Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 9.316
Filtrar
1.
Int J Comput Dent ; 23(3): 235-244, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32789311

RESUMO

AIM: The traditional hinge axis theory of temporomandibular joint (TMJ) dynamics is increasingly being replaced by the theory of instantaneous centers of rotation (ICR). Typically, ICR determinations are based on theoretical calculations or three-dimensional approximations of finite element models. MATERIALS AND METHODS: With the advent of real-time magnetic resonance imaging (MRI), natural physiologic movements of the TMJ may be visualized with 15 frames per second. The present study employs real-time MRI to analyze the TMJ biomechanics of healthy volunteers during mandibular movements, with a special emphasis on horizontal condylar inclination (HCI) and ICR pathways. The Wilcoxon rank sum test was used to comparatively analyze ICR pathways of mandibular opening and closure. RESULTS: Mean HCI was 34.8 degrees (± 11.3 degrees) and mean mandibular rotation was 26.6 degrees (± 7.2 degrees). Within a mandibular motion of 10 to 30 degrees, the resulting x- and y-translation during opening and closure of the mandible differed significantly (10 to 20 degrees, x: P = 0.02 and y: P < 0.01; 20 to 30 degrees, x: P < 0.001 and y: P = 0.01). Rotation of both 0 to 10 degrees and > 30 degrees showed no significant differences in x- and y-translation. Near occlusion movements differed only for y-translation (P < 0.01). CONCLUSION: Real-time MRI facilitates the direct recording of TMJ structures during physiologic mandibular movements. The present findings support the theory of ICR. Statistics confirmed that opening and closure of the mandible follow different ICR pathways, which might be due to muscular activity discrepancies during different movement directions. ICR pathways were similar within maximum interincisal distance (MID) and near occlusion (NO), which might be explained by limited extensibility of tissue fibers (MID) and tooth contact (NO), respectively.


Assuntos
Côndilo Mandibular , Articulação Temporomandibular , Fenômenos Biomecânicos , Humanos , Imagem por Ressonância Magnética , Mandíbula , Movimento , Amplitude de Movimento Articular , Rotação
2.
Atlas Oral Maxillofac Surg Clin North Am ; 28(2): 111-118, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32741508

RESUMO

Temporomandibular joint ankyloses are a fusion of the mandibular condyle to the base of skull. Surgical advances have stemmed from innovation in computer planning, guidance, and intraoperative navigation, allowing surgeons to restore form and function with greater precision, predictability, and safety. Preoperative computer virtual surgical planning used the computed tomography scan data to render a 3-dimensional image that can be used for surgical simulations and fabrication of intraoperative aids. Temporomandibular joint reconstruction should be considered as a predictable option in the management of temporomandibular joint ankylosis. Intraoperative navigation allows for continuous real-time 3-dimensional positioning of instruments.


Assuntos
Anquilose , Cirurgia Assistida por Computador , Transtornos da Articulação Temporomandibular , Humanos , Côndilo Mandibular , Articulação Temporomandibular
3.
Med Oral Patol Oral Cir Bucal ; 25(5): e683-e690, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32683387

RESUMO

BACKGROUND: This study aims to evaluate whether the uptake difference by the condyles evaluated using single photon emission computed tomography (SPECT) examination is useful for predicting the activity of the feature and the advance of this pathology. MATERIAL AND METHODS: An observational and prospective study has been carried out on nine patients affected by unilateral condylar hyperplasia (UCH) with complete bone maturation, with a follow-up over 18 months. At the beginning of the study, a test-battery was conducted including dental casts, articular examination, teleradiography and cephalometry, computed tomography and SPECT, creating two groups of patients from a difference in uptake between both condyles greater than 10% over the follow-up period. Evolution of data obtained with the rest of the diagnostic tests were compared to confirm UCH activity predicted by SPECT. RESULTS: The comparison of both groups did not show hardly any significant differences, with little clinical significance. Deviation of the mandibular line, the size of the branches or condyles behaved similarly in both study groups. CONCLUSIONS: From the data obtained in our study, we can conclude that the use of the difference in uptake between both condyles by applying the SPECT technique is not a valid approach for predicting clinical activity in cases of UCH.


