Differences of temporomandibular joint symmetry in patients with unilateral complete cleft lip and palate at different developmental stages / 中南大学学报(医学版)

OBJECTIVES@#Currently, the research results regarding the bilateral temporomandibular joint symmetry in patients at different ages with unilateral complete cleft lip and palate (UCLP) are still controversial. In this study, the position of condyle in the articular fossa and morphology of condyle in UCLP patients at different developmental stages was measured and analyzed to explore the asymmetry difference, which can provide a new theoretical basis for the sequential therapy.@*METHODS@#A total of 90 patients with UCLP were divided into a mixed dentition group (31 cases), a young permanent dentition group (31 cases) and an old permanent dentition group (28 cases) according to age and dentition development. Cone beam computed tomography (CBCT) images were imported into Invivo5 software for 3D reconstruction, and the joint space, anteroposterior diameter, medio-lateral diameter, and height of condylar were measured, and its asymmetry index was calculated.@*RESULTS@#The asymmetry index of condylar height and anteroposterior diameter among the 3 groups, from small to large, was the mixed dentition group<the young permanent dentition group<the old permanent dentition group (both P<0.05). There was no significant difference in condylar anteroposterior diameter and asymmetry index between the mixed dentition group and the young permanent dentition group (both P>0.05), all of them were lower than those in the old permanent dentition group (both P<0.05). Compared with the normal side, the height of fracture condyle was smaller among the 3 groups (all P<0.05), and the anterior joint space was smaller (P<0.05) and the posterior joint space was larger (P<0.05) in the mixed dentition group.@*CONCLUSIONS@#In patients with UCLP, the asymmetry of condylar morphology increases with age, but the condylar position tends to normal. These results suggest that early treatment has important clinical significance for the morphologic development of temporomandibular joint in UCLP patients.

Quality Evaluation of Temporomandibular Joint Images from 3 High-resolution Dynamic Sequences / 中国医学科学院学报

Objective To compare the image quality of three high-resolution dynamic MRI methods for evaluating the motion of temporomandibular joint disc and condyle. Methods Twenty-five patients with suspected temporomandibular joint disorders were examined by single-shot fast spin-echo (SSFSE),fast imaging employing steady-state acquisition (FIESTA),and spoiled gradient echo (SPGR) on the oblique sagittal position.Two radiologists performed subjective and objective evaluation on the images with double-blind method.The subjective evaluation included the signal intensity of mandibular condyle,articular disc,soft tissue around articular disc,and lateral pterygoid muscle,the contrast between articular disc and condyle,the contrast between articular disc and surrounding soft tissue,condylar motion,and disc movement.The objective evaluation indexes included image signal intensity,signal-to-noise ratio (SNR),and contrast-to-noise ratio (CNR).The subjective and objective indexes of the image quality were compared between the three sequences. Results The SSFSE sequence had lower signal intensity of articular disc and higher signal intensity of condyle and surrounding soft tissue than FIESTA and SPGR sequences (all P<0.001).The SPGR sequence showed higher signal intensity of lateral pterygoid muscle than the SSFSE and FIESTA sequences (P=0.017,P<0.001).Among the three sequences,SSFSE sequence showed the clearest articular disc structure (χ2=41.952,P<0.001),the strongest contrast between articular disc and condyle (χ2=35.379,P<0.001),the strongest contrast between articular disc and surrounding soft tissue (χ2=27.324,P<0.001),and the clearest movement of articular disc (χ2=44.655,P<0.001).SSFSE and FIESTA sequences showed higher proportion of disc displacement and reduction than SPGR sequence (all P<0.001).The CNR (χ2=21.400,P<0.001),SNR (χ2=34.880,P<0.001),and condyle signal intensity (F=337.151,P<0.001) demonstrated differences among SSFSE,FIESTA,and SPGR sequences.The CNR of SSFSE sequence was higher than that of FIESTA sequence (P<0.001),while it had no significant difference between SSFSE and SPGR sequences (P=0.472).In addition,the SSFSE sequence had higher SNR and signal intensity than FIESTA and SPGR sequences (all P<0.001). Conclusion The best image quality can be observed from SSFSE sequence where both the structure and movement of temporomandibular joint are well displayed.Therefore,SSFSE is preferred for the examination of temporomandibular joint movement.

Imaging study on the relationship between anterior and posterior occlusal planes and temporomandibular osteoarthrosis / 华西口腔医学杂志

OBJECTIVES@#The aim of this study was to compare the anterior and posterior occlusal plane characteristics of patients with different temporomandibular joint osseous statuses.@*METHODS@#A total of 306 patients with initial cone beam CT (CBCT) and cephalograms were included. They were divided into three groups on the basis of their temporomandibular joint osseous status: bilateral normal (BN) group, indeterminate for osteoarthrosis (I) group, and osteoarthrosis (OA) group. The anterior and posterior occlusal planes (AOP and POP) of the different groups were compared. Then, the regression equation was established after adjusting for confounding factors, and a correlation analysis between the occlusion planes and other parameters was performed.@*RESULTS@#SNA, SNB, FMA, SN-MP, Ar-Go, and S-Go were correlated with the occlusal planes. Relative to the BN and I groups, the FH-OP of the OA group increased by 1.67° on the average, FH-POP increased by 1.42° on the average, and FH-AOP increased by 2.05° on the average.@*CONCLUSIONS@#The occlusal planes were steeper in the patients with temporomandibular osteoarthrosis than in the patients without it, and the mandible rotated downward and backward. The height of the mandibular ramus, the mandibular body length, and the posterior face height were small. In clinical practice, attention should be given to the potential risk of temporomandibular joint osteoarthrosis in such patients. In addition, SNB, FMA, SN-MP, Ar-Go, S-Go, and occlusal planes had moderate correlations.

