Clase metodológica instructiva de la asignatura Sistema Masticatorio, orientada a la relación básico-clínica / Instructive methodological class of the Masticatory System subject, oriented towards the basic-clinical relationship

RESUMEN La preparación del personal docente en las universidades exige un alto nivel científico y de maestría pedagógica. Todo esto requiere un esmerado trabajo metodológico que garantice una planificación organización, regulación y control del proceso docente educativo. Para esto se diseñó una clase metodológica instructiva sobre mucosa oral, de la asignatura Sistema Masticatorio, en la disciplina Histología, con el objetivo de instruir al profesor en la utilización de la vinculación básico-clínica. Se indicó a los profesores cómo relacionar el contenido de la clase con la clínica, desde el punto de vista de las lesiones precancerosas y sus factores de riesgo. Se logró la instrucción de los docentes en la utilización del contenido de las asignaturas y disciplinas de las Ciencias Básicas con la relación básico-clínica, y así se contribuyó a ampliar el espectro científico metodológico de los docentes en la Universidad de Ciencias Médicas de Matanzas (AU).

ABSTRACT Training the teaching staff in the universities demands a high scientific level and pedagogical expertise. All of these requires a careful methodological work guaranteeing the teaching-learning process planning, organization, regulation and control. For that the authors designed an instructive methodological lesson aimed to train the teaching staff in the use of the basic-clinical link during a lesson of the subject Masticatory System about Oral Mucosa, in the subject Histology. They indicate to professors how to relate the lesson content to clinic from the point of view of pre-cancer lesions and its risk factors. Training the teaching staff in the use of subjects and disciplines of the Basic Sciences with the basic-clinical relation, the authors contribute to widening the scientific methodological spectrum of the teaching staff of the Matanzas University of Medical Sciences (AU).

Anatomical and physiological considerations in the 'hip rotators test' related to the stomatognathic system: a brief commentary / Consideraciones anatomofisiológicas en el "test de rotadores de cadera" relacionado con el sistema estomatognático: un breve comentario

Manual tests in clinical investigation must be supported by anatomical and physiological findings in order to obtain an objective information. The application of different mandibular positions in children obtains a variation in the 'hip rotators test' (p < 0.001). The possible relationships behind the muscle tone of the external rotators of the hips and the stomatognathic system are exposed, with special attention on the fascial tissue and its morphological characteristics. Despite these anatomical and physiological connections, there is no further evidence of a strong cause-effect relationship in this test.

Las pruebas manuales en la investigación clínica deben estar respaldadas por hallazgos anatómicos y fisiológicos para obtener una información objetiva. La aplicación de diferentes posiciones mandibulares en niños muestra una variación en la "prueba de rotadores de cadera" (p <0,001). Se exponen las posibles relaciones del tono muscular de los rotadores externos de las caderas y el sistema estomatognático, con especial atención en el tejido fascial y sus características morfológicas. A pesar de estas conexiones anatomofisiológicas, no existe una evidencia mayor de una relación importante causa-efecto en esta prueba.

Radiographic review of anatomy and pathology of the masticator space: what the emergency radiologist needs to know.

The differential diagnosis of a masticator space (MS) lesion is broad, owing in part to the multiple structures contained within such a small region. It is also because the MS is adjacent to many of the other deep spaces within the head and neck, which can act as gateways for disease spread. Therefore, emergency radiologists must be familiar with anatomy of the MS, as well as adjacent spaces in order to provide an accurate diagnosis to the referring clinician. This article illustrates the anatomy and common pathologies within the MS using a case-based multimodality approach. Common masticator space pathologies can be categorized into inflammatory/infectious, neoplastic, and vasoformative lesions. Important imaging features of MS lesions and patterns of disease spread will be discussed, with the aim of making this complex deep space more approachable in the emergent setting.

Morphological and masticatory performance variation of mouth behavior groups.