Assuntos
Côndilo Mandibular , Tomografia Computadorizada de Emissão de Fóton Único , Humanos , Hiperplasia , Mandíbula , Estudos Prospectivos
4.
Orv Hetil ; 161(28): 1166-1174, 2020 07.
Artigo em Húngaro | MEDLINE | ID: mdl-32609624

RESUMO

INTRODUCTION AND AIM: The aim of our study was to investigate the influence of the occlusal support, and mandibular third molars on mandibular angle and condylar fractures. METHOD AND RESULTS: Patients with unilateral and isolated angle or condylar fractures were included in this retrospective, cross-sectional study. Data was collected from patient records and panoramic x-rays. The predictor variables included the type of occlusal support and the presence or absence of third molars. The outcome variable was angle or condylar fracture, while other predictor variables included demographic factors. Bivariate (χ2 test) and logistic regression analyses were conducted to investigate the associations between variables and the outcome. 43 angle (mean age: 29.9 ± 12.8 years; 98.4% male) and 37 condylar (mean age: 46.8 ± 20.2 years; 62.2% male) fracture cases were included in this study. Bilateral occlusal support was present in 81.4% of angle fracture group and in 51.3% of condylar fracture group (p<0.001). In the case of bilateral occlusal support, an odds ratio (OR) of 4.2 was found for angle fractures (p<0.006). A third molar was present in 86% of the angle fracture group and in 43.2% of the condylar fracture group (p<0.001). The presence of a third molar exhibited an odds ratio of 8.1 for the angle fractures (p<0.001). When bilateral occlusal support and third molar were present simultaneously, the risk was 15.9 times higher for an angle fracture (p<0.001). CONCLUSION: The presence of occlusal support and/or third molars was significantly associated with angle fractures, however, the absence of occlusal support and/or third molars significantly correlated with condylar fractures. Orv Hetil. 2020; 161(28): 1166-1174.


Assuntos
Oclusão Dentária , Mandíbula , Côndilo Mandibular/lesões , Fraturas Mandibulares/etiologia , Dente Serotino/anatomia & histologia , Dente Impactado/complicações , Adolescente , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Incidência , Masculino , Fraturas Mandibulares/epidemiologia , Pessoa de Meia-Idade , Dente Serotino/diagnóstico por imagem , Radiografia Panorâmica , Estudos Retrospectivos , Fatores de Risco , Coroa do Dente/diagnóstico por imagem , Adulto Jovem
5.
Bratisl Lek Listy ; 121(6): 379-385, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32484700

RESUMO

AIM: The purpose of this retrospective study was to perform an evaluation of postoperative positional changes of the condyle and mandibular function after bilateral sagittal split osteotomy (BSSO) with manual proximal segment positioning. PATIENTS: 45 patients were divided into the 2 groups ‒ G1 (advancement ‒ 14 patients) and G2 (setback - 31 patients). Rigid internal fixation screws were utilized in all cases. Inclusion criteria were only BSSO, no TMJ symptoms preoperatively and age 18 or older. RESULTS: The differences between pre- and postoperative condyle position were evaluated using measurements taken from preoperative CT scans and compared to CT scans made a minimum of 6 months postoperatively. The positional changes in both the axial and sagittal planes were measured and compared. The recovery of mandibular function was evaluated by measuring maximal interincisal opening (MIO). The results revealed that condylar positional changes after BSSO in both groups were minimal and not significantly different for all three dimensions measured. The recovery of mandibular function was faster in the group G2 than in the group G1. Mandibular function reached almost preoperative level in 6-12 months postoperatively in both groups. CONCLUSION: The results demonstrated that following BSSO, only insignificant condylar displacement and functional changes occurred within 6 to 12 months postoperatively (Tab. 4, Fig. 2, Ref. 47).


