Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 6.006
Filtrar
1.
Plast Reconstr Surg ; 146(5): 599e-606e, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33136957

RESUMO

BACKGROUND: One of the arguments against early intervention for micrognathia in Pierre Robin sequence is the concept that the growth of the mandible will eventually "catch up." Long-term growth of the mandible and occlusal relationships of conservatively managed Pierre Robin sequence patients remain unknown. In this study, the authors evaluated the orthognathic surgery requirements for Pierre Robin sequence patients at skeletal maturity. METHODS: Orthognathic surgical requirements of conservatively managed Pierre Robin sequence and isolated cleft patients (aged ≥13 years) at two institutions were reviewed and analyzed using t test, chi-square test, and Fisher's exact test. Values of p < 0.05 were considered statistically significant. RESULTS: Of the Pierre Robin sequence patients (n = 64; mean age ± SD, 17.9 ± 2.9 years), 65.6 percent were syndromic (primarily Stickler and velocardiofacial syndrome), 96.9 percent had a cleft palate, and 39.1 percent required orthognathic surgery at skeletal maturity. Nonsyndromic and syndromic Pierre Robin sequence patients demonstrated no differences in occlusal relationships or mandibular surgery frequency. The majority of Pierre Robin sequence patients requiring mandibular advancement had a class II occlusion. Comparison of Pierre Robin sequence patients to isolated cleft palate patients (n = 17) revealed a comparable frequency of orthognathic surgery between the two; however, Pierre Robin sequence patients did require mandibular advancement surgery at a greater frequency than cleft palate patients (p = 0.006). CONCLUSIONS: The present study found that 39.1 percent of conservatively managed Pierre Robin sequence patients required orthognathic surgery at skeletal maturity, of which the vast majority required mandibular advancement for class II malocclusion. These data suggest that mandibular micrognathia in conservatively managed Pierre Robin sequence patients may not resolve over time and may require surgical intervention. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.


Assuntos
Fissura Palatina/cirurgia , Tratamento Conservador/efeitos adversos , Má Oclusão de Angle Classe II/epidemiologia , Procedimentos Cirúrgicos Ortognáticos/estatística & dados numéricos , Síndrome de Pierre Robin/terapia , Adolescente , Cefalometria/estatística & dados numéricos , Fissura Palatina/complicações , Tratamento Conservador/métodos , Feminino , Seguimentos , Humanos , Masculino , Má Oclusão de Angle Classe II/diagnóstico , Má Oclusão de Angle Classe II/prevenção & controle , Má Oclusão de Angle Classe II/cirurgia , Mandíbula/anatomia & histologia , Mandíbula/crescimento & desenvolvimento , Mandíbula/cirurgia , Procedimentos Cirúrgicos Ortognáticos/métodos , Síndrome de Pierre Robin/complicações , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
2.
Sci Rep ; 10(1): 16229, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004827

RESUMO

The purpose was to predict the crown-to-implant ratio variation in the edentulous posterior mandibles rehabilitated with short dental implants. Hence, vertical and horizontal dimensions of dentulous posterior mandibles in a sample of 18- to 25-year-olds were measured, and correlations of these dimensions with sex and site were investigated. Mandibular computed tomography scans from 100 subjects were considered. Vertical and horizontal bone and tooth measurements were taken at the sites of the second premolar (PM), and the mesial and distal roots of the first and second molars (M1m, M1d, M2m and M2d, respectively). A hypothetical crown-to-implant ratio (C/I R) was calculated assuming the insertion of short and extra short implants (5, 6 or 7 mm), at 1.5 mm from the inferior alveolar canal, maintaining the position of the existing occlusal plane. All vertical bone dimensions decreased from the PM to the M2d. Width measurements increased from the mesial (PM) to the distal sites (M1m, M1d, M2m and M2d). Males had significantly greater vertical and horizontal measurements than females at all sites. The mean C/I R was higher than 2 for all sizes of implant. The C/I R was lower for the second molar than for the second premolar, while it was similar for the first molar and the second premolar. Males had a higher C/I R than females. Computed tomography can be used to study the anatomical features of alveolar bone, and to predict some clinical aspects of prosthetic rehabilitation with implants, such as the crown-to-implant ratio in conditions of serious bone atrophy.


