorphometric evaluation of periodontal compression and tension sides during orthodontic tooth movement in rats

OBJECTIVE: The purpose of this study was to evaluate the thickness of the periodontal ligament of rat molars during orthodontic tooth movement (OTM). METHODS: Thirty Wistar rats were divided into three groups of 10 animals each: GI, GII and GIII and the mice were euthanized at 7, 14 and 21 days, respectively. Experimental subjects were compared to their respective controls by the Mann-Whitney test. Comparison of values between compression and tension sides were performed during the same and different time periods through Analysis of Variance (ANOVA), Kruskal-Wallis test and, subsequently, Tukey's test. RESULTS: Groups GI and GII showed decreased PDL size in the apical regions of the mesiobuccal root and in the cervical region of the distobuccal root. There was also an increased PDL in the cervical regions of the mesiobuccal root, apical region of the distobuccal root and middle region of both roots. CONCLUSION: The reduction and increase in PDL size were seen in the same root, which characterizes tooth inclination. The apical, middle and cervical regions were compared with one another in each time period and at three times: 7, 14 and 21 days. They were also compared in each region, confirming a tipping movement in GI and GII and a gradual decreased intensity between GI to GII, reaching normal dimension in GIII.

New perspective on Herbst therapy for skeletal Class II malocclusions: a proposal for maxillary protrusion management.

Angle Class II malocclusions may present morphologic deviations originated from the maxilla, mandible, or both. Since its reintroduction by Pancherz, the Herbst appliance has demonstrated effectiveness in the management of patients with mandibular deficiency. Because of the intermaxillary anchorage, the action of mandibular advancement provokes simultaneous reaction of maxillary restriction, similar to high-pull headgear. This aimed of this report is to compare two cases treated in two phases. In the first interceptive phase, the transverse problem was corrected by rapid maxillary expansion, which was followed by a Herbst appliance for mandibular advancement; in the second corrective phase, the cases were finished with fixed appliances. Although Herbst appliances were used in both patients, one patient with maxillary protrusion and another with mandibular deficiency, their use targeted different types of skeletal discrepancies. This difference allowed for the comparison of treatment effects, and although both patients had their malocclusion corrected, it seems reasonable to conclude that the final outcome was more favorable for the patient with maxillary protrusion.

Epidemiologia do Padrão Face Longa em escolares do Ensino Fundamental do município de Bauru - SP / Epidemiology of long face pattern in schoolchildren attending fundamental schools at the city of Bauru - SP

OBJETIVO: o objetivo deste trabalho foi classificar e determinar a prevalência dos indivíduos portadores de comprometimento vertical nas relações faciais, conforme a severidade da discrepância e, especialmente, dos portadores de Padrão Face Longa. MÉTODOS: a amostra constou de 5.020 sujeitos de nacionalidade brasileira, de ambos os sexos, com idades entre 10 anos e 16 anos e 11 meses, matriculados no Ensino Fundamental do município de Bauru-SP. O exame da morfologia facial constou da observação direta da face, em normas frontal e lateral, sempre com os lábios em repouso, buscando identificar aqueles indivíduos que apresentassem comprometimento vertical nas relações faciais. Esses, uma vez identificados, foram classificados, considerando-se a severidade, em três subtipos: moderado, médio e grave. Para fins de determinação da prevalência dos portadores de Padrão Face Longa, apenas os classificados como dos subtipos médio e grave foram considerados. RESULTADOS: observou-se uma prevalência de 34,94 por cento de comprometimento vertical nas relações faciais e 14,06 por cento de Padrão Face Longa. CONCLUSÃO: os resultados obtidos no presente estudo permitiram concluir que a prevalência do comprometimento vertical nas relações faciais e do Padrão Face Longa foi maior do que a presumida com base na literatura.

OBJECTIVE: This study aimed to classify and determine the prevalence of individuals with vertical alteration of facial relationships, according to the severity of discrepancy, especially individuals with long face pattern. METHODS: The sample was composed of 5,020 individuals of Brazilian nationality, of both genders, aged 10 years to 16 years and 11 months, attending fundamental schools at the city of Bauru-SP. Examination of facial morphology comprised direct observation of the face in frontal and lateral views, always with the lips at rest, aiming to identify the individuals presenting vertical alteration of facial relationships. After identification, these individuals were scored, according to severity, into three subtypes, namely mild, moderate and severe. The prevalence of individuals with long face pattern considered only the individuals scored as subtypes moderate and severe. RESULTS: There was prevalence of 34.94 percent of vertical alteration of facial relationships and 14.06 percent of long face pattern. CONCLUSIONS: The results obtained in this study revealed that the prevalence of vertical alteration of facial relationships and long face pattern was higher than reported in the literature.