Multimodal imaging analysis of the cyst like lesion of condyle in temporomandibular joint / 中华口腔医学杂志

Objective: To investigate the imaging features of condylar cystic degeneration of temporomandibular joint (TMJ) by cone-beam CT (CBCT), spiral CT, MRI and radionuclide bone imaging. Methods: From January 2018 to December 2020, thirty-two patients with cyst-like lesions of condylein temporomandibular joint were examined by CBCT, spiral CT, MRI and radionuclide bone imaging at the Department of Oral and Maxillofacial Surgery in General Hospital of Chinese PLA. There were 12 males and 20 females involved, aged from 16 to 65 years with an average age of (33.9±12.5) years. The characteristics of CBCT, spiral CT, MRI and radionuclide bone imaging were analyzed. Condylar cyst like lesions were classified as type A and type B based on the presence or absence of surface bone defects. Condylar cyst like lesions were classified as type Ⅰ(yes) and type Ⅱ(no) according to the accompanying bone marrow edema-like lesions of the condyles. The incidence of condylar bone marrow edema, disc displacement and abnormal bone metabolism were analyzed. Results: A total of 64 joint images of 32 patients were included, including 34 sides with TMJ cyst-like lesion and 6 sides with multiple cyst-like lesions,the total cyst-like lesions were 42. The largest diameter of cyst-like lesion ranged from 1.0 to 12.4 mm, with an average length of (3.7± 1.8) mm. There were 24 cases of type A TMJ cyst like lesion and 10 cases of type B cyst-like lesion. The detection rate of CBCT was 95.2% (40/42) and that of spiral CT was 100% (42/42), there was no significant difference (Calibration Chi-square=0.51, P=0.474). The detection rate of nuclear magnetic resonance was 80.1% (34/42), and the detection rate of cyst-like lesions less than 2 mm was 3/11. In the cyst like lesion side, there were 9 sides with anterior disc displacement with reduction, 20 sides with anterior disc displacement without reduction. In the non-cyst like lesion side, 10 sides with anterior disc displacement with reduction and 6 sides with anterior disc displacement without reduction. There was a significant difference in the displacement of the disc between cyst-like and non-cystic lesion side (χ²=7.80, P=0.005). MRI showed that 6 cases of cystic side[17.6% (6/34)] had bone marrow edema-like lesions (all type A), 1 case of non-cyst like lesions side [3.3% (1/30)] had bone marrow edema-like lesion, there was no significant difference between cystic and non-cystic lesions (Calibration Chi-square=2.04, P=0.153). There was a significant difference between type A and B cystic lesions (Fisher exact probability method, P=0.024). Radionuclide bone imaging showed abnormal bone metabolism in 26 patients in the cyst-like lesion side and 5 patients in the non-cyst like lesion side (χ²=22.82, P<0.001). Conclusions Multi-slice Spiral CT could detect the cyst-like lesion of TMJ condyle in the early stage, which is different from the large joint. And the formation mechanism may vary from the different classifications.

Análisis morfológico del cóndilo mandibular por tomografía computarizada de haz cónico en relación al sexo en población mexicana / Morphological analysis of the mandibular condyle by cone beam computed tomography in relation to sex in a Mexican population

RESUMEN: La articulación temporomandibular es una estructura doble y simétrica, con una compleja gama de movimientos. La morfología condilar puede variar dependiendo al sexo, edad, entre otros factores. Se analizaron 100 tomografías computarizadas de haz cónico (50 hombres y 50 mujeres) divididos en 4 grupos. Se identificó diferencias significativas entre las formas aplanadas vs ovaladas del cóndilo y a su vez se encontró diferencia entre los lados derechos vs izquierdo entre hombres y mujeres. La tomografía computada de haz cónico es un método económico y accesible mediante la exposición a bajas dosis de radiación se obtienen imágenes de alta resolución de los tejidos duros de la ATM. El análisis de la tomografía computarizada de haz cónico tiene una precisión aceptable para el diagnóstico de anomalías óseas de la ATM, componentes articulares, integridad del hueso cortical y anomalías óseas subcorticales.

SUMMARY: The temporomandibular joint is a double and symmetrical structure, whit a complex range of movements. Condylar morphology can vary depending on sex, age, among other factors. 100 cone beam computed tomography scans (50 men and 50 women) divided into 4 groups were analyzed. Significant differences were identified between the flattened vs oval forms on the condyle and, in turn a difference was found between the right vs left sides between men and women. Cone beam computed tomography analysis has acceptable accuracy for the diagnosis of TMJ bone abnormalities, articular components, cortical bone integrity and subcortical bone abnormalities.

