Diagnostic Accuracy on Magnetic Resonance Imaging for the Diagnosis of Osteoarthritis of the Temporomandibular Joint.

OBJECTIVES: Osteoarthritis, which is also called degenerative arthritis or degenerative joint disease, is primarily a disease that results from the breakdown and loss of cartilage in joints. The purpose of this study was to investigate the diagnostic accuracy of magnetic resonance images for the diagnosis of osteoarthritis of the temporomandibular joint. MATERIALS AND METHODS: Fifty patients (50 joints) with closed locking of the temporomandibular joint were examined with magnetic resonance imaging and then underwent arthroscopic surgery. The agreement of osteoarthritis between magnetic resonance images and arthroscopic findings was studied using the κ coefficient. RESULTS: The incidence of osteoarthritis on magnetic resonance images (38%) was significantly lower than that in arthroscopic findings (78%). There was no significant agreement between these two findings (p=.108). The κ coefficient was 0.154. CONCLUSION: The diagnostic accuracy of magnetic resonance images for osteoarthritis of the temporomandibular joint was low; early osteoarthritis could not be diagnosed from magnetic resonance images. Clinicians should understand that the diagnostic accuracy of osteoarthritis without arthroscopy is not always high.

Factors related to the incidence of anterior disc displacement without reduction and bony changes of the temporomandibular joint in patients with anterior open bite.

PURPOSE: We aimed to investigate factors related to the prevalence of anterior disc displacement without reduction (ADDwoR) and bony changes of the condylar head (bony changes) in the temporomandibular joints (TMJs) of patients with anterior open bite. METHODS: Subjects are comprised of 36 preoperative patients (72 joints) with skeletal anterior open bite without facial asymmetry who had undergone orthognathic surgery at the Hokkaido University Hospital; magnetic resonance imaging of the TMJ and cephalometric analysis were performed before treatment. Logistic regression analysis was performed to clarify relationships among age, overbite, overjet, ANB angle, sella to nasion (SN) to mandibular plane angle (SN-MP angle), SN to ramus plane angle (GZN angle), gonial angle, and incidence of ADDwoR or bony changes in patients with anterior open bite. RESULTS: Fifteen patients had bilateral ADDwoR, and five patients had unilateral ADDwoR; 17 patients had bilateral bony changes, and five patients had unilateral bony changes. SN-MP angle was greater in 20 patients with ADDwoR than that in 16 patients without ADDwoR (p < 0.05). GZN angle was greater in the 20 patients showing bony changes than that in the 16 patients without bony changes (p < 0.05). CONCLUSION: In terms of dentofacial morphology, SN-MP angle appears to be associated with the incidence of ADDwoR, and GZN angle appears to be associated with bony changes in the TMJ.

Intra-articular fracture of the mandibular condyle: a case report.

The authors describe a case of intra-articular fracture of the left mandibular condyle, successfully treated by the pumping technique in the upper and lower joint cavities, and show arthroscopic findings in these cavities. The patient was a 15-year-old boy whose maximum mouth opening was 30 mm. Computed tomography revealed a left intra-articular sagittal fracture of the condylar head. Aspiration of the hematoma in the upper and lower joint spaces was performed with ten pumping actions. In the upper and lower joint spaces, arthroscopic examination revealed the disappearance of the hematoma. The patient continued opening, protrusive, and lateral excursive exercises. One month after the surgery, the maximal interincisal distance was improved to 45 mm with straight opening. In the case presented, mouth-opening exercises, along with the pumping technique for treatment of an intraarticular fracture of the mandibular condyle, allowed satisfactory and stable results in the improvement of limited mouth movement.

Natural course of acute closed lock of the temporomandibular joint.

