Estudio de la variación de la inclinación de la cabeza y la evolución de la dentición - Parte I: Dentición Primaria Completa y Mixta Primera Fase

Objetivo: estudiar y comparar la inclinación de la cabeza entre niños con dentición primaria completa y dentición mixta primera fase. Materiales y métodos: el estudio incluyó a 80 voluntarios entre 4 y 9 años, a quienes se les tomó una fotografía facial de perfil derecho estandarizada, en Posición Natural de Cabeza. Éstas fueron analizadas mediante software de edición de imágenes para determinar la inclinación de la cabeza de cada voluntario. Para ello, se definió un plano (plano t-ex) formado por el punto Intertrágico (t) y Exocanto (ex) y se comparó respecto a la horizontal verdadera. Los datos obtenidos fueron tabulados, clasificados en dos grupos según el tipo de dentición y analizados estadísticamente. Resultados: el promedio de inclinación del plano t-ex fue de 22,7º en el grupo de niños con dentición primaria completa y de 25,8º en el grupo de niños con dentición mixta primera fase. La diferencia entre ambos grupos fue de 3,1º, con significancia estadística (p = 0,006). Conclusión: la inclinación de la cabeza de los niños con dentición mixta primera fase es mayor en sentido antihorario, respecto a la de los niños con dentición primaria completa.

Objective: to study and compare head tilt among children with complete primary dentition and first transitional period of the mixed dentition stage. Materials and methods: the study included 80 volunteers between 4 and 9 years of age, who were taken a standardized right profile facial photograph in a Natural Head Position. These photographs were analyzed using image editing software to determine the head tilt of each volunteer. For this, a plane (plane t-ex) formed by the Intertragic point (t) and Exocanth (ex) was defined and compared with respect to the true horizontal. The data obtained were tabulated, classified into two groups according to the type of dentition and statistically analyzed. Results: the average t-ex plane inclination was 22.7º in the group of children with complete primary dentition and 25.8º in the group of children with first transitional period of the mixed dentition stage. The difference between both groups was 3.1º, with statistical significance (p = 0.006). Conclusion: the head tilt of children with first transitional period of the mixed dentition stage is greater in an anti-clockwise direction, compared to that of children with complete primary dentition.

Estudio de la variación de la inclinación de la cabeza y la evolución de la dentición - Parte III

El objetivo de esta investigación fue estudiar la variación de la Posición Natural de Cabeza (PNC) entre personas con dentición mixta segunda fase y dentición permanente, mediante fotogrametría facial. Para esto se realizó un estudio comparativo observacional analítico. La muestra estuvo conformada por 80 voluntarios divididos en dos grupos de 40 participantes cada uno. Se utilizó fotografías faciales de perfil estandarizadas en PNC. Mediante el software Photoshop® se trazó el plano Intertrágico-Exocanto (t-ex) y se midió el ángulo formado respecto a la horizontal verdadera para determinar la inclinación de la PNC. El valor de este ángulo se obtuvo mediante el software UTHSCSA ImageTool 3.0®. Los datos fueron tabulados en una planilla Excel (Microsoft® Excel® 2016) y analizados estadísticamente en el programa Stata 14 S/E®. Se observaron diferencias estadísticas en la inclinación de la PNC entre los grupos, con valores promedio 26.17° y 33.44° para dentición mixta segunda fase y permanente respectivamente, con una diferencia promedio de 7.27°. Se concluyó que la PNC de personas con dentición permanente presenta una rotación antihoraria respecto a personas con dentición mixta segunda fase.

This research aimed at studying the variation of the Natural Head Position (NHP) between people with second transitional mixed dentition and permanent dentition, using facial photogrammetry. For this, an analytical observational comparative study was performed. The sample consisted of 80 volunteers divided into two groups of 40 participants each. Using standardized profile facial photographs in NHP and Photoshop® software, the intertragic-exocanthion plane (t- ex) was traced. The angle formed to the true horizontal was measured to determine the inclination of the NHP using the UTHSCSA ImageTool 3.0® software. The data were tabulated in an Excel Spreadsheet (Microsoft® Excel® 2016) and analyzed with Stata 14 S/E® software. Statistical differences in the inclination of the NHP between groups were observed, with average values ​​of 26.17° for second transitional mixed dentition and 33.44° for permanent dentition, with an average difference of 7.27°. It was concluded that the NHP of people with permanent dentition shows an anti-clockwise rotation in relation to people with second transitional mixed dentition.