Three-dimensional finite element analysis of traumatic mechanism of mandibular symphyseal fracture combined with bilateral intracapsular condylar fractures / 北京大学学报(医学版)

OBJECTIVE@#To analyze the biomechanical mechanism of mandibular symphyseal fracture combined with bilateral intracapsular condylar fractures using finite element analysis (FEA).@*METHODS@#Maxillofacial CT scans and temporomandibular joint (TMJ) MRI were performed on a young male with normal mandible, no wisdom teeth and no history of TMJ diseases. The three-dimensional finite element model of mandible was established by Mimics and ANSYS based on the CT and MRI data. The stress distributions of mandible with different angles of traumatic loads applied on the symphyseal region were analyzed. Besides, two models with or without disc, two working conditions in occlusal or non-occlusal status were established, respectively, and the differences of stress distribution between them were compared.@*RESULTS@#A three-dimensional finite element model of mandible including TMJ was established successfully with the geometry and mechanical properties to reproduce a normal mandibular structure. Following a blow to the mandibular symphysis with different angles, stress concentration areas were mainly located at condyle, anterior border of ramus and symphyseal region under all conditions. The maximum equivalent stress always appeared on condylar articular surface. As the angle between the external force and the horizontal plane gradually increased from 0° to 60°, the stress on the mandible gradually concentrated to symphysis and bilateral condyle. However, when the angle between the external force and the horizontal plane exceeded 60°, the stress tended to disperse to other parts of the mandible. Compared with the condition without simulating the disc, the stress distribution of articular surface and condylar neck decreased significantly when the disc was present. Compared with non-occlusal status, the stress on the mandible in occlusal status mainly distributed on the occlusal surface, and no stress concentration was found in other parts of the mandible.@*CONCLUSION@#When the direction of external force is 60° from the horizontal plane, the stress distribution mainly concentrates on symphyseal region and bilateral condylar surface, which explains the occurrence of symphyseal fracture and intracapsular condylar fracture. The stress distribution of condyle (including articular surface and condylar neck) decreases significantly in the presence of arti-cular disc and in stable occlusal status when mandibular symphysis is under traumatic force.

O uso da artroscopia para diagnóstico e tratamento dos distúrbios internos da articulação temporomandibular / The use of arthroscopy for the diagnosis and treatment of internal temporomandibular joint disorders

Os desarranjos internos da articulação temporomandibular (ATM) são disfunções frequentes associadas a importantes repercussões funcionais e dolorosas, como limitação de abertura bucal e ruídos articulares, que podem provocar prejuízos à qualidade de vida do ser humano. Possuem etiologia multifatorial e são mais frequentemente tratados conservadoramente através de fisioterapia, placas oclusais, psicoterapia, apoio farmacológico, apenas com o insucesso da terapia não cirúrgica é que as modalidades cirúrgicas são indicadas, em somente 2% a 5% dos casos. Dentre elas, a artroscopia se destaca como uma opção minimamente invasiva, com elevados índices de sucesso e baixas taxas de complicações, sendo um instrumento de alta sensibilidade que possibilita a visualização de diversas patologias intra-articulares, o diagnóstico e o tratamento desses distúrbios. Objetivo: revisar a literatura acerca das principais indicações da artroscopia no tratamento dos distúrbios internos da ATM, suas vantagens sobre as demais técnicas cirúrgicas e suas complicações. Considerações finais: a artroscopia é uma ferramenta eficiente e segura para o diagnóstico e o tratamento de diversos distúrbios internos da ATM em pacientes de diversas faixas etárias, destacando-se por seus altos índices de sucesso, menor tempo de internação e suas baixíssimas taxas de mortalidade.(AU)

Internal temporomandibular joint (TMJ) derangements are frequent disorders associated with major functional and painful repercussions, such as limited mouth opening and joint noise, which may harm the quality of life of human beings. They have a multifactorial etiology and are most often treated conservatively through physiotherapy, occlusal plaques, psychotherapy, and pharmacological support. Surgical treatment is indicated only when non-surgical therapy fails, in 2% to 5% of cases. Among them, arthroscopy stands out as a minimally invasive option with high success rates and low complication rates, representing a highly sensitive instrument that allows visualizing several intra-articular pathologies, and diagnosing and treating these disorders. Objective: To review the literature on the main indications for arthroscopy in the treatment of internal TMJ disorders, its advantages over other surgical techniques, and its complications. Final considerations: arthroscopy is an efficient and safe tool for the diagnosis and treatment of various internal temporomandibular joint disorders in patients of different age groups, standing out for its high success rates, shorter hospital stay, and low mortality rates.(AU)

The Role of Magnetic Resonance Imaging of the Temporomandibular Joint to Investigate Tinnitus in Adults with Temporomandibular Joint Disorder: A Comparative Study

Abstract Introduction The prevalence of tinnitus is higher in individuals with temporoman- dibular joint disorder (TMD) than in the general population. Magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ) is the method of choice for investigation, and it has been hypothesized that specific MRI findings might be observed in TMD with comorbid tinnitus. Objective To comparatively describe MRI findings in patients with TMD with and without tinnitus, identifying the most common TMJ alterations and determining whether a correlation exists between severity of TMD and tinnitus. Methods A cross-sectional study of 53 adult patients with bilateral or unilateral TMD (30 with and 23 without tinnitus). The association between tinnitus and morphological aspects of TMD (changes in condylar morphology, articular eminence morphology, and disc morphology), disc displacement (with/without reduction), condylar translation, and intra-articular effusion was analyzed on MRI images. Results The mean patient age was 46.12 ± 16.1 years. Disc displacement was the most common finding in both groups (24 patients with tinnitus versus 15 without; p = 0.043). Only the frequency of disc displacement with reduction was significantly different between groups. Conclusion Additional imaging techniques should be explored to detect specific aspects of the relationship between tinnitus and TMD.