Food texture preference and product acceptance are hypothesized to be influenced by mouth behavior. Recent work identified four mouth behavior (MB) groups that describe most consumers in the United States: Chewers, Crunchers, Smooshers, and Suckers. While these behavioral preferences are thought to play a significant role in food selection and purchasing decisions, it is unknown how closely they relate to body and oral cavity measures as well as masticatory apparatus performance. Our objectives were twofold: to determine whether MB groups are related to (a) morphological variation in body, head, and oral cavity size and (b) masticatory apparatus performance (i.e., maximum jaw gape, maximum bite forces at the incisors and first molar). Measurements were collected following an online MB assessment (JBMB Mouth Behavior Typing Tool) where participants self-identified as one of the four types of consumers. As expected, univariate associations were observed between masticatory performance and overall body as well as oral cavity size. These relationships did not persist when assessed with multivariate methods. MB groups did not differ by body, head, or oral cavity measurements; maximum gape; or maximum bite force. Because of small sample sizes for Smooshers and Suckers-a reflection of their limited prevalence in the U.S. population-we interpret the results for these groups with caution. We can more confidently conclude based on our sample that Chewers and Crunchers do not differ in size, bite force, or maximum gape, suggesting other factors primarily drive food texture choice and preference in these individuals.

General morphology and ultrastructure of the radula of Testudinalia testudinalis (O. F. Müller, 1776) (Patellogastropoda, Gastropoda).

The radular morphology of the patellid species Testudinalia testudinalis (O. F. Müller, 1776) from the White Sea was studied using light, electron, and confocal microscopy. The radula is of the docoglossan type with four teeth per row and consisting of six zones. We characterize teeth formation in T. testidinalis as follows: one tooth is formed by numerous and extremely narrow odontoblasts through apocrine secretion; this initially formed tooth consists of numerous vesicles; the synthetic apparatus of the odontoblasts is localized in the apical and central parts of the cells throughout the cytoplasm and is penetrated by microtubules which are involved in the transport of the synthesized products to the apical part of the odontoblast; the newly formed teeth consist of unpolymerized chitin. Mitotic activity is located in the lateral parts of the formation zone. The first four rows contain an irregular arrangement of teeth, but the radular teeth are regularly arranged after the fifth row. The irregularly arranged teeth early on could be a consequence of the asynchronous formation of teeth and the distance between the odontoblasts and the membranoblasts. The morphological data obtained significantly expands our knowledge of the morphological diversity of the radula formation in Gastropoda.

Determinación del área en diferentes sitios utilizados para colocación de mini implantes en la cresta infracigomática / Determination of the area in different sites used for the placement of mini-implants in the infrazygomatic crest

RESUMEN Introducción: estudios recientes indican que la cresta infracigomática es un sitio favorable para la colocación de mini implantes, sin embargo es importante conocer sus dimensiones anatómicas para colocarlos en una posición segura y lograr buena estabilidad. Objetivo: determinar el área, en diferentes zonas de la cresta infracigomática, que son utilizadas para la colocación de miniimplantes. Materiales y métodos: estudio descriptivo, observacional y transversal de 60 casos, con previo tratamiento de Ortodoncia y que reunieron los criterios de inclusión. Se utilizaron archivos radiográficos y de tomografías con tecnología cone-beam. Se realizó la estadística descriptiva y pruebas ANOVA, t de Student y método de comparación de Tukey para relacionar las variables. Resultados: la zona de mayor área de hueso se encontró a nivel de la cúspide mesiovestibular del segundo molar (30.2+12.1mm2). La clase esqueletal II presentó mayor área (33.6+11.2mm2). Se encontraron diferencias estadísticamente significativas al relacionar las variables área y zona, así como área y clase esqueletal, pero no hubo significancia estadística al relacionar el área con el sexo. Conclusiones. a nivel de la segunda molar superior es la referencia ideal para la colocación de mini implantes, en la cresta infracigomática, ya que esta tiene mayor área. Los casos Clase II presentan también un área mayor. El sexo no fue determinante (AU).

ABSTRACT Introduction: recent studies indicate that the infrazygomatic crest is a favorable site for the placement of miniscrew (mini implante), however it is important to know its anatomical dimensions to place them in a secure position and to obtain good stability. Objective: to determine the area in different sites of the infrazygomatic crest that is used for the placement of mini-implants. Materials and methods: descriptive, observational and cross-sectional study of 60 cases, with previous orthodontic treatment, that fulfilled the inclusion criteria. Radiographic and tomographic files with cone-beam technology were used. Descriptive statistics, ANOVA and t-Student tests, and Tukey's comparison method were used to relate the variables. Results: The zone with the largest area was found at the level of the second molar in the mesiovestibular cusp (30.2 + 12.1 mm2). Skeletal class II showed the largest area (33.6 + 11.2mm2). Statistically significant differences were found when relating the area and site variables as well as area and skeletal class, but there was no statistical significance in relating the area to sex. Conclusions: the level of the upper second molar is the ideal reference for the placement of mini-implants in the infrazygomatic crest since it has a larger area. Class II cases also have a larger area. Sex was not determinant (AU).

Determinación del área en diferentes sitios utilizados para colocación de mini implantes en la cresta infracigomática / Determination of the area in different sites used for the placement of mini-implants in the infrazygomatic crest

RESUMEN Introducción: estudios recientes indican que la cresta infracigomática es un sitio favorable para la colocación de mini implantes, sin embargo es importante conocer sus dimensiones anatómicas para colocarlos en una posición segura y lograr buena estabilidad. Objetivo: determinar el área, en diferentes zonas de la cresta infracigomática, que son utilizadas para la colocación de miniimplantes. Materiales y métodos: estudio descriptivo, observacional y transversal de 60 casos, con previo tratamiento de Ortodoncia y que reunieron los criterios de inclusión. Se utilizaron archivos radiográficos y de tomografías con tecnología cone-beam. Se realizó la estadística descriptiva y pruebas ANOVA, t de Student y método de comparación de Tukey para relacionar las variables. Resultados: la zona de mayor área de hueso se encontró a nivel de la cúspide mesiovestibular del segundo molar (30.2+12.1mm2). La clase esqueletal II presentó mayor área (33.6+11.2mm2). Se encontraron diferencias estadísticamente significativas al relacionar las variables área y zona, así como área y clase esqueletal, pero no hubo significancia estadística al relacionar el área con el sexo. Conclusiones. a nivel de la segunda molar superior es la referencia ideal para la colocación de mini implantes, en la cresta infracigomática, ya que esta tiene mayor área. Los casos Clase II presentan también un área mayor. El sexo no fue determinante (AU).

ABSTRACT Introduction: recent studies indicate that the infrazygomatic crest is a favorable site for the placement of miniscrew (mini implante), however it is important to know its anatomical dimensions to place them in a secure position and to obtain good stability. Objective: to determine the area in different sites of the infrazygomatic crest that is used for the placement of mini-implants. Materials and methods: descriptive, observational and cross-sectional study of 60 cases, with previous orthodontic treatment, that fulfilled the inclusion criteria. Radiographic and tomographic files with cone-beam technology were used. Descriptive statistics, ANOVA and t-Student tests, and Tukey's comparison method were used to relate the variables. Results: The zone with the largest area was found at the level of the second molar in the mesiovestibular cusp (30.2 + 12.1 mm2). Skeletal class II showed the largest area (33.6 + 11.2mm2). Statistically significant differences were found when relating the area and site variables as well as area and skeletal class, but there was no statistical significance in relating the area to sex. Conclusions: the level of the upper second molar is the ideal reference for the placement of mini-implants in the infrazygomatic crest since it has a larger area. Class II cases also have a larger area. Sex was not determinant (AU).

Is the buccal compartment a masticatory space extension or an anatomic space in itself? Evidence based on medical images and human cadaver dissection.

OBJECTIVES: According to some authors, the buccal space is incompletely closed with no real anatomical separation from the masticator space, and also has no fascial limit toward the cranial and caudal regions. However, several other authors consider this anatomic area to be a separated space. The goal of this study was to provide a detailed description of the normal anatomy using medical images and human cadaveric head material dissection of this facial anatomic region, to precisely clarify its condition as an extension of the masticator space or an independent space. METHODS: The buccomasseteric area in 25 male and female patients aged 14-68 years, who were referred for various head and neck disorders that did not compromise the masticatory and buccal area, was analyzed by magnetic resonance imaging on the axial and coronal planes. The region was further examined by dissection of the buccomasseteric area in four heads of fresh adult male and female human cadavers aged 30-65 years. RESULTS: The findings demonstrated that the buccal compartment should be considered part of the masticator space, rather than a space in itself. This was mainly because a corridor was positioned medially to the tendon of the masseter muscle that communicated the infratemporal region of the masticator space with the buccal region, with no fascial barrier at this level that could separate it from the masticator space. CONCLUSIONS: The present study suggests that the buccal compartment is part of the masticator space, rather than a space in itself.

Multimedia educativa sobre el sistema masticatorio para estudiantes de la carrera de Estomatología / Educational multimedia on the masticatory system for students of the Stomatology career

Introducción: las tecnologías de la información y las comunicaciones constituyen hoy uno de los recursos más importantes de la sociedad, trayendo como consecuencia una explosión exponencial en la transmisión e intercambio de datos, información y conocimientos. La educación médica no está exenta de ello. Objetivo: elaborar una multimedia educativa para proporcionar a los estudiantes de segundo año de la carrera de Estomatología el aprendizaje de los contenidos sobre la asignatura Sistema Masticatorio, perteneciente a la disciplina de Morfofisiología. Método: se elaboró una multimedia mediante las herramientas Mediator v9.0, Adobe Photoshop v8.0 y el Pinnacle Studio v14.0. Se revisaron las bibliografías más actualizadas del tema tanto en bases de datos nacionales como internacionales. Resultados: el producto cuenta con una página principal de la cual se puede acceder al resto de las páginas que componen la multimedia, a través de los distintos hipervínculos preestablecidos. Posee videos y galerías de imágenes. Se ofrecen materiales de apoyo a la docencia. Conclusiones: el producto informático obtenido fue pertinente y puede ser eficaz su aplicación para generar aprendizajes con respecto al tema que aborda(AU)

Introduction: information and communication technologies are today one of the most important resources of society, resulting in an exponential explosion in the transmission and exchange of data, information and knowledge. Medical education is not exempt from it. Objective: develop an educational multimedia to provide second-year students of the Stomatology career in the learning of the contents on the subject: Masticatory System belonging to the discipline of Morphophysiology. Method: a multimedia was developed using the tools Mediator v9.0, Adobe Photoshop v8.0 and Pinnacle Studio v14.0. The up- date bibliographies of the subject were reviewed in both national and international databases. Results: the product has a main page from which you can access the rest of the pages that make up the multimedia, through the different pre-established hyperlinks. It has videos and image galleries. Teaching support materials are offered. Conclusions: the computer product obtained was relevant and its application can be effective to generate learning with respect to the subject it addresses(AU)

Zygomatic Arch Cortical Area and Diet in Haplorhines.

The influence that various types of ingested foods have on the form (size and shape) of specific features of the masticatory system is an area in which many questions remain unanswered. The bony zygomatic arch, the focus of this study, is directly linked to the masticatory system because it serves as the anchor for the masseter muscle, a primary muscle of chewing and source of masticatory force. However, the influence of diet and the forces associated with different diet types on the arch's internal bone architecture is not well understood. Despite the breadth of work centered around the craniofacial complex and biomechanics of mastication, there is a need for further investigations into the functional relationships between specific bony features that experience high strains, (e.g., the zygomatic arch), and the masticatory forces generated by different diets (e.g., mechanically resistant versus non- mechanically resistant) across non-human primates. A hypothesis and series of predictions assessing diet in relation to variability in cortical area distributions and values of section moduli (measures of bone strength) throughout the zygomatic arch were tested in a sample of haplorhine primates. Cortical area and measures of section moduli appear to track with the known masticatory strain distribution along the zygomatic arch. Pairwise comparisons between closely related taxa of different diets reveal significant differences in anterior cortical area and section moduli values. These results imply that differences in masticatory loading due to diet manifest in the zygomatic arch's internal bone structure. Anat Rec, 299:1789-1800, 2016. © 2016 Wiley Periodicals, Inc.

Drug-Induced Sleep Endoscopy.

Drug-induced sleep endoscopy (DISE) is an upper airway evaluation technique in which fiberoptic examination is performed under conditions of unconscious sedation. Unique information obtained from this 3-dimensional examination of the airway potentially provides additive benefits to other evaluation methods to guide treatment selection. This article presents recommendations regarding DISE technique and the VOTE Classification system for reporting DISE findings and reviews the evidence concerning DISE test characteristics and the association between DISE findings and treatment outcomes.

Enseñanza integrada de anatomía e histología en la Facultad de Odontología de la Universidad Nacional de Córdoba, Argentina / Integrated teaching of anatomy and histology in the School of Dentistry, National University of Córdoba, Argentina