Estudio comparativo de la posición natural de cabeza entre las clases esqueléticas mediante fotogrametría facial

El objetivo de esta investigación es evaluar si existen diferencias en la inclinación de la Posición Natural de Cabeza (PNC) entre las clases esqueléticas, mediante fotogrametría. Para esto se realizó un estudio observacional analítico de corte transversal. La muestra fue de 45 voluntarios de entre 18 y 50 años. Se determinó la clase esquelética mediante análisis de Steiner y Wits, en radiografías laterales de cráneo, utilizando el software BlueSkyPlan®. A cada participante se le tomó una fotografía de perfil en PNC. Posteriormente, en Photoshop®, se trazó un plano entre los puntos tragion y exocanto (plano t-ex) y la horizontal verdadera, para finalmente medir el ángulo formado en el programa UTHSCSA ImageTool3.0®, determinando así la inclinación de la cabeza. Luego de tabular los datos, se realizaron análisis estadísticos. Este estudio evidenció una diferencia de 6,68° en promedio en la inclinación de la PNC entre los pacientes clase II y I esquelética, con significación estadística, por lo que se concluye que los pacientes clase II esquelética tienen una PNC más inclinada en sentido horario respecto a los pacientes clase I, en la muestra analizada. Los pacientes clase III no mostraron diferencias.

The objective of this research is to evaluate the differences in the inclination of the Natural Head Position (NHP) between skeletal classes, using photogrammetry. For this, a cross-sectional analytical observational study was carried out. The sample consisted of 45 volunteers between 18 and 50 years old. The skeletal class was determined by Steiner and Wits analysis, in lateral skull radiographs, using the BlueSkyPlan® software. Each participant had a profile photograph taken at NHP. A plane was drawn between the tragion and exocanthion points and the true horizontal using Photoshop®, and the angle was measured using UTHSCSA ImageTool3.0® software, assessing the inclination of the head. After data tabulation, statistical analyses were performed. This study showed an average difference of 6.68° in the inclination of the NHP between skeletal class II and I patients, with statistical significance. It was concluded that skeletal class II patients have a more inclined NHP in a clockwise direction compared to class I patients, in the analyzed sample. Class III patients did not show differences.

Protocolo fotográfico estandarizado para análisis facial en Posición Natural de Cabeza

RESUMEN: Introducción: La fotogrametría es el proceso por el que se obtienen medidas a partir de una fotografía. Para realizar una correcta toma fotográfica es de suma importancia estandarizar la técnica con el objetivo de obtener registros confiables y reproducibles. Uno de sus requisitos es definir la posición de la cabeza, ya que una postura incorrecta puede conducir a errores en el diagnóstico y planificación del tratamiento. Objetivo: Establecer un protocolo clínico para estandarizar registro fotográfico y posicionamiento del paciente para fotogrametría facial. Materiales y métodos: Se realizaron fotografías faciales estandarizadas a un total de 163 estudiantes. A 76 estudiantes se les realizaron mediciones faciales directas e indirectas. A 87 estudiantes se les comparó su Posición Natural de Cabeza en 3 momentos del día. Se compararon estadísticamente los resultados. Resultados: Al aplicar un protocolo estandarizado, no hubo diferencia estadística entre las medidas directas e indirectas ni al comparar la posición de la cabeza de cada estudiante. Conclusión: La estandarización del set fotográfico expuesto en este trabajo es válida para realizar registros fiables y útiles como examen complementario utilizando la Posición Natural de Cabeza, que permite mantener una posición confiable y estable en el tiempo.

ABSTRACT: Introduction: Photogrammetry is the process by which measurements are obtained from a photograph. To take a correct photographic shoot, it is very important to standardize the technique in order to obtain reliable and reproducible records. One of its requirements is to define the position of the head. Thus, an incorrect posture can lead to errors in diagnosis and treatment planning. Objective: Establish a clinical protocol to standardize photographic registration and patient positioning for facial photogrammetry. Materials and methods: Standardized facial photographs were taken to a total of 163 students. 76 students had direct and indirect facial measurements. 87 students had their Natural Head Position compared at 3 times of the day. The results were statistically compared. Results: When applying a standardized protocol, there was no statistical difference between direct and indirect measurements, nor when comparing the head position of each student. Conclusion: The standardization of the photographic set exposed in this work is valid for making reliable and useful records as a complementary examination using the Natural Head Position, which allows to maintain a reliable and stable position over time.

