[Epidemiologic study of patients with craniomandibular disorders. Report of data and clinical findings]

BACKGROUND

The purpose of this retrospective study was to identify the subjective and objective characteristics of a population referred to a clinic for diagnosis and treatment of orofacial pain and/or temporomandibular disorders.

METHODS

Beginning in 1993, 825 patients, consecutively referred to the University of Naples Federico II , were examined and their records entered into a database. These data were collected by trained clinicians. Diagnostic subgroups were identified following the Research Diagnostic Criteria for temporomandibular disorders (RDC).

RESULTS

Seventy-nine percent of patients were female, the mean age of the sample was 31.3+/-13 years (range: 5 to 74 years), most of patients were between 15 and 39 years of age. Based on diagnostic subgroups, patients were divided into: patients affected with myogenous pain (59%), arthrogenous pain (13%), arthrogenous and myogenous pain (16%) and fibromyalgia (4%). Sixty-three percent of the sample reported recent headaches, 53% reported parafunction, and 28% reported a previous trauma. Eighty-one percent reported spontaneous pain, which was chronic in 83% of them. The majority of patients (78%) presented a relatively high cultural BACKGROUND.

CONCLUSIONS

These data appear to agree with other epidemiologic studies and depict the TMD treatment-seeking population as a predominantly female population during child-bearing years with multiple chronic pain complaints.

Mandibular rest position and electrical activity of the masticatory muscles

STATEMENT OF PROBLEM

The determination of a correct vertical dimension of occlusion is a critical procedure in clinical dentistry.

PURPOSE

The objectives of this study were to analyze the relation between mandibular rest position and electrical activity of masticatory muscles and to compare clinical and electromyographic rest position in subjects with different vertical facial morphologic features.

MATERIAL AND METHODS

Clinical rest position and electromyographic rest position were investigated in 40 subjects. Electromyographic rest position ranged from 0.4 to 12.7 mm (average 7.7 +/- 2.7 mm). Clinical rest position ranged from 0.1 to 4.4 mm (average 1.4 +/- 1.1 mm). The average difference between electromyographic rest position and clinical rest position was 6.3 +/- 2.5 mm (range 0.3 to 10.3 mm). Sixteen subjects were selected according to the Frankfort mandibular plane angle and separated in two groups having a mandibular plane angle > or = 28 degrees.

RESULTS

Rest position was significantly greater (p < 0.05) in the low-angle group (2 +/- 1.3 mm) than in the high angle group (0.8 +/- 0.8 mm). Electromyographic rest position did not differ between subjects with different facial morphologic features (8.1 +/- 1.7 mm low-angle group; 7.6 +/- 4.1 mm high angle group). By varying the vertical dimension millimeter by millimeter, masseter and anterior temporal electromyographic activity demonstrated a considerable decrease over an interocclusal distance of 3 to 4 mm. Further mandibular opening up to 18 mm corresponded to small changes in postural activity.

CONCLUSION

This study suggests that a jaw posture with a few millimeters of interocclusal distance involves a great reduction of masticatory muscle activity.