Assuntos
Mandíbula , Côndilo Mandibular , Osteotomia , Humanos , Côndilo Mandibular/cirurgia , Osteotomia/métodos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
6.
Dental Press J Orthod ; 25(2): 61-68, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32490922

RESUMO

INTRODUCTION: Facial asymmetry associated with unilateral condylar hyperplasia (UCH) is a complicated clinical condition. OBJECTIVE: The objective of this study was to describe morphological characteristics of the mandible and the temporomandibular joint in patients with facial asymmetry, using computed tomography and 3D reconstruction. METHODS: A retrospective observational study was performed with patients displaying facial asymmetry evaluated by single photon emission computed tomography (SPECT)/CT analysis, for suspected UCH, between 2015 and 2018. The following variables were compared between the affected side (producing the asymmetry) and the contralateral side (side to where the jaw is deflected): condylar length, condylar medial and lateral pole length, mandibular ramus length, intra-articular spaces, articular eminence height and position of the posterior wall of the glenoid fossa. RESULTS: Forty-three patients (21 women, mean age: 20.7 ± 7.25 years) with facial asymmetry were included, 19 patients presented right side deviation and 24 patients had left side deviation. Condylar length, lateral pole length, the sum of maximum values and articular eminence height were greater in the affected side (p< 0.05). A positive correlation was found between the position of the posterior wall of the glenoid fossa and the articular eminence height in the affected side (r = 0.442). CONCLUSIONS: In patients with suspected UCH, evaluated through CT, craniofacial measurements showed significantly larger condylar length and the condylar sum of maximum values in the affected side. A positive correlation was found between the increased dimensions of the articular eminence and the more posterior position of the glenoid fossa in the affected side.


Assuntos
Mandíbula , Côndilo Mandibular , Adolescente , Adulto , Assimetria Facial , Feminino , Humanos , Hiperplasia , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Adulto Jovem
7.
Am J Orthod Dentofacial Orthop ; 158(2): 209-220, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32451206

RESUMO

INTRODUCTION: This study aimed to evaluate the morphologic and positional features of the mandible in children, adolescents, and adults with skeletal Class I and unilateral posterior crossbite. METHODS: The sample included cone-beam computerized tomography images of 76 subjects, divided in 3 groups: (1) children (aged 6.77 ± 1.5 years; n = 25), (2) adolescents (aged 14.3 ± 1.7 years; n = 26), and (3) adults (aged 32.66 ± 13.4 years; n = 25) with unilateral posterior crossbite. Condylar and mandibular linear distances and angles were performed using a mirrored 3-dimensional overlapped model. Intragroup asymmetries were determined by a comparison between crossbite and no crossbite sides. The differences between both sides of all measurements were compared among groups and correlated to mandibular horizontal rotation (yaw) and age. RESULTS: The crossbite side showed shorter distances in the condyle and mandibular regions. Asymmetries were slightly but significantly greater in adults, as expressed by the lateromedial condylar distance, total ramus height, and mandibular length with an average 0.7 mm, 2.0 mm, and 1.5 mm, respectively. The mandibular yaw rotation was not correlated to age but moderately associated (r = 0.467) to asymmetry in mandibular length and total ramus height. CONCLUSIONS: Patients with skeletal Class I and unilateral crossbite showed small mandibular asymmetries and these conditions were slightly greater in adults, specifically in lateromedial condylar distances and mandibular body and length.


Assuntos
Má Oclusão , Adolescente , Adulto , Criança , Pré-Escolar , Tomografia Computadorizada de Feixe Cônico , Assimetria Facial , Humanos , Mandíbula , Côndilo Mandibular , Pessoa de Meia-Idade , Adulto Jovem
8.
J Contemp Dent Pract ; 21(2): 133-139, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32381816

RESUMO

AIM: The aim of the current study was to correlate the clinical symptoms that are associated with temporomandibular disorder (TMD) to the osseous changes occurring in the affected temporomandibular joint (TMJ), as detected by cone-beam computed tomography (CBCT). MATERIALS AND METHODS: The clinical data of patients that presented with TMJ symptoms was collected and correlated with the CBCT findings for the same patients. Patient recruitment took place over a 1-year period in the Oral and Maxillofacial Surgery and Oral and Maxillofacial Radiology department of the same academic institution. RESULTS: There was a limited mouth opening (MO) (<3 cm). More importantly, there was a statistically significant positive relation between pain and loss of cortication. CONCLUSION: There was no significant correlation between CBCT findings consistent with TMJ degeneration and clinical symptoms. CLINICAL SIGNIFICANCE: Cone-beam computed tomography evaluation of the TMJ is important for providing information about the state and level of TMJ degeneration if any. However, clinical findings should be the most important factor when considering management options for symptomatic TMJ.


