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1.
J Oral Rehabil ; 45(8): 640-646, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29745983

RESUMO

The impression of increased muscle hardness in painful muscles is commonly reported in the clinical practice but may be difficult to assess. Therefore, the aim of this review was to present and discuss relevant aspects regarding the assessment of muscle hardness and its association with myofascial temporomandibular disorder (TMD) pain. A non-systematic search for studies of muscle hardness assessment in patients with pain-related TMDs was carried out in PubMed, Cochrane Library, Embase and Google Scholar. Mechanical devices and ultrasound imaging (strain and shear wave elastography) have been consistently used to measure masticatory muscle hardness, although an undisputable reference standard is yet to be determined. Strain elastography has identified greater masseter hardness of the symptomatic side in patients with unilateral myofascial TMD pain when compared to the contralateral side and healthy controls (HC). Likewise, shear wave elastography has shown greater masseter elasticity modulus in patients with myofascial TMD pain when compared to HC, which may be an indication of muscle hardness. Although assessment bias could partly explain these preliminary findings, future randomised controlled trials are encouraged to investigate this relationship. This qualitative review indicates that the muscle hardness of masticatory muscles is still a rather unexplored field of investigation with a good potential to improve the assessment and potentially also the management of myofascial TMD pain. Nonetheless, the current evidence in favour of increased hardness in masticatory muscles in patients with myofascial TMD pain is weak, and the pathophysiological importance and clinical usefulness of such information remain unclear.


Assuntos
Técnicas de Imagem por Elasticidade , Músculos da Mastigação/fisiopatologia , Contração Muscular/fisiologia , Mialgia/fisiopatologia , Síndromes da Dor Miofascial/fisiopatologia , Transtornos da Articulação Temporomandibular/fisiopatologia , Dureza/fisiologia , Humanos , Músculos da Mastigação/diagnóstico por imagem , Síndromes da Dor Miofascial/diagnóstico por imagem , Padrões de Referência , Transtornos da Articulação Temporomandibular/diagnóstico por imagem
2.
Dentomaxillofac Radiol ; 44(3): 20140258, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25411712

RESUMO

OBJECTIVES: To verify the use of a single coupling agent as a reference to obtain the elasticity index (EI) ratios and to investigate the EI ratios of the masseter muscles of healthy volunteers. METHODS: Muscle phantoms with known elasticity (20, 40 and 60 kPa in the Young's modulus) were examined by strain-type sonoelastography using a coupling agent as the reference. Eight examiners tested soft (with 7 kPa) and hard (with 40 kpa) reference coupling agents separately. The correlation coefficients were determined between the EI ratio and Young's modulus of muscle phantoms. The interclass correlation coefficients were calculated for inter- and intraexaminer agreement. RESULTS: Strong correlations were found between the EI ratios and Young's modulus for both soft and hard references. The variations of the EI ratios were larger with soft coupling agents than those with hard coupling agents, and they increased in phantoms with 60 kPa elasticity. There were no differences in the EI ratios of the masseter muscle at rest between males and females or between the right and left sides. The ratio increased during clenching. CONCLUSIONS: The hard reference coupling agent was suitable for obtaining EI ratio of the masseter muscle. No differences were found in the EI ratios of the masseter muscle either between sexes or between the right and left sides at rest, and the ratios increased with the widening of their variations during clenching.


Assuntos
Técnicas de Imagem por Elasticidade , Músculo Masseter/diagnóstico por imagem , Módulo de Elasticidade , Feminino , Voluntários Saudáveis , Humanos , Masculino , Imagens de Fantasmas
3.
Dentomaxillofac Radiol ; 40(3): 133-40, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21346078