Cone-beam CT evaluation of temporomandibular joint in skeletal class Ⅱ female adolescents with different vertical patterns / 北京大学学报(医学版)

OBJECTIVE@#To compare temporomandibular joint (TMJ) morphology and position among skeletal class Ⅱ female adolescents with different vertical patterns using cone-beam CT (CBCT).@*METHODS@#Diagnostic CBCT images of 80 female patients aged 11 to 14 years were assessed retrospectively. According to subspinale-nasion-supramental angle (ANB) and Frankfort horizontal plane-gonion-gnathion angle (FH-GoGn), the participants were categorized into four groups (20 subjects each), i.e. class Ⅰ normal angle (group 1, 0°≤ANB < 4°, 22°≤FH-GoGn≤32°), class Ⅱ low (group 2, ANB≥4°, FH-GoGn < 22°), normal (group 3, ANB≥4°, 22°≤FH-GoGn≤32°) and high angle (group 4, ANB≥4°, FH-GoGn > 32°). Cephalometrics, morphology and position of TMJ were measured in Dolphin software. Using paired-samples t test to analyze TMJ symmetry, One-way analysis of variance (One-way ANOVA) and Chi-square tests to detect differences among the groups. The correlations between cephalometrics and TMJ measurements were also analysed within the skeletal class Ⅱ patients.@*RESULTS@#(1) Analysing TMJ morphologic symmetry, some measurements differed statistically although the mean diffe-rences were negligibly relative to their values. No statistically significant difference was found among the groups though group 4 showed the highest probability of condylar position asymmetry (65%). (2) Comparing group 1 with group 3, statistical difference was found in condylar position (χ2=6.936, P < 0.05) instead of morphologic measurements. Anterior and concentric condylar position were more frequently observed in group 1, yet posterior position was more prevalent in group 3. (3) In groups 2, 3, and 4, statistically, group 2 had the deepest glenoid fossa depth (H2&4=10.517, P=0.002), biggest superior (LSD-t2&3=3.408, LSD-t2&4=5.369, P < 0.001) and lateral (LSD-t2&3=2.767, LSD-t2&4=3.350, P=0.001) joint spaces, whereas group 4 showed the shortest condylar long axis diameter (H2&4=13.374, P < 0.001), largest glenoid fossa vertical distance (LSD-t2&4=4.561, P < 0.001, LSD-t3&4=2.713, P=0.007), smallest medial (LSD-t2&4=-4.083, P < 0.001) and middle (LSD-t2&4=-4.201, P < 0.001) joint spaces. The posterior condylar position proportion gradually increased from groups 2 to 3 to 4. Correlation analysis revealed ANB correlated with anterior joint space positively (r=0.270, P=0.037) and condylar long axis angle negatively (r=-0.296, P=0.022). FH-GoGn correlated with superior (r=-0.488, P < 0.001), posterior (r= -0.272, P=0.035), mesial (r=-0.390, P=0.002), middle (r=-0.425, P=0.001), and lateral (r=-0.331, P=0.010) joint spaces, articular eminence inclination (r=-0.259, P=0.046), as well as condylar long axis diameter (r=-0.327, P=0.011) negatively, and glenoid fossa depth (r=0.370, P=0.004) positively.@*CONCLUSION@#TMJ characteristics of skeletal class Ⅱ sagittal pattern mainly reflected in condylar position rather than morphology. TMJs of different vertical patterns differed more in joint spaces, position of condyle and glenoid fossa than in morphologic measurements. Vertical position of glenoid fossa and proportion of posterior condyle increased gradually from hypodivergent to hyperdivergent. Highest glenoid fossa position, maximum ratio of posterior positioned condyle, smallest joint spaces, shallowest glenoid fossa depth, and narrowest condylar long axis diameter were found in skeletal class Ⅱ high angle group, which means that patients with this facial type have considerable joint instable factors, and we should especially pay attention when orthodontic treatment is carried out on them.

Clinical study on the posterior occlusal plane and morphology of temporomandibular joint / Estudio clínico sobre el plano oclusal posterior y la morfología de la articulación temporomandibular

The objective of the study was to investigate the morphological features of the temporomandibular joint in adult patients with posterior occlusal plane and different inclinations. Fifty five skeletal I occlusion patients with average were included, shooting CBCT in the intercuspal position, divided into 3 groups according to OPP-FH angle, and measurement of the temporomandibular joint morphology was calculated with cone beam computed tomography (CBCT) special software Invivo 5.0, Statistical analysis of three groups of data using SPSS23.0. The condyle usually locates in the middle of the fossa, the maximum axial area of the condyle (A) was statistically significant between the group 1 and the group 3. The internal and external diameter (MD) of the condyle was statistically significant between group 1 and group 3, and group 2 and group 3. The bilateral TMJ morphological features of the three groups were basically symmetrical. The position of the condyle in the fossa is mostly centered, and some of the posterior, the maximum axial area and the internal and external diameter of the condyle are different in three groups.