Assuntos
Cirurgia Bucal , Transtornos da Articulação Temporomandibular , Tomografia Computadorizada de Feixe Cônico , Humanos , Côndilo Mandibular , Articulação Temporomandibular
9.
Eur. j. anat ; 24(3): 249-256, mayo 2020. tab, ilus, graf
Artigo em Inglês | IBECS | ID: ibc-191475

RESUMO

The lateral pterygoid muscle is a chewing muscle that is found bilaterally in the cranial region. Anatomically, the lateral pterygoid muscle is made up of two bellies, an upper belly and a lower belly. Its anatomical description present in the scientific lit-erature showed that there is an anatomical differ-ence or variation, mainly the insertions of the up-per belly of the lateral pterygoid muscle at the level of the temporomandibular joint, and specifically in the disc and articular condyle, although distribu-tions are reported similarly. They are not entirely accurate in smaller quantities: some articles re-ported variations in the insertion of the lower belly and others the appearance of a third belly of the lateral pterygoid muscle or medial belly. As men-tioned above, a high number of studies that presented some type of lateral pterygoid muscle vari-ation was associated with some type of temporo-mandibular disorders of the joint or some of its in-tra or extra-articular components. A review of the literature in scientific databases was carried out after the selection of the scientific articles, which were analyzed in full text, and the relationship between the anatomy of the lateral pterygoid muscleand the temporomandibular disorders was sought


No disponible


Assuntos
Humanos , Variação Anatômica , Músculos Pterigoides/anatomia & histologia , Articulação Temporomandibular/anatomia & histologia , Transtornos da Articulação Temporomandibular , Algoritmos , Côndilo Mandibular/anatomia & histologia , Disco da Articulação Temporomandibular/anatomia & histologia , Osso Temporal/anatomia & histologia
10.
Rev. cient. odontol ; 8(1): e006-e006, ene.-abr. 2020. tab.
Artigo em Espanhol | LILACS, LIPECS | ID: biblio-1095497

RESUMO

Introducción: Las alteraciones morfológicas de los cóndilos se determinan por la disminución de tejido óseo en el cóndilo mandibular, lo que cambia su forma y tamaño. Entre los signos más frecuentes encontramos el aplanamiento condilar, que se presenta entre los procesos dinámicos. Los cambios morfológicos más frecuentes son aplanamiento condilar, caracterizado por la pérdida de la convexidad del cóndilo articular. Radiográficamente, se presenta como una superficie convexa, la cortical ósea condilar es continua con ausencia de zonas radiopacas o radiolúcidas irregulares. Objetivos: Evaluar las características radiográficas de aplanamiento condilar de la articulación temporomandibular en pacientes dentados y no dentados mediante el uso de la radiografía panorámica. Métodos: Se evaluaron 520 radiografías panorámicas (260 de pacientes dentados y 260 no dentados), de pacientes de ambos sexos, entre 18 a 70 años, que fueron tomadas en el Centro de Radiología Digital Oral y Maxilofacial D3RX de Floridablanca (Colombia), entre enero de 2017 y diciembre de 2018, elegidos de forma aleatoria simple. La muestra fue definida mediante una base de datos de estudios científicos referenciados bibliográficamente, y mostró en este estudio una población evaluada con más alto promedio. Resultados: Los pacientes desdentados tienen mayor incidencia a presentar alguna alteración en la forma, el lado y el tipo de aplanamiento según la radiografía panorámica. Conclusiones: Los cambios morfológicos de los cóndilos observados en la radiografía panorámica según género mostró mayor prevalencia en mujeres que en hombres, mayor incidencia en cóndilos redondeados y afectación mayor en pacientes no dentados. Los resultados de este estudio muestran que, a pesar de que la radiografía panorámica no es considerada la mejor herramienta para determinar la presencia de cambios morfológicos leves a nivel de la mandíbula, puede ser utilizada por el odontólogo como la primera ayuda diagnóstica para obtener una visión general no solo de la articulación temporomandibular, sino de otras estructuras anatómicas y dentarias que deben ser estudiadas en trastornos de la articulación temporomandibular. (AU)