RESUMO

OBJECTIVE: The aim of this study was to clarify the characteristic imaging features that can be used to differentiate ameloblastomas from keratocystic odontogenic tumours and to examine the significant imaging features contributing to a correct diagnosis. METHODS: 60 observers (39 specialists in oral and maxillofacial radiology and 21 non-specialists) examined CT and/or panoramic images of 10 ameloblastomas and 10 keratocystic odontogenic tumours shown on a webpage and made diagnoses. Their correct answer ratios were then calculated. The imaging features of the tumours were evaluated and expressed as binary numbers or quantitative values. The imaging features that contributed to a correct diagnosis were elucidated using logistic regression analysis. RESULTS: The mean correct answer ratio was 61.3% ± 17.2% for the diagnosis of ameloblastomas and keratocystic odontogenic tumours. CT images produced higher correct answer ratios for diagnosis of keratocystic odontogenic tumours by specialists. The significantly different imaging features between ameloblastomas and keratocystic odontogenic tumours were the degree of bone expansion and the presence of high-density areas. The significant imaging features contributing to a correct imaging diagnosis were the number of locules, the presence of high-density areas and the inclusion of impacted teeth. CONCLUSION: The presence of high-density areas is the most useful feature in the differential diagnosis of ameloblastomas and keratocystic odontogenic tumours based on comparison of the imaging features of both tumours and examination of the diagnostic contributions of these features.


Assuntos
Ameloblastoma/diagnóstico por imagem , Neoplasias Mandibulares/diagnóstico por imagem , Tumores Odontogênicos/diagnóstico por imagem , Adolescente , Adulto , Ameloblastoma/patologia , Criança , Densitometria , Diagnóstico Diferencial , Feminino , Humanos , Internet , Modelos Logísticos , Masculino , Neoplasias Mandibulares/patologia , Pessoa de Meia-Idade , Razão de Chances , Tumores Odontogênicos/patologia , Reconhecimento Automatizado de Padrão , Radiografia Panorâmica , Estatísticas não Paramétricas , Tomografia Computadorizada por Raios X , Adulto Jovem
4.
Dentomaxillofac Radiol ; 39(2): 85-90, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20100919

RESUMO

OBJECTIVES: The aim was to investigate the effect of changes in horizontal X-ray beam angulation in intraoral radiography on the detection accuracy of furcation defects in the mandibular first molar, and to examine the anatomical relationship between the roots and furcation area as a possible cause of changes in detectability. METHODS: Simulated furcation defects with various depths were created in five mandibular first molars. Intraoral radiographs were taken at various horizontal angulations of the projection beams. The diagnostic accuracies were determined based on receiver operating characteristic analysis. The geometric relationship that might influence the accuracy was investigated through use of a compact cone beam CT in 59 first molar areas. RESULTS: Although the horizontal angulations showing the highest accuracies were shifted mesially, no differences were found between the angles of -10 degrees and 20 degrees . The relationship between the roots and the furcation area was relevant to the range of angulations showing high detectabilities. CONCLUSIONS: The angulations traditionally used for detecting proximal caries are also suitable for detecting furcation defects.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Defeitos da Furca/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Radiografia Dentária/métodos , Adulto , Cadáver , Humanos , Mandíbula , Curva ROC
5.
J Oral Rehabil ; 36(9): 627-35, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19602100

RESUMO

To examine the stiffness of the masseter muscle using sonographic elastography and to investigate its relationship with the most comfortable massage pressure in the healthy volunteers. In 16 healthy volunteers (10 men and 6 women), the Masseter Stiffness Index (MSI) was measured using EUB-7000 real-time tissue elastography. They underwent massages at three kinds of pressures using the Oral Rehabilitation Robot (WAO-1). A subjective evaluation regarding the comfort of each massage was recorded on the visual analogue scale. Elastography was also performed in two patients with temporomandibular joint dysfunction with the myofascial pain. The mean MSI of the right and left muscles in the healthy volunteers were 0.85 +/- 0.44 and 0.74 +/- 0.35 respectively. There was no significant difference between the right and left MSI in the healthy volunteers. The MSI was related to massage pressure at which the healthy men felt most comfortable. The two temporomandibular disorder patients had a large laterality in the MSI. The MSI was related to the most comfortable massage pressure in the healthy men. The MSI can be one index for determining the massage pressure.