To clarify the features of acute closed lock of the temporomandibular joint we compared the clinical condition of patients with acute and chronic closed lock, and investigated the natural history of acute closed lock. Forty patients with unilateral acute closed lock who were given no treatment and 40 patients with unilateral chronic closed lock were enrolled in the study. The duration of locking in those with acute closed lock ranged from 1 to 7 days, and that of those with chronic closed lock from 3 to 4 months. Differences between the groups in sex, age, maximum mouth opening, and joint pain were analysed. In those with acute closed lock who had had no treatment, maximum mouth opening and joint pain were measured at the initial visit and after 2, 4, 8, and 12 weeks. The number of dysfunctional joints was counted during each period and the natural course of the acute closed lock investigated. There were more women and older patients among those with chronic, than among those with acute, closed lock. We found no significant differences in the symptoms in the two groups. After 2 weeks of allowing the acute closed lock to take its natural course only 15 of the 40 had not resolved successfully, and after 12 weeks of taking its natural course only 2 had been unsuccessful. The number of joints that did not resolve successfully decreased progressively over time. Any treatment for acute closed lock should be easier and more effective than that of following its natural course.

Diagnostic accuracy of fat-saturated T2-weighted magnetic resonance imaging in the diagnosis of perforation of the articular disc of the temporomandibular joint.

The accuracy of diagnosing a perforation of the articular disc of the temporomandibular joint (TMJ) is poor with conventional magnetic resonance imaging (MRI). We recently reported that a high signal-intensity area is usually found on fat-saturated T2-weighted MRI in the joint space between the articular disc and cartilage surface in joints in which the disc is displaced. A discrete image with an area of high signal-intensity in the middle of the articular disc may indicate perforation or rupture. The purpose of this study was to compare the accuracy of diagnosis of a perforated articular disc by fat-saturated T2-weighted MRI with that of arthroscopy. We studied 50 joints in 50 patients with closed lock of the TMJ who were examined with MRI and then by arthroscopy using an ultra-thin arthroscope. The agreement between the two methods of diagnosis was assessed using the κ coefficient. Evidence of perforation of the disc on MRI and arthroscopically was found in the same 7 joints; there was complete concordance (κ=1.00, p<0.001). The accuracy of diagnosis of perforation of a disc by fat-saturated MRI was therefore the same as that by arthroscopy using an ultra-thin arthroscope.

Relationship between the Effectiveness of Arthrocentesis under Sufficient Pressure and Conditions of the Temporomandibular Joint.

Background. The purpose of this study is to investigate the conditions of the temporomandibular joint relative to the effectiveness of an arthrocentesis-like enforced manipulation technique followed by irrigation under high pressure in patients with closed lock. Methods. We performed arthroscopic examination and manipulation followed by irrigation as the initial treatment in 50 joints with closed lock. Relationship between the effectiveness of the procedure and conditions of the temporomandibular joint was statistically analyzed using multiple regression analysis. Results. Significant inverse correlations were found between the extent of improvement in maximum mouth opening after treatment and the initial maximum opening before treatment. There were no significant correlations between improvement of joint pain at mouth opening and in biting and conditions of the temporomandibular joint. Conclusions. Pathologic conditions of the temporomandibular joint did not have an influence on the efficacy of the technique. This result suggests that this procedure has wider application than conventional arthrocentesis.

Reconstruction of a defect on the buccal mucosa and prolabium.

We describe the procedure for reconstruction of a defect on the buccal mucosa and the prolabium with a buccal mucosal transposition flap and an artificial dermis graft. The preparation of the flap started with an incision extending from the border of the defect to the corner of the mouth. The pivot point of the flap was near the stump of the excised prolabium. Only the buccal mucosa was elevated from the buccal surface. It was transposed onto the defect of the prolabium and sutured to the edges of the defect. After reconstruction of the prolabium, the artificial dermis was trimmed and sutured to the mucosal and skin edges of the surgical defect. This is an easy and minimally invasive procedure to cover a defect of the buccal mucosa and the prolabium. In our experience, the wound healed with good, functional, and cosmetic results.

A case of angiomyolipoma arising in the tongue.

A 61-year-old woman was referred to our hospital with a mass in the left proglossis. The lesion was excised with a provisional diagnosis of hemangioma. The mass was well-demarcated and easily dissected with an ultrasonic surgical aspirator. The histopathologic diagnosis was angiomyolipoma arising in the tongue. There were no signs of recurrence at followup at 18 months.