Introduction: Morphological alterations of the condyles are determined by a decrease of bone tissue in the mandibular condyle, changing its shape and size. One of the most frequent signs of these alterations involves condylar flattening that occurs among dynamic processes and is characterized by a loss of convexity of the articular condyle. Radiographically this is observed as a convex surface, the condylar bone cortex is continuous and there is an absence of irregular radiopaque or radiolucent areas. Objectives: To evaluate the radiographic characteristics of condylar flattening of the temporomandibular joint in dentate and non-dentate patients using panoramic radiography. Methods: We evaluated panoramic radiographs obtained at the D3RX Oral and Maxillofacial Digital Radiology Center in Floridablanca-Colombia from January 2017 to December 2018. Patients were randomly selected according to fulfillment of the following inclusion criteria:availability of panoramic radiographs showing the entire condylar structure of male and female patients aged 18 to 70 years attending from January 2017 to December 2018. This number of radiographs was defined according to a database. We evaluated the presence of flattening, the shape and the affected side and sex. The Chi-square test was applied. P <0.005. Results: A total of 520 panoramic radiographs were obtained; 260 from dentate patients and 260 from non-dentate patients. Patient characteristics show that edentulous patients had a higher incidence of alterations in the shape, side and type of flattening in the panoramic radiographs. Edentulous patients have a higher incidence of presenting some alteration in their shape, side and flattened condyles observed in panoramic radiographs in 51.2% versus 35.1% of dentate patients (P <0.001). Conclusions: The morphological changes of the condyles observed in panoramic radiographs were more prevalent in women than men, with a higher incidence in rounded condyles and greater involvement in edentulous patients. The results of this study show that although panoramic radiography is not considered the best tool to determine the presence of slight morphological changes at the level of the jaw, it can be used as the first diagnostic aid to obtain an overview of not only the temporomandibular joint but also other anatomical and dental structures that should be studied in disorders of the temporomandibular joint. (AU)


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Articulação Temporomandibular , Radiografia Panorâmica , Côndilo Mandibular
11.
Int. j. morphol ; 38(2): 458-460, abr. 2020.
Artigo em Inglês | LILACS | ID: biblio-1056462

RESUMO

The study of the temporomandibular joint (TMJ) through imaging, is useful for the analysis of intra-articular procedures in view of its complex anatomy. Precise knowledge of the depth at which the TMJ is located is required to achieve an ideal puncture technique. The aim of this study was to measure the depth of the TMJ through magnetic resonance imaging (MRI) in patients with temporomandibular disorders (TMD). A cross-sectional study was conducted, selecting 150 MRI of patients who attended the Polyclinic for TMD and Orofacial Pain. The variables analyzed were: 1) Depth of the right and left TMJ; 2) Age of the patients; and 3) Sex of the patients. Of the total MR, 114 corresponded to women with a median age of 23 years. The median depth of the right TMJ was 17.16 mm and median on the left side was 16.98 mm, there was no statistically significant difference (p> 0.05) but there was a strong correlation (r = 0.842). There were no differences between the depths and the sex of the patients in both the right and left TMJ. There was no correlation between age and depth of TMJ. In conclusion the depth of the right and left condyle are highly correlated, being approximately 17 mm according to the population studied. There is no association between patient age and condylar depth, and there are no differences in average according to sex.