El objetivo de este estudio fue investigar las características morfológicas de la articulación temporomandibular (ATM) en pacientes adultos con plano oclusal posterior y diferentes inclinaciones. Se incluyeron 55 pacientes con oclusión esquelética tipo I, visualizados por tomografía computarizada de haz cónico (CBCT) en posición intercuspiana, y se dividieron en 3 grupos según el ángulo OPP-FH. La medición morfológica de la articulación temporomandibular se calculó con CBCT y mediante el software especial Invivo 5.0. El análisis estadístico de datos se realizó con el software SPSS 23.0. El cóndilo de la mandíbula generalmente se ubica en el centro de la fosa; el área axial máxima del cóndilo de la mandíbula (A) fue estadísticamente significativa entre los grupos 1 y 3. Los datos de los diámetros medial y lateral (DM) del cóndilo de la mandíbula fueron estadísticamente significativos entre los grupos 1 y 3 y los grupos 2 y 3. Las características morfológicas de la ATM de los tres grupos fueron básicamente simétricas. La posición del cóndilo de la mandíbula en la fosa fue principalmente centrada, y parte del área axial máxima, posterior y los diámetros medial y lateral del cóndilo de la mandíbula fueron diferentes en los tres grupos.

Tomografia computadorizada de feixe cônico como método de avaliação da pneumatização da articulação temporomandibular / Cone-beam computed tomography as a method of evaluating pneumatization of the temporomandibular joint

Introdução: A pneumatização, considerada um processo fisiológico, são cavidades cheias de ar no interior dos ossos do crânio resultante de áreas de células epiteliais. Objetivo: Determinar a prevalência de pneumatização na fossa articular (PFA) e da eminência articular (PEA) do osso temporal por meio de exames de tomografia computadorizada de feixe cônico (TCFC). Material e métodos: Trezentas e noventa imagens de articulações temporomandibulares foram avaliadas por dois examinadores, devidamente calibrados, com experiência em imagens de TCFC. Nos casos em que foi detectada pneumatização, esta foi classificada de acordo com o tipo (unilocular e multilocular) e lateralidade (unilateral ou bilateral). Resultados: A PFA ou a PEA foi diagnosticada em 97 (49,74%) pacientes. Destes pacientes, 61 (31,3%) apresentaram PFA e 36 (18,5%) PEA. Em relação à lateralidade, na PFA, 36 (59%) apresentaram a condição unilateralmente e 25 (41%) bilateralmente. Dentre os pacientes com PEA, 24 (66,7%) apresentaram a condição unilateralmente e 12 (33,3%) bilateralmente. A pneumatização foi correlacionada entre os lados pelo coeficiente de correlação de Spearman e foi significativa para os casos multiloculares (fossa articular: rs=0,52 / p<0,0001 e eminência articular: rs=0,42 p<0,0001). Conclusão: A pneumatização da região temporomandibular é uma característica relativamente comum e, apesar de não necessitar de tratamento, a observação é fundamental para evitar complicações do tratamento ou diagnóstico errôneo na região.

Introduction: Pneumatization, considered a physiological process, are air-filled cavities within the skull bones resulting from areas of epithelial cells. Objective: To determine the prevalence and characteristics of pneumatization of the glenoid fossa and articular eminence on cone beam computed tomography. Material and methods: Images of 195 patients (195 temporomandibular joints) were evaluated and the age and gender of the individuals were collected. In cases where pneumatization was detected, this was classified according to type (unilocular and multilocular) and laterality (unilateral or bilateral). Results: The pneumatization of the glenoid fossa and articular eminence were diagnosed in 63 (32.3 %) patients. Of these patients, 61 (31.3%) had pneumatization of glenoid fossa and 36 (18.5%) had pneumatization of articular eminence. Regarding laterality, in PGF 36 (59%) presented the condition unilaterally and 25 (41%) bilaterally. The patients with PAE, 24 (66.7%) presented the condition unilaterally and 12 (33.3%) bilaterally. Pneumatization was correlated between the sides using the Spearman correlation coefficient and was significant for multilocular cases (glenoid fossa: rs= 0,52/p<0,0001 and articular eminence: rs=0,50 p<0,0001). Conclusion: The pneumatization of temporomandibular region is a relatively common feature, and even though it does not require treatment, observation is crucial to avoid complications of treatment or wrong diagnosis in the region.

CBCT analysis of rabbit temporomandibular joints with osteoarthrosis induced by monoiodoacetate and papain / Análisis por TCCB de la articulación temporomandibular de conejos con osteoartrosis inducida por monoiodoacetato y papaina

Osteoarthrosis (OA) is a degenerative disease characterized by loss of joint cartilage, remodelling of the subchondral bone, narrowing of joint spaces and the formation of osteophytes. Animal models are used to study the mechanisms of OA, as well as to test the effects of anti-osteoarthrosis drugs. The objective of the present study was to determine the changes identifiable by imaging techniques occurring in rabbit temporomandibular joints (TMJ) at 15, 25 and 45 days after OA inducement by monoiodoacetate (MIA) and papain. The imaging technology used was cone-beam computerised tomography (CBCT). The model animals were 22 young adult male New Zealand rabbits, divided randomly into three study groups: Four rabbits in the control group, nine in the papain experimental group and nine in the monoiodoacetate (MIA) experimental group. OA was induced by arthrocentesis in the lower compartment of both TMJs. The rabbits were examined by CBCT at 15, 25 and 45 days after the injection of MIA and papain. The mandibular condyles presented loss of their rounded shape, deformation of the condyle or mandibular fossa, cortical irregularity, cortical wear and changes in the dimensions of the condyle. OA induction by MIA and papain generates changes observable by CBCT in the dimensions of the mandibular condyle in rabbits. Both inducers promote signs compatible with OA on the joint surfaces of the TMJ; MIA promotes more expressive changes.

