The efficacy of video monitoring-supported student self-evaluation of dental explorer skills in dental hygiene education.

OBJECTIVE: The objective of this study was to investigate whether having dental hygiene students monitor video recordings of their dental explorer skills is an effective means of proper self-evaluation in dental hygiene education. METHODS: The study participants comprised students of a dental hygiene training school who had completed a module on explorer skills using models, and a dental hygiene instructor who was in charge of lessons. Questions regarding 'posture', 'grip', 'finger rest' and 'operation' were set to evaluate explorer skills. Participants rated each item on a two-point scale: 'competent (1)' or 'not competent (0)'. The total score was calculated for each evaluation item in evaluations by students with and without video monitoring, and in evaluations by the instructor with video monitoring. Mean scores for students with and without video monitoring were compared using a t-test, while intraclass correlation coefficients were found by reliability analysis of student and instructor evaluations. RESULTS: A total of 37 students and one instructor were subject to analysis. The mean score for evaluations with and without video monitoring differed significantly for posture (P < 0.0001), finger rest (P = 0.0006) and operation (P < 0.0001). The intraclass correlation coefficient between students and instructors for evaluations with video monitoring ranged from 0.90 to 0.97 for the four evaluation items. CONCLUSION: The results of this study suggested that having students monitor video recordings of their own explorer skills may be an effective means of proper self-evaluation in specialized basic education using models.

The effects of apology and perspective taking on interpersonal forgiveness: a dissonance-attribution model of interpersonal forgiveness.

The author investigated (a) the effects of a victim's perspective taking and a transgressor's apology on interpersonal forgiveness and (b) forgiveness as a mode of dissonance reduction. Before the participants read a scenario describing a situation in which they imagined being mistreated by a classmate, the author randomly assigned them to 1 of 4 perspective-taking conditions: (a) recalling times when they had mistreated or hurt others (i.e., the recall-self-as-transgressor condition); (b) imagining how they would think, feel, and behave if they were the classmate (i.e., the imagine-self condition); (c) imagining how the classmate would think, feel, and behave (i.e., the imagine-other condition); or (d) imagining the situation from their own (i.e., the victim's/control) perspective. After reading the scenario, the participants read an apology from the classmate. The participants in the recall-self-as-transgressor condition were significantly more likely than those in the control condition to (a) make benevolent attributions, (b) experience benevolent emotional reactions, and (c) forgive the transgressor. The relationship between the perspective-taking manipulation and forgiveness was mediated by the benevolent attributions and positive emotional reactions experienced by the victims.

Long-term magnetic resonance imaging after temporomandibular joint discectomy without replacement.

PURPOSE: The intracapsular changes in patients who underwent discectomy without disc replacement were evaluated by magnetic resonance imaging (MRI) to determine the long-term outcome of this procedure. PATIENTS AND METHODS: Thirty-three patients observed for an average of 9 years 4 months (5 to 24 years) and 10 asymptomatic volunteers underwent MRI using T1- and T2-weighted images and 3-dimensional fast imaging with a steady precession sequence (FISP-3D) technique. The intracapsular changes, especially those in the joint space, were compared with the postoperative clinical findings. RESULTS: MRI examination of the temporomandibular joint in the 33 patients (35 joints) indicated the presence of tissue with an intermediate or high signal intensity in the joint space. This tissue covered the articular surface of the condyle and fossa. Thirty-two joints had no pain or only occasional, mild pain (3 joints). No patient had severe joint pain or a low signal intensity in the joint space on MRI examination. There was no correlation between joint noise and the presence of a tissue deformity in the joint space. MRI of 2 patients with limited mouth opening showed tissue with high signal intensity in the joint space as well as an exostosis on the eminence and hypertrophy of the condyle. CONCLUSION: Long-term success is possible with discectomy without replacement. This appears to be attributable to the formation of new tissue between the condyle and fossa that acts as a pseudodisc.

Interleukin-1 beta, interleukin-6, and tissue inhibitor of metalloproteinase-1 in the synovial fluid of the temporomandibular joint with respect to cartilage destruction.