Posición Natural de Cabeza y su relación con el Plano de Frankfurt en cefalometría ortodóncica

RESUMEN: Objetivo: el objetivo de este estudio fue determinar la discrepancia del Plano de Frankfurt evaluado en fotogrametría y en cefalometría de radiografías laterales de cráneo respecto a la horizontal verdadera. Materiales y métodos: el estudio consideró a 34 voluntarios de la clínica del Postítulo de Ortodoncia y Ortopedia Dento Máxilo Facial de la Facultad de Odontología de la Universidad de Chile. Se utilizaron sus radiografías laterales de cráneo orientadas según el Plano de Frankfurt paralelo al piso y se les tomó una fotografía facial de perfil estandarizada en Posición Natural de Cabeza. Se trazó el Plano de Frankfurt y la Horizontal Verdadera en ambos exámenes y se midió el ángulo formado entre estos planos. Resultados: al comparar los ángulos mediante T-test, no hubo diferencia estadística. Conclusiones: mediante la aplicación de un protocolo sistematizado tanto para el registro fotográfico como para la obtención de la Posición Natural de Cabeza, se puede lograr que el Plano de Frankfurt sea prácticamente coincidente en radiografías laterales de cráneo y en fotografías clínicas, demostrando su uso hasta el día de hoy en la ortodoncia moderna.

ABSTRACT: Objective: the aim of this study was to determine the Frankfurt plane variation evaluated in photogrammetry and lateral skull x-ray cephalometry in relation to the true horizontal. Materials and methods: the study included 34 volunteers from the Universidad de Chile Dento-maxillofacial Orthodontics and Orthopedics Postgraduate Clinic. Their lateral skull radiographs, oriented according to the Frankfurt Plane parallel to the floor, were used and a standardized profile facial photograph was taken in Natural Head Position. The Frankfurt Plane and True Horizontal were drawn in both examinations and the angle formed between these planes was measured. Results: when comparing the angles through T-test, there was no statistical difference. Conclusions: through the application of a systematized protocol for both photographic record and natural head position obtained, the Frankfurt Plane can be practically coincident in lateral skull x-rays and clinical photographs, showing its usefulness up to the present days in modern orthodontics.

La vertical verdadera al punto A´(blando), al Pg´(blando), al Labrale superior y al Labrale inferior en posición ideal asistida de la cabeza (PIAC) / The true vertical from point A´(soft), to Pg´ (soft), to superior Labrale and inferior Labrale in Ideal Assisted Head Position (PIAC)

El 81,3% de una encuesta realizada a 96 ortodoncistas y ortopedistas calificados y técnicos radiólogos consultados informan que ubican la cabeza del paciente en una posición ideal, subjetiva del profesional instruido que lo asiste, ya que muchas de sus fotografías y telerradiografías no son posiciones naturales de la cabeza genuinas. Se ha utilizado la vertical verdadera como parámetro para mediciones, todas angulares, para definir la disposición ánteroposterior del punto A´ (de construcción) para el cuerpo del labio superior, el punto Pg´para el mentón, el Labrale superior y el Labrale inferior para el bermellón de cada labio, con la finalidad de planificar correcciones ortopédicas, ortodóncicas u ortodóncicas-quirúrgicas de acuerdo a la anomalía detectada (AU)

Relación entre la Posición Natural de Cabeza y el Plano de Frankfort / Relation between the Natural Head Position and the Frankfort Plane

RESUMEN: Objetivo: El objetivo de este estudio fue comparar el paralelismo entre el Plano de Frankfort (PF) trazado en tejidos blandos y la horizontal verdadera cuando el paciente se ubica en Posición Natural de Cabeza (PNC). Materiales y métodos: La muestra contó con 97 voluntarios. A cada uno de los participantes se le tomó una fotografía facial de perfil para luego analizar mediante el software Photoshop® la angulación del PF trazado en tejidos blandos. Se utilizó t-test para determinar si existía diferencia estadística entre el PF trazado en tejidos blandos y la horizontal verdadera. Resultados: El resultado del t-test nos indica que en la muestra general existen diferencias estadísticas entre el PF trazado en tejidos blandos y la horizontal verdadera. Conclusiones: Al encontrarse los pacientes en PNC existe una diferencia estadística entre el PF trazado en tejidos blandos y la horizontal verdadera.

