Abstract Aim: Polymorphisms in the COMT gene can alter enzymatic functions, raising levels of endogenous catecholamines, which stimulates beta-adrenergic receptors related to pain. This study aimed to evaluate whether a polymorphism in the COMT gene (rs4818) is associated with dental pain in children. Methodology: A cross-sectional study was conducted with a representative sample of 731 pairs of children and parents randomly selected from a population-based sample of eight-year-old children. Reports of dental pain was evaluated using a question directed at the parents and self-reported pain using the Faces Pain Scale – Revised. Dental caries experience was determined using the Decayed, Missing, and Filled Teeth (DMFT) index. For genetic analysis, DNA was obtained from oral mucosa epithelial cells of 352 children randomly selected from the initial sample. Results: Children with the CC genotype had higher odds of reporting moderate to intense pain than those with the GG genotype (OR=3.60; 95% CI=0.80–16.20; p=0.03). These same children had greater odds of parental reports of pain (OR=1.93; 95% CI=0.91-4.08; p=0.02). Moreover, lower schooling of parents/guardians and caries experience in the primary dentition were significantly associated with greater odds of a parental report of dental pain (OR=2.06; 95% CI=1.47–2.91; p<0.001; OR=6.26; 95% CI=4.46–8.78; p<0.001). Conclusions: The rs4818 polymorphism of the COMT gene is associated with dental pain. Children with the C allele are more likely to report higher levels of pain. Clinical Relevance: Even though the experience of pain is subjective and multifactorial, this study raises the hypothesis that there is a genetic predisposition to dental pain that should be considered in clinical practice.

Abstract Objective Many genes and signaling molecules are involved in orthodontic tooth movement, with mechanically and hypoxically stabilized HIF-1α having been shown to play a decisive role in periodontal ligament signaling during orthodontic tooth movement. Thus, this in vitro study aimed to investigate if genetic polymorphisms in HIF1A (Hypoxia-inducible factor α-subunits) influence the expression pattern of HIF-1α protein during simulated orthodontic compressive pressure. Methodology Samples from human periodontal ligament fibroblasts were used and their DNA was genotyped using real time Polymerase chain reaction for the genetic polymorphisms rs2301113 and rs2057482 in HIF1A . For cell culture and protein expression experiments, six human periodontal ligament fibroblast cell lines were selected based on the patients’ genotype. To simulate orthodontic compressive pressure in fibroblasts, a 2 g/cm2 force was applied under cell culture conditions for 48 hours. Protein expression was evaluated by Western Blot. Paired t-tests were used to compare HIF-1α expression with and without compressive pressure application and unpaired t-tests were used to compare expression between the genotypes in rs2057482 and rs2301113 (p<0.05). Results The expression of HIF-1α protein was significantly enhanced by compressive pressure application regardless of the genotype (p<0.0001). The genotypes in the genetic polymorphisms rs2301113 and rs2057482 were not associated with HIF-1α protein expression (p>0.05). Conclusions Our study confirms that compressive pressure application enhances HIF-1α protein expression. We could not prove that the genetic polymorphisms in HIF1A affect HIF-1α protein expression by periodontal ligament fibroblasts during simulated orthodontic compressive force.

ABSTRACT Objective: To compare the body mass index (BMI) and the weight loss (WL) in patients with dentofacial deformities who underwent monomaxillary versus bimaxillary orthognathic surgery. Materials and Methods: This prospective longitudinal study included 69 patients with dentofacial deformities who underwent surgical orthodontic treatment. Patients were divided into two groups according to the type of orthognathic surgery: monomaxillary or bimaxillary. A preoperative nutritional assessment based on BMI was performed; the percentage of involuntary WL between the preoperative and postoperative periods was also calculated. Data were collected at preoperative and 10, 40, and 90 days postoperative (PO). Statistical analysis was performed using SPSS 17.0 (IBM Corp., Armonk, NY, USA), and data are reported with 95% confidence interval. Results: According to BMI, patients who underwent monomaxillary surgery presented: underweight = 2.6%, normal weight = 51.3%, overweight = 35.9%, and obese = 10.3%. The subjects who underwent bimaxillary surgery presented: normal weight = 43.3%, overweight = 36.7%, and obese = 20%. BMI was similar between the groups at all time points (preoperative, p= 0.237; 10 days PO, p= 0.325; 40 days PO, p= 0.430; and 90 days PO, p= 0.609). All patients lost weight postoperatively, and WL was similar among the PO measurements (p= 0.163). Conclusions: Although both monomaxillary and bimaxillary orthognathic surgeries resulted in WL and lower BMI, there was no statistically significant difference in these metrics between the two types of surgery.

RESUMO Objetivo: Comparar o Índice de Massa Corporal (IMC) e a perda de peso (PP) de pacientes com deformidades dentofaciais após cirurgia ortognática monomaxilar e bimaxilar. Material e Métodos: Foi realizado um estudo longitudinal prospectivo em 69 pacientes com deformidade dentofacial submetidos a tratamento cirúrgico-ortodôntico. Os pacientes foram divididos em dois grupos: cirurgia ortognática monomaxilar e bimaxilar. Foi realizada avaliação nutricional pré-operatória de acordo com o IMC. Foi calculada a porcentagem de PP involuntária entre o pré e o pós-operatório (PO). A coleta de dados foi realizada no pré-operatório e aos 10, 40 e 90 dias PO. A análise estatística foi realizada no software SPSS v. 17.0, com intervalo de confiança de 95%. Resultados: De acordo com o IMC, os indivíduos submetidos à cirurgia monomaxilar apresentaram: baixo peso = 2,6%, peso normal = 51,3%, sobrepeso = 35,9% e obesidade = 10,3%. Entre os indivíduos submetidos à cirurgia bimaxilar, 43,3% estavam com peso normal, 36,7% estavam com sobrepeso e 20% eram obesos. O IMC foi semelhante em todos os períodos (pré-operatório, p= 0,237; 10 dias PO, p= 0,325; 40 dias PO, p= 0,430; e 90 dias PO, p= 0,609). Todos os pacientes perderam peso no pós-operatório. A PP foi semelhante entre os tempos de PO (p= 0,163). Conclusões: A cirurgia ortognática monomaxilar ou bimaxilar pode causar redução do peso corporal e diminuição no IMC, mas não há diferença estatisticamente significativa entre esses dois tipos de cirurgia em relação à PP e ao IMC.

Aim The aim of the present study was to evaluate the microbial contamination in internal and external walls of cone morse implant walls. Methods Eleven patients with edentulous mandibular posterior area were selected to received dental implants, divided into groups: submerged (S), non-submerged (NS), and immediately loaded (IL). Microbiological evaluations (microorganisms’ number, aerobic and anaerobic colony forming units (CFU) number and microorganisms’ qualification) were divided into internal and external collection of the implant walls, at different stages: T0 (surgical procedure), T2 (suture removal), T4 (reopening S group), T6 (suture removal S group), and T8 (abutment placement in S and NS). All data were submitted to statistical analyses, with confidence level of 0.05. Results There was difference in number of microorganisms observed over time within the same group (p < 0.05). A difference was observed in CFU when evaluated within the same group over time (p < 0.05), except for the IL group. In internal collection, a predominance of non-formation of microorganisms was observed at T0 in all groups, while formation of Gram-positive Diplococci and Gram-positive Bacilli was observed at T8 (p>0.05). In external collection, an increase in number of microorganisms was observed at T0. Conclusion There was no difference in microbial contamination among the evaluated groups. The microorganism’s colonization changed over time.