Assuntos
Técnicas de Imagem por Elasticidade/métodos , Massagem/métodos , Músculo Masseter/diagnóstico por imagem , Síndrome da Disfunção da Articulação Temporomandibular/reabilitação , Adulto , Técnicas de Imagem por Elasticidade/instrumentação , Feminino , Humanos , Masculino , Massagem/instrumentação , Músculo Masseter/fisiologia , Pessoa de Meia-Idade , Medição da Dor , Pressão , Limiar Sensorial , Síndrome da Disfunção da Articulação Temporomandibular/diagnóstico por imagem
6.
Br J Radiol ; 82(973): e3-7, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19095811

RESUMO

(18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET) is an effective tool for evaluating the results of radiotherapy. However, some false-positive appearances caused by physiological or pathological accumulation are reported. We report on three patients who showed a high accumulation of FDG in the lingual muscles but had no recurrent tumour after definitive radiotherapy for the mobile tongue. All patients had squamous cell carcinoma of the tongue and received interstitial radiotherapy with small sources. High uptake was seen in the lingual muscles without recurrence or inflammation, based on physical and MR examinations. This false-positive appearance is thought to relate to ill-balanced high activity of the lingual muscles after definitive radiotherapy.


Assuntos
Carcinoma de Células Escamosas/diagnóstico por imagem , Recidiva Local de Neoplasia/diagnóstico por imagem , Neoplasias da Língua/diagnóstico por imagem , Adulto , Braquiterapia , Carcinoma de Células Escamosas/radioterapia , Reações Falso-Positivas , Fluordesoxiglucose F18 , Humanos , Masculino , Tomografia por Emissão de Pósitrons/métodos , Neoplasias da Língua/radioterapia , Adulto Jovem
7.
Dentomaxillofac Radiol ; 34(1): 36-8, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15709104

RESUMO

Acute parotitis occasionally spreads rapidly down the neck with severe symptoms of swelling and pain. However, the inflammatory course of parotitis with extraglandular spread has seldom been described. On CT images, we have noticed a unique area just below the parotid gland that is surrounded by the platysma muscle and the superficial layer of the deep cervical fascia (DCF). In this case report, we describe the CT imaging features of acute parotitis, focusing on this area.


Assuntos
Músculos do Pescoço/diagnóstico por imagem , Pescoço/diagnóstico por imagem , Parotidite/diagnóstico por imagem , Adulto , Feminino , Humanos , Radiografia
8.
Dentomaxillofac Radiol ; 33(5): 345-50, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15585815

RESUMO

Adenoid cystic carcinoma (ACC) is known for its slow-growing but severely infiltrative nature with little tissue reaction. Although the masticatory muscles are often involved, their imaging features have not been well elucidated. We hereby report three patients with widespread ACC, which initially appeared with trismus and/or temporomandibular symptoms and involved the masticator space. Possible features of masticator space involvement are presented on magnetic resonance (MR) images. Masticatory muscle changes on MR images consisted of two aspects, namely, denervation changes and direct tumour invasion.


Assuntos
Carcinoma Adenoide Cístico/diagnóstico , Imageamento por Ressonância Magnética , Neoplasias Musculares/diagnóstico , Músculos Pterigoides/patologia , Adulto , Meios de Contraste , Feminino , Gadolínio DTPA , Humanos , Músculo Masseter/patologia , Pessoa de Meia-Idade , Invasividade Neoplásica , Degeneração Neural/diagnóstico , Transtornos da Articulação Temporomandibular/diagnóstico , Trismo/diagnóstico
9.
Dentomaxillofac Radiol ; 32(3): 160-5, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12917281