Assuntos
Processo Alveolar/diagnóstico por imagem , Implantes Dentários , Mandíbula/diagnóstico por imagem , Coroa do Dente/diagnóstico por imagem , Adolescente , Adulto , Processo Alveolar/anatomia & histologia , Humanos , Arcada Edêntula/diagnóstico por imagem , Arcada Edêntula/patologia , Masculino , Mandíbula/anatomia & histologia , Radiografia Dentária , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Coroa do Dente/anatomia & histologia , Adulto Jovem
3.
Medicine (Baltimore) ; 99(43): e22778, 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33120788

RESUMO

BACKGROUND: To analyze the sagittal positions of the mandibular prominence and maxillary central incisors in adult Chinese Han men to establish their aesthetic profile characteristics. METHODS: Seventy-four Chinese Han men aged 18 to 40 years underwent cone beam computed tomography for detecting the distances between Glabella and Subnasale, Subnasale and Menthon of soft tissue, Condyle and Gonion, Pogonion and Pogonion's Anterior Limit Line, Facial Axis point of maxillary central incisor and the Goal Anterior Limit Line as well as the angle of the Occlusal Plane. Dolphin Imaging and Photoshop software packages were used to generate silhouette profiles. Thirteen orthodontists assessed the silhouette profiles and assigned visual analog scale scores. Scores >70 were assigned to the aesthetic (group 1), scores of 60to 70 to the general (group 2), scores of 50 to 60 to the acceptable (group 3), and scores of <50 to the unaesthetic profile (group 4). RESULTS: A total of 15 men were assigned to group 1, 35 to group 2, 14 to group 3, and 10 to group 4. There were no significant differences in the variables examined between groups 1, 2, and 3, but comparing group 1 with group 4, Pogonion and Pogonion's Anterior Limit Line (1.16 ±â€Š2.61 mm vs -1.44 ±â€Š2.92 mm, P = .046) and Facial Axis-Goal Anterior Limit Line (-0.61 ±â€Š2.54 mm vs 1.70 ±â€Š2.62 mm, P = .038) there were significant differences. CONCLUSION: Compared with the unaesthetic profile group, the sagittal positions of the maxillary central incisors were slightly posterior, and the chin was slightly anterior in adult Chinese Han men with an aesthetic profile.


Assuntos
Grupos Étnicos , Incisivo/anatomia & histologia , Incisivo/diagnóstico por imagem , Maxila/anatomia & histologia , Maxila/diagnóstico por imagem , Adolescente , Adulto , Cefalometria/métodos , Queixo/anatomia & histologia , Queixo/diagnóstico por imagem , China , Tomografia Computadorizada de Feixe Cônico/métodos , Humanos , Masculino , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem , Estudos Prospectivos , Valores de Referência , Adulto Jovem
4.
J Appl Oral Sci ; 28: e20200092, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33111881

RESUMO

BACKGROUND: The period of functional adaptation to a new conventional complete denture embraces many transitory issues, and this period is directly related to the rehabilitation success. OBJECTIVE: This clinical trial evaluated the influence of the height of mandibular ridge on the masticatory function of complete denture (CD) wearers during the adaptation period. METHODOLOGY: A total of 28 individuals wearing new CDs (NR, n=14, normal mandibular ridges, 64±12.5 years, 9 female; RR, n=14, resorbed mandibular ridges, 69±6.8 years, 9 female) were assessed at 24 hours, 30 days, three months and six months after the insertion of the CDs for masticatory performance (MP, sieves method), satisfaction with CDs (questionnaire) and maximum occlusal bite force (MOBF) (gnatodynamometer). The classification of the mandibular ridges followed the Kapur index. Data of MP and MOBF were analyzed by two-way ANOVA and satisfaction with CDs was analyzed by Generalized Estimating Equations (GEE), α=.05. RESULTS: Participants with NR presented better masticatory performance (p=.000 - NR 30.25±9.93%, RR 12.41±7.17%), general satisfaction (p=.047), retention of mandibular denture (p=.001), chewing ability (p=.037), and comfort of wearing a mandibular denture (p=.000). Regardless of the mandibular ridge, MP (p=.000) was higher at three (21.26±12.07%) and six months (24.25±12.26%) in comparison to 24 hours (18.09±10.89%), the MOBF (p=.000) was higher at three months (78.50±6.49 N) compared to 24 hours (57.34±5.55 N) and 30 days (62.72±5.97 N), and the comfort of wearing a mandibular denture (p=.002) at three months (1.61 ± 0.07) was greater than 24 hours (1.29±0.10) and 30 days (1.36±10). CONCLUSIONS: The study suggests that the participants with NR have higher MP and satisfaction with their CD, regardless of the follow-up period after the insertion of the new CD. After subjects received the CD, a period of 3 months was necessary for achieving better achievement MOBF, MP, and self-perceived comfort with the mandibular denture, regardless of the height of the mandibular ridge.


