Assessment of the relationship between size, shape and volume of the sella turcica in class II and III patients prior to orthognathic surgery.

PURPOSES: The main purpose of this study was to assess the measurements and shape of the sella turcica by using cone beam computed tomography (CBCT) and to associate the data to skeletal class II and class III patients, including correlations with gender, age and measurements of the anterior cranial base. MATERIAL AND METHODS: A trained examiner specialist in dental radiology selected and evaluated randomly 95 CBCT images of pre-orthognathic surgery patients, 60 (63.2%) being female and 35 (36.8%) male with age between 16 and 57 years. All images were evaluated to determine the size, shape and volume of the sella turcica. The anterior cranial base, represented by the S-N line (sella-nasion), was also measured. RESULTS: Of these 95 patients, 48 (50.5%) had class III facial skeletal pattern, whereas 47 (49.5%) had class II. No statistically significant differences were found between class II and class III patients in the measurements and shape of the sella turcica (P > 0.05). The diameter and volume of the sella turcica had higher values in female patients, whereas the measurements of the anterior cranial base were higher in males (P < 0.05). CONCLUSION: Therefore, one can conclude that measurements of the sella turcica are not reliable parameters to evaluate whether a class II or class III patient will or will not need orthognathic surgery.

Evaluation of slot height in Roth prescription orthodontic brackets.

The dimensional accuracy of orthodontic brackets slots is extremely important, since inaccuracy can affect orthodontic mechanics. The aim of this study was to investigate the slot heights of Roth prescription brackets from several commercial manufacturers. A total of 360 maxillary and mandibular incisor brackets from 6 different commercial models (Kirium Line, Ovation, Roth Light, Synthesis, Integra, and Miniature Twin) were selected and divided into 18 experimental groups containing maxillary central incisor, maxillary lateral incisor, or mandibular central incisor brackets (n = 20). Brackets were viewed under a scanning electron microscope to acquire a clear image of all slot edges, and slot heights were measured at 2 locations on each bracket to acquire mean values. Group means and standard deviations were calculated and compared with the manufacturer reference value of 0.5588 mm (0.0220 inch) plus or minus a tolerance level of 0.0100 mm (∼0.0004 inch). With the exception of Synthesis maxillary lateral incisor brackets (P = 0.230), all brackets had slot heights that were significantly smaller than 0.5588 mm (P < 0.05). The measured slot heights were 1.84% to 14.91% smaller than the reference value. Virtually all measured bracket slot heights were smaller than claimed by the manufacturers, with great variability within the same brand and indication, revealing a lack of precision in the fabrication process.

Evaluation of distances between the mandibular teeth and the alveolar process in Brazilians with normal occlusion.

INTRODUCTION: The aims of this study were to evaluate the distances between the mandibular permanent teeth and the alveolar process in Brazilians with normal occlusion and to compare them with normal American values. METHODS: We used 59 mandibular casts from untreated subjects who had permanent dentition and the 6 keys to normal occlusion. A computer program was used to calculate the distances between the dental reference points and the alveolar process for each tooth. The mean values were then compared to the normal values by applying the Student t test at a significance level of 0.05. RESULTS: The results showed a progressive increase of these distances from the anterior region (incisors) to the posterior region (molars), from 0.00 to 2.49 mm. All measurements had statistically significant differences from the American sample, except for the values for canines and first premolars. CONCLUSIONS: Brazilians with normal occlusion have more lingual crown positions for the incisors, second premolars, and molars compared with Americans with normal occlusion. Although these findings were statistically significant, they are unlikely to be clinically significant.

Tomographic evaluation of dentoskeletal changes due to the treatment of class II malocclusion with Forsus appliance.