RESUMO

OBJECTIVES: The purpose of this study was to clarify the CT features of odontogenic myxoma. METHODS: CT appearances were analysed in 17 patients with histologically verified odontogenic myxoma collected from five dental hospitals in Japan. RESULTS: On the CT images, tumour borders were generally well defined with a smooth margin both for bony and soft tissue structures in all patients. Cortical status was clearly evaluated using CT and the continuity was interrupted in nine patients. Intralesional trabeculations were observed in 13 patients. Of these 13, 6 patients showed the characteristic appearance of angular or straight trabeculations within the tumour. The trabeculations were frequently observed at the peripheral portion of the tumour. In three maxillary tumours, soft tissue margins were observed beyond the cortical margin and/or intralesional trabeculations. In 10 of the 13 lesions evaluated, the majority of the whole tumour area showed relatively lower density compared with surrounding muscles. CONCLUSION: CT clearly demonstrated characteristic features of odontogenic myxoma. CT analysis may contribute to establishing a consensus regarding the interpretation of conventional radiographic appearances in odontogenic myxoma.


Assuntos
Tumores Odontogênicos/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Mandíbula/diagnóstico por imagem , Neoplasias Mandibulares/diagnóstico por imagem , Músculos da Mastigação/diagnóstico por imagem , Maxila/diagnóstico por imagem , Neoplasias Maxilares/diagnóstico por imagem , Pessoa de Meia-Idade
10.
Int J Oral Maxillofac Surg ; 31(2): 165-9, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12102414

RESUMO

The aims of this study were to determine the pathways of odontogenic infection spread into the submandibular space and their relationship to the clinical symptoms. Computerized tomography (CT) and magnetic resonance (MR) images of 33 patients with submandibular involvement were analyzed. The spread of infection was evaluated by lateral asymmetry of the shape and density of the fascial spaces and tissues, and by obliteration of the interfascial fat spaces. Imaging findings were classified into three types: in 19 patients (57.6%), infection spread through the mylohyoid muscle or sublingual space (type I). In five patients (15.2%), infection spread through the bony structures of the mandible with periosteal reaction or perforation of the cortical plate (type II) and was associated with relatively mild symptoms. In four patients (12.1%), infection spread from the masticatory space (type III). Seven of 11 patients with dysphagia or fever showed submandibular involvement spreading into the parapharyngeal space. CT and MR imaging clearly demonstrated different pathways of the spread of odontogenic infection into the submandibular space, which influenced the manifestation of clinical symptoms.


Assuntos
Infecção Focal Dentária/classificação , Infecção Focal Dentária/patologia , Doenças Mandibulares/patologia , Músculos do Pescoço/patologia , Pescoço/patologia , Tecido Adiposo/diagnóstico por imagem , Tecido Adiposo/patologia , Transtornos de Deglutição/etiologia , Fáscia/diagnóstico por imagem , Fáscia/patologia , Feminino , Infecção Focal Dentária/complicações , Infecção Focal Dentária/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Doenças Mandibulares/complicações , Doenças Mandibulares/diagnóstico por imagem , Músculo Masseter/diagnóstico por imagem , Músculo Masseter/patologia , Soalho Bucal/diagnóstico por imagem , Soalho Bucal/patologia , Pescoço/diagnóstico por imagem , Músculos do Pescoço/diagnóstico por imagem , Periostite/diagnóstico por imagem , Periostite/patologia , Faringe/diagnóstico por imagem , Faringe/patologia , Tomografia Computadorizada por Raios X , Trismo/etiologia
11.
Dentomaxillofac Radiol ; 31(3): 204-8, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12058270

RESUMO

We report on a patient with denervation atrophy of the masticatory muscles due to nasopharyngeal cancer who received therapeutic irradiation. Magnetic resonance imaging has significantly contributed to aid diagnosis of this pathology. Masticatory muscle atrophy should be a definitive finding of perineural invasion caused by head and neck tumors. Radiologists should be familiar with this appearance to avoid confusion with tumor invasion of the muscle.


Assuntos
Carcinoma de Células Escamosas/complicações , Imageamento por Ressonância Magnética , Músculos da Mastigação/patologia , Atrofia Muscular/etiologia , Neoplasias Nasofaríngeas/complicações , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/radioterapia , Quimioterapia Adjuvante , Neoplasias dos Nervos Cranianos/patologia , Seguimentos , Humanos , Masculino , Nervo Mandibular/patologia , Músculo Masseter/inervação , Músculo Masseter/patologia , Músculos da Mastigação/inervação , Pessoa de Meia-Idade , Neoplasias Nasofaríngeas/radioterapia , Invasividade Neoplásica , Degeneração Neural , Músculos Pterigoides/inervação , Músculos Pterigoides/patologia , Dosagem Radioterapêutica
12.
Aust Dent J ; 47(1): 63-5, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12035960

RESUMO

BACKGROUND: Trismus and jaw pain are not only caused by temporomandibular disorders (TMD), but also by various pathologies, namely infection, trauma, or neoplasms. TMD-like symptoms, as a result of the pathologies, may be confusing to a clinician. This paper reports two cases of chronic dental infection mimicking TMD. METHODS: Two patients were initially diagnosed with, and treated for, TMD. However the patients did not respond to the treatment. Limited range of motion and jaw pain were then clinically evaluated for differential diagnoses. Laboratory examinations and computerized tomography (CT) scans were carried out to disclose any underlying lesion. RESULTS: Laboratory examination, such as, C-reactive protein helped to detect latent infection. CT scans revealed insidious chronic dental infection imitating TMD. Surgical drainage and chemotherapy resolved the symptoms. CONCLUSION: The importance of a rational diagnostic process, including clinical and laboratory examinations and radiologic imaging, cannot be over-emphasized in elucidating true cause of the symptoms.


Assuntos
Abscesso Periapical/diagnóstico , Transtornos da Articulação Temporomandibular/diagnóstico , Idoso , Proteína C-Reativa/análise , Doença Crônica , Diagnóstico Diferencial , Feminino , Humanos , Contagem de Leucócitos , Masculino , Músculo Masseter/diagnóstico por imagem , Músculo Masseter/patologia , Pessoa de Meia-Idade , Dente Serotino/patologia , Abscesso Periapical/complicações , Tomografia Computadorizada por Raios X , Trismo/etiologia
13.
Arch Oral Biol ; 46(11): 1059-64, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11543713

RESUMO

Muscle oedema, which can be seen as a thickness increment by ultrasonography, is important in provoking pain and fatigue during low-level contraction. Although oedema is related to the balance of inflow and outflow of blood, there are no data on the correlation between muscle thickness change and blood-flow. Blood-flow velocities in the facial artery and the muscle thickness changes were measured by colour Doppler ultrasonography in 30 healthy volunteers during 20 min contraction with 10% of maximum force. Thickness and velocity changes both reached a peak in the initial phase of contraction. The initial change of thickness did not correlate with the velocity in the facial artery, while those immediately after exercise showed a high correlation. The velocity changes in the facial artery might depend on both the general response to contraction and local metabolic or mechanical factors in the contracted masseters.


Assuntos
Face/irrigação sanguínea , Músculo Masseter/diagnóstico por imagem , Contração Muscular/fisiologia , Ultrassonografia Doppler em Cores , Adolescente , Adulto , Artérias , Velocidade do Fluxo Sanguíneo/fisiologia , Edema/fisiopatologia , Eletromiografia , Feminino , Seguimentos , Humanos , Masculino , Músculo Masseter/irrigação sanguínea , Músculo Masseter/fisiopatologia , Fadiga Muscular/fisiologia , Dor/fisiopatologia , Fluxo Sanguíneo Regional/fisiologia , Estatísticas não Paramétricas , Transdutores
14.
Acta Radiol ; 42(3): 306-11, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11350290