Assuntos
Prótese Total , Mandíbula/anatomia & histologia , Mastigação , Idoso , Força de Mordida , Oclusão Dentária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Inquéritos e Questionários
5.
Sci Rep ; 10(1): 16431, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009429

RESUMO

Mandibular tumors and radical oral cancer surgery often cause bone dysmorphia and defects. Most patients present with noticeable mandibular deformations, and doctors often have difficulty determining their exact mandibular morphology. In this study, a deep convolutional generative adversarial network (DCGAN) called CTGAN is proposed to complete 3D mandibular cone beam computed tomography data from CT data. After extensive training, CTGAN was tested on 6 mandibular tumor cases, resulting in 3D virtual mandibular completion. We found that CTGAN can generate mandibles with different levels and rich morphology, including positional and angular changes and local patterns. The completion results are shown as tomographic images combining generated and natural areas. The 3D generated mandibles have the anatomical morphology of the real mandibles and transition smoothly to the portions without disease, showing that CTGAN constructs mandibles with the expected patient characteristics and is suitable for mandibular morphological completion. The presented modeling principles can be applied to other areas for 3D morphological completion from medical images.Clinical trial registration: This study is not a clinical trial. Patient data were only used for testing in a virtual environment. The use of the digital data used in this study was ethically approved.


Assuntos
Inteligência Artificial , Mandíbula/anatomia & histologia , Doença , Feminino , Humanos , Masculino , Tomografia Computadorizada por Raios X/métodos
6.
Int. j. morphol ; 38(4): 924-932, Aug. 2020. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-1124878

RESUMO

El canal mandibular es una estructura de especial interés considerando que es vital su preservación durante actos clínicos. Por encontrarse al interior del hueso requiere un estudio in vivo mediante el uso rayos X, involucrando técnicas entre las que destaca la TC Cone Beam (TCCB). El objetivo de este trabajo es comparar la biometría del canal mandibular humano obtenida en la disección anatómica con la morfometría de las imágenes generadas en TCCB. A partir de cortes coronales realizados en los sectores anterior, medio y posterior del canal mandibular en mandíbulas secas, y mediante imágenes generadas en la TCCB, se obtuvieron 216 mediciones en cada una de técnicas aplicadas. Las mediciones lineales del canal mandibular se efectuaron utilizando marcadores radiopacos que fueron dispuestos en relación a las paredes vecinas que corresponden a las corticales alveolar/residual, basal, interna y externa. Se midió el diámetro vertical y transversal del canal, junto con las distancias entre la cortical alveolar/residual y basal, y entre la cortical interna y externa. Se obtuvieron los valores promedio de cada una de las mediciones lineales, tanto de la biometría en la mandíbula seca como de la morfometría realizada en la TCCB. Luego se determinó las diferencias estadísticas de cada medición (L1-L6 y D1-D2) entre ambas técnicas, utilizando la prueba de correlación de Pearson, donde se obtuvo una correlación positiva muy alta (p›0,987). Adicionalmente se determinó que las mediciones no se ven afectadas por el sector del canal analizado (p›0,987). En las mediciones realizadas L1-L6 y D1-D2, no se encontraron diferencias significativas entre la biometría con respecto a las medidas de morfometría hechas en las imágenes de la TCCB. Las medidas L4 y L5 son las que ofrecen menor diferencias porcentuales con otras investigaciones, debido a una menor absorción de las corticales involucradas.


The mandibular canal is a structure of special interest, considering that its preservation during clinical procedures is vital. Given its location inside the bone, in vivo studies including X-rays and Cone Beam CT (CBCT) analysis are among the techniques required for an evaluation. The aim of this paper is to compare biometrics of the human mandibular canal from an anatomic dissection, with the morphometry of images obtained with CBCT. In this study, 216 measurements were obtained from cross sections carried out in the anterior, middle and posterior sectors of the mandibular canal in dry jaws, through CBCT images. Linear measurements of the mandibular canal were carried out using radiopaque markers that were arranged with respect to the outlying walls that correspond to the alveolar/residual, basal, internal and external corticals. The vertical and transverse diameters of the canal was measured, along with the distances between the alveolar/residual and basal cortex, and between the internal and external corticals. The average values of each of the linear measurements were obtained, both of the biometrics in the dry jaw and the morphometry performed in the CBCT. Then the statistical differences of each measurement (L1-L6 and D1-D2) between both techniques were determined, using the Pearson correlation test, where a very high positive correlation was obtained (p ›0.987). Additionally, it was determined that measurements are not affected by the sector of the analyzed channel (p ›0.987). The measurements made L1-L6 and D1-D2, no significant differences were found between the biometrics with respect to the morphometry measurements made in the CBCT images. Measures L4 and L5 are those that offer the lowest percentage differences with other research, due to lower absorption of the corticals involved.