El estudio por imágenes de la articulación temporomandibular (ATM) es útil para el análisis de procedimientos intra-articulares debido a la compleja anatomía que presenta. Se requiere un conocimiento preciso de la profundidad a la cual se encuentra la ATM para una adecuada técnica de punción. El objetivo de este estudio fue medir la profundidad de laATM en relación a la piel a través de resonancia magnética (RM) en pacientes con trastornos temporomandiblaes (TTM). Se realizó un estudio transversal, seleccionando 150 RM de pacientes que asistieron al Policlínico de TTM y Dolor Orofacial. La variables analizadas fueron: 1) Profundidad de la ATM derecha e izquierda; 2) Edad de los pacientes; y 3) Sexo de los pacientes. Del total de RM, 114 correspondían a mujeres con una mediana de edad de 23 años. La mediana de la profundidad de la ATM derecha fue de 17,16 mm y la mediana del lado izquierdo fue de 16,98 mm, no hubo una diferencia estadísticamente significativa (p>0,05) pero si una fuerte correlación (r=0,842). No hubo diferencias entre las profundidades y el sexo de los pacientes tanto en la ATM derecha como en la izquierda. No hubo correlación entre la edad y la profundidad de la ATM. La profundidad de los cóndilos derecho e izquierdo están altamente correlacionados, siendo 17 mm aproximadamente en la población estudiada. No existe asociación entre la edad de los pacientes y la profundidad condilar, y no hay diferencias en promedios por sexo.


Assuntos
Humanos , Masculino , Feminino , Adulto , Imagem por Ressonância Magnética , Transtornos da Articulação Temporomandibular/diagnóstico por imagem , Côndilo Mandibular/diagnóstico por imagem , Transtornos da Articulação Temporomandibular/patologia , Estudos Transversais
12.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(4): 276-279, 2020 Apr 09.
Artigo em Chinês | MEDLINE | ID: mdl-32268630

RESUMO

MicroRNA (miRNA) are a class of small non-coding single-stranded RNA that exert their biological effects by binding to target messenger RNA (mRNA). There is new evidence that miRNA may play an important role in regulating the growth and development of mandibular condylar cartilage. In this paper, the production and mechanism of miRNA are reviewed, and the progress of studies on the growth and development of mandibular condylar cartilage, which is helpful to further study the growth and development of mandibular condylar cartilage.


Assuntos
Cartilagem Articular/crescimento & desenvolvimento , Côndilo Mandibular/crescimento & desenvolvimento , MicroRNAs , Cartilagem , Crescimento e Desenvolvimento , Humanos , RNA Mensageiro
13.
J Oral Sci ; 62(2): 197-201, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32224572

RESUMO

Magnetic resonance imaging (MRI) was used to observe growth of the mandibular condyle, mandibular fossa, and articular disc as a single unit. Changes in each component's relative position and size were observed using 7-tesla MRI. Mandibular condyle chondrocytes' growth was evaluated with immunohistochemistry, using the expression of zinc transporter ZIP13. Three-dimensional T1-weighted (T1w) MRI was used to obtain images of the TMJ of Sprague Dawley rats at 4-78 days old (P4-78) with a voxel resolution of 65 µm. Two-dimensional T1w MR images were acquired after a subcutaneous injection of the contrast reagent gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA). The T1w MR images showed that the mandibular condyle was located posterior to the mandibular fossa until P20; however, it then moved to a location underneath the mandibular fossa. In the Gd-DTPA enhanced images, the articular disc was identified as a region with lower signal intensity from P20. The number of ZIP13-positive chondrocytes at P6 was larger than the number at P24. In conclusion, the mandibular condyle with cartilage and disc grows on the posterior side of the mandibular fossa until P20, which was the weaning age. Then, the condyle fit into the mandibular fossa and completed the functional unit.


Assuntos
Côndilo Mandibular , Articulação Temporomandibular , Animais , Imagem por Ressonância Magnética , Ratos , Ratos Sprague-Dawley , Desmame
14.
Compend Contin Educ Dent ; 41(4): e1-e6, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32250125

RESUMO

OBJECTIVE: The authors' objective was to determine, by means of cone-beam computed tomography (CBCT), if there is a significant difference between the cephalometric and condylar measurements obtained in maximum intercuspation (MIP) and those obtained in centric relation (CR), which would interfere in orthodontic diagnosis and planning. METHODS: The sample consisted of 30 randomly selected patients (15 men and 15 women, mean age 14 years, CR ≠ MIP between 1 mm and 2 mm) who had undergone orthodontic treatment. This retrospective study used CBCT scans, one in MIP and the other in CR. Cephalometric measurements and sagittal, axial, and vertical condylar variations between the CR and MIP positions were analyzed in a tridimensional (3D) imaging software. RESULTS: Patients with a small CR-MIP discrepancy (<2 mm) presented significant differences in the cephalometric analysis carried out in CR and MIP, although these differences might be of low clinical significance. The condyle-fossa relationships in sagittal, coronal, and axial planes did not seem to be relevant, because only one measurement presented significant change between CR and MIP positions. CONCLUSIONS: Class II malocclusion in patients with a large CR-MIP discrepancy may be exacerbated in the CR position, which may in turn increase treatment difficulty. In these cases, not only must cephalometrics be registered in CR, but dental casts and photographs of the patient are needed to permit orthodontists to plan an appropriate treatment.


Assuntos
Oclusão Dentária Central , Má Oclusão , Adolescente , Relação Central , Tomografia Computadorizada de Feixe Cônico , Feminino , Humanos , Masculino , Côndilo Mandibular , Estudos Retrospectivos
16.
J Orthod ; 47(2): 163-169, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32114870

RESUMO

Osteochondroma of the condyle is a rare, slow-growing, benign tumour of the temporomandibular joint that can result in facial asymmetry, limited mouth opening, temporomandibular joint dysfunction and malocclusion. The large majority of osteochondromas occur at the distal metaphysis of the femur and the proximal metaphysis of the tibia, whereas only 0.6% of osteochondromas have been reported as occurring in the craniofacial region. We discuss the diagnosis and treatment of a 56-year-old fit and well male patient who presented to the Orthodontic Department at Wexham Park Hospital with a four-year history of progressive facial asymmetry and functional concerns, owing to a rare osteochondroma of the condyle.


Assuntos
Neoplasias Mandibulares , Transtornos da Articulação Temporomandibular , Assimetria Facial , Humanos , Masculino , Côndilo Mandibular , Pessoa de Meia-Idade , Articulação Temporomandibular
17.
J Orthod ; 47(2): 156-162, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32126863

RESUMO

This case report describes the successful second surgical treatment of a 26-year-old white female patient with a retrognathic mandible and previous bilateral total joint prostheses placement. The patient had previously presented with bilateral idiopathic condylar resorption (ICR) which caused clockwise mandibular rotation and resulted in anterior open bite and a retrognathic mandible. The patient had undergone definitive corrective for the ICR where condylectomies were performed bilaterally. In addition, total joint prostheses using 'stock joints' were used to restore the condyle and glenoid fossa on both sides. Although the previous surgery corrected the anterior open bite and restored the condyles, the patient was still suffering from joint symptoms (significant pain), restricted mandibular movements, increased overjet (12 mm) and a retrognathic mandible. The treatment plan included a combined orthodontic surgical approach: (1) bimaxillary orthognathic surgery: a surgical procedure on the mandible to reposition the prosthetic joints and correct the mandible position, and a segmental LeFort I to expand the maxilla; and (2) post-surgical orthodontics treatment to detail the occlusion. At the end of the treatment, good aesthetic and functional results were obtained with the cooperation of two specialties. This case emphasises the importance of three-dimensional planning and multidisciplinary treatment when addressing complex jaw movements. It also emphasises the importance orthodontic planning and collaboration with the orthodontist.


