Novel 3-dimensional analysis to evaluate temporomandibular joint space and shape.

INTRODUCTION: The purpose of this study was to present and validate a novel semiautomated method for 3-dimensional evaluation of the temporomandibular joint (TMJ) space and condylar and articular shapes using cone-beam computed tomographic data. METHODS: The protocol for 3-dimensional analysis with the Checkpoint software (Stratovan, Davis, Calif) was established by analyzing cone-beam computed tomographic images of 14 TMJs representing a range of TMJ shape variations. Upon establishment of the novel method, analysis of 5 TMJs was further repeated by several investigators to assess the reliability of the analysis. RESULTS: Principal components analysis identified 3 key components that characterized how the condylar head shape varied among the 14 TMJs. Principal component analysis allowed determination of the minimum number of landmarks or patch density to define the shape variability in this sample. Average errors of landmark placement ranged from 1.15% to 3.65%, and none of the 121 landmarks showed significant average errors equal to or greater than 5%. Thus, the mean intraobserver difference was small and within the clinically accepted margin of error. Interobserver error was not significantly greater than intraobserver error, indicating that this is a reliable methodology. CONCLUSIONS: This novel semiautomatic method is a reliable tool for the 3-dimensional analysis of the TMJ including both the form and the space between the articular eminence and the condylar head.

Comparison of subjective symptoms of temporomandibular disorders in young patients by age and gender.

The authors assessed the subjective symptoms of temporomandibular disorders (TMDs) in 167 young patients using self-reported forms, with five ratings for pain intensity and six ratings for difficulty in activities of daily living (ADL), to compare TMD symptoms according to gender and three age groups: group 1: 6- to 12-year-olds (juvenile); group 2: 13- to 15-year-olds (early adolescent); group 3: 16- to 18-year-olds (late adolescent). No significant gender differences were found in the symptoms among the groups, except for headache and neck pain in group 3. Pain intensity and tightness in the jaw/face, headache, and neck pain, as well as the ADL-related difficulty in prolonged jaw opening, eating soft/hard foods, and sleeping significantly differed among the groups (p < 0.01, Kruskal-Wallis test). Therefore, late adolescent patients with TMDs have higher pain intensity in the orofacial region and greater difficulty in ADL than do early adolescent and juvenile patients with TMDs.

Comparison of patients with orofacial pain of different diagnostic categories.

The authors compared the pain intensity and difficulty experienced in performing activities of daily living (ADL) among 237 patients with orofacial pain. The patients underwent comprehensive examinations and recorded their subjective symptoms on a form (five items for pain intensity and six for ADL-related difficulty). On the basis of the primary diagnosis, the patients were divided into the temporomandibular joint dysfunction (TMJ), myofascial pain (MP), neuropathic pain (NP), and fibromyalgia (FM) groups. The intensity of pain in the jaw/face, tightness in the jaw/face, pain in the neck, and toothache significantly differed among the groups (p < 0.01, Kruskal-Wallis test). Compared to other patients, the FM and NP groups reported greater pain intensity, whereas those in the TMJ group reported lesser pain intensity. The ADL-related difficulty was not significantly different among the groups. Thus, compared to pain due to joint-related disorders, myalgic and neuropathic pain seem to be of higher intensity.

Comparison of subjective symptoms among three diagnostic subgroups of adolescents with temporomandibular disorders.

AIM: To compare subjective symptoms among three diagnostic subgroups of young patients with temporomandibular disorders (TMDs). DESIGN: We comprehensively examined 121 patients with TMDs (age ≤20 years; 90 female patients and 31 male patients) who completed self-reported forms for assessing subjective symptoms, which consisted of five items on pain intensity in the orofacial region and six items on the level of difficulty in activities of daily living (ADL) (rating scale, 0-10). They were divided into three diagnostic subgroups: temporomandibular joint (TMJ) problem (JT) group, masticatory muscle pain (MM) group, and the group with a combination of TMJ problems and masticatory muscle pain (JM group). Their symptoms were compared using the Kruskal-Wallis and Mann-Whitney U-tests. RESULTS: The intensity of jaw or face tightness and difficulty in talking and yawning were not significantly different among the groups. However, the MM and JM groups had a significantly higher rating for jaw or face pain, headache, neck pain, tooth pain, and difficulty in eating soft foods (P < 0.01). CONCLUSIONS: Young patients with MM or JM report more intense pain in the orofacial region and have more difficulties in ADL than those with JT problems alone.

The impact of synthetic pyrethroid and organophosphate sheep dip formulations on microbial activity in soil.

Sheep dip formulations containing organophosphates (OPs) or synthetic pyrethroids (SPs) have been widely used in UK, and their spreading onto land has been identified as the most practical disposal method. In this study, the impact of two sheep dip formulations on the microbial activity of a soil was investigated over a 35-d incubation. Microbial utilisation of [1-(14)C] glucose, uptake of (14)C-activity into the microbial biomass and microbial numbers (CFUs g(-1) soil) were investigated. In control soils and soils amended with 0.01% sheep dip, after 7d a larger proportion of added glucose was allocated to microbial biomass rather than respired to CO(2). No clear temporal trends were found in soils amended with 0.1% and 1% sheep dips. Both sheep dip formulations at 0.1% and 1% concentrations resulted in a significant increase in CFUs g(-1) soil and [1-(14)C] glucose mineralisation rates, as well as a decline in microbial uptake of [1-(14)C] glucose, compared to control and 0.01% SP- or OP-amended soils. This study suggests that the growth, activity, physiological status and/or structure of soil microbial community may be affected by sheep dips.

Reproducibility of visual analog scale (VAS) pain scores to mechanical pressure.

This study tested the reproducibility of visual analog scale (VAS) pain scores to measure changes in masseter muscle pain evoked by maximally tolerable mechanical stimulation over a short time period in healthy subjects. This study also evaluated gender differences in reproducibility of VAS scores to mechanical stimulation. Ten healthy female and eight healthy male individuals participated in this study. The recordings of VAS pain scores to an identical mechanical pressure on the masseter muscle were performed at three different sessions (T1, T2, and T3). The subjects rated their pain on a VAS to a maximally tolerable stimulus that was recorded on an algometer at the first session. The algometer pressure reading was recorded for each subject and then used to duplicate the same identical mechanical stimulus at each of the three sessions. This identical pressure was repeated in the same marked spot at six minutes and after 30 minutes. The subjects rated the pain on a VAS to this identical stimulus at each session. There was no significant difference in VAS pain scores of all subjects at T1, T2, and T3. There was no significant difference in reproducibility of VAS pain scores in females compared to males. Intraclass correlation coefficients were 0.811 on the right masseter and 0.844 on the left masseter. VAS pain scores to mechanical stimulation were reproducible over a short time period. Gender did not affect the reproducibility. This previously unreported method of measuring pain to repeated identical mechanical stimulation appears to have potential for both clinical and research application.

Acupuncture and sham acupuncture reduce muscle pain in myofascial pain patients.

AIMS: To compare the effectiveness of dry needling in classically recognized acupuncture points ("acupuncture") with dry needling in skin areas not recognized as acupuncture points ("sham acupuncture") in reducing masseter muscle pain in a group of patients with myofascial pain of the jaw muscles. METHODS: Eighteen patients were randomly assigned to 1 of 2 experimental groups: Ten patients received acupuncture and 8 received sham acupuncture. A visual analog scale (VAS) was used to measure changes in masseter muscle pain evoked by mechanical stimulation of the masseter muscle before and after the experiment. RESULTS: Both groups showed a statistically significant reduction in VAS pain scores (P = .001). Seven out of 10 acupuncture subjects had a 10 mm or greater VAS reduction in pain, while 4 out of 8 of the sham acupuncture subjects had that great a pain reduction. There was no significant difference between the 2 groups. CONCLUSION: Both acupuncture and sham acupuncture reduced pain evoked by mechanical stimulation of the masseter muscles in myofascial pain patients. However, this reduction in pain was not dependent on whether the needling was performed in standard acupuncture points or in other areas of the skin. These results suggest that pain reduction resulting from a noxious stimulus (i.e., needling) may not be specific to the location of the stimulus as predicted by the classical acupuncture literature.