Repair of oral mucosal defects using artificial dermis: factors related to postoperative scar contracture.

OBJECTIVE: To clarify wound-healing situations with artificial dermis used for the repair of oral mucosal defects, we investigated the incidence of postoperative scar contracture and studied factors related to cicatrization. STUDY DESIGN: Forty patients who underwent repair of oral mucosal defects using artificial dermis participated in this study. The degree of scar contracture was recorded 1 month after surgery. To study the factors related to cicatrization, patient characteristics of sex, age, excision region, fixation used, size of the graft, and number of days for silicon seat removal were examined. Logistic regression analysis was used for analysis of the relationship between cicatrization and patient characteristics. RESULTS: One month after surgery, 70% of patients had no contracture, 22.5% of patients had moderate contracture, and 7.5% of patients had severe contracture. A significant correlation was found between cicatrization and the minimum diameter of the artificial dermis (P < .001). CONCLUSIONS: Reducing the minimum diameter of the artificial dermis may contribute to a decrease in scar contracture.

Procedures of endoscopic periradicular surgery.

When a tooth with an apical lesion is identified, an apicoectomy is frequently performed when nonsurgical treatment is considered unfeasible or has previously failed. However, the treatment is usually difficult in molars. This article describes a minimally invasive procedure for removing a gutta-percha point under the maxillary sinus mucosa using an ultrathin arthroscope and a visualization approach in apicoectomy using an intranasal endoscope. These surgical techniques using endoscopes are minimally invasive and reliable procedures that provide limited incision and bone removal and respect the integrity of the maxillary sinus.

Hyperintensity signal in the joint space of the temporomandibular joint on fat-saturated T2-weighted magnetic resonance imaging.

Our aim was to investigate the incidence of a hyperintense signal in the joint space of the temporomandibular joint (TMJ) on fat-saturated T2-weighted magnetic resonance images (MRIs). We studied 112 patients (224 joints) with disorders of the TMJ who were examined by T2-weighted MRI, and recorded the association between displacement of the disc and the hyperintense signal using the κ coefficient. A hyperintense signal was found in 4 of 91 joints (4%) when the disc was in the normal position, in all 19 joints with anterior disc displacement with reduction, and in 108 of the 114 joints (95%) with anterior disc displacement without reduction. There was a significant correlation between displacement of the disc and the hyperintense signal (p<0.001). The κ coefficient was 0.91. Such a signal in the joint space of the TMJ on fat-saturated T2-weighted MRI may indicate the presence of synovial fluid in the joint space with displacement of the disc.

Access to the maxillary sinus using a bone flap with sinus mucosal and mucoperiosteal pedicles.

We describe a procedure for removing lesions in the maxillary sinus using bone flaps with the sinus mucosa and mucoperiosteum. The surgical design is to construct a rectangular trapdoor using 3 consecutive bur-cuts, fracture the upper margin, and lift the bone lid upward. The osteotomy site on the inferior, medial, and lateral sides of the bone lid was exposed subperiosteally, but the mucoperiosteal and sinus mucosal attachments on the superior and central areas of the lid were maintained. Then, following fracture of the upper bone margin, the lid was lifted upward. In this way, the integrity of the mucoperiosteum and sinus mucosa was maintained. Advantages of the bone flap with soft tissue pedicles technique may be quick recovery and restored integrity of the sinus wall, with a low probability of infection because of vascularization of the bone lid. To realize this, a bone flap with both sinus mucosal and mucoperiosteal pedicles is more suitable.

Magnetic resonance imaging of the temporomandibular joint in patients with skeletal open bite and subjects with no dentofacial abnormalities.