La osteoartrosis (OA) es una enfermedad degenerativa caracterizada por la pérdida de cartílago articular, remodelación ósea subcondral, estrechamiento del espacio articular y formación de osteofitos. El modelo animal es utilizado para estudiar los mecanismos de la OA, así como testar el efecto de drogas anti-osteoartrosis. El objetivo de este estudio fue determinar los cambios imagenológicos, mediante tomografía computarizada cone-beam (TCCB), que se generan en 15, 25 y 45 días, luego de la inducción de OA por medio de Monoiodoacetato (MIA) y Papaína sobre la ATM de conejos. Fueron utilizados 22 conejos machos, adultos jóvenes, de raza New Zealand divididos aleatoriamente en 3 grupos de estudio: 4 conejos para un grupo control, 9 conejos para el grupo experimental con Papaína y 9 conejos para el grupo experimental con monoiodoacetato (MIA). Se realizó la inducción de OA por la técnica de artrocentesis en el compartimiento inferior de ambas ATMs. Se les realizó examen de TCCB en los días 15, 25 y 45 tras la inyección de MIA y de papaina. Los cóndilos mandibulares presentaron pérdida de forma redondeada de cóndilo, deformidad de cóndilo o fosa mandibular, irregularidad de corticales, desgaste de corticales, cambio de dimensiones de cóndilo. La inducción de OA por medio de MIA y papaína genera cambios en la dimensión del cóndilo mandibular de conejos observables a través de TCCB. Además, ambos inductores promueven signos compatibles con OA en las superficies articulares de la ATM, siendo que la MIA promueve cambios más expresivos.

Dosimetry in CBCT with Different Protocols: Emphasis on Small FOVs Including Exams for TMJ

Abstract This study aimed to estimate the absorbed dose in cone beam computed tomography (CBCT) exams according to different exposure parameters and size and position of the field of view (FOV). In addition was compared the absorbed dose of two smaller FOV scans with that of a larger FOV scan for evaluation of temporomandibular joint (TMJ), as it is a bilateral structure. CBCT scans were obtained on OP300 Maxio unit varying scanning mode (standard, high and endo) as well as size (5x5, 6x8 and 8x15 cm) and positioning of FOV. With a small FOV, different areas were scanned (maxilla or mandible, anterior or posterior and TMJ). Absorbed doses were determined using thermoluminescent dosimeters on the skin surface of sensitive organs of an anthropomorphic phantom. Endo mode showed the highest dose, followed by the high and standard modes in all FOV positions. With small FOV, doses were higher in the posterior region, especially in the mandible. Dose reduction occurred when small FOVs were used, but it was not proportional to FOV size reduction. For TMJ, the dose in a single acquisition with large FOV was greater than two acquisitions with small FOV, but lower than two acquisitions with medium FOV (6x8 cm). In conclusion, scanning mode, size and FOV position have great influence on the absorbed dose. Small FOV decreases the dose, but there is no linear relation between FOV size and dose. For bilateral exams of TMJ, double acquisition with small FOVs produces decrease in absorbed dose relative to a large FOV.

Resumo O objetivo deste estudo foi estimar a dose absorvida em exames de tomografia computorizada de feixe cônico (TCFC) de acordo com diferentes parâmetros de exposição, tamanho e posição do campo de visão (FOV, do inglês field of view). Além disso, comparou-se a dose absorvida em uma única aquisição com FOV grande com aquela em duas aquisições com FOVs menores para avaliação de estruturas bilaterais como a articulação temporomandibular (ATM). As aquisições de TCFC foram obtidas no aparelho OP300 Maxio, variando o modo de aquisição (standard, high e endo), bem como o tamanho (5x5, 6x8 e 8x15 cm) e o posicionamento do FOV. Com o FOV pequeno, foram escaneadas diferentes áreas (maxila ou mandíbula, anterior ou posterior e ATM). As doses absorvidas foram determinadas por meio da utilização de dosímetros termoluminescentes na superfície da pele em órgãos sensíveis de um phantom antropomórfico. O modo endo mostrou a dose mais alta, seguido pelos modos high e standard em todas as posições dos FOVs. Com um FOV pequeno, as doses foram maiores na região posterior, especialmente na mandíbula. A redução da dose ocorreu quando foram utilizados pequenos FOVs; contudo, essa redução não foi proporcional à redução do tamanho do FOV. Para a ATM, a dose em uma única aquisição com FOV grande foi maior que duas aquisições com FOV pequeno, porém inferior à dose de duas aquisições com FOV médio (6x8 cm). Em conclusão, o modo de aquisição, o tamanho e a posição do FOV têm grande influência na dose absorvida. FOVs pequenos apresentaram doses mais baixas em relação aos FOVs grandes, entretanto não há uma relação linear entre o tamanho do FOV e a dose absorvida. Para estruturas bilaterais como a ATM, a dupla aquisição com FOV pequeno representa uma diminuição na dose absorvida em relação a uma aquisição com FOV grande.

Relationship between articular eminence inclination and alterations of the mandibular condyle: a CBCT study

Abstract This study aimed at verifying the correlation among angulation of the articular eminence (AE), shape of the condyle and its degenerative bone diseases (DBDs), according to age and sex, through Cone Beam Computed Tomography (CBCT). Five hundred and twenty-eight temporomandibular joints (TMJ) were evaluated. The condyles were classified as: flat, convex, angled and rounded, and the AE angulation was measured. The DBDs evaluated were osteophytes, flattening, erosion, subcortical cysts and spinal sclerosis. There was no difference in the mean angulations in relation to age group (p>0.05). In age groups of 60-69 years (p=0.003) and 70 years or over (p=0.021), the angulation was higher in males. There was an association between DBD and sex (p=0.047), in that the prevalence was higher in females. Differences in AE angles were not observed in condyles with one or no DBDs (p>0.05). However, the presence of two or more DBDs led to a decrease in the angle (p<0.05). Angled condyles showed higher AE angulations than the flat and convex types (p<0.01). In conclusion, the AE inclination is influenced by DBD and condyle shape; an association of two or more bone diseases in the condyle, or its flat or convex anatomy, results in a decrease in the angulation.

Efectos del láser de baja intensidad (As-Ga-Al 904 nm) sobre el cóndilo mandibular de conejos: análisis a través de tomografía computadorizada cone beam / Effects of low-level laser (Ga-Al-As 904 nm) on the mandibular condyle of rabbits: analysis by cone beam computed tomography

En la literatura científica los efectos adversos del láser de baja intensidad (LBI) no están descritos de forma precisa, tampoco su inocuidad. El objetivo de este estudio fue evaluar el efecto de distintas dosis de LBI en el cóndilo mandibular de conejos. Dieciséis conejos divididos aleatoriamente en cuatro grupos experimentales (GE) de 4 animales fueron utilizados en este estudio. Se realizó un examen de tomografía computarizada cone beam (TCCB) de ambas articulaciones temporomandibulares (ATMs) de todos los animales que fueron utilizadas como control (GC). Luego, irradiamos cada ATM con LBI (As-Ga-Al 904 nm), 100 mW, spot 0,2 cm2, dos puntos, 3 veces/semana, totalizando 10 veces, con dosis de 15 J/cm2 (GE-1), 45 J/cm2 (GE-2), 60 J/ cm2 (GE-3) y 90 J/cm2 (GE-4). Después de 20 días de la última irradiación se realizó un nuevo examen de TCCB y luego se obtuvo las mediciones de los cóndilos en los planos coronal y sagital. Para el análisis estadístico se utilizó las pruebas de ANOVA y t-student. Los valores promedios encontrados para el GE fueron mayores que los encontrados para el GC, en los planos coronal y sagital. Hubo diferencia estadística significativa para el grupo 1 y entre los grupos 1 y 2. Concluimos que los valores promedios encontrados en las mediciones de los cóndilos mandibulares, sometidos a las dosis de LBI utilizadas en este estudio, fueron mayores que los encontrados para el GC en los planos coronal y sagital. Además, la TCCB demostró ser un método eficaz para el análisis de las dimensiones condilares.

In the scientific literature the adverse effects of Low Level Laser (LLL) are not precisely described, neither is their safety. The aim of this study was to evaluate the effect of different protocol doses of laser on the mandibular condyle of rabbits. Sixteen rabbits randomly divided into four experimental groups (EG) of 4 animals were used in this study. We carried out a cone beam computed tomography (CBCT) examination of both temporomandibular joints (TMJs) of all animals which were used as control. Subsequently, we radiated each TMJ with LLL (Ga-Al-As 904 nm), 100mW, spot 0.2 cm2, two points, 3 times/week, totaling 10 times, with doses of 15 J/cm2 (EG-1), 45 J/cm2 (EG-2), 60 J/cm2 (EG-3) and 90 J/cm2 (EG-4). After 20 days of the last irradiation we performed a new CBCT exam and then the measurement of the condyles on the coronal and sagittal planes was obtained. In the analysis of the results ANOVA and t-student for correlated samples was used. The average values found for the EG were higher than those found for CG for both the coronal and sagittal planes. There was a significant statistical difference for group 1 and between the groups 1 and 2. We concluded that the average values found in the measurements of the mandibular condyles, submitted to doses of LLL used in this study, were higher than those found for the control group in both the coronal and sagittal planes. Furthermore, the CBCT proved to be an effective method for analysis of condylar dimensions.

Tomographic evaluation of the temporomandibular joint in malocclusion subjects: condylar morphology and position

Abstract The aim of this study was to investigate condyle concentricity and morphology, and their association with Class I and II malocclusions (Angle). The sample consisted of 49 individuals of both genders, between 11 and 35 years old, divided into two groups, G1: 26 patients with Class I malocclusion, and G2: 23 patients with Class II malocclusion, selected for orthodontic treatment. Evaluation of the condyle morphology and position was performed by the same previously calibrated examiner using cone-beam computed tomography (CBCT) images of the subjects. The CBCT scans were analyzed by means of a 3D program (Dolphin 11.5, Dolphin Imaging & Management Solutions, Chatsworth, CA, USA), with a 25% level of sensitivity. The images obtained from the coronal slices were employed for the condyle morphology analysis, which classified the condyle form as rounded, as flat or convex, and as triangular or angled. The sagittal slices were used to classify further the condyles as concentric and displaced anteriorly or posteriorly. A clinical examination was also performed, including TMJ and muscle palpation. The kappa test was used to evaluate investigator calibration; the Chi-square and paired t-tests were used for analysis. The convex and anteriorly positioned condyles were found most frequently, regardless of the type of malocclusion. No association was observed between the groups regarding condylar characteristics.