Assuntos
Humanos , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem , Dissecação , Tomografia Computadorizada de Feixe Cônico
7.
Int. j. morphol ; 38(4): 899-902, Aug. 2020. graf
Artigo em Espanhol | LILACS | ID: biblio-1124873

RESUMO

La correcta identificación del canal mandibular es esencial cuando se pretende realizar procedimientos quirúrgicos del sector posterior o incluso odontología clínica. La tomografía computarizada de haz cónico (CBCT) utiliza diferentes planos para la evaluación de este. Para conocer las variaciones anatómicas del canal mandibular se lleva a cabo un estudio en 100 adultos mayores de 30 años, donde la ubicación, la forma y la orientación se estudia mediante la tomografía computarizada de haz cónico. Así, el principal objetivo de nuestro estudio es conocer la variabilidad y tipo de presentación del canal bífido en el Canal mandibular en pacientes dentados o parcialmente edéntulos adultos mayores de 30 años.


The correct identification of the mandibular canal is essential when trying to perform surgical procedures in the posterior sector or even clinical dentistry. Computed tomography (CBCT) uses different planes for the evaluation of this. In order to know the anatomical variations of the mandibular canal, a study is carried out in 100 adults over 30 years of age, where the location, shape and orientation is studied by cone beam computed tomography. The main objective of our study is to know the variability and type of presentation of the bifid canal in the mandibular duct in dentate or partially edentulous adult patients over 30 years.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem , Estudos Transversais , Estudos Retrospectivos , Fatores Etários , Tomografia Computadorizada de Feixe Cônico , Variação Anatômica
8.
Leg Med (Tokyo) ; 47: 101770, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32795932

RESUMO

BACKGROUND: A missing mandible is a common problem in facial identification cases requiring forensic facial approximation or reconstruction. The Sassouni and Sassouni-Plus methods which are currently used to predict the missing mandible from the cranium produce low levels of accuracy. AIMS: This study proposes a new method for the estimation of the overall dimensions of the mandible based upon linear cranial measurements, the proposed method has the potential to be utilised in the facial reconstruction of a range of adult skulls with dentition. SAMPLE AND METHOD: 21 measurements were taken from a sample of 90 skulls, 44 male, 43 female and three juvenile, originating from 9 different geographical areas. Ordinary least-squares regression, hierarchical cluster analysis and analysis of variance (ANOVA) were used to investigate trends in the data and to produce equations for the estimation of condylar height, corpus length and anterior height. CONCLUSION: When tested the equations produced an overall mean error of 0.09 mm with a standard deviation of ±4.84. The proposed method offers an improvement upon the currently used methods. It can be used to estimate the overall mandibular dimensions with a good level of accuracy.


Assuntos
Restos Mortais/anatomia & histologia , Cefalometria/métodos , Face/anatomia & histologia , Antropologia Forense/métodos , Mandíbula/anatomia & histologia , Adolescente , Adulto , Idoso , Criança , Grupos de Populações Continentais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Crânio/anatomia & histologia , Adulto Jovem
9.
BMC Evol Biol ; 20(1): 95, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32736512

RESUMO

BACKGROUND: Adaptive radiations are characterized by extreme and/or iterative phenotypic divergence; however, such variation does not accumulate evenly across an organism. Instead, it is often partitioned into sub-units, or modules, which can differentially respond to selection. While it is recognized that changing the pattern of modularity or the strength of covariation (integration) can influence the range or rate of morphological evolution, the relationship between shape variation and covariation remains unclear. For example, it is possible that rapid phenotypic change requires concomitant changes to the underlying covariance structure. Alternatively, repeated shifts between phenotypic states may be facilitated by a conserved covariance structure. Distinguishing between these scenarios will contribute to a better understanding of the factors that shape biodiversity. Here, we explore these questions using a diverse Lake Malawi cichlid species complex, Tropheops, that appears to partition habitat by depth. RESULTS: We construct a phylogeny of Tropheops populations and use 3D geometric morphometrics to assess the shape of four bones involved in feeding (mandible, pharyngeal jaw, maxilla, pre-maxilla) in populations that inhabit deep versus shallow habitats. We next test numerous modularity hypotheses to understand whether fish at different depths are characterized by conserved or divergent patterns of modularity. We further examine rates of morphological evolution and disparity between habitats and among modules. Finally, we raise a single Tropheops species in environments mimicking deep or shallow habitats to discover whether plasticity can replicate the pattern of morphology, disparity, or modularity observed in natural populations. CONCLUSIONS: Our data support the hypothesis that conserved patterns of modularity permit the evolution of divergent morphologies and may facilitate the repeated transitions between habitats. In addition, we find the lab-reared populations replicate many trends in the natural populations, which suggests that plasticity may be an important force in initiating depth transitions, priming the feeding apparatus for evolutionary change.