Abstract: This cross-sectional study aimed to assess if genetic polymorphisms in TNF- α are associated with a negative impact on Oral Health-Related Quality of Life (OHRQoL) in children with dental caries. A total of 307 pairs of parents/caregivers and children aged two to five years were selected. The children were clinically evaluated and classified according to caries experience and severity of active caries. The Brazilian Portuguese version of the Early Childhood Oral Health Impact Scale (ECOHIS) was used to assess OHRQoL. Genotyping analysis of genetic polymorphisms in TNF- α (rs1799724, rs1799964, and rs1800629) was performed using real-time polymerase chain reaction. In the recessive model, children with the CC genotype of TNF-α (rs1799964) had a significantly high chance of poor OHRQoL in the symptom domain (pain), in both the caries experience (p = 0.045) and the high-severity active caries phenotypes (p = 0.033) (Mann-Whitney U test). It was concluded that genetic polymorphisms in TNF-α are associated with OHRQoL related to the symptom domain (pain), suggesting that TNF-α could be used as a potential biomarker for OHRQoL. Understanding the genetic aspects associated with OHRQoL will allow the early identification of patients with OHRQoL disparities and provide personalized healthcare.

Abstract This study aimed to evaluate the associations between oral health-related quality of life (OHRQoL) and patient-associated factors and polymorphisms in the estrogen receptor 1 (ESR1) and 2 (ESR2) genes in patients with dentofacial deformities (DFD). This cross-sectional study included 234 adult individuals. Data such as age, sex, and the type of facial profile (I, II, or III), were collected, and the short-form oral health impact profile 14 (OHIP-14) questionnaire was used to assess their OHRQoL. DNA was collected from oral mucosa cells, and the polymorphisms in ESR1 (rs2234693 and rs9340799) and ESR2 (rs1256049 and rs4986938) were evaluated using real-time polymerase chain reaction. The data were subjected to statistical analysis at a significance level of 5%. Individuals over 28 years of age exhibited worse OHRQoL (p = 0.003) than individuals aged less than or equal to 28 years. Women had worse OHRQoL than men (p < 0.001). Profile II individuals had worse OHRQoL in the social disability domain than profile III individuals (p = 0.030). Genetic analysis showed that rs9340799 was associated with OHRQoL in the functional limitation domain, and GG individuals exhibited worse OHRQoL than individuals carrying the AA/AG genotypes (p < 0.030). In the social handicap domain, individuals with GG genotype in rs9340799 exhibited worse OHRQoL than AG individuals (p < 0.043). Collectively, our results reveal that factors including age, sex, and type of facial profile, are associated with OHRQoL in patients with DFD. In addition, individuals with the GG genotype in rs9340799 (ESR1) may experience a negative impact on OHRQoL in the functional limitation and social handicap domains.

Abstract Objective: To assess the association between temporomandibular disorder (TMD) with sociodemographic factors, health-related factors, and oral conditions in adolescents. Material and Methods: This cross-sectional study was developed with 89 adolescents between 13 to 18 years. TMD diagnosis was obtained by the Research Diagnostic Criteria for Temporomandibular Disease (RDC/TMD) Axis I. Diagnoses of chronic pain, depression, presence of non-specific physical symptoms, including pain and anxiety, were obtained by the RDC/TMD Axis II. The feeling of happiness was measured by the Subjective Happiness Scale. Socio-economic and demographic characteristics were collected through self-administered questionnaires. Patients were examined for dental caries, dental trauma, malocclusion, and tooth wear. Parents answered a sociodemographic, economic, and general health questionnaire. Data were submitted to descriptive statistics, and a logistic regression model was used to assess the association between TMD and the socio-economic, demographic, health-related, and clinical variables. Results: TMD prevalence was 42%. TMD was associated to skin color (p=0.040), use of medications in the past year (p = 0.020) and previous dental trauma (p=0.030). Also, it tended to be associated with the presence of probable awake bruxism (p=0.053). Conclusion: Sociodemographic factors, health-related factors, and oral conditions play a role in TMD, with nonwhite adolescents, those who had used medications in the past year and/or had previous dental trauma having a greater chance of present this disorder.

Abstract Objective: To assess the knowledge of Brazilian dentists and final-year dental undergraduates concerning COVID-19. Material and Methods: We conducted a self-administered online questionnaire about the symptoms, incubation period, and transmission routes of COVID-19. In total, there were three questions addressing these topics and 15 correct answers, so each participant could score from 0 to 15 points. Besides that, data such as sex, age, education level, years of work experience and place of work were collected. All data were submitted to statistical analysis with a 5% significance level. Results: 476 participants were recruited. Regarding the respondents' perception of the most common symptoms of COVID-19, 99.4% responded fever, 95.2% cough, and 99.2% dyspnea. About the incubation period, 56.3% answered from 1 to 14 days. About the transmission routes, 98.3% recognized transmission through droplets, 80.3% through direct contact with infected persons, and 70.4% through indirect routes. The median knowledge score was 10 (4 – 14). Regarding the socio-demographic variables, participants aged 30 years or more had a higher score than those aged up to 29 years old (p=0.004). For education level, specialist dentists presented a higher score than undergraduates (p=0.006), general dentists (p=0.048) and Ph.D. (p=0.016). Participants with 15 years or more of work experience had a higher score than undergraduates (p=0.003). Concerning the workplace, participants working in the public sector had a higher score than those working in the private sector or universities (p=0.015). Conclusion: Participants recognized the main symptoms, incubation period, and transmission routes of the COVID-19 virus; however, the knowledge level of specialist dentists, older dentists, more experienced dentists, and dentists working in the public sector was higher than the other participants.

Abstract: The aim of this study was to evaluate patient perception of surgical discomfort in third molar surgery and the association with clinical variables and polymorphisms associated with the FKBP5, SLC6A4, and COMT genes. This cross-sectional observational study was carried out on 196 participants aged between 18 and 64 years at the Federal University of Paraná in 11 months. The intensity of surgical discomfort was assessed using the QCirDental questionnaire. Data on surgical and individual procedures were also cataloged. The oral health related quality of life was assessed by the Oral Health Impact Profile questionnaire (OHIP-14). The DNA sample was obtained from cells of the oral mucosa. Five markers of the FKBP5, SLC6A4, and COMT genes were genotyped. The data were submitted to statistical analysis with a significance level of 5%. Women reported greater intensity of discomfort associated with third molar surgery compared to men (p = 0.001). In the recessive model, the AA genotype of the rs3800373 marker was associated with greater surgical discomfort (p = 0.026). Therefore, women and individuals of the AA genotype for the rs3800373 marker in the FKBP5 gene reported greater surgical discomfort associated with third molar surgery.

Abstract The objective of this study was to evaluate if individuals with dentofacial deformities (DFD) who require orthognathic surgery are affected more by depression and pain. A case-control study was performed with 195 individuals. In the DFD group, 145 individuals with Class II and III malocclusion requiring orthognathic surgery were selected. The control group was composed of 50 individuals with no DFD. All patients were diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). Data were analyzed with a significance level of 0.05. The DFD group more often presented severe depression (p = 0.020) and chronic pain (p = 0.017). They also presented higher prevalence of Nonspecific Physical Symptoms Including Pain (P = 0.002) and Nonspecific Physical Symptoms Excluding Pain (p = 0.002). Concerning TMD symptoms, the DFD group had more myofascial (p = 0.002) and articular pain (p = 0.041). Therefore, the results of this study suggest that depression and pain are more common in individuals with DFD requiring orthognathic surgery compared with individuals without DFD.

Resumo Este estudo visou avaliar o efeito de dois métodos de aplicação local de alendronato e de paratormônio (PTH) no reparo ósseo e avaliar as implicações sistêmicas. Um defeito de tamanho crítico (5 mm) foi criado na calota craniana de vinte e cinco ratos Wistar machos, e o osso removido foi particulado e enxertado de volta no defeito com diferentes tratamentos. Os animais foram divididos aleatoriamente em cinco grupos: A1: imersão do enxerto ósseo em solução de alendronato (3 mg/kg) durante 5 min; P1- imersão do osso em solução de PTH (20 μg); A2- aplicações locais semanais de alendronato 1 mg/kg; P2- aplicações locais semanais de PTH 20 μg; C: não foram utilizados medicamentos. Os animais foram eutanasiados 60 dias após a cirurgia. Foram removidos os blocos ósseos envolvendo a região do defeito para realização das análises histológica, histomorfométrica e imuno-histoquímica. MMP2 e MMP9 foram as imunomarcações utilizadas. Os rins, fígado e cérebro também foram removidos de todos os ratos para análise histológica. Os dados foram submetidos à análise estatística com um nível de significância de 0,05 (One-way ANOVA). A análise histológica revelou que o grupo C e o grupo P2 apresentaram maior quantidade de partículas ósseas viáveis do que as apresentadas pelos demais grupos. Os grupos A1, A2 e P1 apresentaram menos partículas ósseas viáveis em comparação com o grupo controle com predominância de tecido conjuntivo não mineralizado. A análise histomorfométrica não revelou diferenças entres os grupos na área óssea relativa ou em MMP2 e MMP9 (p>0,05). O grupo A2 mostrou presença de gordura no fígado consistente com esteatose hepática. Alterações no tecido cerebral foram observadas nos grupos A1 e P1.

Abstract This study aimed to evaluate the effect of two methods of local application of alendronate and parathyroid hormone (PTH) on bone repair and the systemic implications. A critically sized defect (5 mm) was created in the cranial region of twenty-five male Wistar rats, and the bone removed was particulated, and grafted back to the defect with different treatments. The animals were randomly divided into five groups: A1- bone graft immersion in alendronate solution (3 mg/kg) for 5 minutes; P1- bone graft immersion in PTH solution (20 µg); A2- weekly local applications of alendronate 1 mg/kg; P2- weekly local applications of PTH (20 µg); C- no drugs were used. The animals were euthanized 60 days after surgery. Cranial bone blocks were removed for histological, histomorphometric, and immunohistochemical analyses. MMP-2 and MMP-9 were used for immunolabeling. The kidneys, liver, and brain were also removed from all the rats for histological analysis. The data were submitted for statistical analysis with a level of significance of 0.05 (One-way ANOVA). The group C and group P2 presented a higher quantity of viable bone particles than the remaining groups. Groups A1, A2, and P1 presented with fewer viable bone particles than the control group, with a predominance of non-mineralized connective tissue. The histomorphometric analysis revealed no differences in relative bone area or MMP-2 or MMP-9 immunolabeling between the groups (p>0.05). Group A2 showed presence of fat in the liver consistent with hepatic steatosis. Changes in brain tissue were observed in groups A1 and P1.

Cleidocranial Dysplasia (CCD) is an autosomal dominant bone disorder caused by a defect in the CBFA1 gene and characterized by skeletal, craniofacial and orodental anomalies. This paper describes the main aspects of a case of CCD from diagnosis and planning to the first step of the interventions. An 11-year-old male patient sought the pediatric dentistry clinic of the Federal University of Paraná (Brazil) with the complaint of the prolonged retention of nearly all his primary teeth. Clinical and imaging exams led to the diagnosis of CCD and the treatment plan was outlined. The first step consisted of the extraction of 4 primary, 2 permanent and 2 supernumerary teeth from the maxilla, followed by palate separation, traction of the impacted teeth and reverse traction of the maxilla. The patient remains in treatment. Clinical follow up as well as the awareness and motivation of the family are important factors in such cases.

La displasia cleidocraneal (CCD) es un trastorno óseo, autosómico dominante, causado por un defecto en el gen CBFA1 y se caracteriza por anomalías esqueléticas, craneofaciales y bucodentales. En este trabajo se describen los principales aspectos de un caso de CCD, desde el diagnóstico y la planificación para la primera etapa de las intervenciones. Un paciente varón de 11 años de edad, concurrió a la Clínica de Odontología Pediátrica de la Universidad Federal de Paraná (Brasil) con un problema de retención prolongada de casi todos sus dientes de leche. Se describen los exámenes clínicos y de imagen dirigidos al diagnóstico de la CCD y el plan de tratamiento. La primera etapa consistió en la extracción de cuatro dientes primarios, dos dientes permanentes y dos dientes supernumerarios del maxilar, seguido de separación del paladar, tracción de los dientes afectados y tracción inversa del maxilar. El paciente permanece en tratamiento. El seguimiento clínico, así como la concientización y motivación de la familia son factores importantes en este tipo de casos.

Resumo O objetivo deste estudo foi verificar o estresse e a resistência ao deslocamento, pela análise de elementos finitos, de diferentes tipos de fixação em cirurgia ortognática mandibular. Um modelo 3D de elementos finitos sólidos de uma hemi-mandíbula foi obtido. Uma osteotomia sagital bilateral foi simulada e o segmento distal foi avançado 5 mm. Após o ajuste e sobreposição dos segmentos, foram simulados 9 diferentes tipos de osteossíntese com miniplacas e parafusos 2.0: A, uma miniplaca reta convencional de 4 furos; B, uma miniplaca reta lock de 4 furos; C, uma miniplaca convencional de 4 furos e um parafuso bicortical; D, uma placa lock de 4 furos e 1 parafuso bicortical; E, uma miniplaca reta convencional de 6 furos; F, uma miniplaca lock de 6 furos; G, duas miniplacas retas convencionais de 4 furos; H, duas miniplacas lock de 4 furos; e I, três parafusos bicorticais em um padrão L invertido. Em cada modelo foram aplicadas forças simulando os músculos mastigatórios. Foram verificados os valores da tensão nas placas e parafusos. A resistência ao deslocamento foi verificada no segmento proximal, uma vez que o segmento distal era estável. Foi medida a região com o maior deslocamento inferior e superior. O deslocamento entre os segmentos osteotomizados foi verificado por intervalos milimétricos. Parafusos bicorticais em L invertido foram o modelo que teve o menor descolamento inferior, e o modelo com a tensão mais baixa foi o de duas placas convencionais. Os resultados sugerem que a tensão foi melhor distribuída nas miniplacas do tipo lock, mas os parafusos de fixação apresentaram maior concentração de tensão.

Abstract The aim of this study was to evaluate the stress and dislodgement resistance by finite element analysis of different types of fixation in mandibular orthognathic surgery. A 3D solid finite element model of a hemi-mandible was obtained. A bilateral sagittal split osteotomy was simulated and the distal segment was advanced 5 mm forward. After the adjustment and superimposing of segments, 9 different types of osteosynthesis with 2.0 miniplates and screws were simulated: A, one 4-hole conventional straight miniplate; B, one 4-hole locking straight miniplate; C, one 4-hole conventional miniplate and one bicortical screw; D, one 4-hole locking miniplate and 1 bicortical screws; E, one 6-hole conventional straight miniplate; F, one 6-hole locking miniplate; G, two 4-hole conventional straight miniplates; H, two 4-hole locking straight miniplates; and I, 3 bicortical screws in an inverted-L pattern. In each model, forces simulating the masticatory muscles were applied. The values of stress in the plates and screws were checked. The dislodgement resistance was checked at the proximal segment since the distal segment was stable because of the screen at the occlusal tooth. The regions with the lowest and highest displacement were measured. The offset between the osteotomized segments was verified by millimeter intervals. Inverted-L with bicortical screws was the model that had the lowest dislodgment and the model with the lowest tension was the one with two conventional plates. The results suggest that the tension was better distributed in the locking miniplates, but the locking screws presented higher concentration of tension.

Dental treatment and surgery is a well-established method of correcting dentofacial deformities, and such treatment has an impact on the quality of life of individuals. The objective of this study was to evaluate the effect of orthognathic surgery on the quality of life of patients receiving treatment at the Universidade Federal do Paraná – UFPR. Clinical data were evaluated for the control group, and a quality-of-life evaluation questionnaire was completed [Oral Health Impact Profile (OHIP-14)]. For the case group, the same data were gathered along with information regarding their dentofacial deformity. The OHIP-14 questionnaire was also completed at three distinct stages of the experiment. The median age in the control group was 23.5 years. In the case group, the predominant gender was female, and the mean age of patients was 29.4 years. There was a statistically significant association between gender and OHIP-14 (p< 0.001). No such association was observed between age and OHIP-14 scores (p= 0.616). In the control group the OHIP-14 median score was 11.5. In the case group, the average OHIP-14 score at was 18 at T0, 21 at T1, and 8 at T2. The results demonstrated a statistically significant association between the three time stages at which OHIP-14 was analyzed (p< 0.001). There was a smaller reduction in the negative impact for transversal deformities of the jaw when compared with other deformities. Orthognathic surgery led to a reduction in the negative effects on the quality of life of patients.

Resumo Introdução: pacientes portadores de deformidades dentofaciais podem submeter-se a tratamento ortodôntico ou ortodôntico-cirúrgico. Ambos podem modificar a estética do paciente. Objetivo: esse estudo tem por objetivo avaliar, clinicamente e radiograficamente, as mudanças na exposição dos incisivos centrais superiores em pacientes submetidos à cirurgia ortognática de avanço de maxila. Métodos: foram selecionados 17 pacientes submetidos à cirurgia ortognática de avanço maxilar no período de setembro de 2010 a julho de 2011. A exposição dos incisivos centrais superiores foi avaliada clinicamente e por meio de radiografias cefalométricas em norma lateral. Essas medidas foram tomadas uma semana antes e três meses depois da cirurgia. Os dados foram, por meio de testes estatísticos (CI 95%), correlacionados por sexo, idade, ângulo nasolabial, altura e espessura do lábio superior, quantidade de avanço maxilar, exposição clínica e inclinação dos incisivos centrais superiores. Resultados: após o avanço maxilar, houve um aumento da exposição clínica dos incisivos tanto com o lábio superior relaxado quanto sob sorriso forçado. Além disso, obteve-se um aumento médio de 23,33% na exposição dos incisivos nas radiografias cefalométricas em norma lateral. Houve correlação inversa entre a espessura do lábio superior e a exposição pós-cirúrgica dos incisivos nas imagens radiográficas (p = 0,002). Conclusão: mudanças significativas na exposição dos incisivos centrais superiores ocorrem após o avanço maxilar, sob influências de certos fatores, especialmente a espessura do lábio superior.

Abstract Introduction: Patients with dentofacial deformities may undergo orthodontic or orthodontic-surgical treatment. Both modalities can affect esthetics. Objective: This study aims to evaluate clinical and radiographic changes in exposure of maxillary central incisors occurring after orthognathic surgery for maxillary advancement. Methods: A total of 17 patients who underwent orthognathic surgery for maxillary advancement between September, 2010 and July, 2011 were selected. Exposure of maxillary central incisors was evaluated clinically and by lateral cephalograms. Measurements were taken one week before and three months after surgery. Data were paired in terms of sex, age, nasolabial angle, height and thickness of the upper lip, the amount of maxillary advancement, clinical exposure and inclination of maxillary central incisor by statistical tests (CI 95%). Results: After maxillary advancement, incisor clinical exposure had increased even with relaxed lips and under forced smile. Moreover, there was a mean increase of 23.33% revealed by lateral cephalograms. There was an inverse correlation between upper lip thickness and incisors postsurgical exposure revealed by radiographic images (p = 0.002). Conclusions: Significant changes in the exposure of maxillary central incisors occur after maxillary advancement, under the influence of some factors, especially lip thickness.