Concordancia entre las Evaluaciones de la Articulación Temporomandibular Realizadas con los CDI/TTM y con Imágenes de Resonancia Magnética / Concordance between the Evaluations of the Temporomandibular Joint Performed with the RDC/TMD and with Images of Magnetic Resonance

Los Criterios Diagnósticos para la Investigación de los Trastornos Temporomandibulares (CDI/TTM) ofrecen un sistema estandarizado para evaluar la Disfunción Temporomandibular (DTM). Sin embargo, la validez del diagnóstico clínico obtenido con estos criterios al compararlo con el diagnóstico obtenido de las imágenes de Resonancia Magnética (RM) es controversial. El objetivo fue determinar la concordancia que existe entre la evaluación clínica realizada con los CDI/TTM e imágenes de RM de la articulación temporomandibular (ATM), de pacientes atendidos en la Clínica Integral del Adulto, de la Escuela de Odontología de la Universidad del Valle, en Cali, Colombia. Se evaluó clínicamente a 36 individuos, con edades comprendidas entre 18 y 60 años, utilizando los CDI/TTM y se les realizaron exámenes de RM. Las variables estudiadas fueron sexo, edad, signos y síntomas de la ATM, Posición Normal del Disco (PND), Desplazamiento Discal con Recaptura (DDCR) y Desplazamiento Discal Sin Recaptura (DDSR). Los datos obtenidos fueron sometidos a pruebas estadísticas para determinar el índice Kappa y características operativas de la prueba clínica. El Índice Kappa fue 0,53, con una concordancia entre las evaluaciones clínicas e imagenológicas moderada. De la población estudiada, 91,6% fue del sexo femenino, con 31 años como promedio de edad. El signo hallado con mayor frecuencia fue el ruido articular (77%) y el síntoma más frecuente fue el dolor facial (69%). La sensibilidad de los CDI/TTM para determinar la PND fue 0,52 y la especificidad 0,87; la sensibilidad para el DDCR fue 0,8780 y la especificidad 0,709; la sensibilidad para el DDSR fue 0,5714 y la especificidad 0,948. La DTM se presentó con mayor frecuencia en las mujeres, con edad promedio de 31 años. Los CDI/TTM pueden considerarse confiables, especialmente para el DDCR; sin embargo, tratamientos invasivos, permanentes o quirúrgicos, requerirían confirmación con un diagnóstico imagenológico para evitar falsos positivos.

The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) offer a standardized system to clinically evaluate the most common subtypes of Temporomandibular Disorders (TMD). However, the validity of the clinical diagnose obtained with these criteria when compared with the diagnose obtained from the images of Magnetic Resonance (MR) is controversial. The objective of this study was to determine the concordance existing between the clinical evaluation obtained from the RDC/TMD and that obtained from MR images of the temporomandibular joint (TMJ) of patients attending the Clínica Integral del Adulto ­ Clínica de ATM, of the Escuela de Odontología of the Universidad del Valle, Cali, Colombia. A population of 36 patients of both sexes, with ages between 18 and 60 years, were clinically evaluated with the RDC/TMD and MR. The variables considered were sex, age, signs and symptoms of the TMJ, Normal Disc Position (NDP), Disc Displacement with Reduction (DD-R) and Disc Displacement without Reduction (DD-NR). The data obtained were submitted to statistical tests to determine the Kappa Index and operative characteristics of the clinical evaluation. The Kappa Index obtained was 0.53, which shows that the concordance between the clinical and the imagenological evaluations is moderate. Of the total population studied, 91.6% were females, with 31 years as average age. The most frequent sign found was the joint sound (77%) and the most frequent symptom was facial pain (69%). The sensitivity of the RDC/TMD to determine NDP was 0.52 and the specificity 0.87; the sensitivity for the DD-R was 0.8780 and the specificity 0.709; the sensitivity for the DD-NR was 0.5714 and the specificity 0.948. The TMD were found most frequent in women, with average age of 31 years. The RDC/TMD can be considered reliable, especially for the DD-R; however, invasive, permanent or surgical treatments would require confirmation with imagenological diagnoses to avoid false positives.

Anquilosis de ATM: riesgos anatómicos y potencialidad del sistema piezoeléctrico / TMJ ankylosis: anatomical risk and piezoelectric system potentiality

El objetivo de este trabajo es presentar los riesgos anatómicos en el abordaje de la anquilosis de la articulación temporo mandibular (ATM) y el uso del sistema piezoeléctrico para realizar la resección de la misma. La paciente sexo femenino, 12 años, presento una anquilosis de la ATM derecha, previamente operada en base a reconstrucción con un injerto costocondral. Luego de 4 años de realizada la primera reconstrucción se presentó con una nueva anquilosis del área presentando una masa de tejido óseo de 31 mm en sentido latero-medial, que abarcaba hasta el foramen oval en la base de cráneo y de 28 mm en sentido anteroposterior. La lesión fue abordada con un acceso preauricular y posterior resección con sistema piezoeléctrico, utilizando una técnica de resección en bloque. Se presenta la técnica y se discute la potencialidad de realizar este procedimientos con los nuevos sistemas piezoeléctrico.

The aim of this report is to present the anatomical risk for to treat the temporo mandibular joint (TMJ) ankylosis and the use of the piezoelectric system for to make the bone resection. Female patient, 12 years old, presented a right TMJ ankylosis, that was previously operated with a costocondral graft reconstruction. After 4 year from these reconstructive surgery the patient was involved in a new TMJ anklylosis of the same side showing a bone mass with 31mm in an meddle-lateral direction, with compromise until to oval foramen in the skull base and 28mm in the anterior-posterior direction. The lesion was operated by a preauricular approach and then a bone resection with the piezoelectric system, using a block resection technique. In this report it´s present the technique and is discusses the potentiality of the new piezoelectric system for these procedures.