INTRODUCCIÓN: Docentes de anatomía, histología y asesoría pedagógica conformaron un equipo para diseñar e implementar una experiencia de enseñanza integrada (EI) en la Facultad de Odontología, Universidad Nacional de Córdoba, Argentina. El objetivo fue promover una mayor integración entre la anatomía e histología del sistema estomatognático y guiar la transferencia a situaciones clínicas. MATERIALES Y MÉTODOS: En 2010 se rediseñó una propuesta sobre EI para su aplicación a la totalidad de alumnos y con todos los docentes, quienes participaron en ateneos interdisciplinarios para la actualización de contenidos, unificación de criterios, etc. Los alumnos realizaron cuatro clases teórico-prácticas y un trabajo práctico elaborado sobre un caso clínico, con la participación de un docente de anatomía y otro de histología. En el trabajo práctico, los alumnos efectuaron una exploración guiada de la cavidad bucal y trabajaron grupalmente para resolver preguntas sobre el caso clínico. Evaluaron cada actividad de EI, indicando aspectos positivos y a mejorar. Los docentes se expresaron a través de una encuesta. RESULTADOS: Los alumnos destacaron que el abordaje integrado les permitió una mejor comprensión y relación de los temas de las dos asignaturas; valoraron el dinamismo, las explicaciones claras y bien ilustradas de las clases, y el trabajo sobre situaciones clínicas. Los docentes consideraron que la EI es una experiencia positiva, desafiante, enriquecedora, que mejora los nexos con sus colegas y alumnos. CONCLUSIONES: La experiencia de EI permitió lograr los objetivos de aprendizaje propuestos para los alumnos y constituyó una valiosa oportunidad formativa para los docentes

INTRODUCTION: Professors of Anatomy, Histology and from the pedagogic area formed a team with the objective of designing and carrying out an experience based on integrated teaching (IT) at the School of Dentistry, National University of Córdoba, Argentina. The main purpose was to achieve more integration between the anatomy and histology of the stomatognathic system as well to guide the transference to clinical situations. MATERIAL AND METHODS: In 2010 a new experience of IT was designed for its application to all the students and with all the professors, who participated in interdisciplinary meetings tending to content updating, criteria unification, and so on. The students attended four theoretical and practical classes and one practical activity elaborated on the basis of a clinical situation, guided by one professor of Anatomy and another of Histology. During the practical activity the students performed an oral cavity examination and worked in groups so as to answer questions referred to the clinical situation. They evaluated each IT activity, indicating positive aspects as well as those requiring adjustments. The teachers gave their opinions through an anonymous quest. RESULTS: The students remarked that the integrated approaching allowed them a better comprehension and the possibility of relating anatomical and histological contents. They also remarked the class dynamism and illustrations, clear explanations, and the activities based on clinical situations. The professors considered that the IT was a positive, defying and enriching experience that also improved the nexus with colleagues and students. CONCLUSIONS: The IT experience allowed to reach the proposed learning objectives for the students and constituted a valuable formative opportunity for the teachers

Imaging evaluation of the suprahyoid neck.

Evaluating the complex anatomy of the suprahyoid neck on imaging studies can be a daunting task without a sound understanding of anatomy and a systematic approach. In this article, the suprahyoid neck is divided into characteristic anatomic spaces, which allow for the accurate localization of both normal structures and abnormal pathology in the neck. Once a lesion is localized to a specific suprahyoid space, imaging characteristics and clinical data can be used in a logical fashion to provide a clinically useful imaging differential diagnosis.

Covariation in the human masticatory apparatus.

Many studies have described shape variation of the modern human cranium in relation to subsistence; however, patterns of covariation within the masticatory apparatus (MA) remain largely unexplored. The patterns and intensity of shape covariation, and how this is related to diet, are essential for understanding the evolution of functional masticatory adaptations of the human cranium. Within a worldwide sample (n = 255) of 15 populations with different modes of subsistence, we use partial least squares analysis to study the relationships between three components of the MA: upper dental arch, masseter muscle, and temporalis muscle attachments. We show that the shape of the masseter muscle and the shape of the temporalis muscle clearly covary with one another, but that the shape of the dental arch seems to be rather independent of the masticatory muscles. On the contrary, when relative positioning, orientation, and size of the masticatory components is included in the analysis, the dental arch shows the highest covariation with the other cranial parts, indicating that these additional factors are more important than just shape with regard to covariation within the MA. Covariation patterns among these cranial regions differ mainly between hunting-fishing and gathering-agriculture groups, possibly relating to greater masticatory strains resulting from a large meat component in the diet. High-strain groups show stronger covariation between upper dental arch and masticatory muscle shape when compared with low-strain groups. These results help to provide a clearer understanding of constraints and interlinkage of shape variation within the human MA and allow for more realistic modeling and predictions in future biomechanical studies.

Functional geometric morphometric analysis of masticatory system ontogeny in papionin primates.