PURPOSE: This study evaluated dentoalveolar skeletal changes promoted by the Forsus appliance, associated to fixed orthodontic appliance, in the correction of Class II, division 1 malocclusion, from Computed Tomography (CT). METHODS: sample consisted of 10 youngsters (7 males and 3 females), with a mean age of 13.86 years. Two Forsus® models were installed after the alignment and leveling phase of the teeth. Two tomographic images of each patient, T1 and T2 (initial and immediately after removal of Forsus® appliance) were done to perform the anatomical tracings and obtain the variables of interest. The data were described by means and standard deviations. For the comparison between the initial and final phases, the paired "t" test was used and a significance level of 5% was considered (p < 0.05). RESULTS: small skeletal changes were observed, such as posterior maxillary displacement and a slight mandibular growth. Larger dentoalveolar changes occurred as extrusion, retrusion and lingualization of upper incisors; Intrusion, protrusion and vestibularization of the lower incisors; Mesialization and extrusion of lower molars. CONCLUSION: Considering the patients evaluated in this study, Forsus® presented similar results to other mandibular propulsion appliances, with dentoalveolar effects that favored Class II correction, however, with very slight skeletal modifications.

Subjective analysis of the application of enhancement filters on magnetic resonance imaging of the temporomandibular joint.

OBJECTIVE: The aim of this study was to investigate the effect of enhancement filters on magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ). STUDY DESIGN: In total, 66 MRI scans of the TMJ were analyzed without filtration and with the application of 2 filters: Sharpen 1 and Sharpen 2 (OnDemand software). Two dentomaxillofacial radiologists examined the original and filtered images individually. Intra- and interobserver concordance was measured by using generalized estimating equations. The observers evaluated the subjective image quality and the visibility of 3 components of the TMJ: disk, condyle, and articular eminence. The images were ranked on a 4-point scale, from poor to excellent. The image quality of all filtered images was compared by using the χ2 test and Bonferroni correction for multiple comparisons. RESULTS: Intra- and interobserver concordance was good. The images filtered with Sharpen 1 and Sharpen 2 provided better definition of the structures compared with nonfiltered images, providing the highest scores for subjective image quality for all structures (P < .0001). CONCLUSIONS: The use of enhancement filters led to improved subjective quality and may improve the diagnostic efficacy of MRI in TMJ evaluation.

Evaluation of lower anterior dental changes in patients treated with self-ligating brackets.

The aim of this study was to evaluate and compare changes in linear distance and inclination of lower incisors and canines and intercanine distance after a 30 months orthodontic treatment with self-ligating appliances. Seven patients were treated orthodontically with a Roth prescription passive self-ligating bracket. To perform the measurements and comparisons, CBCT scans were taken before the start of the orthodontic treatment (T1) and after a period of 30 months treatment (T2). The following measurements were performed: (1) the lower incisors and canines inclination in relation to the mandibular plane, (2) intercanine linear distance in millimeters and (3) linear distance in millimeters of the incisal and apical part of lower anterior teeth to a plane (POGM) passing through pogonion point and perpendicular to the mandibular plane. No significant difference were observed between T1 and T2 for canine inclination (p = 0.835), incisors inclination (p = 0.149), canine incisal distance to POGM (p = 0.423) and incisors incisal distance to POGM (p = 0.966), however canine apical distance (p = 0.049) and incisors apical distance (p = 0.002) to POGM was lower at T1 than at T2. The intercanine distance was significantly lower (p = 0.022) at T1 when compared to T2. The use of passive self-ligating brackets in orthodontic treatment to solve 4 mm tooth crowding were able to produce dental arch expansion by bodily tooth movement.

Cone Beam Computed Tomography-Based Anatomical Assessment of the Olfactory Fossa.

