Influence of the palatal plane cant and skeletal patterns in the hard palate thickness?

INTRODUCTION: The aim of the present study was to evaluate the thickness of the hard palate at the different angles formed by the palatal plane and the Frankfort horizontal line using computed tomography in patients with different facial patterns for planning the installation of MARPE. MATERIALS AND METHODS: The measurements were analysed in the hard palate of 106 patients. Four regions were selected passing through the mesial face, tangent at the level of the cemento-enamel junction of the premolars and molars. The bone thickness was measured from the floor of the nasal cavity to the cortical bone of the hard palate, 02 measurements with a distance of 05 mm between them (2.5 mm on each side starting from the midsagittal line) and 2 more with a distance of 7 mm between measurements (3.5 mm on each side starting from the midsagittal line). The palatal plane cant was determined based on the palatal plane and the Frankfort horizontal plane. The sagittal skeletal pattern was determined based on the ANB angle and the vertical skeletal pattern based on the SN.Go.Gn angle. RESULTS: Palatal bone thickness was greater in males than in females. Regarding the sagittal skeletal pattern, patients with Class II were found to have a thinner hard palate than Class I and Class III patients. No difference in the vertical skeletal pattern was observed between groups. Regarding the palatal plane cant, bone thickness was greater in patients with clockwise rotation. CONCLUSIONS: Careful planning should be considered in the case of female patients; patients with greater angles of the palatal plane cant and Class II patients have a smaller bone thickness.

Evaluation of anteroposterior and vertical stability 25 years after Angle class II division 1 treatment with cervical headgear.

PURPOSE: The goal was to investigate long-term (minimum 20 years) skeletal and dental changes in Angle class II division 1 patients treated with full-fixed orthodontic appliances and cervical pull headgear. METHODS: A longitudinal retrospective study was performed with 20 orthodontic patients, who were treated exclusively by one experienced clinician and whose treatment had been completed a minimum of 20 years ago. Former patients who had been treated from the mid-1970s to the early 1990s were actively sought. After the recall, 20 patients agreed to participate in the study. Lateral cephalometric radiographs at pretreatment (T1), posttreatment (T2), and long-term follow-up (T3) were digitized and measurements were performed. Angular variables used were SNA, SNB, ANB, OcclPl-FH, PalPl-FH, GoMe-FH, 1­NA, and Y axis. Linear measures were A­NPerp, Pg-NPerp, 1­NAmm, Wits, and LAFH. RESULTS: From T1 to T2, a significant reduction (p < 0.01) in ANB angle from 4.70 to 2.48° and in Wits value from 3.42 to 0.98 mm were observed. It was also noticed a significant increase (p < 0.01) in LAFH from 62.02 to 67.39 mm, probably due to normal facial growth. From T2 to T3, these variables remained stable. No significant changes were observed for any other measure in any of the periods studied. CONCLUSIONS: In the assessed sample, Angle class II division 1 patients treated with cervical pull headgear presented cephalometric outcome stability of treatment, even after a long-term follow-up of a mean of 25 years postretention.

Perception of facial profile attractiveness of a brown subject displaying different degrees of lip projection or retrusion, in the city of Salvador/Bahia.

INTRODUCTION: The attractiveness and facial aesthetics are commonly defined by the media in modern society and the number of patients seeking for changes in the facial appearance is progressively increasing. Augmented face convexity is believed to be non aesthetic and among the treatments available for its correction, the extraction of premolars followed by anterior teeth retraction produces a significant effect. However, it is questionable whether the procedure is reasonable in brown and black patients, since dental protrusion is considered a common morphological feature in these groups. METHODS: A photograph of a brown female subject was manipulated with image-editing program to generate a set of images with different degrees of labial retraction/protrusion. Two hundred individuals, randomly selected, were asked to rate each photograph and select which one showed the best aesthetic appearance. The survey was carried out in Salvador / Bahia (Brazil), which is a city with strong African slavery background and high proportion of brown and black population. RESULTS: Regardless of color, sex or income, the interviewees chose primarily the straight facial profile and secondarily the slightly concave or convex as more pleasant for a brown female individual (p< 0.05). The moderate and extreme convexity had the lowest scores (p< 0.05). CONCLUSIONS: It is suggested that among the accessed population, straight and slightly convex or concave profiles were preferred for a brown subject and moderate or excessive facial protrusion were not well accepted. It is expected that these data can guide orthodontists about the need for extraction to reduce dental protrusion in brown patients.