ABSTRACT: Aims: The aim of this study was to compare the parallelism between the Frankfort Plane (FP) traced in soft tissues and the true horizontal plane when the patient is in the Natural Head Position (NHP). Methods: The sample included 97 volunteers. A profile facial photograph of each of the participants was taken and the angulation of the FP traced in soft tissues was then analyzed with Photoshop® software. T-test was used to determine if there was statistical difference between the FP traced in soft tissues and the true horizontal. Results: The result of the t-test indicates that in the general sample there are statistical differences between the FP traced in soft tissues and the true horizontal. Conclusions: When patients are in NHP, there is a statistical difference between the FP traced in soft tissues and the true horizontal.

Inclination of crown and tooth longitudinal axis in cephalometric analysis of normal occlusions / 华西口腔医学杂志

<p><b>OBJECTIVE</b>We measured and analyzed the angle between the longitudinal axis of incisor crown and tooth to provide a reference for orthodontists for selecting orthodontic methods and evaluating treatment results.</p><p><b>METHODS</b>A total of 120 participants were included according to the criteria of Andrews' six keys, and cephalometric radiograph under the instructions of modified natural head position acquirement method was performed. The angles of maxillary incisor crown longitudinal axis, tooth longitudinal axis, occlusion plane (OP), and true vertical (TV) plane were measured, as well as mandibular incisors.</p><p><b>RESULTS</b>As for maxillary incisors, the angle between crown longitudinal axis and TV plane, OP, and tooth longitudinal axis were 11.72°±4.71°, 73.29°±5.69°, and 20.04°±3.71°, respectively. For mandibular incisors, the angle between crown longitudinal axis and TV plane, OP, and tooth longitudinal axis were 16.03°±5.40°, 81.76°±4.81°, and 14.82°±4.01°, respectively. For the maxillary incisor, the angles between crown longitudinal axis and tooth longitudinal axis were mainly within 15° to 25°, whereas those for mandibular incisors were within 10° to 20°.</p><p><b>CONCLUSIONS</b>The longitudinal axis inclinations of the maxillary and mandibular incisor crown and of the incisor tooth need to be considered when cephalometric radiographs are used for treatment planning or for evaluating the treatment result.</p>

Assessment of anterior-posterior jaw relationships in Korean adults using the nasion true vertical plane in cone-beam computed tomography images / 대한치과교정학회지

OBJECTIVE: The aims of this study were to investigate a simple method for assessing anterior-posterior jaw relationships via cone-beam computed tomography (CBCT) images taken in the natural head position (NHP) relative to the nasion true vertical plane (NTVP), and measure normative data in Korean adults with normal profiles. METHODS: Subjects were selected from patients presenting for third molar extraction and evaluated as having normal profiles by three examiners. The CBCT images of 80 subjects (39 males, 41 females) were taken in the NHP according to Solow and Tallgren's method. Linear measurements of the A-point, B-point, and Pog were calculated relative to the NTVP. Student's t-test was used to assess sexual differences in these measurements. RESULTS: The mean linear measurements of the A-point, B-point, and Pog relative to the NTVP were 0.18 mm (standard deviation [SD], 4.77 mm), -4.00 mm (SD, 6.62 mm), and -2.49 mm (SD, 7.14 mm) respectively in Korean males, and 1.48 mm (SD, 4.21 mm), -4.07 mm (SD, 6.70 mm) and -2.91 mm (SD, 7.25 mm) in Korean females respectively. There were no statistically significant differences between Korean males and females (p < 0.05). CONCLUSIONS: Three-dimensional CBCT analysis using the NTVP is a simple and reliable method for assessing anterior-posterior skeletal relationships.

Efecto del aumento de la dimensión vertical oclusal en la posición natural de cabeza en pacientes portadores de prótesis removible / Effect of occlusal vertical dimension increase on natural head position in patients with removable prostheses

OBJETIVO Estudiar la variación de la posición natural de la cabeza al aumentar la dimensión vertical oclusal (DVO) en pacientes portadores de prótesis removible. PACIENTES Y MÉTODOS El estudio analítico, cuasi experimental, incluyó un total de 56 adultos mayores portadores de prótesis removibles totales y parciales (solo con grupo V remanente) atendidos en la Facultad de Odontología de la Universidad de Chile el año 2011, en los cuales se analizó la posición de la cabeza en sentido sagital al modificar la DVO aumentando progresivamente la altura oclusal en 5, 10 y 15 mm, mediante el uso de fotografías de perfil estandarizadas en posición natural de la cabeza. Hipótesis: el aumento de la DVO se asocia con una rotación posterior de la cabeza. RESULTADOS Todos los voluntarios mostraron cambio de la posición natural de cabeza, rotando posteriormente al modificar la DVO. El test ANOVA no mostró que esta diferencia fuera estadística. Hubo asociación positiva entre el cambio gradual de la DVO y el grado de rotación de la cabeza. El test de Pearson mostró asociación estadística. CONCLUSIÓN Los resultados permiten concluir que mientras mayor sea el aumento de altura oclusal mayor es la rotación posterior de la cabeza. Los hallazgos de este estudio apoyan el concepto de que existe una integración anatómica y funcional entre los distintos elementos que componen la unidad cráneo cérvico mandibular, actuando como un todo frente a la variación de uno de sus componentes.

OBJECTIVE To determine the variation in the natural head positionon increasing the Occlusal Vertical Dimension (OVD) in patients who use removable dentures. PATIENTS AND METHODS An analytical, quasi-experimental study was conducted on 56 elderly patients volunteers, carriers of removal full and partial (only with group V remaining) dentures seen in the Odontology Faculty of the University of Chile in 2011. An analysis was made of the head position in a sagittal direction to change the OVD, gradually increasing the occlusal height by 5, 10 and 15 millimeters, using standardized profile photographs of the natural head position. Hypothesis: The increase in the OVD is associated with a posterior rotation of the head. RESULTS All the volunteers showed a change in the natural head position, posteriorly rotated to change the OVD. The ANOVA test showed that this change was not statistically different. There was a positive association between a gradual change in OVD and the degree of head rotation. The Pearson test showed a statistical association. CONCLUSION It could be concluded from the results that, the greater the increase in occlusal height, the greater is the posterior rotation of the head. The findings of this study support the concept that there is an anatomical integration between the different elements that make up the cranio-cervico-mandibular unit, acting together against the variation of one of its components.

Relationships between vertical facial pattern and natural head position,cervical posture in patients with skeletal class Ⅰ relationship / 吉林大学学报(医学版)

Objective To investigate the natural head position and cervical posture in the patients with different vertical facial patterns with skeletal class Ⅰ relationship,and to clarify the relationships between vertical facial patterns and natural head position, cervical posture in the patients with skeletal class Ⅰ relationship. Methods 94 patients aged 8- 15 years old with skeletal class Ⅰ relationship were selected as the subjects.The subjects were classified into high angle group,average angle group,and low angle group according to their mandibular plane angles.The cephalometric radiographs in natural head position were taken,and the variables representing craniofacial morphology,head position,and craniocervical posture were measured.The intergroup differences in variables were compared.Results The inclinations of mandible to the true vertical and cervical column (ML/VER,ML/OPT,ML/CVT)were smallest in high angle group,and they were largest in low angle group (P 0.05). Conclusion The significant differences exist in natural head position and cervical posture among the patients with skeletal class Ⅰ relationship with different vertical facial patterns (high angle,average angle,low angle);the subjects with high angle show extended head position and cervical posture,while the subjects with low angle exhibit the opposite tendency.

Cervical vertebrae morphology in skeletal class Ⅱ and class Ⅰ malocclusion patients / 中国组织工程研究

BACKGROUND:The incidence rate of cervical abnormalities of the patients with skeletal class Ⅱ and normal occlusion has been studied abroad, but the researches on the incidence of cervical abnormalities in different malocclusion patients is rare at home. OBJECTIVE:To observe the imaging of patients with cervical abnormalities and to statistics the incidence of cervical abnormalities in different malocclusion patients through analyzing the lateral cephalogram of different malocclusion patients. METHODS:Skeletal class Ⅱ group was consisted of 93 patients, 41 male (aged 18-40 years) and 52 female (aged 22-35 years), with the A point-nasion-B point angle>5°. Class Ⅰ group was consisted of 45 patients, 31 female (aged 20-36 years) and 14 male (aged 17-38 years), with the 1°

Discrepancies in Soft Tissue Profile of Patients for Orthognathic Surgery between Preoperative Lateral Facial Photograph, Lateral Cephalogram and Supine Position on Operation Table

Introducing of the Novel Midsagittal Line for Diagnosis of Craniofacial Asymmetry With P. A Cephalometry Radiography / Introdução de uma Nova Linha Média Sagital para Diagnóstico de AssimetriaCraniofacial com Radiografia Cefalométrica P.A.

Objetivo: Determinação da linha de referência sagital mediana (LRSM), para avaliação de assimetrias craniofaciais, traçando uma linha paralela da crista galli à linha vertical verdadeira, em cefalometria PA, utilizando a técnica da posição natural da cabeça (PNC).Metodologia: 60 indivíduos (30 homens e 30 mulheres, com idade variando de 9 a 13 anos, de uma população iraniana), com oclusão normal Classe I sem história de tratamento ortodôntico ou cirurgia mandibular, foram selecionados no Departamento de Ortodontia, Universidade de Shahid Beheshti, MC Faculdade de Odontologia, Teerã, Irã, 2009-2010. Os pacientes não portavam supranumerários ou ausência dentária, nem anormalidade esquelética. Radiografias cefelométricas PA foram obtidas para todas as amostras pela técnica da posição natural da cabeça (PNC). A linha sagital mediana também foitraçada paralelamente da corrente pendurada à referência intracraniana selecionada (crista galli). Esta linha é a linha vertical verdadeira. A linha horizontal verdadeira foi traçada perpendicularmente à corrente pendurada da crista galli (Cg). Mensurou-se a assimetria craniofacial com medições linear, angular e trigonométrica por meio de radiografias cefalométricas PA pela técnica da posição natural da cabeça (PNC), usando as verdadeiras linhas vertical e horizontal. As diferenças médias entre as medidas acima nos lados direito e esquerdo foram analisadas pelo teste t.Resultados: Cada variável foi avaliada independentemente; os valores da média e desvio padrão foram calculados separadamente. Ademais, relações transversais foram preparadas na nossa amostra (faixa etária de 9 a 13 anos). Todos os pacientes eram descendentes iranianos.

Para a validação da linha media sagital (LMS), foi medida a distância entre a espinha nasal anterior (ENA) e o Mento (Me).Conclusão: Os achados deste estudo evidenciam que a cefalometria PA com a técnica da posição natural da cabeça (PNC) pode medir a assimetria facial com o nível de 96% de intervalo de confiança. Contudo, a introdução da linha média sagital pelo uso da técnica da posição natural da cabeça (PNC) poderia fornecer a capacidade de diagnosticar assimetrias faciais

Objective: Determination of midsagittal reference line (MSL) for craniofacial asymmetries assessment by drawing a line from crista gali parallel to true vertical line in PA cephalometry , using NHP technique. Method: 60 samples (30 males and 30 females, within the age range of 9-13 years old Iranian population) were selected with normal Class I occlusion without any history of orthodontic or jaw surgery treatments in Department of Orthodontics, Shahid Beheshti University, Tehran. Iran, 2009-2010. Patients had no supernumerary or missing teeth and any skeletal anomaly. PA cephalometry radiographs were taken from all samples with NHP technique. The midsagittal line was also traced parallel to the hanging chain from our selected intracranial reference point (Crista gali). This line is a true vertical line. True horizontal line traced perpendicular to the hanging chain from Crista gali (Cg). We assessed craniofacial symmetry with linear, angular and trigonometrical measurements in PA cephalometric radiographs by NHP technique, using true vertical and horizontal lines. The mean differences of above measurements in left and right sides were analyzed by T- test.Results: Each variable was measured independently; then the mean values and S.D was calculated separately. Also, transverse ratios were prepared in our samples (age range of 9-13 years). All patients were from Iranian decent. For midsagittal line (MSL) validity, the ANS (Anterior Nasal Spine) distance in the middle third and Me (Menton) distance in lower third from MSL was measured.Conclusion: Findings of this study showed that P.A.cephalometry with NHP technique could assess the facial symmetry with the rate 96% confidence interval. Therefore, the introduced midsagittal line by using NHP Technique, could prove the ability for diagnosis of facial asymmetries

Reprodutibilidade da posição natural da cabeça em fotografias de perfil de crianças de 8 a 12 anos, com e sem o auxílio de um cefalostato / Reproducibility of natural head position in profile photographs in children aged 8 to 12 years old, with and without an auxiliary cephalostat

OBJETIVO: este estudo avaliou a reprodutibilidade da posição natural da cabeça (PNC) em crianças. MÉTODOS: foram fotografados 25 pacientes da Clínica Infantil do Curso de Graduação em Odontologia da Universidade Estadual de Maringá com idades entre 8 e 12 anos, sendo 12 do gênero feminino e 13 do masculino. As tomadas fotográficas registraram a PNC com uma câmera digital e foram realizadas com e sem o uso de um cefalostato. Uma linha vertical (LV) foi usada como referência para as mensurações. Após um intervalo de 15 dias, as fotografias foram repetidas, respeitando-se o mesmo protocolo utilizado na primeira série de tomadas fotográficas. A reprodutibilidade da PNC entre os dois momentos das tomadas fotográficas foi avaliada utilizando-se a medida angular entre a linha vertical de referência e uma linha do perfil, passando pelo pogônio tegumentar e pelo ponto labial superior. RESULTADOS E CONCLUSÃO: embora algumas variações de posição tenham sugerido que os pacientes dessa idade devam receber orientações adicionais quanto à PNC, não foram observadas diferenças significativas quanto à reprodutibilidade das fotografias tomadas no intervalo de 15 dias, com ou sem a utilização do cefalostato auxiliar. Dessa forma, a PNC mostrou-se como um método de boa reprodutibilidade em crianças.

AIM: This study assessed the reproducibility of natural head position (NHP) in children. METHODS: 25 children, 12 female and 13 male, aged from 8 to 12 years old, patients of Dentistry School of the State University of Maringá were photographed. Photographs were taken in NHP, using a digital camera, with and without cephalostat. A vertical line (VL) was used as reference for measurements. The photographs were repeated after a 15-day interval respecting the same protocol. Reproducibility of NHP between both moments of photographs was evaluated using an angular measurement between the reference vertical line and a profile line, from soft pogonion and upper lip point. RESULTS AND CONCLUSION: Although some positional variations have suggested that patients in these ages should receive additional orientation on NHP photographs, there were no significant differences in reproducibility of NHP in this 15-day interval, with or without auxiliary cephalostat. NHP showed to be a good method of reproducibility in children.

Assessment of antero-posterior skeletal relationships in adult Korean patients in the natural head position and centric relation / 대한치과교정학회지

OBJECTIVE: This study aimed to verify the intra-individual reproducibility of the natural head position (NHP) in adult Korean patients in the centric relation (CR) position and to prove the inter-individual variability of the Frankfurt horizontal (FH) plane and sella-nasion (SN) line compared to the true horizontal line (THL). In addition, the study aimed to investigate the correlations between linear measurements from A-point and B-point to the nasion true vertical line (NTVL) and angular measurements from A-point and B-point to the SN line. METHODS: Two lateral cephalograms were taken of 116 subjects (23 males, 93 females) with CR wax bites in a NHP at a one-week interval. RESULTS: Method errors of three variables and intraclass correlation coefficients of six parameters proved the intra-individual reproducibility of NHP (p 0.05), but it was clinically variable (SD 3.89degrees) on the inter-individual level. Conversely, the angle of the SN line to the THL was significantly different from 7degrees (p < 0.05). Very low correlation was found between the linear measurements and angular measurements of A-point and B-point (p < 0.01). CONCLUSIONS: The NTVL could be a useful reference line for assessing the antero-posterior position of the maxilla and mandibleof Korean adult patients in NHP and CR.

Estudo comparativo entre avaliações esqueléticas e do perfil tegumentar utilizadas no diagnóstico ortodôntico sagital / Comparative study between skeletal and tegumental measurements used in sagital orthodontic diagnosis

OBJETIVO: este trabalho objetivou comparar o diagnóstico de grandezas cefalométricas angulares e lineares rotineiramente utilizadas na determinação da posição sagital das bases ósseas, comparando-as com o diagnóstico de medidas lineares de tecido tegumentar, verificando a possibilidade ou não de concordância entre elas. METODOLOGIA: analisou-se 30 telerradiografias, obtidas em norma lateral e em posição natural da cabeça (PNC), de jovens do gênero feminino, entre 20 e 26 anos de idade (média de 21,3 anos). Comparou-se os diagnósticos das medidas cefalométricas sagitais (SNA, SNB, profundidade facial, profundidade maxilar, Nperp-A e Nperp-P) entre si e com os das medidas sagitais tegumentares (Snvert-Ls, Snvert-Li e Snvert-Pog'). Resultados e CONCLUSÃO: os resultados permitiram concluir que ocorreu uma fraca concordância entre os diagnósticos sugeridos pelas medidas esqueléticas e tegumentares, bem como aquele sugerido pelas diferentes medidas esqueléticas, quando comparados entre si.

AIM: This study aimed to evaluate skeletal measures used in sagital diagnosis of both jaws in comparison with tegumental measures, verifying the agreement between themselves. METHODS: Cephalometric radiographs in natural head position were obtained from 30 white females, between 20 and 26 years of age, mean 21,3 years. Cephalometric tracings were taken and the following measurements recorded: SNA, SNB, Facial depth, Maxillary depth, Nperp-A, Nperp-Pog, and then compared to the tegumental measurements Snvert-Ls, Snvert-Li Snvert-Pog'. Results and CONCLUSIONS: The results showed low agreement between the diagnosis proposed by different hard tissue and soft tissue analysis, as well as the different hard tissue measures when compared to themselves.

A comparative study of soft tissue profile between Korean and Caucasian young adults under NHP / 대한치과교정학회지

This study was performed to establish Korean soft tissue cephalometric norms, to compare the norms between sexes and between races, and then to suggest a guideline to execute orthodontic diagnosis and treatment planning for dentofacial deformities in Korean. Young Korean adults were selected. They were 27 males (23.8 2.6-year-old) and 20 females (22.5 1.7-year-old) who had harmonious facial balance. After taking lateral cephalograms under the natural head position which is widely known as a highly reliable and reproducible reference position, films were traced and analysing factors were measured as introduced by Arnett et al. Comparisons were done between male and female groups and between Korean and Caucasian groups using unpaired t-test. From the results it was concluded that Korean male had generally thicker lower facial soft tissue and smaller nasolabial angle, longer facial height, deeper facial depth, and more protrusive lower face than Korean female. From the comparison with Caucasian norms adopted from the research of Arnett et al., both Korean male and female showed longer facial lengths generally except less exposed maxillary incisor, and shorter facial depth than Caucasian counterparts. Also, both races showed similar horizontal position of maxillary structures from TVL (true vertical line), but there were more significant anteroposterior differences of maxilla-mandible in Korean groups. These results mean Korean had relatively more retruded mandibular structures from the reference line, TVL. Individuals who had harmonious facial balance showed similar facial angle, more or less 170 degree, regardless of sexes or races.

A study on the reproducibility of the natural head position according to the skeletal malocclusion type and sex / 대한치과교정학회지

This study was performed to evaluate the reproducibility of natural head position according to skeletal malocclusion types and sex using cephalometric radiographs for establishing orthodontic diagnosis and treatment planing. The sample consisted of 90 young adults (male 45, female 45) who had the skeletal malocclusion. Cephalometric radiographs were taken on natural head position, and statistical analysis was performed and method error of 6 postural variables were estimated to evaluate the reproducibility of the natural head position. The following results were obtained: 1. In the reproducibility of the natural head position, postural variables had no statistical significance in male and female(P>0.05) 2. In the reproducibility of the natural head position, postural variables had no statistical significance in Class I, II, III and total group (P>0.05). 3. The reproducibility of natural head position using method error was excellent in all group.

Frontal cephalogram study on the natural head position of facial asymmetry patients / 대한치과교정학회지

The purpose of this study was to find the characteristics of the frontal natural head position(NHP) of patients with facial asymmetry, and to contribute to the diagnosis of facial asymmetry in the clinical examination of orthodontic patients. Twenty adult patients who had apparent facial asymmetry and no severe sagittal skeletal discrepancy were selected as the asymmetry group, and 21 young adults who had symmetric faces were selected as the symmetry group. Frontal cephalograms were obtained in the state of NHP using a pivot-mounted fluid level device. The degree of the menton deviation was defined as the angle between the line drawn through crista galli and anterior nasal spine and the line drawn through crista galli and menton. The following angles were measured and each of them was compared with the degree of the menton deviation: one is the angle between the true vertical line and the supra-orbital line which is a tangent line to the extreme cranial point on the supra-orbital margin, and the other is the angle between the true vertical line and the cervical line drawn through the midpoint of atlas and the 4th cervical vertebra. Through the statistical analysis, following results were obtained. 1. The angle between the supra-orbital line and the true vertical line was much more deviated from the right angle in the asymmetry group than in the symmetry group. 2. The angle between the cervical line and the true vertical line in the asymmetry group showed greater tendency than in the symmetry group, but the difference was not statistically significant. 3. In the asymmetry group, the degree of the menton deviation was positively correlated with the angle between the supra-orbital line and the true vertical line. The above results suggest that facial asymmetry patients show the tendency to have the tilted NHP to compensate the deviation of menton position.