Características cefalométricas do Padrão Face Longa: considerando o dimorfismo sexual / Cephalometric features of Long Face Pattern: concerns about sexual dimorphism

OBJETIVO: o presente estudo avaliou a hipótese de variação das características cefalométricas de acordo com o gênero para portadores de Padrão Face Longa. METODOLOGIA: foi analisado um total de 73 telerradiografias em norma lateral, sendo 34 Padrão Face Longa e 39 Padrão I (grupo controle), selecionadas com base na morfologia facial, sem considerar as relações oclusais. Foram avaliados: padrão de crescimento facial, alturas faciais anteriores e posterior, relação maxilomandibular, além das relações dentárias com suas bases apicais. RESULTADOS: o grupo controle (Padrão I) apresentou dimorfismo (p<0,001) no comprimento efetivo da maxila e da mandíbula, além das alturas faciais avaliadas. Foram significantes também (p<0,05) as proporções entre as alturas faciais e as distâncias entre os incisivos e molares em relação aos planos palatino e mandibular. Para os portadores de Padrão Face Longa, as mesmas variáveis cefalométricas não mostraram diferenças significantes entre os gêneros (p>0,05), exceto os comprimentos efetivos da maxila e da mandíbula, além da altura facial anterior inferior e posterior (p<0,05). CONCLUSÕES: concluiu-se que enquanto ocorreu dimorfismo nos indivíduos Padrão I, para as estruturas influenciadas pela diferença no tamanho esquelético entre os gêneros, isso não aconteceu nos portadores de Padrão Face Longa. Essa maior similaridade entre os gêneros provavelmente ocorreu porque a deformidade, mais grave no gênero feminino, foi suficiente para anular o menor tamanho esquelético esperado para estes indivíduos.

AIM: The purpose of this study was to evaluate the presence of different cephalometric characteristics between genders with Long Face Pattern. METHODS: a total of 73 lateral cephalometric radiographs were evaluated, with 34 Long Face Pattern and 39 Class I Pattern (control) subjects, sampled with basis on the facial morphology, regardless the sagital occlusal relationships. Facial growth pattern, anterior and posterior facial heights, inter-jaw relationship and dentoskeletal relationship were evaluated. RESULTS: It was observed sexual dimorphism in Class I Pattern subjects (p<0.001) in the effective length of maxilla and mandible, as well as the facial heights. Also, significant differences were observed among facial height ratios and the distances from incisors and molars to palatal and mandibular plane. For Long Face Pattern subjects, these cephalometric variables showed no sexual dimorphism (p>0.05), except the effective length of maxilla and mandible, lower anterior and posterior facial heights (p<0.05). CONCLUSIONS: It was concluded that sexual dimorphism was evident in Class I Pattern subjects due to the skeletal size differences. However, in Long Face Pattern subjects, similarity was observed between genders, showing that the skeletal deformity was more severe in female subjects, enough to achieve skeletal size comparable to those of male subjects.

Maxillary canine--first premolar transposition.

Tooth transpositions present at a relatively low incidence in the world population and primarily affect maxillary canines and premolars. Treatment of this disturbance should take into account aspects such as facial pattern, age, malocclusion, tooth-size discrepancy, stage of eruption, and magnitude of the transposition. Mechanics for correction should be entirely individualized, reducing the risks and adverse effects. Practitioners often select simpler options, indicating extraction of permanent teeth, which is an irreversible procedure that may bring about damages to the patient. This study presents a case report and treatment of unilateral transposition of maxillary canine and premolar with repositioning of affected teeth to their respective normal positions.

Histomorfometria do periodonto em estado diabético inicial após movimentação dentária experimental em ratos / Periodontal histomorphometry following experimental tooth movement in short-term diabetic rats

Este estudo avaliou histomorfometricamente o periodonto após a movimentação dentária experimental em ratos sob estado diabético inicial. Numa amostra de 40 ratos, 20 normais e 20 diabéticos induzidos por estreptozotocina, utilizou-se o lado esquerdo como lado experimental, movimentando o primeiro molar superior com uma mola fechada de 25 cN, enquanto que o lado direito, sem acessório, serviu como controle. Realizou-se a eutanásia dos animais, respectivamente, 3, 7, 14 e 21 dias após movimentação para proceder preparo histológico convencional e análises microscópicas quantitativas e qualitativas. Macroscopicamente, exceto no terceiro dia, os ratos diabéticos demonstraram menores magnitudes de movimentação dentária. Microscopicamente, houve diferenças significantes quando as áreas do espaço periodontal dos ratos normais (p<0,01) e diabéticos (p<0,05) foram comparadas com seus respectivos controles nos quadrantes cervicais diastais, respectivamente, no 3º, 7º e 14º dia. Não se observou diferenças significantes entre os ratos normais e diabéticos exceto o quadrante apical distal (p<0,05) no 7o dia pós-movimentação. Qualitativamente, a neoformação do osso alveolar dos ratos diabéticos foi menor quando comparado com os normais. Apesar das diferenças qualitativas nas respostas teciduais do periodonto, a condição diabética em estado inicial mostrou pouco impacto clínico sobre o procedimento de movimentação dentária induzida

A utilização da Estatística na Ortodontia / The application of Statistics in Orthodontics

A estatística exerce um papel fundamental no método científico, a qual se preocupa em organizar, descrever, analisar e interpretar os dados obtidos a partir de uma observação ou de um experimento. Todavia, ela continua sendo pouco acessível na interpretação, seja por parte do leitor ou por parte daquele que a utiliza. Às vezes, a estatística é mal aplicada ou não compreendida devido aos termos, com significado próprio. Além disso, existem poucos artigos científicos da área de Ortodontia relacionados com este assunto. Assim, o presente artigo propõe realisar um levantamento sobre as freqüências do uso da estatística, fazer considerações sobre a seleção dos seus métodos e explanar sobre as possíveis interpretações dos resultados