Cone-beam computed tomography study of root length of maxillary and mandibular anterior teeth and central incisor crown-root morphology in high-angle Class Ⅱ open bite patients / 口腔疾病防治

Objective@#This study aimed to explore the root length of maxillary and mandibular anterior teeth and central incisor crown-root morphology in patients with high-angle skeletal Class Ⅱ open bite, aiming to provide a reference for clinical treatment.@*. Methods@#This study was reviewed and approved by the Ethics Committee, and informed consent was obtained from the patients. CBCT images of eighty-one untreated patients (40 anterior open bite patients and 41 normal overbite patients) with high-angle skeletal Class Ⅱ malocclusion were selected before treatment. Dolphin software was used to study the root length of maxillary and mandibular anterior teeth and central incisor crown-root morphology, and the differences between the two groups were analyzed.@*Results@#There was no statistical significance in the root length of maxillary lateral incisor and canine between the open bite group and the normal overbite group, significant differences were found in the root length of maxillary central incisor （11.12 ± 1.37） mm、mandibular central incisor（10.15 ± 1.09）mm, mandibular lateral incisor（11.27 ± 1.15）mm and mandibular canine（12.81 ± 1.48）mm between the open bite group and the normal overbite group（P<0.05）. On the other hand, the two groups were significantly different in crown-root morphology of the maxillary central incisor (1.10° ± 3.62° vs. 4.53° ± 2.30°, P<0.01) but not in the mandibular central incisor.@*Conclusion@#The root length of the maxillary central incisor, mandibular central incisor, mandibular lateral incisor, mandibular canine in high-angle Class Ⅱ open bite patients is shorter than that in high-angle Class Ⅱ normal overbite patients, and the long axis of the crown of the maxillary central incisor in high-angle Class Ⅱ open bite patients obviously deviates toward the labial side relative to the long axis of the root. The crown-root angle is smaller, which is beneficial to torque control or adduction movement of the anterior teeth in high-angle Class Ⅱ open bite patients.

Idiopathic Bilateral Mandibular Condylar Resorption Causing AnteriorOpen Bite - A Case Report

Introduction: Mandibular condylar resorption (MCR) is a rare pathological entity, often affecting young females. Patient Concerns: It is accompanied by pain, malocclusion and compromised quality of life including aesthetic perception. Due to this multiplicity of features, the diagnosis, treatment and management of MCR are always a challenge. Diagnosis: This article reports a 25?year?old female suffering from progressive temporomandibular joint pain and compromised aesthetics. This article describes the clinical and radiological findings of this case. Treatment: The possible aetiopathogenesis and treatment are described.

Evaluation of temporomandibular joint space and condylar morphology in patients with anterior open-bite based on cone-beam CT / 口腔疾病防治

Objective@#To investigate the difference of the temporomandibular joint between patients with anterior open-bite and normal overbite with cone beam CT (CBCT).@*Methods @# Fifty-four patients with anterior open bites and 54 patients with normal overbites were selected from the Department of Orthodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University from June 2014 to August 2020. Sagittal and coronal images of the temporomandibular joint were reconstructed with multiplanar reconstruction techique. The Kamelchuk method was used to measure the superior, posterior and anterior space of the temporomandibular joint, and the condylar morphology was divided into two types: normal and abnormal. The joint space and condylar morphology of the anterior open-bite group and the normal overbite group were statistically analyzed. The anterior open-bite group was divided into 3 subgroups: ① Ⅰ° open-bite (open bite distance < 3 mm), ② Ⅱ° open-bite (open bite distance ≥ 3 mm and ≤ 5 mm) and ③ Ⅲ° open-bite (open bite distance > 5 mm). The difference of overbite spaces of the temporomandibular joint was compared among these three subgroups.@*Results@#Compared to the normal group, no significant differences were found for the anterior and superior space of the temporomandibular joint in the anterior open-bite group (P > 0.05), but the posterior space increased significantly (P < 0.01). A total of 52.8% of patients in the anterior open-bite group had abnormal condyles, whereas 21.3% of patients in the normal group, overbite significant differences was found between the two groups (P < 0.01). Compared with patients with Ⅰ° and Ⅱ° openbite, the condyle of patients with III° open bites was more forward in the fossa (P < 0.05).@*Conclusion @#The position of the condyle in the fossa of patients with anterior open bites is more forward, and abnormal condylar bone is more common found.

Anclaje esquelético para el tratamiento de las anomalías de clase II y mordida abierta anterior: informe de un caso / Skeletal anchorage for the treatment of class II anomalies and anterior open bite: report of a case

El reporte de este caso tiene como objetivo demostrar la utilidad de los anclajes esqueléticos temporarios como son las miniplacas cigomáticas y los microimplantes "buccal shelf" en el tratamiento ortodóncico, en una paciente de 17 años 10 meses de edad, clase II vertical, dólicofacial, con mordida abierta anterior y aumento de la altura facial inferior. Después de la primera fase de tratamiento, siguiendo la secuencia de arcos para completar la alineación, se utilizaron anclajes esqueléticos extrarradiculares con una mecánica de intrusión con fuerzas elásticas durante 10 meses. Se intruyeron sus piezas posteriores superiores e inferiores y se distalizó la arcada superior, corrigiéndose la oclusión. El mentón retrognático y su perfil convexo mejoraron con la autorrotación de la mandíbula (AU)

The objective of this report case is to demonstrate the usefulness of temporary skeletal anchors such as zygomatic miniplates and buccal shelf microimplants in orthodontic treatment, in a 17-year-old 10-month-old, vertical class II, dollicofacial patient with anterior open bite and increased lower facial height. After the first treatment phase, following the arch sequence to complete the alignment, extra-radicular skeletal anchors were used with intrusion mechanics with elastic forces for 10 months. Its upper and lower posterior pieces were intruded and the upper arch was distalized, correcting the occlusion. e retrognathic chin and its convex profile improved with autorotation of the jaw (AU)

Treatment of adult patient with hyperdivergent retrognathic phenotype and anterior open bite: report of a case with non-surgical orthodontic approach

ABSTRACT Adult patients with anterior open bite and hyperdivergent retrognathic phenotype demand complex treatments, as premolar extractions, molar intrusion or orthognathic surgery. In the present clinical case, a young adult patient without significant growth, with Class I and anterior open bite, was treated with four premolar extractions. The therapeutic result shows good intercuspation, good facial esthetic, good function balance, and stability in a two-year post-fixed treatment follow-up.

RESUMO Pacientes adultos com mordida aberta anterior e fenótipo hiperdivergente retrognata demandam tratamentos complexos, com extrações de pré-molares, intrusão de molares ou cirurgia ortognática. No presente caso clínico, uma jovem adulta sem potencial significativo de crescimento, apresentando Classe I e mordida aberta anterior, foi tratada com extrações de quatro primeiros pré-molares. O resultado terapêutico alcançou boa intercuspidação, boa estética facial e bom equilíbrio funcional, e mostrou-se estável depois de dois anos da remoção do aparelho fixo.

Negligible tooth resorptions after anterior open bite treatment using skeletal anchorage with miniplates

ABSTRACT Introduction: When miniplates are used as anchoring for orthodontic mechanics for anterior open bite correction by retraction of anterior teeth and posterior teeth intrusion and retraction, orthodontically induced inflammatory external apical root resorption is clinically negligible. Methods: A homogeneous sample of 32 patients was used, and the roots of the teeth were compared on CT scans performed before and after orthodontic treatment. Results: The observed root resorption was minimal, and this can be explained by the uniform distribution of forces in several teeth, simultaneously, in the set of the dental arch and in the bone that supports the teeth. Conclusion: The most important thing to prevent root resorption in orthodontic practice, besides being concerned with the intensity of the applied forces, is to be careful with its distribution along the roots of each tooth, in the dental arch and in the bone that supports the teeth.

RESUMO Introdução: Quando são utilizadas miniplacas como ancoragem para a mecânica ortodôntica de correção da mordida aberta anterior por meio da retração dos dentes anteriores e intrusão e retração dos dentes posteriores, as reabsorções radiculares apicais externas inflamatórias induzidas ortodonticamente são clinicamente irrelevantes. Métodos: Usou-se uma amostra homogênea de 32 pacientes, e comparou-se as raízes dos dentes em tomografias realizadas antes e depois do tratamento ortodôntico. Resultados: As reabsorções radiculares observadas foram mínimas, e isso pode ser explicado pela distribuição uniforme das forças em vários dentes, simultaneamente, no conjunto da arcada dentária e no osso que suporta os dentes. Conclusão: O mais importante para se prevenir as reabsorções radiculares na prática ortodôntica, além de se preocupar com a intensidade das forças aplicadas, é tomar cuidado com a sua distribuição ao longo das raízes de cada dente, na arcada dentária e no osso que suporta os dentes.