We aimed to record the prevalence of disc displacement and bony changes in the temporomandibular joints (TMJs) of patients with skeletal open bite. We studied 25 patients (50 joints) with skeletal open bite, 25 volunteers with no dentofacial abnormalities (50 joints), and 44 patients with closed lock and no dentofacial abnormalities (60 joints) using magnetic resonance imaging (MRI) of the TMJ. We found anterior disc displacement without reduction in 6 of the volunteers and in 24 of the patients with skeletal open bite (p=0.01). Among the 24 affected joints, 16 showed signs of bony change (67%) as did 24 of those with closed lock (40%). The fact that we found a significant difference in the incidence of anterior disc displacement without reduction and bony change between patients with skeletal open bite and control groups without deformities of the jaw indicates that these changes may be caused by skeletal open bite.

Mandibular coronoid hyperplasia: a case report.

A case of unilateral coronoid hyperplasia successfully treated by coronoidotomy with prolonged postoperative physiotherapy and reveal the postoperative radiographic changes between the sectioned part of the coronoid process and the mandibular ascending ramus is described. The patient was a 28-year-old man whose maximum mouth opening was 30 mm. A coronoidotomy of the left coronoid process was performed. Nine days after surgery, the patient started physiotherapy with a HU-OS(r) appliance. After coronoidotomy and physiotherapy, the maximum mouth opening had increased to 43 mm. Radiographic follow-up showed that the coronoid process apparently united with the mandibular ascending ramus, with moderate dislocation and inclination posteriorly. In the case presented, an intraoral coronoidotomy with postoperative physiotherapy for treatment of coronoid process hyperplasia allowed satisfactory and stable results in the correction of coronoid-malar interference.

Oral tumor resection and salivary duct relocation with an ultrasonic surgical aspirator.

We describe a procedure of oral tumor resection and salivary duct relocation with an ultrasonic surgical aspirator. After mucosal incision, resection of the underlying musculature was performed using an ultrasonic surgical aspirator. Using the apparatus, the salivary duct was easily exposed without damaging or cutting the duct. After identification of the salivary duct, salivary duct relocation was performed. After resection of the tumor, the artificial dermis was trimmed and sutured to the mucosal edges of the surgical defect. This method is a reliable and simple procedure that can be used to avoid postoperative complications such as salivary fistula or swelling of the gland.

Three minimally invasive procedures for removing lesions in the maxillary sinus.

We describe here 3 minimally invasive procedures for removing lesions from the maxillary sinus using an ultrathin endoscope, microscope, and otoscope.Preoperatively, a lesion in the maxillary sinus was identified by radiographic examination. Then the access hole position and advance direction of the endoscope and forceps were planned. Under local anesthesia, a small incision on the buccal mucosa was made in the planned position. The anterior bony wall of the sinus was exposed subperiosteally, and a small access hole for the insertion of an endoscope was made in the planned position and angled with a fissure bur. After identification of the lesion endoscopically, microscopically, or otoscopically, a forceps was inserted into the sinus cavity through the hole, and the lesion was seized and withdrawn from the sinus.The surgical procedures are suggested to be reliable, easy, and minimally invasive that provide a limited incision and bone removal and respect the integrity of the sinus.

A combination of three minimally invasive surgical procedures for implant placement in the posterior maxilla with insufficient bone quantity.

We describe a combination of 3 surgical procedures for implant placement in the posterior maxilla with insufficient bone quantity and quality. In these situations, we have performed 3 minimally invasive, safe, and reliable surgical procedures: buccal bone graft with bone harvested from the mandibular molar region, submucous vestibuloplasty using artificial dermis, and bone-added osteotome sinus floor elevation under endoscopic control. These modified procedures can be performed in the office setting under outpatient local anesthesia and may minimize patient discomfort and reduce postoperative complications.

Procedure of endoscopic removal of a gutta-percha point under the maxillary sinus mucosa by using an ultrathin arthroscope.

We describe here a procedure of endoscopic removal of a gutta-percha point under the maxillary sinus mucosa by using an ultrathin arthroscope. In this study, a 1.2-mm-diameter ultrathin arthroscope was introduced for observation into the maxillary sinus. The surgical technique is suggested to be a reliable and minimally invasive procedure that provides limited incision and bone removal and respects the integrity of the sinus.