Assuntos
Prótese Articular , Procedimentos Cirúrgicos Ortognáticos , Adulto , Feminino , Humanos , Mandíbula , Côndilo Mandibular , Reoperação , Articulação Temporomandibular
18.
Int J Comput Dent ; 23(1): 17-26, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32207458

RESUMO

When recording condylar movement paths with the aid of electronic measuring systems, it is often found that, especially in jaw opening and closing movements, excursive and incursive paths of movement are not congruent but run separately, independently of one another to a greater or lesser degree. The objective of the study was to investigate this phenomenon in the context of rotation vs translation behavior, also taking into consideration additional side-specific condylar movement patterns. For this purpose, the electronic movement records of habitual jaw opening of 259 participants of the associated project of the population-representative basic study SHIP 0 were evaluated. The condylar movement path (condylar tracing, ConTrac) at the arbitrary axis point, the excursion vs incursion behavior in the condylar tracing grid (ExInGrid), and the rotation vs translation behavior (RotTrans) were classified, and the translational condylar path and the maximum angle of rotation were determined metrically. Relationships between the parameters ConTrac, ExInGrid, and RotTrans were statistically analyzed using cross tabulations and Spearman's correlation coefficient. Only about 18% of ConTrac showed congruence of excursive and incursive movement path components, while 39% demonstrated noncongruent paths, and 43% showed further conspicuous features in the movement path. For the parameter ExInGrid, recognizable to highly pronounced loop formation patterns to a degree of 89% were observed in the condylar tracing grid. An average of 12.5 mm (min 2.1 mm, max 21.7 mm) was determined for the purely translational component of the condylar movement path, and 32.1 degrees (min 12 degrees, max 45 degrees) for the maximum angle of rotation. Concerning the rotation vs translation behavior, the linear basic pattern occurred at around 9%; the sigmoidal pattern at 28%; and the hysteretic, loopy or irregular pattern at 63%. The parameters RotTrans and ExInGrid showed a strong correlation, whereas the strength of the correlation for ConTrac and ExInGrid or RotTrans and ConTrac was evaluated as weak or very weak. The rotation vs translation behavior influences condylar movement paths in the positional relationship of excursive and incursive components. The visualization of several condylar movement paths in the form of a condylar tracing grid helps to capture complex rotational and translational motion components of the real condyles more effectively than the assessment of a single condylar movement path.


Assuntos
Mandíbula , Côndilo Mandibular , Humanos , Registro da Relação Maxilomandibular , Movimento , Rotação , Articulação Temporomandibular
19.
Int J Comput Dent ; 23(1): 39-48, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32207460

RESUMO

BACKGROUND: The Dental Motion Decoder system (DMS-System) is a medical device based on magnetic field technology that records mandible movements. The data can be used to program an articulator or can be directly processed over a computer-aided design (CAD) interface. The present study aimed to assess the reproducibility of this system in vitro and in vivo. MATERIAL AND METHODS: Protrusive and laterotrusive movements were simulated in vitro using an articulator (SAM SE) (Group M) and in vivo (Group P) on one test individual. Measurements were carried out in two ways: 1) Measurements were taken after initializing and referencing the system using the reference points (RPs) once, followed by 30 protrusive and laterotrusive movements (M1 and P1); and 2) Thirty individual measurements were recorded using the RPs before each measurement (M2 and P2). Values for the sagittal condylar path inclination angle (sCPIA) and the Bennett angle (BA) were exported and analyzed. The reproducibility of the system was evaluated using the standard deviations (SDs) of the measurement series (sCPIA and BA for M1, M2, P1, and P2). RESULTS: In vitro tests M1 (SD: sCPIA = 0.08 degrees; BA = 0.06 degrees) and M2 (SD: sCPIA = 0.26 degrees; BA = 0.11 degrees) showed significantly higher reproducibility (P < 0.001) compared with the in vivo measurements P1 (SD: sCPIA = 0.61 degrees; BA = 0.45 degrees) and P2 (SD: sCPIA = 1.4 degrees; BA = 0.65 degrees). CONCLUSION: Within the limitations of the present study, the deviation in vitro, representing the reproducibility of the DMD-System, is smaller than the biologic variance observed in vivo. Therefore, reliable measurements under clinical conditions can be assumed.


Assuntos
Articuladores Dentários , Côndilo Mandibular , Humanos , Registro da Relação Maxilomandibular , Imãs , Movimento , Reprodutibilidade dos Testes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA