Evaluation of condylar position in patients with malocclusion and changes in condylar position before and after orthodontic treatment using cone beam computed tomography / 口腔疾病防治

@#The functional health and stability of the oral and maxillofacial system is one of the basic goals of orthodontic treatment. Currently, it is believed that, in general, the condyle is located in the center of the joint fossa when the mandible is in an intercuspal position (ICP) in healthy normal people. At this time, the function of the temporomandibular joint (TMJ) is stable. Due to orthodontic tooth movement and subsequent occlusal changes, patients with malocclusion may experience related remodeling of the temporomandibular joint, especially changes in the position of the condyle. The position of the mandibular condyle is traditionally evaluated using a condylar position indicator. However, this method lacks consistency in obtaining condylar position changes. In recent years, in the clinical application of orthodontic treatment, cone beam computed tomography (CBCT) has become the first choice for examination. CBCT can accurately measure the interarticular space and determine changes in condylar position. This article reviews the CBCT assessment of condylar position and related research on condylar position changes in patients with malocclusion before and after orthodontic treatment. The literature review results indicate that there are differences in the condylar position of patients with different malocclusions, and the condylar position may also change before and after orthodontic treatment. With a lower radiation dose, CBCT has higher accuracy in evaluating the condylar position in patients with malocclusion who undergo orthodontic treatment, thus promoting further study of the mechanism of condylar position changes in patients with malocclusion in the future and providing more accurate and personalized guidance for patient treatment.

Factores morfofuncionales de interés en prostodoncia que dependen de los biotipos craneofaciales / Morphofunctional factors of interest in prosthodontics depending on the craniofacial biotypes

El presente es un trabajo de investigación bibliográfica que busca establecer la posibilidad de utilizar las cefalometrías como elementos de diagnóstico pronóstico y elaboración de prótesis. Centra su objeto de estudio en encontrar y clasificar los factores morfológicos y funcionales que varían con los biotipos craneofaciales y que son de interés en la prostodoncia. La metodología empleada fue la revisión de la literatura histórica hasta la actualidad en la que se relacionan temas de prostodoncia a los biotipos craneofaciales. Si bien solo dos autores relacionaron la prostodoncia con los biotipos cráneo faciales, sí se encontraron varios temas de interés asociados directamente a la prostodoncia. Se clasificaron en temas de oclusión: Curva de Spee, plano de oclusión, movimientos mandibulares, dimensión vertical oclusiva y de especio libre interoclusal. Tema de maloclusiones. Tema de fuerza muscular. Tema variaciones morfológicas de procesos alveolares, corticales ósea y de la forma dentaría. Encontrándose para cada uno de ellos alguna correlación positiva con los distintos tipos faciales. De este estudio, se concluye que es necesario sistematizar el estudio de los conocimientos que puede aportar la cefalometría como una importante herramienta de diagnóstico al prostodoncista a partir de haberse encontrado variaciones muy importantes en los aspectos mencionados que hacen al interés de la rehabilitación prostodóncica (AU)

This Work is a bibliographic research that seeks to establish the use of cephalometries as elements of diagnosis prognostic and prosthesis elaboration. Its focus is to find and classify morphological and functional factors that vary with facial types which are of interest in prosthodontics. This was a review of the historical literature to date, in which prosthodontics are related to facial types. Although only two authors related prosthodontics to facial ypes, they did find several topics of interest directly associated with prosthodontics. They were classified into occlusion themes: Spee curve, occlusion plane, mandibular movements, occlusive vertical dimension and interocclusal free space. Malocclusion issue. Muscle strength theme. Morphological variations of alveolar processes, cortical bone and dental morphology. They found some positive correlation with the different facial types for each of them. From this study, it is concluded that it is necessary to systematize the study of cephalometries because they can provide to be an important diagnostic tool to the prosthodontist because there were found very important variations in the mentioned aspects that are of interest in prosthodontic rehabilitation (AU)

Study on cone beam computed tomography for detecting bone thickness of skeletal class Ⅱ infrazygomatic crest in teenagers / 重庆医学

Objective To adopt the cone beam computed tomography(CBCT) to analyze the bone thickness of infrazygomatic crest with different vertical skeletal facial types in teenagers.Methods Sixty teenagers of skeletal class were collected,including each 20 cases of high angle,average angle and low angle.The CBCT scanning data of oral maxillofacial region were collected.The bone thickness at different coronary slices in buccal side of infrazygomatic crest region at 13,15,17 mm above the maxillary occlusal plane was measured.The measured data were analyzed statistically.Results The bone thickness of infrazygomatic crest was gradually thinned from down to up,and the difference was statistically significant(P＜0.05);the bone thickness(except 3 points at 13 mm from maxillary plane) at each measured point in the high,average and low angle groups showed the change trend of low angle ＞average angle＞high angle,the difference was not statistically significant(P＞0.05).Conclusion In teenagers,the bone thickness of infrazygomatic crest in skeletal class Ⅱ is gradually thinned from cranial direction and rearward,the high angle is thinnest and the low angle is thickest.

Vertical facial types and chin morphology effects on the facial profile attractiveness / 中国组织工程研究

BACKGROUND:Individuals with different vertical facial types have different chin morphologies. For the individuals with different vertical facial types, what is the most beautiful chin morphology? OBJECTIVE:To evaluate the effects of vertical facial types and chin morphology on facial profile attractiveness. METHODS:Three beautiful females were selected, including one with high mandibular angle, one with average angle and one with low angle. Their facial profile photographs were taken. A series of new pictures were generated by the smal scale (2 mm per unit) modification of soft tissue chin in the sagittal direction and vertical direction. Raters consisting of 17 orthodontists and 35 laypersons were selected for aesthetic ratings, in order to evaluate the facial profile attractiveness of the individuals with different vertical facial types. RESULTS AND CONCLUSION:There was no esthetic difference of vertical change in female with high angle;while slightly protrude chin was perceived to be more beautiful than retruded chin. For the female with average angle, lower chin was more attractive than higher chin;slightly protruded chin was beautiful than excessive protruded chin and retruded chin. For the individual with low angle, higher chin was preferred by raters;slightly protruded chin was more beautiful than excessive protruded chin and retruded chin.The results indicate that the effects of vertical facial types and chin morphology to facial profile attractiveness are different. In clinical orthodontic, vertical facial types should be taking into consideration to change the chin morphology of the patents, in order to obtain better profile attractiveness.

Posterior arch length of individual normal occlusion of adults in Lanzhou / 中国组织工程研究

BACKGROUND:Posterior arch length deficiency is closely related to the formation and development of malocclusion. OBJECTIVE:To measure the posterior arch length in individual normal occlusions of adults in Lanzhou. METHODS:A total of 102 current col ege students with individual normal occlusions, with a mean age of (19.33±2.67) years (range 18-24 years), including 47 males and 55 females from Gansu Province, were chosen to take lateral cephalograms. Al research objects were divided into three groups according to mandibular plane angle:high angle group (Frankfort mandibular-plane angle>32°), low angle group (Frankfort mandibular-plane angleRESULTS AND CONCLUSION:Posterior arch length of maxil ary arch was slightly longer in male group than that in female group, and the difference was not significant (P>0.05). The posterior arch length of mandibular arch was slightly longer in male group than that in female group, but the difference was no significant (P>0.05). Comparison between groups revealed that the posterior arch length of low angle mandibular arch was significantly longer than that of high angle mandibular arch in male group, and the difference was significant (P<0.05). The results indicate that the gender wil not influence the development of posterior arch length. Different vertical facial types and different genders have different posterior arch length in individual normal occlusions of adults

Avaliação da atresia maxilar associada ao tipo facial / Evaluation of maxillary atresia associated with facial type

OBJETIVOS: associar a atresia maxilar aos tipos faciais, verificar o dimorfismo entre os gêneros masculino e feminino, bem como a correlação entre os gêneros e os tipos faciais. MÉTODOS: inicialmente, a amostra constou de 258 telerradiografias da cabeça, em norma lateral. Após aplicada a análise do Vert de Ricketts, foram excluídas 108 telerradiografias, por não satisfazerem o critério de seleção. Portanto, a amostra final foi de 150 telerradiografias e 150 modelos pertencentes a 150 indivíduos brancos na faixa etária de 14 anos a 18 anos e 11 meses, independentemente do tipo de má oclusão. A mesma foi dividida em: 50 mesofaciais; 50 braquifaciais e 50 dolicofaciais. Para os 150 modelos, aplicou-se a análise de Schwarz. RESULTADOS: a presença da atresia maxilar na amostra selecionada correspondeu a 64 por cento nos dolicofaciais, 58 por cento nos braquifaciais e 52 por cento nos mesofaciais. CONCLUSÕES: não houve evidência de associação da atresia com o tipo facial. Quanto ao dimorfismo de gênero, foi proporcionalmente maior para o dolicofacial masculino enquanto o feminino não apresentou proporções diferentes.

OBJECTIVES: To associate maxillary atresia with facial types, investigating whether dimorphism occurs between males and females and evaluating the percentage of such dimorphism according to gender and facial type. METHODS: Initially, the sample consisted of 258 lateral cephalometric radiographs. After analyzing Ricketts' VERT index, 108 radiographs were excluded for not meeting the selection criteria. Therefore, the sample consisted of 150 lateral cephalometric radiographs and 150 models of 150 Caucasian individuals aged 14 years to 18 years and 11 months, regardless of malocclusion type. The sample was divided into 50 mesofacials, 50 brachyfacials and 50 dolichofacials. The Schwarz's analysis was applied to all 150 models. RESULTS: The presence of maxillary atresia in the sample consisted of 64 percent in dolichofacials, 58 percent in brachyfacials and 52 percent in mesofacials. CONCLUSIONS: There was no evidence showing that atresia is in any way associated with facial type. Gender dimorphism was proportionally greater in dolichofacial males while females did not exhibit different proportions.

Avaliação da profundidade do palato e das dimensões do arco dentário superior em indivíduos com má oclusão e diferentes tipos faciais / Evaluation of palatine depth and dimensions of the upper dental arch in patients with malocclusion and different facial types

OBJETIVO: o deste estudo foi avaliar a profundidade do palato e as dimensões do arco dentário superior de indivíduos com má oclusão e diferentes tipos faciais. METODOLOGIA: a amostra empregada neste estudo foi constituída por telerradiografias em norma lateral e modelos de estudo de 135 pacientes com más oclusões de Classe I (n = 45), Classe II (n = 45) e Classe III (n = 45) de Angle, sendo 67 do gênero feminino e 68 do gênero masculino, com faixa etária entre 12 e 21 anos de idade, divididos igualmente em três grupos conforme o tipo facial apresentado: braquifacial, mesofacial e dolicofacial. RESULTADOS E CONCLUSÕES: os resultados obtidos demonstraram que, quanto ao tipo facial, houve diferença estatisticamente significante apenas para a medida da profundidade do palato, sendo que os indivíduos braquifaciais apresentaram palato com menor profundidade (média = 18,18mm), quando comparados aos indivíduos dolicofaciais (média = 19,52mm). Quanto ao dimorfismo sexual, pudemos verificar que os indivíduos do gênero masculino apresentaram médias da distância intermolares superiores (51,36mm) e da profundidade do palato (19,61mm) aumentadas, de forma significante, em relação às médias obtidas para o gênero feminino (50,15mm e 18,37mm para as medidas da distância intermolares e da profundidade do palato, respectivamente). Avaliando o tipo de má oclusão, pudemos constatar que houve diferença estatisticamente significante apenas para a medida do comprimento do arco, sendo que indivíduos com má oclusão de Classe II apresentaram arcos dentários superiores com maior comprimento ântero-posterior (média = 31,23mm) que indivíduos com má oclusão de Classe III (média = 29,64mm). Entretanto, a média da medida comprimento do arco encontrada para o grupo Classe I (30,52mm) não apresentou diferença estatisticamente significante quando comparada às médias obtidas para os grupos Classe II e Classe III.

AIM: The aim of this study was to evaluate palatine depth and dimensions of the upper dental arch in patients with malocclusion and different facial types. METHODS: The sample was constituted of profile cephalograms and dental casts of 135 individuals, 67 females and 68 males, with age between 12 to 21 years and malocclusions: Class I (n = 45), Class II (n = 45) and Class III (n = 45), Angle. The sample was divided in three groups, according to the facial type: brachyfacial (n = 45), mesofacial (n = 45) and dolichofacial (n = 45). The transversal dimensions (intercuspids and inter-first molars distances) and upper dental arch length were obtained with auxiliary of digital caliper. In order, to obtain palatine depth measurement was used a special equipment developed and adapted to the digital caliper. RESULTS AND CONCLUSION: Based on our results, we concluded that: (1) no statistically significant differences between these measurements were found considering the facial types, except for the palatine depth, that was smaller in brachyfacial group (18.18mm) than dolichofacial group (19.52mm); (2) according to sex, only two variables, the depth palatine and inter-first molar distance, demonstrated statistically significant differences, that appeared to be bigger in males than females; (3) according to the malocclusion, statistically significant differences between these measurements were found only to the upper dental arch length, that was bigger in Class II group (31.23mm) than Class III group (29.64mm).

A comparison study of the effects of nasal breathing dysfunction due to adenoid obstruction on dentition by facial type / 대한치과교정학회지

In discussing the effects of adenoids on the development of the face and dentition, it is important to note their influence on the mode of breathing and to relate this to specific facial types and dentition. This study, therefore, assumed that the ability to adapt to individual's neuromuscular complex is various. And tried to investigate the effects of reduced nasal respiratory function on the development of dentition by facial type. This paper is based on children patients with enlarged adenoids and comparing them to data taken from a control group with normal respiratory function. Among the three facial types, the most statistical significant difference was observed from dolichofacial type between experimental and control group. In dolichofacial type, the experimental group showed labioversion of upper incisor, decrease in the width of upper arch, increase in overjet, increase in the rate of cross-bite, and increase in the height of palatal vault. No significant difference was observed between the two groups in the inclination of upper and lower incisors in mesofacial type, but the experimental group was observed to show decrease in the width of upper arch and increase in the height of palatal vault. On the other hand, in brachyfacial type, no significant difference was observed between the two groups in dentition variables except showing linguoversion of upper incisor. The results, which were observed in dolichofacial type, consist with Nordlund's theory of Compression.

The comparison of influence of difficulties in nasal breathing on dentition between different facial types / 영남의대학술지

It is. commonly assumed that nasorespiratory function can exert a dramatic effect upon the development of the dentofacial complex. Specially, it has been stated that chronic nasal obstruction leads to mouth breathing, which causes altered tongue and mandibular positions. If this occurs during a period of active growth, :the .outcome is development of the "adenoid facies". Such patients characteristically: manifest a vertically long lower third facial height, narrow alar bases, lip incompetence, a long and narrow maxillary arch and a greater than normal mandibular plane angle. But several authors have reported that so-called adenoid facies is not always associated with adenoids and mouth breathing, and that a particular type of dentition is not alwarys found in mouth breathers with or without adenoids. Some authors have believed adenoids lead to mouth breathing in cases with particular facial characteristics and types of dentition. We assumed that the ability to adapt to individual's neuromuscular complex is various. So, we compared the difference of influence of mouth breathing between childrens who have different facial types. This study included 60 patients and they were divided into three groups by Rickett's facial type. Their dentition and tongue position were compared. The results are as follows. 1. There is a significant difference in arch width of upper molars between different facial types. Especially dolichofacial type patients have narrowest arch width. 2. There is a significant difference in tongue position between different facial types. Especially dolichofacial type patients have lowest positioned tongue.