Comparison of speech changes caused by four different orthodontic retainers: a crossover randomized clinical trial.

OBJECTIVE: This study aimed to compare the influence of four different maxillary removable orthodontic retainers on speech. MATERIAL AND METHODS: Eligibility criteria for sample selection were: 20-40-year subjects with acceptable occlusion, native speakers of Portuguese. The volunteers (n=21) were divided in four groups randomized with a 1:1:1:1 allocation ratio. The four groups used, in random order, the four types of retainers full-time for 21 days each, with a washout period of 7-days. The removable maxillary retainers were: conventional wraparound, wraparound with an anterior hole, U-shaped wraparound, and thermoplastic retainer. Three volunteers were excluded. The final sample comprised 18 subjects (11 male; 7 female) with mean age of 27.08 years (SD=4.65). The speech evaluation was performed in vocal excerpts recordings made before, immediately after, and 21 days after the installation of each retainer, with auditory-perceptual and acoustic analysis of formant frequencies F1 and F2 of the vowels. Repeated measures ANOVA and Friedman with Tukey tests were used for statistical comparison. RESULTS: Speech changes increased immediately after conventional wraparound and thermoplastic retainer installation, and reduced after 21 days, but not to normal levels. However, this increase was statistically significant only for the wraparound with anterior hole and the thermoplastic retainer. Formant frequencies of vowels were altered at initial time, and the changes remained in conventional, U-shaped and thermoplastic appliances after three weeks. CONCLUSIONS: The thermoplastic retainer was more harmful to the speech than wraparound appliances. The conventional and U-shaped retainers interfered less in speech. The three-week period was not sufficient for speech adaptation.

Comparison of smile attractiveness in cases with gummy smile treated with botulinum toxin and maxillary impaction surgery: A retrospective study.

This study aimed to compare the smile's attractiveness in patients submitted to the treatment of gummy smiles with botulinum toxin or maxillary impaction surgery. The retrospective sample comprised 26 patients divided into two groups: Group 1 (BTX): 13 patients (12 females and 1 male) with a mean age of 28.06 years (s.d. = 6.09) and mean gingival exposure during smile of 5.18 mm (s.d. = 1.51) treated with botulinum toxin; Group 2 (SURGICAL): 13 patients (9 females and 4 males) with a mean age of 30.59 years (s.d. = 5.72) and mean gingival exposure during smile of 5.21 mm (s.d. = 1.55) treated with orthognathic maxillary impaction surgery. The group of evaluators comprised 317 participants, divided into 143 orthodontists (85 females and 58 males) with a mean age of 41.40 (s.d. = 9.30); 62 dentists (47 female and 15 male) with a mean age of 35.44 (s.d. = 10.44), and 112 lay people (74 female and 38 male) with a mean age of 46, 91 (s.d. = 10.11) in a questionnaire on Google Forms. Without knowing the therapy used, the evaluators assigned scores to the photographs of the posed smile taken before (T1) and after (T2) treatment. Intergroup comparison of smile attractiveness was performed using the t-independent, one-way ANOVA, and Tukey tests. There was a significant improvement in smile attractiveness with treatment in both groups; however, the improvement was significantly better in the surgical group than in the BTX group. Orthodontists rated smile attractiveness significantly higher than dentists and laypersons for the final phase of the BTX and surgical groups. There was a significant improvement in the smile attractiveness with botulinum toxin application and orthodontic-surgical treatment. However, orthognathic surgery promoted a greater improvement in smile attractiveness than the application of botulinum toxin.

Comparative cephalometric study of the airways between different ethnic groups with normal occlusion.

OBJECTIVE: This study aimed to compare the nasopharynx and oropharynx airway dimensions of Caucasians, Blacks, Japanese, Japanese Brazilians, and Black Caucasians. METHODS: A sample of 216 lateral radiographs of untreated young Brazilian subjects (mean age of 12.94 years; SD 0.88) were divided into five groups: Black Caucasian, Black, Caucasian, Japanese, and Japanese Brazilian. Lateral radiographs were used to measure the oropharynx (from the midpoint on the soft palate to the closest point on the anterior pharyngeal wall) and the nasopharynx (from the intersection of the posterior border of the tongue and the inferior border of the mandible to the closest point on the posterior pharyngeal wall). Analyses of variance (ANOVA) and Tukey's test were performed (p< 0.05). RESULTS: The linear dimension of the oropharynx was similar among the different ethnic groups. Caucasian individuals presented a significantly greater linear dimension of the nasopharynx than Black Caucasian and Black individuals. CONCLUSIONS: All the groups had similar buccopharyngeal values. However, Caucasian individuals had significantly higher values when compared to Black Caucasians and Black individuals.

Effect of poly-L-lactic acid and polydioxanone biostimulators on type I and III collagen biosynthesis.

OBJECTIVE: Safe, effective, and biocompatible minimally invasive procedures with the potential to stimulate collagen production have been made to recover dermal thickness and skin quality. The main of this animal model experiment was to observe the effect of poly-L-lactic acid (PLLA) and polydioxanone (PDO) biostimulators in collagen I and III after hypodermal injection. METHODOLOGY: Sixteen adult female rats (Wistar) were randomized into four groups and had dorsal treatment with: G1: hypodermic subcision (HS) only; G2: HS and PLLA hypodermic injection (HI), G3: HS and PDO HI; G4: Control, with no treatment. RESULTS: In histochemical, it was observed hypodermal and dermal tissue in more organized thickness in G3 and in G4 when compared to G1 and G2. There was few difference in G1 compared to G4. The tissue of G2 showed irregularities in the arrangement of collagen fibers, less defined structure and lower distribution of type I collagen compared to the other groups. There is a greater tendency for the proportions of type III collagen among tissues treated with both biostimulators (G2 and G3). PLLA and PDO had relatively similar percentages of collagen when compared to G4. The amount of type I collagen was higher in tissues treated with subcision, while type III collagen was higher in tissues treated with both biostimulators. CONCLUSION: G3 showed better performance in collagen production, although small, when compared with G2.

Third Molar Comparison in Class I and II Extraction and Non-extraction Orthodontic Treatment: A Retrospective Longitudinal Study.

Objective: This study compared third molar angulation and eruption status in Class I and II malocclusions after orthodontic treatment with and without first premolar extractions. Methods: The sample comprised 93 patients divided into four groups: Group 1, Class I malocclusion treated with first premolar extractions; Group 2, Class I malocclusion treated without extractions; Group 3, Class II malocclusion treated with first premolar extractions; and Group 4, Class II malocclusion treated without extractions. Panoramic radiographs were used to evaluate the third molar mesiodistal angulations at T1 (pretreatment), T2 (posttreatment), and T3 (long-term posttreatment). Third molar eruption status was assessed in dental casts. Intergroup angulations and eruption status comparisons were performed using one-way analysis of variance (ANOVA), followed by Tukey's test and Kruskal-Wallis test, respectively. Results: Significantly greater mesial angulation and percentage of erupted right maxillary third molars were observed in the Class I extraction group. Significantly greater eruption status of the right mandibular third molars was observed in the Class I and Class II malocclusion extraction groups. Conclusion: Class I and II malocclusion extraction treatment exhibited more favorable angulations and a greater number of erupted third molars than non-extraction treatment. The non-extraction groups exhibited a greater percentage of unerupted third molars.

Relationship Between Dentofacial Features and Bullying in School children.

Purpose: The purpose of this cross-sectional study was to evaluate the association between clinician-assessed (actual) and self-assessed (perceived) dentofacial features and their association with bullying in schoolchildren. Methods: The sample comprised 519 schoolchildren aged 10 to 12 years old (235 boys and 284 girls) randomly selected from private and public schools. Clinical evaluations were performed to record dento- facial features, and the children were asked a self-reported questionnaire about their personal experience of bullying and perceived dentofacial features. Descriptive statistics (counts and percentages) as well as chi-square to analyze the association between variables were applied. Results: The results showed that 57.2 percent of the children reported being bullied, and the mainly perceived dentofacial features cited were: "crooked teeth" (46.3 percent), "shape or color of teeth" (45.5 percent), "upper front teeth sticking out" (43.8 percent), and "having a gap between the teeth or having missing teeth" (35.5 percent). Statistically significant associations between actual and perceived dentofacial features and involve- ment in bullying were observed for anterior crowding (P=0.01), anterior crossbite (P<0.001), lip competence (P=0.008), and anterior dental trauma (P=0.04). Conclusion: Some actual and perceived dentofacial traits are associated with bullying, so these features and the schoolchil- dren's compliances should be considered to determine the treatment need.