Cone-beam computed tomography for evaluating root length of maxillary and mandibular anterior teeth in open bite patients / 中南大学学报(医学版)

OBJECTIVES@#To compare the root length of maxillary and mandibular anterior teeth between open bite patients and normal overbite patients via cone-beam computed tomography (CBCT) as well as the root length of anterior teeth in different degree of open bite patients, and to analyze the correlation between the degree of open bite and root length.@*METHODS@#A total of 106 untreated patients were enrolled retrospectively (53 anterior open bite patients and 53 normal overbite patients).Three-dimensional position of the CBCT image for the patient's teeth was performed using Dolphin software. The median sagittal plane of the tooth was used as the measurement plane, and the line connecting the apical point and the midpoint between the labial and lingual cementoenamel junctions was defined as the root length. Independent @*RESULTS@#Significant differences were found in the root length of maxillary and mandibular anterior teeth between the open bite group and the normal overbite group (@*CONCLUSIONS@#The root length of maxillary and mandibular anterior teeth in the open bite patients is shorter than that in the normal overbite patients, and the severer the degree of open bite, the shorter the root length of the mandibular central incisor tends to be. There is a certain relationship between maxillary anterior teeth and the root length of anterior teeth.

Perfil do aleitamento e a ocorrência de má oclusão em crianças participantes da bebê-clínica / Breastfeeding profile and the occurrence of malocclusion in children participating at Baby Clinic

Essa pesquisa trata-se de uma análise transversal do perfil do aleitamento de crianças que frequentam a Bebê Clínica, um Programa Educativo/Preventivo em Saúde Bucal, e a ocorrência de oclusopatias. O objetivo foi analisar a influência do perfil do aleitamento sobre a condição oclusal de crianças que participam de um programa odontológico educativo-preventivo. Participaram da pesquisa 400 crianças entre 27 e 48 meses, sendo 200 que frequentam a Bebê-Clínica e 200 de escolas do município de Araçatuba, não participantes da Bebê-Clínica, Esta pesquisa constou da coleta de informações retrospectivas sobre o tempo, o tipo e a forma de aleitamento, além dos hábitos de sucção não nutritiva, por meio de um questionário realizado com as mães. Foi realizada também uma avaliação clínica da oclusão dentária dessas crianças, utilizando o índice de má oclusão preconizado pela OMS. Os dados foram analisados pelo teste do qui-quadrado. Os resultados indicaram em ambos os grupos uma elevada porcentagem de mães que amamentaram seus filhos (acima de 84%); elevada porcentagem de crianças com hábitos de sucção não nutritiva (acima de 57%) e um elevado índice de má oclusão dentária, sendo a principal, a mordida aberta anterior. Considerando os aspectos estudados nesta pesquisa, verificamos que ambos os grupos apresentaram resultados semelhantes, portanto não havendo influência da participação no programa da Bebê-Clínica(AU)

This research deals with a cross-sectional analysis of the breastfeeding profile that is frequent in the Baby Clinic, in an Educational / Preventive Oral Health Program, and an occurrence of occlusions. The objective was to analyze the influence of the breastfeeding profile on the occlusal condition of children who participate in an educational-preventive dental program. Participated in the research 400 children between 27 and 48 months, 200 of them attending the Baby Clinic and 200 from schools in the city of Araçatuba, not participating in the Baby Clinic. This research consisted of collecting retrospective information about time, type and form of breastfeeding, and non-nutritive sucking habits, through a questionnaire conducted with mothers. A clinical evaluation of the dental occlusion of these children was also performed, using the malocclusion index recommended by WHO. Data were analyzed by chi-square test.The results indicated in both groups a high percentage of mothers who breastfed their children (over 84%); high percentage of children with non-nutritive sucking habits (above 57%) and a high rate of dental malocclusion, the main one being the anterior open bite.Considering the aspects studied in this research, we found that both groups presented similar results, therefore there was no influence of participation in the program of the Baby Clinic(AU)

Three-dimensional assessment of external apical root resorption after maxillary posterior teeth intrusion with miniscrews in anterior open bite patients

ABSTRACT Objective: The objective of this study was to assess the external apical root resorption (EARR) of the maxillary posterior teeth after intrusion with miniscrews. Methods: Fifteen patients (13 females and 2 males) with age ranging from 14.5 to 22 years (mean 18.1 ±2.03 years) were selected to participate in this study. All patients presented with anterior open bite of 3 mm or more. An intrusion force of 300 g was applied on each side to intrude the maxillary posterior teeth. Cone beam computed tomography (CBCT) scans were taken pretreatment and post-intrusion and were analyzed to evaluate the EARR. Results: The maxillary posterior teeth were intruded in average 2.79 ± 0.46 mm (p< 0.001) in 5.1 ± 1.3 months, and all examined roots showed statistically significant EARR (p< 0.05) with an average of 0.55 mm, except the distobuccal root of the left first permanent molars and both the palatal and buccal roots of left first premolars, which showed no statistically significant changes. Conclusions: The evaluated teeth presented statistically significant EARR, but clinically, due to the small magnitude, it was not considered significant. Moreover, the CBCT provided a good visualization of all roots in all three planes, and it was effective in detecting minimal degrees of EARR.

RESUMO Objetivo: o objetivo desse estudo foi verificar a existência de reabsorção radicular apical externa (RRAE) em dentes posterossuperiores após intrusão ancorada em mini-implantes. Métodos: quinze pacientes (13 mulheres e 2 homens) com a idade variando entre 14,5 e 22 anos (média de 18,1 ± 2,03 anos) foram selecionados para participar desse estudo. Todos os pacientes possuíam mordida aberta anterior de 3mm ou mais. Uma força de 300 gramas foi aplicada em cada lado para intruir os dentes posterossuperiores. Tomografias computadorizadas de feixe cônico (TCFC), adquiridas antes do tratamento e após a intrusão, foram comparadas para se avaliar a RRAE. Resultados: os dentes posterossuperiores foram intruídos em média 2,70 ± 0,46 mm (p< 0,001) em 5,1 ± 1,3 meses, e todas as raízes examinadas mostraram RRAE estatisticamente significativa (p< 0,05), com média de 0,55 mm, exceto pela raiz distovestibular dos primeiros molares permanentes esquerdos, e pelas raízes palatina e vestibular dos primeiros pré-molares esquerdos, que não apresentaram mudanças estatisticamente significativas. Conclusões: os dentes avaliados apresentaram RRAE estatisticamente significativa, a qual, porém, não foi considerada clinicamente significativa, devido à sua reduzida magnitude. Além disso, a TCFC possibilitou uma boa visualização de todas as raízes nos três planos espaciais, e foi eficaz para detecção de níveis mínimos de RRAE.

Genetic Polymorphism in MMP9 May Be Associated With Anterior Open Bite in Children

Abstract Anterior open bite (AOB) has a multifactorial etiology caused by the interaction of sucking habits and genetic factors. The aim of this study was to evaluate the association between AOB and polymorphisms in genes that encode Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). Four hundred and seventy-two children that presented at least one sucking habit were evaluated. Children were examined clinically for the presence of AOB. Genomic DNA was extracted from saliva. Genotyping of the selected polymorphisms in MMP2, MMP3, MMP9, TIMP1 and TIMP2 was carried out by real-time PCR using the TaqMan method. Allele and genotype frequencies were compared between the groups with and without AOB using the PLINK® software in a free and in a recessive model using a chi-square test. Logistic regression analysis was implemented (p≤0.05). Two hundred nineteen children had AOB while 253 did not. The polymorphism rs17576 in MMP9 was significantly associated with AOB (p=0.009). In a recessive model GG genotype was a protective factor for AOB (p=0.014; OR 4.6, 95%CI 1.3-16.2). In the logistic regression analysis, none of the genes was associated with AOB. In conclusion, the polymorphism rs17576 (glutamine for arginine substitution) in MMP9 was a protective factor for AOB.

Resumo A mordida aberta anterior apresenta uma etiologia multifatorial causada pela interação entre hábitos de sucção e fatores genéticos. O objetivo deste estudo foi avaliar a associação entre mordida aberta anterior e polimorfismo nos genes que codificam as metaloproteinases da matriz (MMPs) e seus inibidores teciduais (TIMPs). Foram avaliadas 472 crianças que apresentvam pelo menos um hábito de sucção. As crianças foram clinicamente examinadas para avaliar a presença de mordida aberta anterior. DNA genômico foi extraído da saliva. A genotipagem dos polimorfismos selecionados em MMP2, MMP3, MMP9, TIMP1 e TIMP2 foi realizada por PCR em tempo real, usando o método de TaqMan. As frequências alélicas e genotípicas foram comparadas entre os grupos com e sem mordida aberta anterior usando o software PLINK®. Duzentas e dezenove crianças apresentavam mordida aberta anterior enquanto 253 não a apresentavam. O polimorfismo rs17576 em MMP9 estava significativamente associado com mordida aberta anterior (p=0,009). No modelo recessivo (GG versus AG+AA) o genótipo GG foi um fator protetor para mordida aberta anterior (p=0,014; OR 4,6; 95%CI 1,3- 16,2). Concluindo, o polimorfismo rs17576 (substituição de glutamina por arginina) em MMP9 está associado com mordida aberta anterior. Os resultados obtidos suportam a hipótese de que fatores genéticos estão envolvidos com a etiologia da mordida aberta anterior.

Root surface areas of maxillary permanent teeth in anterior normal overbite and anterior open bite assessed using cone-beam computed tomography

PURPOSE: The aim of this study was to compare the root surface areas of the maxillary permanent teeth in Thai patients exhibiting anterior normal overbite and in those exhibiting anterior open bite, using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: CBCT images of maxillary permanent teeth from 15 patients with anterior normal overbite and 18 patients with anterior open bite were selected. Three-dimensional tooth models were constructed using Mimics Research version 17.0. The cementoenamel junction was marked manually. The root surface area was calculated automatically by 3-Matic Research version 9.0. The root surface areas of each tooth type from both types of bite were compared using the independent t-test (P < .05). The intraclass correlation coefficient was used to assess intraobserver reliability. RESULTS: The mean root surface areas of the maxillary central and lateral incisors in individuals with anterior open bite were significantly less than those in those with normal bite. The mean root surface area of the maxillary second premolar in individuals with anterior open bite was significantly greater than in those with normal bite. CONCLUSION: Anterior open-bite malocclusion might affect the root surface area, so orthodontic force magnitudes should be carefully determined.

Full-mouth rehabilitation in an amelogenesis imperfecta patient with anterior open bite using CAD/CAM system / 대한치과보철학회지

Amelogenesis imperfecta characterized as abnormally formed enamel is caused by a defect of unique group of genes. Patients affected by this disease might have difficulties in social and psychological aspects due to non-esthetic teeth as well as functional problems caused by enamel detachment and tooth wear from their early ages. Adult patients with amelogenesis imperfecta can be treated with full-mouth restorations, which make functional and esthetic rehabilitations of severely worn tooth. However, the anterior open bite and lack of occlusal clearance for posterior teeth restorations due to compensatory extrusion are the intervening factors in the prosthetic treatment. Therefore, the determination of anterior tooth lengths, vertical dimension, and anterior guidance should be set carefully. Recently, computer-aided design and computer-aided manufacturing (CAD/CAM) techniques help systematic approaches and enable dentists to reduce time-consuming procedures in the diagnosis and treatment of full-mouth rehabilitation. This case report demonstrates the successful full mouth rehabilitation using a CAD/CAM system in a young adult patient with amelogenesis imperfecta and anterior open bite.

Full-mouth rehabilitation of skeletal anterior open bite with severely decayed dentition: A case report / 대한치과보철학회지

The open bite malocclusion is a common clinical entity and has multifactorial causes. Development of effective treatment plan and management is dependent on proper diagnosis. The skeletal open bite patient requires a coordinated orthodontic and orthognathic surgical approach to achieve stable occlusion, acceptable esthetics, and improved function. But in case of open bite with severely decayed dentition, restoration in the entire dentition is necessary. Using the facial analysis and diagnostic wax-up, the most effective treatment was prosthetic rehabilitation. The provisional restorations were fabricated to satisfy esthetic and functional requirements, which result in the uniformly distributed occlusal force, anterior and canine guidance. The inter-arch relationship, labio-dental harmony, and the soft tissue aspect, which is important to estimate the longevity were evaluated. Definitive restorations of monolithic zirconia were made by replicating provisional restorations by using the latest CAD/CAM technology. They were delivered to the patient and clinical follow-up observation was satisfactory.

Occlusal and cephalometric characteristics of anterior open-bite among Colombian 5-10 years old school children / Características oclusales y esqueléticas de mordida abierta anterior en escolares colombianos de 5 a 10 años

Abstract: objetive. The aim of this study was to determine oclussal and skeletal characteristics of anterior open bite (AOB) according to sex and socioeconomic status (SES) in school children in the municipality of Pasto, Colombia. Methodology. A cross-sectional study was carried out involving 384 children between 5 and 10 years of age. A clinical assessment was performed to evaluate AOB, and information regarding socio-demographic variables, such as sex and SES according to Colombian standards, was obtained. Standardized lateral cephalograms and cast models were taken from participating subjects. A statistical analysis was performed using frequencies, percentages, t-student, ANOVA, Mann-Whitney and Kruskal-Wallis tests. Results. Prevalence of AOB was 8.1 percent, showing a significant difference according to SES. The most common Angle’s classification was Class II with 70.6 percent in the right molars, and 58.8 percent in the left molars, according to occlusal characteristics. Statistically significant differences were observed in the ratio of posterior and anterior facial height (PFH:AFH) (p=0.050) according to sex. The distance between the upper first molar and palatal plane (U6-PP) (p=0.028), the Overbite (p=0.032) and Gonial° (p=0.033) values showed statistically significant differences according to SES in vertical skeletal measures. The 64.7 percent of AOB were of dental origin. Conclusion. Results suggest variations in some vertical skeletal measures according to sex and SES in children with AOB. Since a high percentage of AOB is caused by dental factors, preventive programs are required to control this condition.

Resumen: el objetivo de este estudio fue determinar las características oclusales y esqueléticas de mordida abierta anterior (MAA) según sexo y nivel socioeconómico en escolares de Pasto, Colombia. Metodología. Se diseñó un estudio transversal con la participación de 384 niños entre 5 y 10 años. Se realizó una valoración clínica para evaluar la MAA y se obtuvo información sobre variables socio-demográficas como edad, sexo y estrato socioeconómico (ESE) basado en los parámetros de Colombia. A los participantes se les tomó cefalometrías laterales estandarizadas y modelos de estudio de yeso. Se hizo un análisis estadístico usando frecuencias, porcentajes, t-student, ANOVA, Mann- Whitney y Kruskal-Wallis. Resultados. La prevalencia de MAA fue 8,1 por ciento y existió una diferencia significativa según ESE. La clasificación de Angle más común fue la Clase II para el molar derecho en 70,6 por ciento e izquierdo: en 58,8 por ciento de acuerdo a las características oclusales. Diferencias estadísticamente significativas fueron observadas en la razón entre la altura facial posterior y anterior (PFH: AFH) según sexo (p=0,05). Los valores de la distancia entre el primer molar superior y el plano palatino (U6-PP) (p=0,028), el Overbite (p=0,032) y Gonial° (p=0,033) tuvieron una diferencia estadísticamente significativa con respecto al ESE en las medidas esqueléticas verticales. El 64,7 por ciento de MAA fueron de origen dental. Conclusión. Los resultados sugieren variaciones en algunas medidas esqueléticas verticales según sexo y ESE. Debido a que existe un alto porcentaje de MAA dental, se requieren programas preventivos para controlar esta condición.

Multidisciplinary correction of anterior open bite relapse and upper airway obstruction / 대한치과교정학회지

A 27-year-old man presented an anterior open bite relapse. He had low tongue posture positioned anteriorly at rest and during swallowing and reported chronic difficulty in nose breathing. Head cone-beam computed tomography revealed nasal septum deviation, right turbinate hypertrophy, and left maxillary sinus congestion, which were thought to contribute to the breathing problem, encourage the improper tongue posture, and thereby cause the relapse. Multidisciplinary treatment involving an otorhinolaryngologist, an orthodontist, and a periodontist resolved the upper airway obstruction and corrected the malocclusion. The follow-up examination after 3 years 5 months demonstrated stable results.

Early treatment of anterior open bite: Comparison of the vertical and horizontal morphological changes induced by magnetic bite-blocks and adjusted rapid molar intruders / 대한치과교정학회지

OBJECTIVE: This prospective clinical study aims to determine the differences between two treatment modalities for anterior open bite in growing patients. The treatment modalities involved the use of magnetic bite-blocks (MBBs) or rapid molar intruders (RMIs) applied with posterior bite-blocks. METHODS: Fifteen consecutive patients with a mean age of 11.2 (standard deviation [SD] = 1.6) years and a mean open bite of -3.9 mm were treated with MBBs. Another 15 consecutive patients with a mean age of 10.9 (SD = 1.8) years and a mean open bite of -3.8 mm were treated with RMIs applied on bite-blocks. Cephalometric radiographs were obtained before (T1) and immediately after appliance removal (T2). The treatments lasted four months, during which the appliances were cemented to the teeth. The morphological changes were measured in each group and compared using logistic regression analysis. RESULTS: The MBB group exhibited significantly greater decreases in SNA angle, ANB angle, overjet, and maxillary incisor angle (p < 0.05). The MBBs induced greater effects on the maxilla and maxillary dentition. The MBBs restrained maxillary forward growth and retracted the maxillary incisors more effectively than did the RMIs. Consequently, changes in the intermaxillary relationships and overjets were more distinct in the MBB group. CONCLUSIONS: The anteroposterior differences between the appliances suggest that MBBs should be preferred for the treatment of patients with Class II open bites and maxillary incisor protrusions.

Aporte del pediatra en la prevención de la mordida abierta anterior / Contribution of the pediatrician in the prevention of the anterior open bite

Históricamente es bien sabido que la mordida abierta anterior, conocida como la falta de contactos de los dientes anteriores superiores e inferiores es uno de los tipos de maloclusión que, aunque prevenible, afecta a gran parte de la población. La mayoría de los casos está asociada con la presencia de hábitos orales como la deglución atípica, la succión digital y la respiración bucal; así como, en menor proporción, con trastornos hereditarios y congénitos. El odontólogo especialista en ortodoncia es el profesional que tiene la tarea de aplicar el tratamiento correctivo adecuado una vez instalada la mordida abierta anterior ya que la misma afecta no sólo la cavidad bucal, sino también el aspecto facial del paciente, dependiendo de la severidad. Este podrá variar desde tratamientos ortopédicos, tratamientos ortodónticos, inclusive con extracción de premolares hasta cirugía ortognática. Afortunadamente este trastorno se puede prevenir y es el médico pediatra quien conjuntamente con el odontopediatra tiene el mayor peso en este sentido, a través del diagnóstico oportuno de los hábitos parafuncionales mediante una simple evaluación intra y extra oral del paciente. El trabajo preventivo del médico pediatra ayudaría a disminuir notoriamente la morbilidad de la mordida abierta anterior.

It is well known that the anterior open bite, previously known as lack of contact of upper and lower anterior teeth is one of the types of malocclusions that, although preventable, affects a large part of the population. Most cases are associated with the presence of oral habits such as atypical swallowing, thumb sucking and mouth breathing as well as hereditary and congenital disorders in a lesser extent. The dental specialist in orthodontics is the professional who has the task of applying the appropriate treatment after the anterior open bite is installed. According to its severity it not only affects the oral cavity but also the patient's facial appearance. Treatment may range from orthopedic treatments, including orthodontic treatment with premolar mutilation to orthognathic surgery. Fortunately this condition is preventable and it is the pediatrician together with the pediatric dentist who has the greatest importance in regard to the early diagnosis of parafunctional habits through a simple intra and extra oral assessment. The preventive approach of the pediatrician would help reduce the morbidity due to the anterior open bite.

Compensatory orthodontic treatment of Angle Class II malocclusion with posterior open bite

The present case report addresses the treatment of an Angle Class II malocclusion in an adult female patient, long face pattern, with posterior open bite and dental arches extremely expanded, due to previous treatment. The patient and parents rejection to a treatment with orthognathic surgery led to orthodontic camouflage of the skeletal discrepancies. This clinical case was presented to the Brazilian Board of Orthodontics and Facial Orthopedics (BBO) as one of the requirements to become a BBO Diplomate.

O presente relato de caso aborda o tratamento de uma má oclusão de Classe II de Angle em paciente do sexo feminino, adulta, face longa, com mordida aberta posterior, e arcadas dentárias extremamente expandidas, decorrente de tratamento prévio. A não aceitação, por parte da paciente e de seus pais, de um tratamento envolvendo cirurgia ortognática levou à realização de camuflagem ortodôntica das discrepâncias esqueléticas. Esse caso clínico foi apresentado à Diretoria do Board Brasileiro de Ortodontia e Ortopedia Facial (BBO) como parte dos requisitos para obtenção do título de Diplomado pelo BBO.

Angle Class II malocclusion treated with extraction of permanent teeth

Angle Class II malocclusion associated with anterior open bite in adult patients demands a carefully elaborated orthodontic planning, aiming at restoring not only harmonious dental and facial esthetics, but also a balanced masticatory function. Orthognathic surgery or permanent teeth extraction are often the choice of treatment, therefore, treatment decision is related to all dental, skeletal and functional aspects. The present report discusses orthodontic compensation carried out by means of upper premolar extraction performed to correct the Class II canine relationship and, consequently, the anterior open bite, accepting that the upper incisors be retroclined. This clinical case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO) as part of the requirements for obtaining the BBO Certification.

A má oclusão Classe II de Angle associada à mordida aberta anterior, em pacientes adultos, envolve um planejamento ortodôntico bem elaborado e cuidadoso, tendo como objetivo principal devolver a estética facial e dentária harmoniosa, e uma função mastigatória equilibrada. O tratamento, muitas vezes, está no limite para cirurgia ortognática ou para extrações de dentes permanentes, fazendo com que a decisão esteja ligada a todos os aspectos dentários, esqueléticos e funcionais. O presente relato mostra a compensação ortodôntica por meio de extrações de pré-molares superiores, a fim de corrigir a relação de Classe II dos caninos e, consequentemente, a mordida aberta anterior, aceitando que os incisivos superiores estejam retroinclinados. Esse caso clínico foi apresentado à diretoria do Board Brasileiro de Ortodontia e Ortopedia Facial (BBO) como parte dos requisitos para a obtenção do título de Diplomado pelo BBO.

Estabilidade do tratamento precoce da mordida aberta anterior com esporão colado e mentoneira / Stability of early anterior open bite treatment with bonded spurs associated with high-pull chincup therapy

O objetivo desta pesquisa retrospectiva foi avaliar cefalometricamente a estabilidade do tratamento precoce da mordida aberta anterior com esporão colado associado à mentoneira, após 3 anos do término do tratamento. A amostra foi constituída por dois grupos. O grupo experimental foi composto inicialmente por 33 jovens, sendo 22 do gênero feminino e 11 do masculino, que receberam tratamento durante 12 meses com aparelho esporão lingual colado associado à mentoneira e apresentavam previamente ao tratamento, a má oclusão de Classe I com mordida aberta anterior. Estes pacientes foram radiografados em 3 períodos: T1 (início do tratamento), T2 (final do tratamento) e T3 (3 anos após o término do tratamento) e apresentavam, nestes períodos, as idades médias de 8,10 anos, 9,13 anos e 12,18 anos, respectivamente. Em T3, o grupo experimental consistiu de 25 pacientes. O grupo controle consistiu de 23 jovens, sendo 13 do gênero feminino e 10 do gênero masculino, com oclusão normal e idades compatíveis com as idades do grupo experimental nas 3 fases do tratamento (8,45 anos em T1; 9,45 anos em T2 e 12,51 anos em T3). A comparação intergrupos das alterações ocorridas 3 anos após o término do tratamento (T3-T2) foram realizadas pelo teste t, a um nível de significância de 5% e a comparação intragrupo experimental, no perído de tratamento e 3 após o término do mesmo, foi realizada através do teste t pareado. Os resultados permitiram concluir que não houve recidiva estatisticamente significante entre os grupos, 3 anos após o término do tratamento. Apenas 4% dos casos apresentaram recidiva clinicamente significante, o que correspondeu a 1 paciente do total de 25 avaliados no período pós-tratamento, com estabilidade clínica em 96% dos casos. Além disso, não houve correlação entre a magnitude inicial e a quantidade de correção da mordida aberta anterior com a recidiva do tratamento realizado.

The aim of this research was to cephalometrically investigate the stability of early anterior open bite treatment with bonded spurs associated with high-pull chincup therapy three years after the treatment end. Two groups were studied. The experimental group consisted of 33 patients (22 female and 11 male), presenting a Class I malocclusion with anterior open bite at the pretreatment stage. This patients had undergone orthodontic treatment with bonded spurs associated with high-pull chincup therapy for one year and their cephalometric headfilms were obtained at the pretreatment (T1), posttreatment (T2), and three years posttreatment (T3) stages and in these period they had average ages of 8.10 years, 9.13 years and 12, 18, respectively. At T3 stage, the experimental group consisted of 25 patients. The control group consisted of 23 patients (13 female and 10 male), with normal occlusion and with ages comparable with the experimental group in the 3 treatment stages (8.45 years at T1; 9.45 years at T2 and 12.51 years at T3). The differences between the observation stages in the experimental group were analyzed with paired t tests and the three years posttreatment changes were compared with the changes of the control group with t tests. The results showed that there was no statistically significant relapse of open bite between the groups, three years after the treatment end. Only one patient (4%) had a clinically significant relapse of open bite and 24 (96%) did not. Therefore, 96% had a clinically stable correction of early open bite treatment. Furthermore, there was no association between the initial magnitude and the amount of correction of anterior open bite with the relapse of treatment.