The three-dimensional configuration of the primate masticatory system is constrained by the need to maximize bite forces while avoiding distraction of the temporomandibular joint (TMJ). Within these bounds, shape variation has predictable effects on functional capacities such as mechanical advantage and gape. In this study, geometric morphometric analysis is used to investigate the ontogeny of masticatory function in papionin monkeys and test the hypothesis that biomechanical constraints determine the location of molar eruption. This "constrained eruption hypothesis" predicts that the distalmost molar (DMX) will occupy a consistent location anterior to the TMJ and that jaw adductor muscles will maintain consistent positions relative to both DMX and TMJ. Craniometric landmarks were digitized on cross-sectional ontogenetic series of nine papionin species. Form-space PCA of Procrustes residuals, visualization of Bookstein shape coordinates, and nonparametric ANOVA were used to identify ontogenetic shape trends and test for significant ontogenetic changes in relative landmark positions. In most taxa, DMX maintains a consistent position relative to the TMJ while the anterior dentition migrates anteriorly. Where significant intraspecific ontogenetic differences occur, they involve anterior migration of DMX in later dental stages, likely due to late adolescent growth of the posterior palate. Attachments of the anterior temporalis and deep masseter also maintain consistent positions relative to the TMJ; however, the superficial masseter migrates anteriorly throughout ontogeny. All muscle attachments migrate laterally relative to the TMJ, reflecting positive scaling of adductor PCSA. Overall, results support the constrained eruption hypothesis and suggest mechanisms by which functional capacity is maintained during ontogeny.

The impact of simplifications on the performance of a finite element model of a Macaca fascicularis cranium.

In recent years finite element analysis (FEA) has emerged as a useful tool for the analysis of skeletal form-function relationships. While this approach has obvious appeal for the study of fossil specimens, such material is often fragmentary with disrupted internal architecture and can contain matrix that leads to errors in accurate segmentation. Here we examine the effects of varying the detail of segmentation and material properties of teeth on the performance of a finite element model of a Macaca fascicularis cranium within a comparative functional framework. Cranial deformations were compared using strain maps to assess differences in strain contours and Procrustes size and shape analyses, from geometric morphometrics, were employed to compare large scale deformations. We show that a macaque model subjected to biting can be made solid, and teeth altered in material properties, with minimal impact on large scale modes of deformation. The models clustered tightly by bite point rather than by modeling simplification approach, and fell out as being distinct from another species. However localized fluctuations in predicted strain magnitudes were recorded with different modeling approaches, particularly over the alveolar region. This study indicates that, while any model simplification should be undertaken with care and attention to its effects, future applications of FEA to fossils with unknown internal architecture may produce reliable results with regard to general modes of deformation, even when detail of internal bone architecture cannot be reliably modeled.

[The study of stomatognathic muscles morphological changes after zygomatic plasty combined with mandibular angel plasty].

OBJECTIVE: To investigate the morphology change of stomatognathic muscles after zygomatic plasty combined with mandibular angel plasty. METHODS: 3D-CT facial soft tissue measurement was performed pre-operative and at 10 days,3 months post-operatively in 59 cases with prominent malar-complex and mandibular angle. The q test (Newman-Keuls method) was used to analyze the variance. RESULTS: The cross sectional area of masseter muscle and medial pterygoid muscle were both increased at 10 days, reduced at 3 months post-operatively (P < 0.05). The masseter muscle and medial pterygoid muscle cross sectional areas were (4.73 +/- 0.21) cm2 and (3.24 +/- 0.21) cm2 at anterior nasal spine plane, respectively; the pterygoid muscle cross-sectional area was (1.37 +/- 0.35 ) cm2 at the root of coronoid process plane, showing significant difference, when comparing with those before operation (P < 0.05). Lateral pterygoid muscle and temporal muscle had no statistical difference between the pre-and 10 days post-operatively(P > 0.05), however, the temporal muscle was reduced while the lateral pterygoid muscle was increased at 3 months post-operatively. The temporal muscle cross-sectional area was(2.35 + 0.25) cm2 at coronoid process plane; the temporal muscle and lateral pterygoid muscle cross-sectional areas were (1.00 +/- 0.16) cm2 and (3.54 +/- 0.61) cm2 at the root of coronoid process plane, which were significantly different from those before operation (P < 0.05 ). CONCLUSIONS: Because of osteotomy, muscles attached position are changed in the short term after zygomatic plasty combined with mandibular angel plasty. Masseter muscle and medial pterygoid muscle are inevitably injuried during the operation. With the postoperative recovery, muscles have adaptive changes which reduced compared with those before operation after their reattachment. Zygomatic plasty can cause temporal muscle atrophy;while the lateral pterygoid muscle is rarely involved, the cross sectional area had no statistical difference between the pre- and 10 days post-operative, and the cross sectional area increase at 3 months post-operatively may be due to a compensational enlargement.