This study aimed to investigate the olfactory fossa according to the Keros classification using cone beam computed tomography. This cross-sectional study analysed cone beam computed tomography images selected from a database belonging to a radiology centre. The scans of 174 healthy patients were analysed by using the Xoran software. Gender, age, and side were correlated with the Keros classification. The mean age of the 174 patients was 45.3 years. The most prevalent Keros classification was type II (65.52%), followed by type III (20.69%) and type I (13.79%). No significant differences were found between Keros classification and the variables age, right side (p value = 0.4620), and left side (p value = 0.5709). There were also no significant differences between gender and the variables right side (p value = 0.1421) and left side (p value = 0.2136). Based on these results, we suggest that cone beam computed tomography can be recommended for analysis of the anterior skull base. Keros type II was the most prevalent type in our sample.

A new concept of mandibular dental arch forms with normal occlusion.

INTRODUCTION: Because it is important to maintain dental arch dimensions during orthodontic therapy, all possible dental arch forms must be evaluated. METHODS: A mathematical method associated with a polynomial function was used to evaluate the dental arch forms of 63 mandibular models of Brazilian adolescents in the permanent dentition with normal occlusion. A bead was glued to each tooth to simulate an orthodontic accessory and help in the measurement of distances between the center of the bead to the x- and y-axes. The dental casts were digitized, and images were plotted on a computer program to obtain the sixth-degree polynomial and the graph of this function. These segments were organized into 8 groups according to the form of the anterior curve of the dental arch; these were named forms A through H. Each group was subdivided into 3 subgroups: small, medium, and large sizes. RESULTS: Form A was the most frequently observed at 22%, whereas form G was observed in only 2% of the total sample. Forms A, B, C, D, E, and F had more curve segments in medium size, and forms G and H had more curves in small size. A mean dental arch curve was calculated; however, this form coincided with form C, which had an incidence of 10%. CONCLUSIONS: The mandibular dental arch is represented by 23 forms; thus, a normal dental arch cannot be represented by only 1 simple arch form.

Agenesis of all permanent maxillary incisors: A rare clinical case with an interdisciplinary solution.

BACKGROUND: Clinical cases involving agenesis of all four maxillary incisors are rare, with no previous reports in the literature. CASE REPORT: The present case report describes an orthodontic treatment combined with esthetic dentistry in a 10-year-old girl with agenesis of all four permanent maxillary incisors, anterior crossbite, permanence of deciduous maxillary canines and transmigration of permanent maxillary canines into the region of the maxillary central incisors. For this case, it was decided on space closure using a fixed orthodontic apparatus and reshaping of the first premolars transforming them into canines. Porcelain veneers were used on the permanent and deciduous canines, substituting the maxillary central and lateral incisors, respectively. Regarding outcome, there was an improvement in facial profile, correction of the anterior crossbite, satisfactory intercuspidation of the teeth and significant esthetic improvement in smile. Maintaining the patient´s natural dentition also kept the bone plate intact for future placement of implants to substitute maxillary deciduous canines at the appropriate age. CONCLUSIONS: Interdisciplinary planning combining orthodontics and esthetic dentistry was key in resolving this case. Key words:Tooth agenesis, upper incisors, orthodontic treatment.

Analysis on the precision of the dimensions of self-ligating brackets.

OBJECTIVE: The present study aimed to evaluate the precision of the torque applied by 0.022" self-ligating brackets of different brands, the precision of parallelism between the inner walls of their slots, and precision of their slot height. Eighty brackets for upper central incisors of eight trademarked models were selected: Abzil, GAC, American Orthodontics, Morelli, Orthometric, Ormco, Forestadent, and Ortho Organizers. Images of the brackets were obtained using a scanning electron microscope (SEM) and these were measured using the AutoCAD 2011 software. The tolerance parameters stated in the ISO 27020 standard were used as references. The results showed that only the Orthometric, Morelli, and Ormco groups showed results inconsistent with the ISO standard. Regarding the parallelism of the internal walls of the slots, most of the models studied had results in line with the ISO prescription, except the Morelli group. In assessing bracket slot height, only the Forestadent, GAC, American Orthodontics, and Ormco groups presented results in accordance with the ISO standard. The GAC, Forestadent, and American Orthodontics groups did not differ in relation to the three factors of the ISO 27020 standard. Great variability of results is observed in relation to all the variables.

Determining shapes and dimensions of dental arches for the use of straight-wire arches in lingual technique.

INTRODUCTION: This study aims to determine the shape and dimension of dental arches from a lingual perspective, and determine shape and size of a straight archwire used for lingual Orthodontics. METHODS: The study sample comprised 70 Caucasian Brazilian individuals with normal occlusion and at least four of Andrew's six keys. Maxillary and mandibular dental casts were digitized (3D) and the images were analyzed by Delcam Power SHAPET 2010 software. Landmarks on the lingual surface of teeth were selected and 14 measurements were calculated to determine the shape and size of dental arches. RESULTS: Shapiro-Wilk test determined small arch shape by means of 25th percentile (P25%)--an average percentile for the medium arch; and a large one determined by means of 75th percentile (P75%). T-test revealed differences between males and females in the size of 12 dental arches. CONCLUSION: The straight-wire arch shape used in the lingual straight wire technique is a parabolic-shaped arch, slightly flattened on its anterior portion. Due to similarity among dental arch sizes shown by males and females, a more simplified diagram chart was designed.

Atendimento odontológico de paciente submetido à radioterapia em região de cabeça e pescoço: relato de caso clínico / Dental care of patient submitted to radiotherapy in the head and neck region: a case report

O tratamento do câncer de cabeça e pescoço depende da idade do paciente, presença de comorbidades, tamanho do tumor, localização, grau, estágio, presença de linfonodos afetados e de metástases, e inclui cirurgia, radioterapia e quimioterapia, combinadas ou separadamente. As complicações bucais da radioterapia em região de cabeça e pescoço são amplamente conhecidas, tais como, mucosite, xerostomia, disgeusia, trismo, cárie de radiação e osteorradionecrose. A prevenção ou redução da incidência e severidade dessas complicações são fundamentais para a manutenção da saúde bucal, tendo o dentista um papel primordial antes, durante e após a radioterapia. Dessa forma, este relato de caso visa discutir o atendi¬mento odontológico de uma paciente irradiada em região de cabeça e pescoço, salientando as principais complicações bucais, manejo odontológico e a importância da Odontologia na equipe multidisciplinar no tratamento do câncer bucal

The head and neck cancer treatment depend on age, comorbidities, tumor size, site, stage, grade, lymph nodes status and metastases, and include surgery, radiotherapy and chemotherapy, combined or separately. Oral complications of radiotherapy in the head and neck region are widely known, such as mucositis, xerostomia, dysgeusia, trismus, radiation caries and osteoradionecrosis. The prevention or reduction of incidence and severity of oral complications are essential in the maintenance of oral health, and the dentist having a primary role before, during and after radiotherapy. Thus, this case report aims to discuss the dental care of a patient irradiated in the head and neck region, highlighting the main oral complications, dental management and the importance of Dentistry in the multidisciplinary team in the treatment of oral cancer

Upper airway expansion after rapid maxillary expansion evaluated with cone beam computed tomography.

OBJECTIVE: Cone-beam computed tomography (CBCT) is a reliable method of assessing the oral cavity and upper airways. We conducted this study to examine the changes introduced by rapid maxillary expansion in the nasal cavity, nasopharynx, and oropharynx as seen with images obtained by CBCT. MATERIALS AND METHODS: We evaluated 15 patients with maxillary width deficiency treated with RME. Patients were subjected to CBCT at the beginning of RME and after the retention period of 4 months. RESULTS: The nasal cavity presented a significant transverse increase in the lower third, in the anterior (1.08 mm ± 0.15), medium (1.28 mm ± 0.15), and posterior regions (0.77 mm ± 0.12). No significant change occurred in the nasopharynx in volume (P  =  .11), median sagittal area (P  =  .33), or lower axial area (P  =  .29) resulting from the RME. A significant change was noted in the oropharynx in volume (P  =  .05), median sagittal area (P  =  .01), and lower axial area (P  =  .04) before and immediately after the RME. CONCLUSIONS: RME is able to increase the transverse width of the nasal cavity, but it does not have the same effect in the nasopharynx. Changes noted in the oropharynx may be due to the lack of a standardized position of the head and tongue at the time of image acquisition.

O efeito de diferentes níveis de PH em soluções de flúor a 1, 1% na corrosão de arcos NITI / The effect of different PH levels on fluoride solutions at 1. 1% on corrosion of NITI archs

Objetivo: Determinar o pH crítico para ocorrer a corrosão de arcos NiTi em soluções de flúor a 1,1%, variando o pH de 3,5 a 7,0. Materiais e Métodos: Doze amostras com 10mm de comprimento de fio superelástico NiTi 0017 x 0025 (Abzil), obtidas do segmento distal dos arcos. As amostras foram aleatoriamente separadas e imersas dentro de recipientes contendo 40ml de seis soluções (água, soluções fluoretadas com pH: 3,5; 4,0; 4,5; 5,0; 5,5; 6,0; 6,5 e 7,0), sob uma mesa agitadora durante 90 minutos. Todas as amostras foram, então, levadas ao MEV. As imagens das amostras imersas em água e soluções fluoretadas com pH 7,0, 6,5 e 6,0 não se apresentaram diferentes, no entanto a partir da solução fluoretada com pH 5,5, as imagens superficiais apresentaram características diferentes dos grupos anteriores. Conclusão: Com base nos resultados obtidos neste estudo, o pH crítico para corrosão de arcos NiTi em soluções de flúor a 1,1% parece estar entre 6,0 e 5,5

Objective: To determine the critical pH to occur corrosion of NiTi arches in 1.1% fluoride solutions by varying the pH between 3.5 and 7.0. Materials and Methods: Twelve samples of 10 mm length superelastic NiTi wire 0017 x 0025 (Abzil) obtained in the distal segment of the arcs. The samples were randomly separated and immersed in 40 ml of six solutions (water, fluoride solutions with pH: 3.5; 4.0; 4.5; 5.0; 5.5; 6.0; 6.5 and 7.0) under a shaker table for 90 minutes. All samples were observed under SEM. The images of the samples immersed in water and fluoride solutions at pH 7.0, 6.5 and 6.0 did not show differences, however from the fluoride solution at pH 5.5, the surface characteristics of images presented differences from above groups. Conclusion: Based on the results obtained in this study the critical pH for corrosion of NiTi arches in fluoride solutions to 1.1% appears to be between 6.0 and 5.5

Prevalência de dentes supranumerários em pacientes de Ortodontia / Supernumerary teeth prevalence in Orthodontic patients

Existem várias alterações nos arcos dentários, entre estas se encontram as de número, forma e tamanho dos dentes. O dente supranumerário representa um fator etiológico importante e frequente da má oclusão. Este trabalho teve o objetivo de avaliar a prevalência de dentes supranumerários nos pacientes tratados nos cursos de pós-graduação em Ortodontia da Universidade Cidade de São Paulo. A amostra, composta por 1117 radiografias panorâmicas de pacientes que se submeteram a tratamento ortodôntico corretivo, foi estudada quanto à distribuição da prevalência de dentes supranumerários entre os gêneros, os arcos dentários e as regiões bucais. A média de idade da amostra foi de 13,7 anos, sendo que 56% dos pacientes eram do gênero feminino e 44% do masculino. Do total analisada, apenas 18 pacientes (1,61%) apresentaram dentes supranumerários. Em relação ao gênero, verificou-se uma prevalência de 1,9% no gênero feminino, enquanto o gênero masculino apresentou prevalência de 1,2%. Na comparação entre os gêneros não se verificou diferença com significância estatística. No total foram constatados 24 dentes supranumerários, uma vez que existiram radiografias de pessoas com a presença de mais de um dente supranumerário. Destes 24 dentes, 16 estavam no arco superior e 8 no arco inferior. A partir da metodologia aplicada e dos resultados obtidos, pôde-se concluir que: a prevalência de dentes supranumerários foi de 1,61% dos indivíduos da amostra; não se pôde verificar diferença significante na prevalência de supranumerários entre os gêneros masculino e feminino; e a prevalência de dentes supranumerários foi estatisticamente semelhante para os arcos dentários superior e inferior, apesar de 66,7% deles terem sido localizados no arco superior

There are several tooth abnormalities in the dental arches, which can be in the number, shape or size of the teeth. The supernumerary teeth represent an important etiologic factor of malocclusion, quietly frequent. This study aimed to evaluate the prevalence of supernumerary teeth in the patients who has been orthodontic treated in the Graduation course of University of São Paulo City (UNICID). The sample, which consisted of 1117 panoramic radiographs of patients who have undergone orthodontic treatment, was studied on the distribution of the prevalence of supernumerary teeth gender, dental arches and mouth regions. The average age of the sample was 13.7 years, and 56% of patients were female and 44% male. Of the total analyzed, only 18 patients (1.61%) had supernumerary teeth. Regarding to gender, there was a prevalence of 1.9% among females, while males showed prevalence of 1.2%. In comparing genders, there was no statistically significant difference. A total of 24 supernumerary teeth were observed, once existed radiographs from people with more than one supernumerary tooth. Considering these 24 supernumerary teeth, 16 were located in the upper arch, while just 8 were in the lower arch. From the applied methodology and the results obtained, it could be concluded that: the prevalence of supernumerary teeth was 1.61% of individuals in the sample; There was not found significant differences in the prevalence of supernumerary between males and females; and prevalence of supernumerary teeth was statistically similar to the upper and lower dental arches, although 66.7% of them being located on the upper arch

Posicionadores de braquetes ortodônticos ? revisão de literatura e desenvolvimento de um projeto de patente / Orthodontic brackets positioning ? literature review and development of a patent project

Em Ortodontia, a colagem de braquetes é um dos passos mais importantes durante o tratamento, principalmente na técnica Straight Wire, na qual os acessórios possuem uma forma específica para levar cada dente à posição prescrita, no que se refere à inclinação, angulação, ou mesmo adequando a posição vestíbulo-lingual das coroas, que variam devido às suas diferentes espessuras anatômicas. Outro ponto fundamental é a altura na qual os braquetes são posicionados, o que interfere diretamente na oclusão e na estética do sorriso. Se ocorre o posicionamento incorreto dos braquetes, além de contatos prematuros e outros possíveis danos, o profissional despenderá mais tempo realizando dobras compensatórias ou recolagens de acessórios. Assim sendo, o objetivo deste trabalho foi desenvolver e inscrever um projeto de patente, composto por um conjunto de posicionadores de braquetes ortodônticos, no intuito de promover um melhor e mais fácil posicionamento dos braquetes durante a colagem, diminuindo a chance de erros, otimizando o processo e tornando a rotina daclínica ortodôntica mais previsível e eficiente

In Orthodontics, brackets bonding is one of the most important steps during the treatment, especially in Straight Wire technique, in which accessories have an specific shape to led each tooth to its correct position, considering inclination, angulation, or even the buccal-lingual crowns position, that varies according to its thickness. Another important point is the height of the brackets, what interferes directly in the occlusion and in smile aesthetics. When an incorrect positioning of the brackets occurs, the clinician wastes time with rebonding or making wire bends. The aim of this study was to develop and submit a patent project, composed by a kit of brackets positioners, to promote a better and easier positioning during bonding, decreasing the chances of errors, optimizing the process and improving the orthodontic routine, with more predictability and efficiency

Determining shapes and dimensions of dental arches for the use of straight-wire arches in lingual technique

INTRODUCTION: This study aims to determine the shape and dimension of dental arches from a lingual perspective, and determine shape and size of a straight archwire used for lingual Orthodontics. METHODS: The study sample comprised 70 Caucasian Brazilian individuals with normal occlusion and at least four of Andrew's six keys. Maxillary and mandibular dental casts were digitized (3D) and the images were analyzed by Delcam Power SHAPET 2010 software. Landmarks on the lingual surface of teeth were selected and 14 measurements were calculated to determine the shape and size of dental arches. RESULTS: Shapiro-Wilk test determined small arch shape by means of 25th percentile (P25%) - an average percentile for the medium arch; and a large one determined by means of 75th percentile (P75%). T-test revealed differences between males and females in the size of 12 dental arches. CONCLUSION: The straight-wire arch shape used in the lingual straight wire technique is a parabolic-shaped arch, slightly flattened on its anterior portion. Due to similarity among dental arch sizes shown by males and females, a more simplified diagram chart was designed. .

INTRODUÇÃO: esse estudo objetiva encontrar a forma e dimensão de arcadas dentária para definir a forma de um arco contínuo que possa ser utilizado na técnica lingual. MÉTODOS: a amostra foi composta por indivíduos brasileiros, leucodermas, com oclusão normal natural, que apresentaram, no mínimo, quatro das seis chaves de oclusão de Andrews. Os modelos das arcadas dentárias superior e inferior foram digitalizados (3D) e as imagens exportadas para o software Delcam Power SHAPETM 2010. Foram selecionados pontos nas superfícies linguais dos dentes e traçadas 14 medidas para determinar a forma e a dimensão da arcada dentária. RESULTADOS: o teste de Shapiro-Wilk possibilitou definir uma forma de arcada pequena utilizando o percentil 25% (P25%), uma arcada média (P50%) e uma forma de arcada grande, pelo percentil 75% (P75%). O teste t de Student comparou se houve uma diferença entre os sexos, e foram encontrados 12 tamanhos de arcadas dentárias. CONCLUSÕES: a partir dos resultados obtidos foi possível definir uma forma de arco contínuo para ser utilizado na técnica lingual Straight Wire (LSW): parábola levemente achatada na região anterior. Devido a similaridade entre alguns tamanhos de arcadas dentárias, encontrados pelo dimorfismo sexual, pôde ser elaborado um diagrama de arcadas de maneira mais simplificada. .

Dental arch morphology in normal occlusions

Aim: The aim of this study was to identify the prevalence of 3 different mandibular dental arch morphologies in individuals with natural normal occlusion. Methods: Fifty-one mandibular dental casts of Caucasian individuals with natural normal occlusion were digitized. Each was without a history of orthodontic treatment and presenting at least four of the six keys to normal occlusion described by Andrews. Twelve orthodontists evaluated the prevalence of the square, oval and tapered arch shapes by analyzing the mandibular digital images. Results: The most prevalent dental arch shape was oval (41%), followed by square (39%), and tapered (20%) shapes. Conclusions: During leveling and alignment phases, when elastic-alloy-wires are greatly used, the orthodontist could use any of the studied arch shapes (oval, square, tapered), once the prevalence of all of them was similar.

Avaliação rotacional mandibular após os efeitos da disjunção rápida da sutura palatina mediana / Evaluation of mandibular rotation after the effects of rapid expansion of the median palatine suture

Os estudos concernentes à disjunção rápida da sutura palatina mediana com a utilização de dispositivos que proporcionam a expansão do arco dental superior mostram que a maxila se move para baixo e para a frente, provocando alterações na oclusão, como a abertura da mordida anterior e o aumento do ângulo dos planos oclusal e mandibular> O presente estudo teve como objetivo avaliar as alterações após expansão rápida da maxila com dois tipos de disjuntores palatinos (Haas-Gl e Hyrax - Gll). A amostra foi constituida de 93 telerradiografias em norma lateral provenientes de 31 pacientes brasileiros, sendo 15 do gênero feminino e 16 do masculino, com faixa etária entre 9 e 16 anos (idade média de 13 anos e dois meses). Cada indivíduo foi radiografado pré-disjunção, imediatamente após a disjunção e ao final do nivelamento. As medidas angulares PP.GoMe, NBa.GoMe e NS.Gn sofreram aumento estatísticamente significativo nas fases pós-disjunção e de nivelamento em ambos os grupos. Conclui-se que o deslocamento rotacinal da mandíbula no sentido horário, para baixo e para trás, foi verificado pelo aumento estatísticamente significativo das medidas angulares estudadas na fase pós-disjunção, permanecendo na fase final de nivelamento em ambos os grupos

Avaliação das proporções faciais em norma lateral de indivíduos com perfil equilibrado / Evaluation of facial proportions in lateral cephalograms of individuals with balanced profile

Após a análise subjetiva utilizando fotografias de perfil de 540 indivíduos, selecionou-se 120 indivíduos adultos jovens (60 do gênero masculino e 60 do feminino), leucodermas, com perfil facial harmonioso, equilíbrio do terço inferior da face e selamento labial passivo, com o objetivo de estabelecer parâmetros cefalométricos para avaliar a estética facial e analisar as correlações entre referências anteroposteriores do tecido tegumentar da face. Utilizando telerradiografias dos indivíduos selecionados, foram desenhadas estruturas anatômicas de interesse e traçada a linha vertical passando pelo ponto sela (LSv) e linhas horizontais verdadeiras passando pelos pontos PRT (ponto de referência da fronte), Pn, A, Ls, Li, B e Pg. Os valores médios cefalométricos obtidos para o gênero masculino e feminino e o total da amostra foram submetidos aos testes estatísticos. As medidas cefalométricas avaliadas mostraram-se maiores no gênero masculino do que no feminino. No gênero masculino, todas as medidas cefalométricas do terço médio e inferior apresentaram correlação positiva estatisticamente significativa com a referência do terço superior da face e todas as correlações mostraram-se valores maiores que no feminino. No gênero feminino, não foram observadas correlações diretas estatisticamente significativas para as medidas Sv-B (p = 0,107) e Sv-Pg (p = 0,091). As fórmulas para a previsibilidade dos valores de Sv - Pn, Sv - A, Sv - Ls, Sv - Li, Sv - B e Sv - Pg para o gênero masculino e o feminino em função da medida Sv-PRT mostraram-se igual para ambos os gêneros, necessitando ser acrescido um valor compensatório a cada medida para os homens.

After subjective analysis of profile photographs of 540 individuals, 120 young adults (60 males and 60 females), leucodermas, with balanced facial profile, equilibrium of the lower facial third and passive lip sealing, in order to establish cephalometrics parameters for facial esthetics and evaluate the correlation between anteroposterior references of facial soft tissues. By using lateral radiographies of the selected individuals, anatomic structures of interesting were drawn, and the true vertical line passing through Sela point (LSv) and true horizontal lines passing through points PRT (reference point of the forehead), Pn, A, Ls, Li, B e Pg. The cephalometric average values which were calculated for masculine, feminine genders and the total of sample were evaluated by statics tests. The cephalometric measures analyzed showed high values to the masculine gender in comparing to the feminine gender. In the masculine gender, all the cephalometric measures of the middle and lower facial third presented positive correlation statistically significant to the reference of the superior facial third and all correlations were higher than female measures. In the feminine gender, direct correlations statistically significant for Sv-B (p = 0,107) e Sv-Pg (p = 0,091) measures. The formulas for the prevision of the values of Sv - Pn, Sv - A, Sv - Ls, Sv - Li, Sv - B e Sv - Pg dimensions for males and females individuals in function of Sv-PRT showed similar in both genders, needing to be added a specific value for each measures for males individuals.