OBJECTIVE: The distribution and biological roles of interleukin (IL)-1 beta, IL-6, and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the synovial fluid of patients with non-inflammatory chronic temporomandibular joint (TMJ) disorders were evaluated in relation to pain upon joint movements and X-ray and magnetic resonance imaging (MRI) findings. MATERIALS AND METHODS: TMJ aspirates were obtained from 48 patients (48 joints) with chronic TMJ disorders and from 18 controls (18 joints). The IL-1 beta and IL-6 levels in the aspirates were determined by using an enzyme-linked immunosorbent assay and the TIMP-1 level was measured by an enzyme immunoassay. Following examinations for pain upon joint movements and X-ray and MRI observations, the IL-1 beta, IL-6, and TIMP-1 levels and frequencies of their detection were compared. RESULTS: The IL-1 beta level and frequency of detection showed no correlation with pain upon joint movements or with the X-ray and MRI findings. In the frequency of detection of IL-6, there were significant differences between control (no detection) and all chronic TMJ disorder groups that were classified by imaging diagnosis (P < 0.001). A correlation was also noted between the presence of IL-6 and pain upon joint movements. The IL-6 level was correlated with the TIMP-1 level and with pain upon joint movements. TIMP-1 level was correlated with pain upon joint movements. The TIMP-1 was present in higher level from patients with chronic TMJ disorders who exhibited osseous changes on the X-ray images. CONCLUSION: The results indicated that the IL-6 and TIMP-1 levels in the TMJ aspirates of patients with chronic TMJ disorders have been raised. The former was not detected in the TMJ aspirates of the control. These findings suggest that IL-6 and TIMP-1 might play a role in the etiology of chronic TMJ disorders, but further studies are needed to validate this.

A comparison between magnetic resonance imaging and pathologic findings in patients with disc displacement.

PURPOSE: This study compared the magnetic resonance imaging (MRI) and pathologic findings in patients with disc displacement without perforation. PATIENTS AND METHODS: Eleven patients and 30 asymptomatic volunteers underwent MRI using the three-dimensional (3D) fast imaging with a steady precession sequence (FISP) acquisition technique. The 11 patients (11 joints) then underwent discectomy, and the pathologic and MRI findings were compared. RESULTS: MRI (FISP-3D) examination of the temporomandibular joint in 11 patients (11 joints) showed low signal intensity in the anterior band and the intermediate zone of the disc, and high signal intensity in the posterior band of the disc and retrodiscal tissue. On microscopic examination, the anterior band and intermediate zone of the disc were found to consist of dense collagenous bundles showing mild hyaline degeneration. Myxomatous degeneration was seen in the posterior band of the disc (11 joints), and edematous change was seen in the retrodiscal tissues (seven joints). CONCLUSIONS: Pathologic changes in the disc and the retrodiscal tissues are accurately depicted by FISP-3D.

Magnetic resonance images in patients with acute traumatic injury of the temporomandibular joint: a preliminary report.

Condylar or subcondylar fractures are severe traumatic lesions of the temporomandibular joint (TMJ) but the damage to the intracapsular soft tissues is not fully defined. In this study, twelve joints in ten patients with condylar and subcondylar fractures of the TMJ between two and twelve days after injury, were examined by magnetic resonance imaging to evaluate the damage to the intracapsular soft tissues in the acute phase. The joint capsule and the retrodiscal tissue were both swollen and showed increased signal intensity. Tears were recognized in the capsule of the eight joints and in the retrodiscal tissue of six joints. All discs were displaced in an anteromedial direction along with the fractured condylar fragments, but tear (rupture) was not recognized. In all cases, high signal intensity was seen in the joint spaces, and haemarthrosis was recognized in six joints during open reduction surgery.

Correlation of magnetic resonance imaging and surgical findings in patients with temporomandibular joint disorders.

PURPOSE: This study compared the magnetic resonance imaging (MRI) and surgical findings in patients with temporomandibular joint disorders. MATERIALS AND METHODS: Forty-three patients and 30 asymptomatic volunteers underwent MRI using the three-dimensional (3D) FISP acquisition technique. The 43 patients (43 joints) then underwent discectomy, and the surgical and MRI findings were correlated. RESULTS: In 28 joints (28 patients), splits surrounded by regions of high-signal intensity were seen in the discs and retrodiscal tissues on MRI. Surgically, a tear was confirmed in 26 (93%) of these joints. Histologically, these areas showed severe myxomatous degeneration. Disc deformity was visualized by MRI in all patients and increases in signal intensity were found in some discs. High-signal intensities also were observed in 30 joint spaces, in which serous joint effusion was confirmed surgically. CONCLUSION: Pathologic intracapsular changes are accurately depicted by FISP-3D, and this method is particularly useful for diagnosing changes in the disc and retrodiscal tissues.

Eliminating effects of an air purifier on infectants during dental procedure.