Perception of facial profile attractiveness of a brown subject displaying different degrees of lip projection or retrusion, in the city of Salvador/Bahia

ABSTRACT Introduction: The attractiveness and facial aesthetics are commonly defined by the media in modern society and the number of patients seeking for changes in the facial appearance is progressively increasing. Augmented face convexity is believed to be non aesthetic and among the treatments available for its correction, the extraction of premolars followed by anterior teeth retraction produces a significant effect. However, it is questionable whether the procedure is reasonable in brown and black patients, since dental protrusion is considered a common morphological feature in these groups. Methods: A photograph of a brown female subject was manipulated with image-editing program to generate a set of images with different degrees of labial retraction/protrusion. Two hundred individuals, randomly selected, were asked to rate each photograph and select which one showed the best aesthetic appearance. The survey was carried out in Salvador / Bahia (Brazil), which is a city with strong African slavery background and high proportion of brown and black population. Results: Regardless of color, sex or income, the interviewees chose primarily the straight facial profile and secondarily the slightly concave or convex as more pleasant for a brown female individual (p< 0.05). The moderate and extreme convexity had the lowest scores (p< 0.05). Conclusions: It is suggested that among the accessed population, straight and slightly convex or concave profiles were preferred for a brown subject and moderate or excessive facial protrusion were not well accepted. It is expected that these data can guide orthodontists about the need for extraction to reduce dental protrusion in brown patients.

RESUMO Introdução: a atratividade e a estética facial são comumente definidas pela mídia, na sociedade moderna, e o número de pacientes buscando mudar seu aspecto facial tem aumentado progressivamente. Acredita-se que a convexidade facial aumentada seja considerada não estética. Entre os tratamentos disponíveis para sua correção, figura, com destaque, a extração de pré-molares seguida da retração dos dentes anteriores. No entanto, é questionável se esse procedimento estaria indicado para indivíduos negros e pardos, visto que a protrusão dentária é considerada um achado morfológico comum nesses grupos. Métodos: a fotografia de um indivíduo pardo do sexo feminino foi manipulada em programa de edição de imagens, de forma a gerar um grupo de imagens com diferentes graus de protrusão ou retrusão labial. Duzentos indivíduos, selecionados aleatoriamente, avaliaram e foram solicitados a escolher a fotografia que melhor se apresentava esteticamente. Essa pesquisa foi executada em Salvador / Bahia (Brasil), que é uma cidade com marcante histórico de escravidão africana, apresentando elevada proporção de negros e pardos. Resultados: independentemente da cor, sexo ou renda, os entrevistados escolheram como mais estético, para um indivíduo pardo, o perfil reto, seguido do perfil levemente côncavo ou convexo (p< 0,05). Conclusões: dentro da amostra entrevistada, o perfil reto foi considerado mais estético para um indivíduo pardo, seguido do perfil levemente côncavo ou convexo. Os perfis moderadamente e excessivamente convexos foram considerados menos atraentes. Espera-se que esses achados possam guiar os ortodontistas no que diz respeito à necessidade de extrações dentárias, com intuito de reduzir a protrusão dentária/labial em pacientes pardos.

Digital models: How can dental arch form be verified chairside?

ABSTRACT Introduction: Plaster dental casts are routinely used during clinical practice to access maxillary dental arch form and assist on fabrication of individualized orthodontic archwires. Recently introduced, digital model technology may offer a limitation for the obtainment of a dental physical record. In this context, a tool for dental arch form assessment for chairside use is necessary when employing digital models. In this regard, paper print of the dental arch seems thus to be useful. Methods: In the present study, 37 lower arch models were used. Intercanine and intermolar widths and dental arch length measurements were performed and compared using plaster dental casts, digital models and paper print image of the models. Ortho Insight 3D scanner was employed for model digitalization. Results: No statistically significant differences were noted regarding the measurements performed on the plaster or digital models (p> 0.05). Paper print images, however, showed subestimated values for intercanine and intermolar widths and overestimated values for dental arch length. Despite being statistically significant (p< 0.001), the differences were considered clinically negligible. Conclusion: The present study suggests that paper print images obtained from digital models are clinically accurate and can be used as a tool for dental arch form assessment for fabrication of individualized orthodontic archwires.

RESUMO Introdução: os modelos de gesso são usados rotineiramente, durante a prática clínica, para avaliação da forma da arcada inferior e para auxiliar na confecção de arcos ortodônticos individualizados. A tecnologia dos modelos digitais, introduzida recentemente, pode oferecer uma limitação na obtenção de um registro físico da arcada dentária. Assim, quando se utilizam modelos digitais, faz-se necessária uma ferramenta clínica para obtenção da forma da arcada. Com essa finalidade, poderia-se imprimir, em papel, uma imagem da arcada dentária obtida a partir do modelo de gesso. Métodos: nesse estudo, 37 modelos da arcada inferior foram utilizados, nos quais foram realizadas medições das distâncias intercaninos, intermolares e comprimento da arcada; sendo, então, comparadas entre modelos de gesso, modelos digitalizados com um scanner Ortho Insight 3D e imagens impressas em folha de papel A4. Resultados: não foram encontradas diferenças estatisticamente significativas nas medidas realizadas nos modelos de gesso e modelos digitais (p > 0,05). As imagens impressas, contudo, mostraram valores subestimados para as distâncias intercaninos e intermolares, e superestimados para o comprimento da arcada. Apesar de serem estatisticamente significativas (p< 0,001), as diferenças foram consideradas clinicamente insignificantes. Conclusão: o presente estudo sugere que as imagens obtidas por meio dos modelos digitais e impressas em papel são clinicamente acuradas e podem ser utilizadas como uma ferramenta auxiliar na confecção dos arcos ortodônticos individualizados.

Digital models: How can dental arch form be verified chairside?

INTRODUCTION: Plaster dental casts are routinely used during clinical practice to access maxillary dental arch form and assist on fabrication of individualized orthodontic archwires. Recently introduced, digital model technology may offer a limitation for the obtainment of a dental physical record. In this context, a tool for dental arch form assessment for chairside use is necessary when employing digital models. In this regard, paper print of the dental arch seems thus to be useful. METHODS: In the present study, 37 lower arch models were used. Intercanine and intermolar widths and dental arch length measurements were performed and compared using plaster dental casts, digital models and paper print image of the models. Ortho Insight 3D scanner was employed for model digitalization. RESULTS: No statistically significant differences were noted regarding the measurements performed on the plaster or digital models (p> 0.05). Paper print images, however, showed subestimated values for intercanine and intermolar widths and overestimated values for dental arch length. Despite being statistically significant (p< 0.001), the differences were considered clinically negligible. CONCLUSION: The present study suggests that paper print images obtained from digital models are clinically accurate and can be used as a tool for dental arch form assessment for fabrication of individualized orthodontic archwires.

Unilateral impaction of a maxillary first molar treated in the transitional dentition.

The purpose of this report was to present the case of a nine-year-old patient with unilateral impaction of the permanent maxillary right first molar treated early using a simple and effective fixed appliance. The proposed intervention involved the construction of a fixed palatal arch with a soldered wire extending distally to the impacted permanent first molar. A button was bonded to the occlusal surface of the molar, which was to be used as a leverage point for engaging chain elastics to produce distal movement to disimpact and allow complete eruption of the molar. Following three months of treatment, the permanent molar was in a physiologic position. This report demonstrates that, when this problem is identified early, pediatric dentists have the opportunity to minimize the complexity of future orthodontic treatment and limit the extent of malocclusion in the permanent dentition.