Assuntos
Ciclídeos/anatomia & histologia , Ecossistema , Comportamento Alimentar , Animais , Arcada Osseodentária/anatomia & histologia , Lagos , Malaui , Mandíbula/anatomia & histologia , Modelos Biológicos , Faringe/anatomia & histologia , Filogenia , Água
10.
Am J Primatol ; 82(9): e23175, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32696564

RESUMO

Although hylobatids are the most speciose of the living apes, their morphological interspecies and intraspecies variation remains poorly understood. Here, we assess mandibular shape variation in two species of Hylobates, white-handed (Hylobates lar) and black-handed (Hylobates agilis) gibbons. Using 71 three-dimensional landmarks to quantify mandibular shape, interspecies and intraspecies variation and geographic patterns of mandibular shape are examined in a mixed sex sample of adult H. lar and H. agilis through generalized Procrustes analysis, Procrustes analysis of variance, and principal components analysis. We find that relative to H. agilis, H. lar exhibits a higher amount of variation in mandibular shape. Both species demonstrate similar allometric patterns in mandibular shape. We also highlight a geographic pattern in mandibular shape variation. Compared to mainland hylobatids, insular hylobatids have relatively lower, more posteriorly oriented, and anteroposteriorly wider mandibular condyles, with an increased distance between the condyles and the coronoid processes. This geographic pattern could reflect differences in functional demands on the mandible during mastication and/or could be driven by factors often associated with evolutionary pressures of island populations relative to mainland populations. The findings of this study highlight how little is known about Hylobates morphological variation and how important this is for using Hylobates to help interpret the primate fossil record. Understanding interspecific and intraspecific variation in extant primates is vital to interpreting variation in the primate fossil record.


Assuntos
Hylobates/anatomia & histologia , Mandíbula/anatomia & histologia , Animais , Feminino , Hylobates/classificação , Ilhas , Masculino , Caracteres Sexuais , Especificidade da Espécie
11.
Sci Rep ; 10(1): 11722, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32678176

RESUMO

The aim of this study is to compare cone-beam computed tomography (CBCT) and bi-dimensional reconstructed lateral cephalograms (RLCs) in assessing mandibular body length and growth and to evaluate how mandibular reshaping influences the error in measuring mandibular body growth in bi-dimensional radiographs. Twenty-five patients with two CBCT scans taken at a mean distance of 2.21 ± 0.5 years were selected. The following measurements were performed: right and left mandibular body length at each point in time, mandibular growth, inter-gonial distance and mandibular symphyseal angle. From each CBCT, an RLC was obtained, and mandibular body length and growth were measured. Data analysis revealed a statistically and clinically significant difference in CBCT and RLC regarding the mandibular length of each patient at each point in time. However, mandibular growth was almost identical. A linear regression was performed to predict growth distortion between RLCs and CBCT depending on the ratio between transverse and sagittal mandibular growth. The expected maximum and minimum distortion, however, appeared not to be significant. In fact, a second linear regression model and a Bland-Altman test revealed a strong correlation between measurements of average mandibular body growth by CBCT and RLCs. As the same distortion occurs in the first and second RLCs, bi-dimensional radiographs remain the method of choice in evaluating mandibular body growth.


Assuntos
Cefalometria , Tomografia Computadorizada de Feixe Cônico , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem , Cefalometria/métodos , Odontologia/métodos , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Mandíbula/crescimento & desenvolvimento , Modelos Teóricos , Tomografia Computadorizada de Feixe Cônico Espiral
12.
Sci Rep ; 10(1): 12670, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-32728121

RESUMO

The jaws of vertebrates display a striking diversity in form and function, but they typically open and close like a trapdoor rather than sliding like a saw. Here, we report unique feeding behaviour in the blunt-headed snail-eating snake, Aplopeltura boa (family Pareidae), where the snake cuts off and circumvents the indigestible part (the operculum) of its prey in the mouth using long sliding excursions of one side of the mandible, while the upper jaws and the mandible on the other side maintain a stable grasp on the prey. This behaviour, which we call 'mandibular sawing', is made possible by extraordinarily independent movements of the jaw elements and is a surprising departure from usual feeding behaviour in vertebrates.


Assuntos
Colubridae/fisiologia , Comportamento Alimentar/fisiologia , Mandíbula/anatomia & histologia , Animais , Comportamento Animal , Colubridae/anatomia & histologia , Mandíbula/fisiologia , Caramujos
13.
Sci Rep ; 10(1): 8809, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32483196

RESUMO

Paleontologists and paleoanthropologists have long debated relationships between cranial morphology and diet in a broad diversity of organisms. While the presence of larger temporalis muscle attachment area (via the presence of sagittal crests) in carnivorans is correlated with durophagy (i.e. hard-object feeding), many primates with similar morphologies consume an array of tough and hard foods-complicating dietary inferences of early hominins. We posit that tapirs, large herbivorous mammals showing variable sagittal crest development across species, are ideal models for examining correlations between textural properties of food and sagittal crest morphology. Here, we integrate dietary data, dental microwear texture analysis, and finite element analysis to clarify the functional significance of the sagittal crest in tapirs. Most notably, pronounced sagittal crests are negatively correlated with hard-object feeding in extant, and several extinct, tapirs and can actually increase stress and strain energy. Collectively, these data suggest that musculature associated with pronounced sagittal crests-and accompanied increases in muscle volume-assists with the processing of tough food items in tapirs and may yield similar benefits in other mammals including early hominins.


Assuntos
Dieta/história , Músculos Faciais/anatomia & histologia , Comportamento Alimentar , Osso Frontal/anatomia & histologia , Hominidae/anatomia & histologia , Mandíbula/anatomia & histologia , Perissodáctilos/anatomia & histologia , Desgaste dos Dentes , Animais , Anisotropia , Dente Pré-Molar/fisiologia , Ecologia , Músculos Faciais/fisiologia , Dureza , Herbivoria , História Antiga , Mandíbula/fisiologia , Mastigação , Dente Serotino/fisiologia , Perissodáctilos/fisiologia , Especificidade da Espécie
14.
Int. j. morphol ; 38(3): 714-719, June 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1098310

RESUMO

The morphological variations of the mental foramen (MF) and mandibular foramen (MBF) have been studied for several years, and the prevalence and morphometric characteristics of double and triple foramina have been reported. The objective of this study was to establish the prevalence of variations in the MF and MBF, and to carry out a morphometric analysis of a Chilean population using digital panoramic radiographs. The study included 927 radiographs; the observed prevalence of double MF was 2.58 %, while the prevalence of double MBF was 1.51 %. No cases of triple foramina were found. In men, double MF was found more frequently in the left hemiarch (64.28 % of cases), while in women it was more frequent in the right hemiarch (80 %). Double MBF was found more frequently in the right hemiarch in women (80 % of cases), while the distribution between left and right in men was even. The mean area, width and height of the double MF were 5.46 mm2, 2.77 mm and 2.57 mm respectively. The means of the same morphometric measurements in double MBF were 6.37 mm2, 2.27 mm and 3.19 mm respectively. In both foramina, statistically significant differences were only found between the height of the foramen and the age of the subjects, with the observation that the greater the subject's age, the smaller the height. Dental surgeons must take these anatomical variants into consideration in clinical and surgical actions; timely diagnosis by radiograph is important to avoid possible complications.


Las variaciones morfológicas del foramen mental (FM) y mandibular (FMB) han sido estudiadas durante varios años, reportándose su prevalencia y las características morfométricas de forámenes dobles y triples. El objetivo de este estudio fue establecer la prevalencia de variaciones de los FM y FMB y realizar un análisis morfométrico a través de radiografías panorámicas digitales de una muestra de población chilena. En el estudio se incluyeron 927 radiografías y se observó una prevalencia de FM doble de 2,58 %, mientras que la prevalencia de FMB doble fue de 1,51 %. No se encontraron casos de forámenes triples. En hombres, el FM doble se encontró mayoritariamente en la hemiarcada izquierda (64,28 % de los casos), mientras que en mujeres fue en la hemiarcada derecha (80% de los casos). Para el caso de los FMB dobles, en mujeres se presentó mayoritariamente en la hemiarcada derecha (80 % de los casos), mientras que en hombres fue equitativo en ambos lados. El promedio del área, ancho y alto de los FM dobles fue de 5,46 mm2, 2,77 mm y 2,57 mm, respectivamente. Asimismo, los promedios de estas medidas morfométricas para el FMB doble fueron 6,37 mm2, 2,27 mm y 3,19 mm, respectivamente. Para ambos forámenes sólo se encontraron diferencias estadísticamente significativas entre el alto y la edad de los sujetos, observando que, a mayor edad menor era el alto del foramen. Los cirujanos dentistas deben tener en consideración estas variantes anatómicas para la realización de distintas acciones clínicas y quirúrgicas, su diagnóstico radiográfico oportuno es importante para prevenir posibles complicaciones.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Adulto Jovem , Variação Anatômica , Forame Mentual/anatomia & histologia , Forame Mentual/diagnóstico por imagem , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem , Radiografia Panorâmica , Prevalência , Estudos Transversais , Distribuição por Idade e Sexo
15.
Head Face Med ; 16(1): 13, 2020 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-32513223

RESUMO

BACKGROUND: The bone thickness of the human mandibular ramus is an important parameter in mandibular surgeries. The aim of this study was to systematically measure the bicortical bone thickness, the ramus dimensions and the position of the lingula. The measurements were tested on significant correlations to the patients' parameters. METHODS: Based on CBCT scans 150 rami were reconstructed as 3D polygon surfaces. An anatomical grid was adapted to the ramus surface to mark the bone thickness measurement points and to achieve comparability between the measurements on different mandibles. The bone thickness, ramus height, ramus width and the gonion angle were measured. A cluster analysis was performed with these parameters to identify clinically relevant groups with anatomical similarities. RESULTS: The median distribution of the bone thickness was calculated and visualized in a pseudo-colour map. The mean ramus height was 44.78 mm, the mean width was 31.31 mm and the mean gonion angle was 124.8°. The average distance from the lingula to the dorsal tangent was 53% of the total width and its distance to the caudal tangent was 65% of the total height. Significant correlations between the bone thickness and the ramus proportions could be identified. Age and sex had no significant influence on the mean bone thickness. The measured rami could be divided into two groups by cluster analysis. CONCLUSION: The dimensions of the human mandibular ramus can be determined from 3D reconstructed surface models from CBCT scans. Measurements could be made comparable by applying an anatomically oriented grid. A cluster analysis allowed the differentiation of two groups with different bone thickness distributions and geometries, which can be used for the optimization of osteosynthesis systems and their precision of adaptation to different ramus morphologies.


Assuntos
Mandíbula , Procedimentos Cirúrgicos Ortognáticos , Tomografia Computadorizada de Feixe Cônico Espiral , Dente , Proteínas Adaptadoras de Transdução de Sinal , Humanos , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem
16.
J Morphol ; 281(6): 662-675, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32356928

RESUMO

The Polynemidae is a family of primarily marine fishes with eight genera and 42 extant species. Many aspects of their morphology are largely unknown, with few reports about their osteology and barely any information on their myology. This paper describes and illustrates in detail all facial and branchial muscles of representative species of polynemids. Our analysis demonstrates the existence of several remarkable and previously unknown specializations in the polynemid musculature. The aponeurotic and completely independent origin of the pars promalaris of the adductor mandibulae is apparently unique among percomorphs. The differentiation of this section into lateral and medial subsections; the total separation of the promalaris from the retromalaris; the differentiation of the pars primordialis of the levator arcus palatini into external and internal subsections are also uncommon features of polynemids that are shared by sciaenids, thus supporting the hypothesis of a closer relationship between these families.


Assuntos
Brânquias/anatomia & histologia , Músculos/anatomia & histologia , Perciformes/anatomia & histologia , Animais , Face/anatomia & histologia , Cabeça/anatomia & histologia , Mandíbula/anatomia & histologia
17.
Eur. j. anat ; 24(3): 229-234, mayo 2020. tab, ilus
Artigo em Inglês | IBECS | ID: ibc-191472

RESUMO

The incidence of a coronoid foramen in a live human subject is rare and hence the scarcity of the literature. The knowledge of any such anatomi-cal variation is important, as surgical procedures on the mandible are regularly performed by dental as well as oral and maxillofacial surgeons. The current script details anomalous morphology of an isolated coronoid foramen in the mandible of a 16-year-old female Saudi patient, which is a first ever documented case along with the presence of two separate accessory mandibular canals encoun-tered during routine dental investigations. A high spatial resolution three-dimensional cone beam computed tomography (CBCT) was used as a di-agnostic investigative method so as to allow an accurate three-dimensional analysis of mandibular coronoid foramen and accessory mandibular canal variations. These variations were documented and a detailed review of literature done. The script fo-cuses on the variations themselves, and the clini-cal implications of the presence of such variations. A thorough understanding of anatomical variants in the mandible and their neurovascular contents al-ways determines the success of any procedural anesthesia, the prevention of surgical misadven-ture and the etiology of pathologic processes


No disponible


Assuntos
Humanos , Feminino , Adolescente , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem , Variação Anatômica , Tomografia Computadorizada de Feixe Cônico/métodos , Radiografia Panorâmica
18.
Plast Reconstr Surg ; 146(3): 622-632, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32459733

RESUMO

BACKGROUND: Facial allotransplantation including the temporomandibular joints may improve the functional outcomes in face transplant candidates who have lost or damaged this joint. METHODS: Linear and angular measurements were taken in 100 dry skulls and mandibles and in 100 three-dimensionally-reconstructed facial computed tomographic scans to determine the variability of the temporomandibular joint, glenoid fossa, and mandible. A vascular study was performed in six fresh cadaveric heads, followed by harvest of the face allograft in three heads. Next, four heads were used for mock transplantation (two donors and two recipients). The full facial allograft included four different segments: a Le Fort III, a mandibular tooth-bearing, and two condyle and temporomandibular joint-bearing segments. Statistical analysis was performed using SAS software. RESULTS: In only one-third of the skulls, the condylar shape was symmetric between right and left sides. There was a wide variability in the condylar coronal (range, 14.3 to 23.62 mm) and sagittal dimensions (range, 5.64 to 10.96 mm), medial intercondylar distance (range, 66.55 to 89.91 mm), and intercondylar angles (range, 85.27 to 166.94 degrees). This high variability persisted after stratification by sex, ethnicity, and age. The temporomandibular joint was harvested based on the branches of the superficial temporal and maxillary arteries. The design of the allograft allowed fixation of the two condyle and temporomandibular joint-bearing segments to the recipient skull base, preserving the articular disk-condyle-fossa relationship, and differences were adjusted at the bilateral sagittal split osteotomy sites. CONCLUSION: Procurement and transplantation of a temporomandibular joint-containing total face allograft is technically feasible in a cadaveric model.


Assuntos
Transplante de Face/métodos , Mandíbula/transplante , Osteotomia de Le Fort/métodos , Osso Temporal/transplante , Articulação Temporomandibular/cirurgia , Adulto , Idoso , Aloenxertos , Cadáver , Feminino , Humanos , Masculino , Mandíbula/anatomia & histologia , Pessoa de Meia-Idade , Osso Temporal/anatomia & histologia , Articulação Temporomandibular/anatomia & histologia , Adulto Jovem
19.
Sci Rep ; 10(1): 6793, 2020 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-32322020

RESUMO

An on-going debate concerning the dietary adaptations of archaic hominins and early Homo has been fuelled by contradictory inferences obtained using different methodologies. This work presents an extensive comparative sample of 30 extant primate species that was assembled to perform a morpho-functional comparison of these taxa with 12 models corresponding to eight fossil hominin species. Finite Element Analysis and Geometric Morphometrics were employed to analyse chewing biomechanics and mandible morphology to, firstly, establish the variation of this clade, secondly, relate stress and shape variables, and finally, to classify fossil individuals into broad ingesta related hardness categories using a support vector machine algorithm. Our results suggest that some hominins previously assigned as hard food consumers (e.g. the members of the Paranthropus clade) in fact seem to rely more strongly on soft foods, which is consistent with most recent studies using either microwear or stable isotope analyses. By analysing morphometric and stress results in the context of the comparative framework, we conclude that in the hominin clade there were probably no hard-food specialists. Nonetheless, the biomechanical ability to comminute harder items, if required as fallback option, adds to their strategy of increased flexibility.


Assuntos
Adaptação Fisiológica/fisiologia , Dieta , Alimentos , Fósseis , Mandíbula/anatomia & histologia , Mastigação/fisiologia , Animais , Evolução Biológica , Análise de Elementos Finitos , Hominidae , Arcada Osseodentária/anatomia & histologia , Arcada Osseodentária/fisiologia , Mandíbula/fisiologia , Primatas/anatomia & histologia , Primatas/classificação , Primatas/fisiologia , Crânio/anatomia & histologia , Crânio/fisiologia , Máquina de Vetores de Suporte
20.
J Appl Oral Sci ; 28: e20190399, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32348443

RESUMO

Objectives To evaluate the acoustic properties of the /s/ sound in individuals with different occlusion types and to investigate relationships between these properties and cephalometric measurements. Methodology Sixty patients were divided into three groups based on malocclusion. Group 1 included 20 patients (mean age: 14.85±2.01 years) with Class I skeletal and dental relationships. Group 2 included 20 patients (mean age: 13.49±1.78 years) with Class II skeletal and dental relationships. Group 3 included 20 patients (mean age: 12.46±2.62 years) with Class III skeletal and dental relationships. Cephalometric tracings were obtained from cephalometric radiographs. All included patients were native speakers of Turkish. The /s/ sound was selected for center of gravity analysis. Correlations between cephalometric values and acoustic parameters were also investigated. Results The center of gravity of the /s/ sound had the lowest value in Group 2 (p<0.05). For the /s/ sound in Group 3, moderate positive correlations were found between center of gravity and Sella-Nasion to Gonion-Gnathion angle (p<0.05, r=0.444) Lower incisor to Nasion-B point (p<0.023, r=0.505), and Lower incisor to Nasion-B point angle (p<0.034; r=0.476). No correlation was found in other cephalometric measurements. Conclusions The /s/ sound was affected by malocclusion due to the changing place of articulation. Therefore, referral to an orthodontist for malocclusion treatment especially patients with class III in the early period is suggested for producing acoustically ideal sound.


Assuntos
Cefalometria , Má Oclusão/fisiopatologia , Acústica da Fala , Distúrbios da Fala/fisiopatologia , Adolescente , Criança , Feminino , Humanos , Masculino , Má Oclusão/complicações , Má Oclusão/diagnóstico por imagem , Mandíbula/anatomia & histologia , Mandíbula/fisiopatologia , Maxila/anatomia & histologia , Maxila/fisiopatologia , Estudos Prospectivos , Radiografia , Valores de Referência , Distúrbios da Fala/diagnóstico por imagem , Distúrbios da Fala/etiologia , Estatísticas não Paramétricas , Língua/anatomia & histologia , Língua/fisiopatologia , Turquia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA