Kunihito Matsumoto

Relationship between the thickness of the roof of glenoid fossa, condyle morphology and remaining teeth in asymptomatic European patients based on cone beam CT data sets

OBJECTIVES The aim of this study was to examine the relationship between the roof of the glenoid fossa (RGF) thickness and condyle morphology and the influence of the number of remaining teeth and age. METHODS Cone beam CT data sets from 77 asymptomatic European patients were analysed retrospectively in this study. The thinnest area of RGF was identified among the sagittal and coronal slices on a computer screen; distance measurement software was used to measure the thickness. Moreover, we applied a free digital imaging and communications in medicine viewer for classification of condyle head type. It was also used to analyse any relation between RGF thickness and the number of remaining teeth. We performed a correlation analysis for RGF, age and missing teeth. Finally, we investigated combining sagittal condyle morphological characterization with coronal condyle morphology in relation to the number of joints and RGF thickness. RESULTS The Kruskal-Wallis test revealed no significant differences in RGF thickness among any of the coronal condyle head morphology groups (p > 0.05). There were significant differences in the thinnest part of RGF in relation to the sagittal plane for condyle morphological characterization, because we observed increased RGF thickness in joints with osteoarthritis features (p < 0.05). There is a non-significant correlation between the thinnest part of the RGF and the number of remaining teeth (p > 0.05). CONCLUSIONS We found that the RGF thickness is unaffected by the coronal condyle head morphology and the number of remaining teeth. Osteoarthritic changes (sagittal condyle morphology) have an effect on RGF.

Discrepancy of coronal morphology between mandibular condyle and fossa is related to pathogenesis of anterior disk displacement of the temporomandibular joint

OBJECTIVE To evaluate whether morphological discrepancy between the mandibular condyle and fossa of the temporomandibular joint (TMJ) is related to disk displacement on magnetic resonance imaging (MRI). STUDY DESIGN This study included 61 patients with unilateral internal derangement based on both MRI and clinical examination. Coronal morphologies of the condyle and fossa were divided into four groups based on Öbergs classification. According to the coronal morphology of the condyle and fossa, all joints were dichotomized into either harmonized group or a discrepancy group (e.g., angled condyle and concave fossa). The incidence of discrepancy and the relationship of the discrepancy to other findings on MRI were statistically evaluated. RESULTS The discrepancy had a significantly higher incidence on the affected side. The discrepancy correlated with incidence of disk deformity on the affected side. CONCLUSION Morphological discrepancy between the condyle and fossa is related to development of anterior disk displacement in the TMJ.

An image-guided technique for puncture of the superior temporomandibular joint cavity: clinical comparison with the conventional puncture technique

OBJECTIVE The objective of this study was to compare an image-guided puncture technique (IGPT) with conventional puncture technique (CPT) with respect to accuracy of needle entry, maximal mouth opening, and pain in pumping manipulation treatment of internal derangement of the temporomandibular joint (TMJ). STUDY DESIGN The subjects comprised 178 patients with internal derangement of the TMJ with closed lock. Treatment was provided using CPT in 102 cases and IGPT in 76 cases. Three variables, number of repunctures, maximal mouth opening distance, and pain threshold according to a visual analogue scale, were measured and compared between IGPT and CPT groups. RESULTS Access to the superior joint cavity was achieved without correcting the puncture point in 97% of patients who underwent IGPT and 82% of patients in the CPT group. Significant differences were seen in 1-week maximal mouth opening and pain threshold between IGPT and CPT groups (P < .05 each) and resetting of the puncture point was significantly less frequent using IGPT compared with CPT (P < .05). CONCLUSIONS IGPT is effective for pain mitigation and improves mouth opening during the early postoperative period after pumping manipulation treatment.

Establishment of temporomandibular joint puncture technique in rats using in vivo micro-computed tomography (R_mCT®)

The aim of the report was to establish puncture techniques for the temporomandibular joint (TMJ) cavity in rats. The experimental sample comprised 30 male Sprague-Dawley rats. Under general anaesthesia the superior joint cavity of the rat was punctured either laterally (lateral puncture technique (LPT), n = 11), anteriorly (anterosuperior puncture technique (ASPT), n = 13) or anteroinferior puncture technique (AIPT), n = 6) using a 27-gauge needle. After the tip of the needle was confirmed by micro-CT (R-mCT®, Rigaku, Tokyo, Japan) located on the mandibular fossa, 0.05 ml of contrast media was injected under micro-CT fluoroscopic guidance. After confirmation that the joint cavity was filled with contrast media, micro-CT imaging was carried out. The puncture for LPT was accurate in 5 of the 11 animals. The ASPT was accurate in all 13 animals. The AIPT punctured 3 of the 6 animals. Furthermore, the ASPT and AIPT demonstrated improved preservation of the needle; it was harder to detach the needle, which led to greater stability. These results suggest that ASPT assisted by R-mCT® is useful for basic research, including drug discovery and pathogenesis of TMJ diseases.

The use of arthrography in the diagnosis of temporomandibular joint synovial chondromatosis

Synovial chondromatosis (SC) involving the temporomandibular joint (TMJ) is very rare and can occur in either or both cavities. Differentiation of the affected cavity in SC is therefore as important as making the diagnosis. This report presents a case of SC in which both cavities were thought to be affected, but arthrography using cone beam CT (CBCT) allowed us to see that involvement was limited to the superior joint cavity. In addition, we describe the usefulness of arthrographic CBCT for diagnosis and treatment planning in SC of the TMJ.

Evaluation of the usefulness of magnetic resonance imaging in the assessment of the thickness of the roof of the glenoid fossa of the temporomandibular joint.

OBJECTIVE The aim of this study was to evaluate the usefulness of magnetic resonance imaging (MRI) in measuring thickness of the roof of the glenoid fossa (RGF) of the temporomandibular joint (TMJ). STUDY DESIGN Minimum RGF thickness in 95 TMJs of 59 patients with temporomandibular disorders were measured and compared on both sagittal-section MRI and cone-beam computed tomography (CBCT). RGF thickness on MRI was also compared with MRI, CBCT, and arthrographic findings. RESULTS Minimum RGF thickness was greater on MRI (1.46 mm) than on CBCT (0.90 mm). Spearmans correlation coefficient by rank for these 2 types of measurements was 0.63. RGF thickness on MRI differed significantly between those with and without degenerative joint changes (1.69 vs 1.32 mm; P < .01) and between those with and without disk displacement (1.58 vs 1.35 mm; P = .04), but showed no associations with disk deformity, joint effusion, or disk perforation. CONCLUSIONS MRI is useful in measuring RGF thickness from diagnostic as well as radiation protection standpoints.

Unusual radiographic appearance of ossifying fibroma in the left mandibular angle

Ossifying fibroma is usually a unilocular lesion with a well-defined, thinly corticated margin radiographically, although various patterns have been noted. The patient was a 27-year-old woman with a painless radiolucent lesion demonstrated on panoramic radiography to involve the root-apex area of the left lower second and third molars. Radiographically, the lesion had some features of a benign tumour, such as an odontogenic myxoma. However, the deep invaginations towards the interalveolar septa suggested a simple bone cyst, whereas the irregular margin and lack of expansion or mandibular canal displacement were consistent with a malignant lesion. A hard tissue component was confirmed only by soft-tissue mode CT. Although this lesion was histopathologically diagnosed as ossifying fibroma, the conflicting imaging findings were challenging and very intriguing.

Clinical use of three-dimensional models of the temporomandibular joint established by rapid prototyping based on cone-beam computed tomography imaging data

Three-dimensional rapid prototyping (3D RP) models based on volumetric image data acquired by various modalities have been used in presurgical planning, implant design, and medical education. To the best of our knowledge, cone-beam computed tomography (CBCT) is the best modality for imaging bone components of the temporomandibular joint (TMJ). 3D RP models of the TMJ are also applied for reconstruction design, simple anatomical evaluation, and education. Although 3D RP models of the TMJ already provide much information during preoperative and anatomical evaluation, we intended to expand the utility of these models. This paper presents two examples of the application of 3D RP models of the TMJ based on CBCT imaging data and briefly reviews the usage of 3D RP models.

Cone-beam computed tomography for the diagnosis of mandibular condylar fractures: 11 case reports

The temporomandibular joint has many complex anatomical and functional features compared with other joints. Therefore, caution should be exercised in the diagnosis of temporomandibular joint fractures. Although panoramic tomography is widely used for the screening of orofacial trauma as well as other diseases, this modality often overlooks evidence of a condylar fracture. Cone-beam computed tomography is also used for diagnosing orofacial diseases. The purposes of this report are to show the usefulness of cone-beam computed tomography in diagnosing condylar fractures and to describe the imaging features of condylar fractures.

Involvement of trigeminal transition zone and laminated subnucleus caudalis in masseter muscle hypersensitivity associated with tooth inflammation.

A rat model of pulpitis/periapical periodontitis was used to study mechanisms underlying extraterritorial enhancement of masseter response associated with tooth inflammation. Periapical bone loss gradually increased and peaked at 6 weeks after complete Freund’s adjuvant (CFA) application to the upper molar tooth pulp (M1). On day 3, the number of Fos-immunoreactive (IR) cells was significantly larger in M1 CFA rats compared with M1 vehicle (veh) rats in the trigeminal subnucleus interpolaris/caudalis transition zone (Vi/Vc). The number of Fos-IR cells was significantly larger in M1 CFA and masseter (Mass) capsaicin applied (M1 CFA/Mass cap) rats compared with M1 veh/Mass veh rats in the contralateral Vc and Vi/Vc. The number of phosphorylated extracellular signal-regulated kinase (pERK)-IR cells was significantly larger in M1 CFA/Mass cap and M1 veh/Mass cap rats compared to Mass-vehicle applied rats with M1 vehicle or CFA in the Vi/Vc. Pulpal CFA application caused significant increase in the number of Fos-IR cells in the Vi/Vc but not Vc on week 6. The number of pERK-IR cells was significantly lager in the rats with capsaicin application to the Mass compared to Mass-vehicle treated rats after pulpal CFA- or vehicle-application. However, capsaicin application to the Mass did not further affect the number of Fos-IR cells in the Vi/Vc in pulpal CFA-applied rats. The digastric electromyographic (d-EMG) activity after Mass-capsaicin application was significantly increased on day 3 and lasted longer at 6 weeks after pulpal CFA application, and these increase and duration were significantly attenuated by i.t. PD98059, a MEK1 inhibitor. These findings suggest that Vi/Vc and Vc neuronal excitation is involved in the facilitation of extraterritorial hyperalgesia for Mass primed with periapical periodontitis or acute pulpal-inflammation. Furthermore, phosphorylation of ERK in the Vi/Vc and Vc play pivotal roles in masseter hyperalgesia after pulpitis or periapical periodontitis.