RESUMO

PURPOSE: To clarify the Doppler sonographic features of the lingual artery in normal subjects and to evaluate those of patients with cancer of the tongue. MATERIAL AND METHODS: Sixty-seven volunteers and 12 patients with cancer and/or leukoplakia of the tongue were examined with an intraoral sonographic probe. The visibility of the deep lingual artery was determined on transverse and anteroposterior images. On the transverse images, the vascular index, which was defined as the number of colored pixels, was measured on bilateral lingual arteries. Thereafter, the degree of symmetry was evaluated for normal subjects and patients. RESULTS: In normal subjects, between younger and older volunteers, there were no significant differences in visibility of the trunk but differences were found between the two groups for the dorsal branches. The vascular indices of the right and left sides were not different. The characteristic Doppler sonographic feature was vasculature in and around the tumors in the patients with cancer of the tongue. The symmetry indices of the cancer patients were significantly different from those of normal subjects. CONCLUSION: Doppler sonography should be an important procedure for evaluation of tongue neoplasms.


Assuntos
Neoplasias da Língua/irrigação sanguínea , Neoplasias da Língua/diagnóstico por imagem , Língua/irrigação sanguínea , Língua/diagnóstico por imagem , Ultrassonografia Doppler em Cores , Adulto , Artérias/diagnóstico por imagem , Carcinoma de Células Escamosas/irrigação sanguínea , Carcinoma de Células Escamosas/diagnóstico por imagem , Feminino , Humanos , Leucoplasia Oral/irrigação sanguínea , Leucoplasia Oral/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade
15.
Artigo em Inglês | MEDLINE | ID: mdl-11312466

RESUMO

OBJECTIVE: The purpose of this study was to clarify the normal findings of arteries in and around the masseter muscle and to present their pathologic changes with the use of color Doppler sonography. STUDY DESIGN: The vascular appearances were examined for the 4 main arteries feeding the masseter muscle in healthy volunteers (n = 38) and patients with inflammation (n = 5) and intramuscular hemangioma (n = 3). The features of these arteries were investigated together with the flow diameter, flow velocities, and arterial resistances. The symmetry indices were also calculated to assess the pathologic changes. RESULTS: The detection rates of the branch from the transverse facial artery, the masseter artery, and the branch from the maxillary or external carotid artery were 98.7%, 21.1%, and 84.2% in healthy volunteers, respectively. The facial artery that feeds the muscle from the inferior part represented 2 patterns according to anatomic variant: the masseteric branch (22.4%) and the main trunk itself (77.6%). The means of the flow diameter, maximum and minimum velocities, resistive index, and pulsatility index in healthy subjects were 1.8 mm, 24.6 cm/s, 5.1 cm/s, 0.80, and 2.51, respectively. In most of the patients with symptoms, the symmetry indices of all measurement values increased in comparison with those of healthy volunteers. CONCLUSION: Color Doppler sonography is useful in describing the arteries in and around the masseter muscle and has the potential of being used to depict the pathologic changes.


Assuntos
Músculo Masseter/irrigação sanguínea , Músculo Masseter/diagnóstico por imagem , Adulto , Artérias/diagnóstico por imagem , Velocidade do Fluxo Sanguíneo , Artéria Carótida Externa/diagnóstico por imagem , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Feminino , Hemangioma/irrigação sanguínea , Hemangioma/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Musculares/irrigação sanguínea , Neoplasias Musculares/diagnóstico por imagem , Miosite/diagnóstico por imagem , Fluxo Sanguíneo Regional , Estatísticas não Paramétricas , Ultrassonografia Doppler em Cores
16.
Dentomaxillofac Radiol ; 29(2): 113-8, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10808226

RESUMO

OBJECTIVE: To compare the morphology of the masseter muscle in patients with mandibular prognathism with that of normal subjects. METHODS: Three-dimensional X-ray computed tomography (CT) was performed on 69 patients with mandibular prognathism and compared with 91 normal subjects. The angle of the muscle direction in relation to the Frankfurt horizontal plane and the area and the ratio of length of the short to long axes (s/l ratio) on the section perpendicular to the muscle direction were measured. RESULTS: The mean angle, area and s/l ratio in patients with mandibular prognathism was 76.6 degrees (s.d. 4.4 degrees), 318.3 mm2 (s.d. 77.2 mm2) and 0.312 (s.d. 0.049), respectively. Those of the normal subjects were 65.1 degrees (s.d. 4.4 degrees), 368.3 mm2 (s.d. 97.2 mm2) and 0.393 (s.d. 0.054), respectively. The angle was significantly larger, and the area and s/l ratio were significantly smaller than those of normal subjects (P < 0.001). CONCLUSION: The morphology of the masseter muscle in mandibular prognathism is significantly different from that of normal subjects. Our results may be helpful in evaluating the results of orthognathic surgery.


Assuntos
Imageamento Tridimensional , Músculo Masseter/diagnóstico por imagem , Prognatismo/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Anatomia Transversal , Estudos de Casos e Controles , Cefalometria , Intervalos de Confiança , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Músculo Masseter/patologia , Variações Dependentes do Observador , Prognatismo/patologia , Análise de Regressão , Estudos Retrospectivos , Sensibilidade e Especificidade
17.
Artigo em Inglês | MEDLINE | ID: mdl-10710450

RESUMO

OBJECTIVE: To observe changes in the pharyngeal airway and the hyoid bone position after mandibular setback osteotomy in 30 patients with mandibular prognathism by means of 3-dimensional computed tomography (3DCT). STUDY DESIGN: Preoperative and postoperative computed tomography (CT) examinations were performed on 17 patients treated by sagittal split ramus osteotomy with rigid osteosynthesis and on 13 patients treated by intraoral vertical ramus osteotomy without osteosynthesis. The amount of mandibular setback was measured by the preoperative to postoperative difference of the mandibular position in axial CT images. The sizes of the preoperative and postoperative pharyngeal airway were evaluated from semitransparent and crosscut 3DCT images. Postoperative displacement of the hyoid bone was evaluated by a technique to superimpose a postoperative hard tissue 3DCT image on the preoperative image. The helical scan technique was used in the CT examination. The volume rendering technique was used to create 3DCT images. RESULTS: The mean mandibular setback was 7.8 +/- 2.1 mm with a range of 5 to 11 mm. Three months after surgery, the lateral and frontal widths of the pharyngeal airway had decreased significantly in comparison with the preoperative width. The mean reduction rates of the lateral and frontal width were 23.6% and 11.4%, respectively. The diminished airway did not recover by either 6 months or 1 year after surgery in most cases. Downward and posterior displacement of the hyoid bone was seen postoperatively. There were positive correlations between the amount of mandibular setback and reduction of the lateral width of the pharyngeal airway (r = 0.54) and the amount of hyoid bone displacement (r = 0.42). There were no significant differences between the two surgical techniques. CONCLUSION: Three-dimensional computed tomography was a practical imaging technique to evaluate the morphologic airway changes. The pharyngeal airway may have irreversible narrowing after mandibular setback surgery.


Assuntos
Osso Hioide/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Mandíbula/cirurgia , Osteotomia/métodos , Faringe/diagnóstico por imagem , Prognatismo/cirurgia , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Cefalometria , Feminino , Seguimentos , Humanos , Osso Hioide/patologia , Masculino , Mandíbula/diagnóstico por imagem , Maxila/diagnóstico por imagem , Faringe/patologia
18.
Clin Oral Implants Res ; 11(5): 409-14, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11168232

RESUMO

When placing osseointegrated dental implants, the site, angulation and depth of implants can be designed using a computed tomography (CT) or conventional X-ray tomography. To correctly identify placement pre-surgically, various kinds of surgical templates have been proposed. Although it is thought to be important to use templates, no material has been published on their accuracy. The purpose of this study was to propose a method for evaluating the placement accuracy using a specific surgical template. Twenty-one implants were evaluated in 6 patients with mean age of 50.7 years. All implants were implanted by two step surgery in the posterior mandible. A surgical template based on the CT images and the abutment replica on the working models were used for the evaluation of the accuracy of implant placement. The difference between the proposed and actual directions was measured by a milling machine. The difference in the angles between the proposed direction and actual direction were from 0.5 degrees to 14.5 degrees. The average was 5.0 degrees, and there were 12 implants (57%) within 5.0 degrees. This study demonstrated the accuracy of the template described in this article.


Assuntos
Implantação Dentária Endóssea/métodos , Modelos Anatômicos , Implantação Dentária Endóssea/instrumentação , Feminino , Humanos , Arcada Edêntula/diagnóstico por imagem , Masculino , Mandíbula/diagnóstico por imagem , Mandíbula/cirurgia , Pessoa de Meia-Idade , Planejamento de Assistência ao Paciente , Reprodutibilidade dos Testes , Stents , Tomografia Computadorizada por Raios X , Resultado do Tratamento
19.
Dentomaxillofac Radiol ; 28(5): 301-4, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10490749

RESUMO

OBJECTIVE: To examine the possible correlation between the stage of internal derangement and the antero-posterior length of the disk in relation to the length of the articular eminence. STUDY DESIGN: Twenty asymptomatic volunteers with normal joints and 120 patients with TMJ dysfunction underwent MR imaging. The A-P length of the disk in relation to the length of the articular eminence (D/E ratio) was measured. RESULTS: The D/E ratio was 0.95 in the asymptomatic volunteers, 0.83 in patients with disk displacement with reduction, 0.74 in those with disk displacement without reduction and 0.57 in the patients with disk displacement and osteoarthritis. The relationship between the D/E ratio and the stage of internal derangement was statistically significant (P<0.01). CONCLUSION: The D/E ratio decreases with advancing internal derangement. We suggest that it is a reliable numerical method for staging the degree of the internal derangement.


Assuntos
Luxações Articulares/patologia , Transtornos da Articulação Temporomandibular/patologia , Articulação Temporomandibular/patologia , Adulto , Análise de Variância , Estudos de Casos e Controles , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Variações Dependentes do Observador , Osteoartrite/patologia , Índice de Gravidade de Doença , Disco da Articulação Temporomandibular/patologia
20.
Artigo em Inglês | MEDLINE | ID: mdl-10442952

RESUMO

OBJECTIVE: The purpose of this study was to evaluate the subjective quality of Joint Photographic Experts Group (JPEG) compressed images of intraoral radiographs with file sizes of 30 kilobytes or less, which can be transmitted quickly on the World Wide Web. STUDY DESIGN: Conventional intraoral radiographs were digitized at sampling rates of 100, 200, 300, 400, and 600 dots per inch through use of a flatbed scanner and saved in JPEG format in 11 compression degrees. Fifty-five combinations of sampling rate and compression degree were evaluated by means of a visual analog scale. Sampling rate and compression degree combinations whose quality was inferior to that of an average image were excluded. The quality of the remaining combinations was subsequently evaluated through assessment of 8 anatomical features in each image. RESULTS: Forty of the 55 combinations provided a file size less than 30 kilobytes. Thirty combinations obtained VAS scores of 0 or higher on the standardized VAS. As a result, 16 combinations of sampling and compression conditions were selected for the second part of the study. Only one combination of sampling rate and compression degree was found to provide sufficient image quality for all 8 anatomical features. CONCLUSIONS: Under the file size limit of the study design, the full-sized compressed image of an intraoral radiograph did not always provide sufficient quality. This problem will be reduced by improvements in telecommunications infrastructure, which will permit faster transfer of files of larger size.


Assuntos
Processamento de Imagem Assistida por Computador/normas , Internet , Radiografia Dentária , Sistemas de Informação em Radiologia/normas , Algoritmos , Registros Odontológicos , Humanos , Controle de Qualidade , Intensificação de Imagem Radiográfica/normas , Padrões de Referência , Validação de Programas de Computador
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