Journal of Oral & Facial Pain and Headache, 02/2000

Aims: A new pressure algometer was used to quantify the pressure-pain threshold (PPT) in the human tongue. Methods: A custom-made device controlled by software and a personal computer was used to measure the PPT in the anterior part of the tongues of 14 young, healthy subjects. The PPT was measured at 3 different rates of pressure application on 3 occasions, 1 week apart. Data were evaluated with analysis of covariance and intraclass correlations. Results: The prototype device had linear output characteristics within the operational range. The mean PPT ranged from 18 to 44 g. The PPT appeared to increase approximately linearly with increasing rate of pressure application (P < 0.001). There were no significant differences in the PPT on different experimental occasions. In individual subjects, the PPT was reliable and uniform. There were significant inter-subject differences in the PPT (P < 0.001). Conclusion: The PPT can be measured consistently in the anterior part of the tongue, provided the pressure rate is controlled. The new pressure algometer appears to have potential clinical utility for quantifying sensation in the human tongue.

Aims: To investigate and compare absolute pressure-pain threshold (PPT) levels and ratios between craniofacial test and reference sites during consecutive PPT recordings, as well as over a 6-month period, in healthy individuals. This study also investigated PPT differences between genders and the clinical usefulness of different reference sites in the craniofacial region. Methods: Twelve female and 12 male healthy individuals participated in the first examination. Six months later, 9 females and all of the males returned for a second examination. An electronic algometer was used to make 5 consecutive recordings of PPTs with a 2-minute interval at 3 reference sites: mental protuberance (PRO), first metacarpal bone (MET), and frontal bone (FRO), as well as at 3 test sites: temporomandibular joint, masseter muscle, and temporalis muscle. Results: Absolute PPTs decreased significantly for all test sites during the 5 recordings, while they increased significantly between the examinations. No ratio with FRO as a reference site changed significantly. The males had significantly higher absolute PPTs than the females at PRO and FRO sites. Conclusion: This study shows that absolute PPT levels in healthy individuals change significantly during consecutive PPT recordings, as well as over a 6-month period; this limits the usefulness of such measurements. This study also shows that the use of relative PPTs with the FRO as a reference site is useful, both for comparison between groups and for longitudinal studies.

Aims: To test the hypothesis that the ovarian cycle influences the pressure-pain threshold of the masticatory muscles. Methods: Eighteen healthy women with a regular menstrual cycle (28 ± 2 days), ranging in age from 18 to 35 years, participated in the study. For each subject, pressure-pain thresholds (PPTs) of the masseter and temporalis muscles were assessed at 4 muscular sites by means of an electronic algometer. Measurements were taken at 4 separate sessions across the menstrual cycle corresponding to the following phases: menstrual, follicular, periovulatory, and luteal. Menstrual cycle phases were determined by a pelvic ultrasonographic screening. The study was carried out in a single-blind design, and the initial session was randomly determined for each individual. Data collected were analyzed by repeated-measures analysis of variance. Results: The findings suggest that the PPTs of several masticatory muscles (2 of 4) are influenced by the ovarian cycle, but to a minor extent (P < 0.05), and the influence is of limited clinical relevance. Conclusion: In healthy subjects, there is a link between mechanical sensitivity of the masticatory muscles and fluctuation of the ovarian hormones. The relationship between PPTs of the masticatory muscles and the ovarian cycle should be also investigated in patients with temporomandibular disorders and/or orofacial pain conditions.

Aims: This study examined whether temporomandibular disorder (TMD) patients with sexual versus physical abuse histories differ in their pain report, psychological distress, and somatic symptoms. Methods: Participants were 114 female TMD patients. The sample was divided into 3 groups based on abuse history: sexual abuse, physical abuse, or no abuse. Abuse histories were assessed with a structured clinical interview. Measures used included the McGill Pain Questionnaire, the State-Trait Anxiety Inventory, the Beck Depression Inventory, and the Pennebaker Inventory of Limbic Languidness. Group differences were analyzed by analysis of variance and Bonferroni post hoc comparisons. Results: Temporomandibular disorder patients with a history of physical abuse reported significantly more pain, anxiety, and depressive symptoms than did patients with a history of sexual abuse or no history of abuse. Furthermore, the results suggest that TMD patients with a sexual abuse history are not significantly different from patients with no abuse history across the domains studied. Conclusion: Based on the differences found, it can be argued that assessment of physical abuse histories by appropriately trained clinicians should be a routine part of any multimodal assessment of female chronic TMD patients.

Aims: The purpose of this study was to examine the influence of clinician bias on patients' reports of referred pain. Diagnosis of temporomandibular disorders is dependent on subjective reports of pain and referred pain upon manual muscle palpation. The influence of biased clinician statements in such subjective reports has not been previously investigated. Methods: Forty subjects with pain and who met specific inclusion criteria were randomly assigned to 1 of 2 experimental groups. One group was subjected to a standardized biasing statement, while the other group was not. Tender points in the masseter muscle were then stimulated with a pressure algometer to the pressure-pain threshold. Subjects then recorded the presence or absence, location, intensity, and unpleasantness of any referred pain. State-trait anxiety and social desirability were also assessed to explore the possibility that anxiety levels or subjects' desires to please the experimenter influenced results. Results: The biased group reported increased presence (P < 0.01), intensity (P < 0.001), and unpleasantness (P < 0.003) of referred pain as compared to the non-biased group. There were no differences between groups on state-trait anxiety or social desirability (P > 0.05). Conclusion: These data suggest that patient reports of pain referral may be subject to clinician bias, and recommendations to control this bias are offered.

AIMS: A new individualized oblique-axial orientation of magnetic resonance imaging scans of the temporomandibular joint (TMJ), corrected to be perpendicular to the tangent of the posterior slope of the articular eminence, has been proposed to improve the representation of the disc. The aim of this study was to evaluate the quality of the images obtained with this new type of scanning plane and to assess the factors that can affect the scans. METHODS: Twenty-nine TMJs were scanned by the use of sagittal, conventional coronal, and individualized oblique-axial scanning planes. On the sagittal images, the angle alpha between the tangent of the posterior slope of the articular eminence and the vertical was measured, and the disc position was evaluated. For both imaging planes, 2 examiners, blind to the scanning techniques, counted the number of conventional coronal and oblique-axial scans in which the disc was visible and in which the medial and lateral disc borders were well demarcated and evaluated the mediolateral disc position. RESULTS: The individualized oblique-axial technique was superior to the conventional coronal technique in depicting the disc and its medial and lateral demarcations (paired t test, P < 0.05). The possibility of correct diagnosis of the mediolateral disc position and the agreement between the observers in this evaluation were better with the oblique-axial technique than with the conventional technique (P < 0.05). This was particularly evident when the disc was anteriorly displaced. CONCLUSION: The individualized oblique-axial scanning planes should be used for a better representation of the disc/condyle complex mediolaterally if the disc is anteriorly displaced.

The purpose of this case report is to highlight the possibility that malignant neoplasms of the deep lobe of the parotid gland may present as a temporomandibular disorder (TMD). Two patients who were eventually diagnosed with deep-lobe parotid tumors were retrospectively analyzed clinically, radiographically, and pathologically. For the first patient, there was a prolonged delay in establishing the correct diagnosis; for the second patient the delay was shorter. This was done primarily by computed tomographic examination. Despite aggressive surgical, radiotherapeutic, and chemotherapeutic treatment, both patients died from their malignant disease. All clinicians who treat TMD must be aware of the rare possibility of deep-lobe parotid tumors presenting as a TMD.

This case report first reviews the intracranial tumors associated with symptoms of trigeminal neuralgia (TN). Among patients with TN-like symptoms, 6 to 16% are variously reported to have intracranial tumors. The most common cerebellopontine angle (CPA) tumor to cause TN-like symptoms is a benign tumor called an acoustic neuroma. The reported clinical symptoms of the acoustic neuroma are hearing deficits (60 to 97%), tinnitus (50 to 66%), vestibular disturbances (46 to 59%), numbness or tingling in the face (33%), headache (19 to 29%), dizziness (23%), facial paresis (17%), and trigeminal nerve disturbances (hypesthesia, paresthesia, and neuralgia) (12 to 45%). Magnetic resonance imaging with gadolinium enhancement or computed tomography with contrast media are each reported to have excellent abilities to detect intracranial tumors (92 to 93%). This article then reports a rare case of a young female patient who was mistakenly diagnosed and treated for a temporomandibular disorder but was subsequently found to have an acoustic neuroma located in the CPA.