Blood and drill dust from dental plaque microorganisms, teeth, and filling materials can cause environmental pollution in the dental clinic. Currently, as a preventive measure against air pollution from a patient's mouth during dental treatment, dust-collecting aspirators such as an extra-oral vacuum aspirator (EOVA) are coming into general use. We tested the eliminating effects by the EOVA with the plaque solution aerosol and the aerosol from drilling a tooth by examining the distribution of floating aerosol in the air turbine's tank when a plaque solution was sprayed and when a human tooth was drilled with a plaque solution. We concluded that infectious aerosol increases in diameter with the drilling of human teeth to the size of about 0.5-5.0 micrometers, which is microbiologically and hygienically hazardous and also can be inhaled without much difficulty.

Long-term evaluation of discectomy of the temporomandibular joint.

A clinical and radiographic survey was conducted with 39 patients (39 joints) who had undergone discectomy of the temporomandibular joint between 1965 and 1974 and whose cases had been followed for an average of 20 years after surgery. There were 3 males and 36 females, ranging in age from 16 to 70 years (average, 33 years) at the time of surgery. Masticatory disorders, arthralgia, limitation of condylar movement, and trismus were the chief symptoms, and clicking and crepitus were present in six and two patients, respectively. Plain radiography showed osteoarthritic changes such as osteophyte formation or lipping on the condyles of eight joints. Arthrography showed disc perforations and peridiscal adhesions in 27 patients, and displacement of the disc in eight. All discs were totally extirpated and condylar shaves were performed in eight patients who had disorders such as osteophytes, exostoses, or lipping on the condyles. In follow-up examinations, 37 patients had no pain, but mild arthralgia was noted occasionally in two patients. Postoperatively, no patients experienced subjective masticatory disorders; 38 patients were able to open their mouth more than 35 mm, and crepitus was heard in only two joints. Plain radiography showed bony changes on the condyles and eminences of all joints. From this long-term follow-up study it is concluded that discectomy is a useful operation for treatment of severe disc pathology causing pain and functional disturbance in the temporomandibular joint.

[Multiple cooperative study of UFT-adjuvant chemotherapy for malignant tumor in the jaw and oral cavities. The Oral Surgery Malignant Tumor Research Association in Kanto Kohshinetsu District].

We studied the usefulness and safety of long-term administration of uracil and tegafur (UFT) after primary therapy of the malignant tumor in jaw and oral cavity regions randomized controlled trial. 112 cases were totallized 6 institutes belonging to the Oral Surgery Malignant Tumor Research Association in Kanto Kohshinetsu District during 2 years and 10 months, beginning in September 1986. After completing the primary therapy, treatment was not performed in group A and 400 mg/day of UFT was orally administered in group B for 1 year. A variation was observed in the stages of background factors such as sex and age (more than 30 years old and less than 80 years old), while no such discrepancy was observed in other stages. No significant difference of 1-year-survival ratio and non-recurrence ratio was noted in either group, while the non-recurrence ratio was more favorable in group B than group A, and the usefulness of UFT for adjuvant chemotherapy was suggested. The incidence of side effects in group B was 42.6%, and no serious side effect was observed.

Validity of salivary thiocyanate as an indicator of cyanide exposure from smoking.

The purpose of this study was to evaluate the validity of salivary thiocyanate as an indicator of cyanide exposure from smoking. The salivary thiocyanate level showed wide variation, and the largest source of thiocyanate was hydrogen cyanide from cigarette smoke. Hydrogen cyanide in the mainstream of cigarette smoke was as high as 40-70 ppm, which is beyond the threshold limit value for occupational health (10 ppm). The hydrogen cyanide level in the sidestream smoke was lower less than 5 ppm. Thus the amount of cyanide intake was larger in active smokers than in passive ones. The correlation between the thiocyanate level in saliva and plasma was statistically significant. Thiocyanate levels in both plasma and saliva increased with the amount of cigarette smoke, and the discriminant powers (smoker versus non smoker) of thiocyanate levels in both plasma and saliva were quite similar. The smoker/non smoker ratio for salivary thiocyanate was 3.04 and that of plasma thiocyanate was 1.73. The result indicated that smoking status could be reflected more by the thiocyanate level in saliva than in plasma. The biological half life of salivary thiocyanate was estimated to be as long as 9.5 days from the changes salivary thiocyanate after stopping smoking. From the results of this study, it was concluded that salivary thiocyanate was a suitable indicator of habitual smoking exposure.