Journal of Oral & Facial Pain and Headache, 03/1998

This study explored the relationship between malocclusion and signs and symptoms of temporomandibular disorders (TMD) in 124 patients with severe Class II malocclusion, before and 2 years after bilateral sagittal split osteotomy (BSSO). Patients were evaluated with the Craniomandibular Index (CMI), the Peer Assessment Rating Index (PAR Index, to assess gross changes in the occlusion), and symptom questionnaires. The results showed a significant improvement in occlusion; PAR Index scores dropped from a mean of 18.1 before surgery to a mean of 6.1 at 2 years postsurgery (P 0.001). The CMI and masticatory index (MI) for muscle pain indicated clinically small but statistically significant improvement (P = 0.0001) from before surgery (mean CMI = 0.14, mean MI = 0.15) to after surgery (mean CMI = 0.10, mean MI = 0.08). The number of patients with clikcing upon opeining decreased significantly from 33 (26.6%) to 13 (10.5%) (P = 0.001). However, the number of patients with fine crepitus increased from 5 (4.0%) before surgery to 16 (12.9%) at 2 years postsurgery (P = 0.005). Significant reductions in subjective pain and discomfort were also found 2 years after surgery. The magnitude of change in muscular pain was not related to the severity of the pretreatment malocclusion, a finding that suggests that factors other than malocclusion may be respondible for the change in TMD.

To assess the latent factor structure of clinical examination findings obtained from temporomandibular disorder patients, exploratory factor analysis was used to examine the relationships of a large number of variables obtained from a clinical examination to a smaller number of latent variables, or factors. Two independent samples of patients - an initial sample that consisted for 330 patients who complained of facial pain and a validation sample of 161 additional patients - were examined to determine whether the factor structure was reliable. A principal axis factor analysis with varimax rotation was used for both sets of data. The factor structure for the two samples was consistent between the two sets of data. Results identified two muscle pain factors (an intraoral muscle factor an an extraoral muscle factor), two unilateral jaw pain factors, and two factors that concern joint noise clicking (clicking and crepitus). The implications of these findings for the current nosologic systems for temporomandibular disorders are discussed.

The purpose of this project was to test the within-day and between-days reproducibility of a new and inexpensive algometer. Twelve symptom-free men and nine women participated. Pressure pain thresholds (PPTs) of the bilateral masseter and temporalis muscles were assessed during four sessions (mornings and afternoons of days 1 and 3). During each session, each palpation point of the masti catory muscles was measured four times. There was an interval of only a few seconds between measurements 1 and 2, and between measurements 3 and 4, respectively, while a t least 5 minutes of rest were allowed between measurements 2 and 3. The PPT values between the morning and afternoon sessions and between days 1 and 3 were not significantly different. When the within-session reproducibility for all muscles was considered, only the PPT values between measurements 2 and 4 were not significantly different. Analysis of variance showed that the interindividual variablity of PPT was 1.4 to 6.8 times higher than the variability observed within or between sessions and days. No gender difference was found.

The outcome of different treatment modalities after 7 years was investigated in a selected group of 50 patients with craniomandibular disorders of muscular origin. To minimize the possible effects of selection on the clinical mat erial, the selected treatment group was compared to a consecutive group of patients in terms of age, gender, intensity/duration of pain, and socioeconomic profile. Both groups were comparable in most respects, but the selected group had a longer duration and a higher intensity of pain at baseline. There were more men in the consecutive group than in the selected group. A combined treatment appraoch resulted in a better outcome than single treatments. Sixty-five percent of all patients in the selected group reported improvement at the 7-year follow-up. All of the 19 patients who received counseling combined with different occlusal treatments improved. Forty-three percent of the patients treated otherwise showed improvement. Patients who were aware of stress responded better to treatment.

This age-matched and sex-matched study examined the influence of postoperative telephone calls on pain perception and on the number of analgesics used for pain relief. Adult periodontitis subjects (n = 118) received perio dontal surgery after examination and sanative therapy (scaling, root planing, and removal of local irritants). All sujbects received similar care, postoperative instructions, and medication, except 59 subjects were phoned 24 hours postoperative (PC group), and 59 were not (NC group). Callers covered 10 points and were reassuring and positive about surgical outcomes. One week postoeprative, subjects completed a questionnaire that rated pain intensity on a visual analogue scale and indicated the number of pills used and whether they had been called. Pain and analgesics used were significantly decreased in the PC group (P 0.001) compared to the NC group. A significant positive correlation was found between pain the pills used in the groups combined (r = 0.79, P 0.001 PC + NC), and in the groups separately (r = 0. 50, P 0.001 PC; r = 0.41, P 0.01 NC). Postoperative communication between healthcare providers and patients significantly reduces pain perception and number of analgesics used for relief.

Based on biomechanic and electromyographic studies, it has been argued that the two heads of the human lateral pterygoid muscle (LPt) are receiprocally active during the masticatory cycle. Thus, it has been propsed that the heads be considered separate muscles. However, questions about the accuacy of these data have arisen. The authors hypot hesized that partition cannot be complete without an indepedent nerve supply. To test this, complete unilateral latertal pterygoidectomies were performed on 20 dissection room cadavers. A novel approach, using an en bloc method, proved optimal to expose the detailed nerve supply to the LPt heads. In the two most frequently observed patterns (15 of the 20 specimens), the heads were supplied from a commo n source that was derived from either the long buccal or mandibular nerve, or from a loop that arose between the long buccal and lingual nerves. In a third pattern, indepedent branches to either head arose from the deep temporal, long buccal, or mandibular nerve. In only 20% of the specimens did the two heads receive exclusive inner vation from separate sources. The most significant finding of the present study is that both LPt heads in humans are usually supplied by a common proximate source, but each head also receives independent nerves in every case. In the absence of precise inforamtion about the functional components in each nerve branch, these data appear to support Juniper's proposal to regard the two LPt heads as entirely separate muscles.