Smile attractiveness in patients treated with or without 4 premolar extractions: A 36-year follow-up.

INTRODUCTION: This study aimed to assess the smile attractiveness in patients treated with or without 4 premolar extractions at a 36-year follow-up. METHODS: The sample comprised 52 patients with Class I and II malocclusion divided into 2 groups. Group 1 consisted of 15 patients treated without extractions (10 females and 5 males), with a mean pretreatment, posttreatment, and long-term posttreatment (T3) age of 13.2, 15.1, and 49.8 years, respectively. The mean treatment time was 1.9 years, and the mean long-term follow-up period was 34.7 years. Group 2 consisted of 37 patients (25 females and 12 males) treated with 4 premolar extractions, with a mean pretreatment, posttreatment, and long-term posttreatment age of 13.3, 15.7, and 53.6 years, respectively. The mean treatment time was 2.3 years, and the mean long-term follow-up period was 37.9 years. The mean retention time was 2 years for both groups. Frontal smiling photographs were obtained at long-term follow-up. Smile attractiveness was evaluated in an online questionnaire in which the evaluator could rate the smiling photographs with a 10-point scale. The randomly selected evaluator sample consisted of 62 laypeople, 33 dentists, and 89 orthodontists. Independent t tests, 1-way analysis of variance, and Tukey tests were used for intergroup comparisons at P <0.05. RESULTS: The smile attractiveness on the long term was similar in the groups treated with 4 premolar extractions (4.70 ± 1.35) or without extractions (4.51 ± 1.46). Women and orthodontists were more critical in assessing smile attractiveness than men, dentists, and laypeople. CONCLUSIONS: After long-term posttreatment, the smile attractiveness was similar in patients treated with 4 premolar extractions or without extractions.

Comparison of the efficiency of initial dental alignment with Invisalign® aligners changed every 7 or 14 days in mature adults: Randomized clinical trial.

OBJECTIVE: To compare the anterior crowding correction after sequential use of the first 5 aligners between two aligner exchange protocols (7 and 14 days) in mature adult patients. MATERIALS AND METHODS: Thirty-six patients over 35 years who received orthodontic treatment with Invisalign® were randomly allocated to two different aligner replacement sequence protocols: Group 1: exchange every 7 days (n = 18); and Group 2: exchange every 14 days (n = 18). All patients were scanned with iTero Element 5D® (Align Technology) in two treatment times: at pre-treatment (T1) and after using the first five aligners (T2). Little's Irregularity Index (LII) and arch widths were evaluated with OrthoCAD software. Intra and intergroup comparisons were performed with the dependent and independent t-tests. The results were considered significant for P < .05. RESULTS: Thirty-five patients completed the study. Both groups' maxillary and mandibular Irregularity Indexesi were significantly lower at T2. There was no significant difference in inter-canine, inter-premolar, and intermolar distances. G2 (14 days) presented a greater decrease in mandibular irregularity than G1 (7 days). CONCLUSION: Both exchange protocols (7 and 14 days) effectively correct anterior crowding in the initial phase of orthodontic treatment with aligners in mature adult patients. However, the 14-day exchange protocol provided a greater correction in mandibular anterior crowding in the evaluated period than the 7-day exchange protocol.

Assessment of patients' knowledge and preferences for the use of orthodontic aligners.

OBJECTIVE: To evaluate the knowledge and preference of patients treated at a Dental School in Jaraguá do Sul, Brazil, about using aligners and the reasons for choosing this device as a treatment option. DESIGN: A cross-sectional study. PARTICIPANTS: A total of 82 participants aged 18-45 years recruited at a screening clinic. METHODS: A questionnaire was completed in person using a tablet with digital forms. RESULTS: Almost half of the participants (49%) knew about aligners; 40% were aged 18-24 years, and 77% were female. When observing the images of the types of orthodontic appliances, the aligners had an acceptance rate of 80%. Among the reasons that led to the preference for choosing aligners, 68% cited aesthetics and 42% comfort. CONCLUSION: Recently, clear aligners have become a popular choice for orthodontic treatment, particularly among adults. Despite their popularity and effectiveness, many patients still need more information about aligner treatment. Over half of the respondents did not know what orthodontic aligners were. Younger participants had more knowledge about aligners than older participants. Patients still need more knowledge about the types of appliances available for orthodontic treatment. When presented with images of the kinds of devices available, almost 80% of participants showed greater satisfaction with aligners.

Long-term profile attractiveness of patients with Class I and II malocclusion treated with and without extractions: A 35-year follow-up.

INTRODUCTION: The objective of this study was to compare the profile attractiveness in subjects treated with and without extractions after the long-term 35-year follow-up, according to laypeople, dentists, and orthodontists. METHODS: A total of 40 patients with Class I and II malocclusion were divided into 2 groups, according to the treatment protocol: extraction (E) group, extractions of 4 premolars (n = 24), with mean pretreatment (T1), posttreatment (T2), and long-term posttreatment (T3) ages of 13.13, 15.50 and 49.56 years, respectively. The mean treatment time (T2 - T1) was 2.37 years, and the long-term follow-up (T3 - T2) was 34.19. Nonextraction (NE) group (n = 16), with mean ages at T1, T2, and T3 of 13.21, 15.07, and 50.32 years, respectively. The mean (T2 - T1) was 1.86 years, and the (T3 - T2) was 35.25 years. Lateral cephalograms were used to perform profile facial silhouettes, and an online evaluation was performed by 72 laypeople, 63 dentists, and 65 orthodontists, rating the attractiveness from 1 (least attractive) to 10 (most attractive). The intragroup comparison was performed with the repeated measures analysis of variance and Tukey tests. Intergroup comparison was performed with t tests, 1-way analysis of variance, and Tukey tests. RESULTS: The E group had a longer treatment time than that of the NE group. In the pretreatment, posttreatment, and long-term posttreatment stages, the E and NE groups showed similar profile attractiveness. Laypersons and dentists were more critical than orthodontists. CONCLUSIONS: At long-term posttreatment follow-up, profile attractiveness was similar in patients treated with and without extractions.

Comparative cephalometric study of the airways between different ethnic groups with normal occlusion

ABSTRACT Objective: This study aimed to compare the nasopharynx and oropharynx airway dimensions of Caucasians, Blacks, Japanese, Japanese Brazilians, and Black Caucasians. Methods: A sample of 216 lateral radiographs of untreated young Brazilian subjects (mean age of 12.94 years; SD 0.88) were divided into five groups: Black Caucasian, Black, Caucasian, Japanese, and Japanese Brazilian. Lateral radiographs were used to measure the oropharynx (from the midpoint on the soft palate to the closest point on the anterior pharyngeal wall) and the nasopharynx (from the intersection of the posterior border of the tongue and the inferior border of the mandible to the closest point on the posterior pharyngeal wall). Analyses of variance (ANOVA) and Tukey's test were performed (p< 0.05). Results: The linear dimension of the oropharynx was similar among the different ethnic groups. Caucasian individuals presented a significantly greater linear dimension of the nasopharynx than Black Caucasian and Black individuals. Conclusions: All the groups had similar buccopharyngeal values. However, Caucasian individuals had significantly higher values when compared to Black Caucasians and Black individuals.

RESUMO Objetivo: Este estudo teve como objetivo comparar as dimensões das vias aéreas da nasofaringe e da bucofaringe de leucodermas, melanodermas, xantodermas, feodermas e nipo-brasileiros. Material e métodos: Uma amostra de 216 telerradiografias laterais de jovens brasileiros não tratados (idade média de 12,94 anos; DP 0,88) foi dividida em cinco grupos: melanodermas, leucodermas, xantodermas, feodermas e nipo-brasileiros. As telerradiografias foram utilizadas para medir a bucofaringe (do ponto médio do palato mole até o ponto mais próximo da parede anterior da faringe) e a nasofaringe (da intersecção da borda posterior da língua e da borda inferior da mandíbula até o ponto mais próximo). Foram realizadas análises de variância (ANOVA) e teste de Tukey (p < 0,05). Resultados: A dimensão linear da bucofaringe foi semelhante entre os diferentes grupos étnicos. Indivíduos leucodermas apresentaram dimensão linear da nasofaringe significativamente maior do que indivíduos feodermas e melanodermas. Conclusões: Todos os grupos apresentaram valores da bucofaringe semelhantes. No entanto, os indivíduos leucodermas apresentaram valores significantemente maiores, quando comparados aos feodermas e melanodermas.

Comparison of maxillary transversal changes between auxiliary beta-titanium expansion arch and miniscrew-assisted rapid palatal expansion.

OBJECTIVE(S): This study compared buccal bone thickness, dental inclinations and maxillary transverse width dimensions changes between auxiliary beta-titanium expansion arch (AEA) and miniscrew-assisted rapid palatal expansion (MARPE). MATERIALS AND METHODS: The sample consisted of 29 patients, aged between 18 and 40 years, with transverse maxillary deficiency and treated without extractions, divided into two groups: group AEA: comprised 13 individuals (initial mean age: 29.23 ± 9.13 years) treated using auxiliary beta-titanium expansion arch; group MARPE: comprised 16 patients (initial mean age: 24.92 ± 7.60 years) treated with miniscrew-assisted rapid palatal expansion. Buccal bone thickness, dental inclinations and transverse width dimensions (dental, nasal base and jugular) were measured in cone-bean computed tomographies at pre- and post-treatment stages. The variables were compared using the independent t-test. RESULTS: The buccal bone thickness was similar for both groups at the post-treatment stage. The second premolars were significantly more buccal inclined in the AEA group and the right maxillary first molars in the MARPE group. The intercanine and intermolar distances were statistically significantly greater in the MARPE group. Changes in dental arch transverse dimensions were significantly greater for the MARPE group. CONCLUSION: Both treatment protocols corrected the maxillary transverse discrepancy; however, MARPE provided greater correction.

A utilização de torques resistentes ao movimento compensatório dos dentes anteriores no tratamento da Classe III no paciente adulto / The use of torques resistant to compensatory movement of anterior teeth in the treatment of Class III in adult patients

Este trabalho visou relatar o caso clínico de um paciente padrão III com mordida cruzada anterior, através de um tratamento compensatório com o uso de bráquetes que geram torques resistentes nos incisivos. O paciente JPCN, 42 anos, leucoderma, gênero masculino, procurou a clínica ortodôntica com a queixa principal de mordida cruzada anterior. Na análise extrabucal, observou-se a presença de padrão horizontal, simetria facial, maxila deficiente, ângulo nasolabial fechado, presença de selamento labial passivo e perfil côncavo com o lábio inferior à frente do superior. A prescrição utilizada foi a biofuncional, apresentado 0° de torque nos incisivos superiores e 10° nos incisivos inferiores. Foram realizados o alinhamento e nivelamento, mecânica de acentuação da curva de Spee no arco superior e reversão no arco inferior simultaneamente aos elásticos intermaxilares. Ao final do tratamento, foram observados correção da relação anteroposterior e intercuspidação dentária, trespasse horizontal e vertical normais, linhas médias coincidentes e selamento labial passivo. Concluiu-se que a utilização de torques resistentes nos incisivos gerados pelo uso de bráquetes da técnica biofuncional foi eficiente para manter uma boa inclinação desses dentes durante a correção damá oclusão de Classe III com o uso de elásticos intermaxilares (AU)

This study aimed to report the clinical case of a patient with pattern III with anterior crossbite, through a compensatory treatment with the use of brackets that generate resistant torques in the incisors. Patient JPCN, 42 years old, caucasian, male, came to the orthodontic clinic with the main complaint of anterior crossbite. In the extraoral analysis, it was observed the presence of a horizontal pattern, facial symmetry, deficient maxilla, closed nasolabial angle, presence of passive lip seal, and concave profile with the lower lip in front of the upper. The prescription used was the biofunctional, with 0° of torque on the upper incisors and 10° on the lower incisors. Alignment and leveling, orthodontic mechanics of Spee curve accentuation in the maxillary arch and reversal in the mandibular arch were performed simultaneously with intermaxillary elastics. At the end of the treatment, Class III correction, correction of the anteroposterior relationship and dental intercuspation, normal overbite and overjet, coinci-dent midlines and passive lip seal were observed. It was concluded that the use of resistant torques on the incisors promoted by the use of biofunctional technique brackets was efficient to maintain a good inclination of these teeth during the correction of Class III malocclusion with the use of intermaxillary elastics (AU)

Incisors' bone height and inclination changes after orthodontic treatment with a self-ligating passive system.

Background: This study aimed to evaluate changes in the alveolar buccal bone height of maxillary and mandibular incisors after orthodontic treatment with a self-ligating passive system and to assess the correlation between bone height and incisor inclination. Material and Methods: Pre (T1) and post-treatment (T2) cone-beam computed tomography images of patients treated with the Damon 3MX appliance system were measured to quantify the alveolar buccal bone height of the maxillary incisors. The incisor's inclination was measured in digital models. Paired t-test was used to evaluate the changes between T1 and T2, and Pearson's coefficient was used to test the correlation. Results: All teeth presented statistically significant alveolar buccal bone loss at T2. A statistically significant buccal inclination was observed only for the lower left lateral incisors. There was no correlation between bone height changes and incisor inclination. Conclusions: Orthodontic treatment with a self-ligating passive system showed changes in alveolar height, but these changes were not correlated with incisor inclination. Key words:Passive self-ligating brackets, orthodontics, corrective, treatment outcome, alveolar bone loss.

Maternal Risk Factors Associated with Negative COVID-19 Outcomes and Their Relation to Socioeconomic Indicators in Brazil.

BACKGROUND: This study aimed to analyze maternal risk factors associated with negative outcomes of COVID-19 and association with socioeconomic indicators in Brazil. METHODS: A cross-sectional study, with data from the Influenza Epidemiological Surveillance Information System (SIVEP-Flu) of pregnant women with COVID-19 and cases of hospitalization and death. For the analysis of risk factors and outcomes, the multiple logistic regression method was used. RESULTS: Pregnant women who had some risk factor represented 47.04%. The chance of death was 2.48 times greater when there was a risk factor, 1.55 for ICU admission and 1.43 for use of ventilatory support. The percentage of cure was 79.64%, 15.46% without any negative outcome, 4.65% death and 0.26% death from other causes. Pregnant women who did not take the vaccine represented 30.08%, 16.74% took it and 53.18% were not specified. The variables HDI, illiteracy, per capita income and urbanization did not influence the cases of COVID-19. CONCLUSIONS: Factors such as age, obesity, asthma and pregnancy were responsible for the increase in hospitalizations, respiratory complications and death. Vaccination reduced the risk of negative outcomes by 50%. There were no correlations between socioeconomic indicators and the negative outcomes of COVID-19 in pregnant women.

Influence of the third molar presence on the thickness and height of the buccal cortical bone of the mandibular first and second molars.

Background: This study aimed to evaluate the influence of the presence of the third molars on the thickness and height of the buccal cortical bone of the first and second mandibular molars. Material and Methods: The retrospective cross-sectional observational sample consisted of 102 CBCTs of patients (mean age of 29 years), divided into two groups: G1: 51 patients (26 female; 25 male, mean age of 26 years) presenting the mandibular third molars and G2: 51 patients (26 female; 25 male, mean age of 32 years) with the absence of the mandibular third molars. The total and the cortical depth were evaluated at 4 and 6mm from the cementoenamel junction (CEJ). The total thickness of the buccal bone was evaluated in two horizontal reference lines located apically 6 mm and 11 mm from the CEJ. Statistical comparisons were performed with Mann Whitney and Wilcoxon tests. Results: In the comparison of buccal bone thickness and height between the groups, there was a statistical difference in tooth 36. In tooth 37 there was a statistical difference in the mesial root. For tooth 47, there was a statistical difference for the total thickness at 6mm, 11mm and 4mm. Concerning age, there was a tendency to decrease the values of these variables with increasing age. Conclusions: The mean values for buccal bone thickness, total and cortical depth of the mandibular molars were higher for patients with mandibular third molars because the buccal bone thickness of the mandibular molars increased in the posterior and apical direction. Key words:Molar tooth, jaw, bone, orthodontic anchorage procedures, cone-beam computed tomography.

Correlation of age and skeletal effects after miniscrew assisted rapid palatal expansion.

Background: To evaluate the skeletal and dentoalveolar effects after miniscrew assisted rapid palatal expansion (MARPE) and their correlation with the age of the patients. Settings and sample population: Sample comprised 19 patients with maxillary atresia and posterior crossbite, treated with MARPE. Cone-beam computed tomographs (CBCT) were evaluated before and after expansion. Three patients were excluded since the midpalatal suture was not opened. Thus, 16 patients (11 female; 5 male) were evaluated, with a mean age of 24.92 years (s.d.=7.60). The time between the installation of MARPE and the second CBCT was, on average, 1.64 months (s.d.=1.12). Material and Methods: Linear and angular measurements were performed: bone thickness and level, tooth inclination, transverse dental widths, and nasal base and jugula widths. Comparison was performed with dependent t-test and correlations with Pearson coefficient. Results: MARPE was 84.2% successful. There was significant reduction in the buccal bone thickness of the first molars and an increase in the palatal bone thickness of all teeth. First molars showed significant buccal inclination. All transverse dimensions showed a significant increase. Older patients tended to show a less maxillary transverse skeletal increase. A greater maxillary transverse increase was accompanied by a greater intermolar width increase and also a greater buccal bone loss in the mesiobuccal roots of the maxillary first molars. Conclusions: MARPE corrected the maxillary atresia in adult patients, with significant transverse increases, a slight decrease in buccal bone thickness and buccal inclination of the first molars, combining skeletal and dental effects. Older patients presented less transverse skeletal increases. Key words:Palatal expansion technique, skeletal anchorage, cone-beam computed tomography.

Incisor irregularity and dental arch dimensions changes in subjects with different severity of anterior crowding: a 37-year follow-up.

BACKGROUND: Occlusal stability is one of the goals of orthodontic treatment, and keeping teeth aligned in the long term is a challenge for the orthodontist. This study aimed to compare the long-term incisors irregularity and dental arches dimensions changes in subjects treated with 4 premolar extractions with different pretreatment Little's irregularity index (LII). The knowledge of long-term outcomes is evidence-based information for the prognosis of future treatments. METHODS: In total, 41 treated subjects were divided into two groups according to mandibular Little irregularity value at pretreatment (mild or severe). The maxillary and mandibular LII, transversal, and longitudinal widths were assessed at pretreatment, posttreatment, and 37-year posttreatment. Chi-square and independent t tests were used for intergroup comparison. RESULTS: The groups presented similar behavior for all stages of maxillary and mandibular arch dimensions changes. Maxillary irregularity was corrected in both groups after treatment, and the alignment was acceptable in the long term. In the mild group, the mandibular incisor irregularity returned to pretreatment values in the long term. The mandibular LII increased in the severe group but did not return to pretreatment values in the long term. CONCLUSIONS: The mild crowding group presented proportionally more relapse of mandibular incisor irregularity than the severe crowding group in the long term. Even so, the correction of mild and severe crowding with the extraction of 4 premolars showed satisfactory results in the long term, even with the presence of maturational changes and relapse.