J Manipulative Physiol Ther 2003 (Sep); 26 (7): 421-425 ~ FULL TEXT
James W DeVocht, DC, PhD, Cynthia R Long, PhD,
Deborah L Zeitler, DDS, Walter Schaeffer, DC
Palmer Center for Chiropractic Research,
741 Brady Street, Davenport, Iowa 52803, USA.
OBJECTIVE: To determine if there was a basis for the treatment of temporomandibular disease (TMD) using the chiropractic protocol developed by Activator Methods, International.
SETTING: Private, solo practice of an Activator advanced proficiency rated chiropractor with 15 years experience.
DESIGN: Prospective case series.
PARTICIPANTS: Nine adult volunteers with articular TMD recruited from the practice of the treating clinician.Main outcome measures Change from baseline to follow-up of Visual Analog Scale (VAS) for temporomandibular joint (TMJ) pain and maximum active mouth opening without pain.
INTERVENTIONS: Full spine and TMJ adjusting in accordance with the advanced protocol of Activator Methods, International. Participants were typically seen 3 times per week for 2 weeks and according to individual progress thereafter for 6 more weeks.
RESULTS: Eight participants completed outcome assessments. The median VAS decrease was 45 mm (range 21-71); all experienced improvement. The median increase of mouth opening was 9 mm (range 1-15); all showed improvement.
CONCLUSION: The results of this prospective case series indicated that the TMD symptoms of these participants improved following a course of treatment using the Activator Methods, International protocol. Consequently, further investigation of this type of chiropractic treatment for patients with the articular type of TMD is warranted.
From the FULL TEXT Article
Although the specific mechanisms of chiropractic treatment are not well understood or mutually agreed upon, they are commonly thought to improve the biomechanics of articulating structures. Chiropractic treatment is most often applied to the spine, but many chiropractic clinicians use well-established protocols to treat other structures, including hands, feet, knees, and even cranial bones, with the belief that they are improving the biomechanical functioning of those structures. Since articular TMD is believed to involve the biomechanical functioning of 1 or more of the structures within the TMJ, it seems reasonable to suppose that chiropractic treatment of the structures of the TMJ may well have a beneficial effect in cases of articular TMD. That notion is supported by the isolated events described in the case histories referred to in the Introduction and now also by the results of this preliminary study.
Maximum mouth opening was found to improve in every one of the 8 cases that had an outcome measure, with a median of a 9-mm increase. In view of Kropmans et al  finding that 9 mm was the smallest detectable difference, this result suggests clinical improvement. This is further strengthened by noting that all 3 of the cases with less than 9-mm improvement (1 mm, 6 mm, and 7 mm) had high baseline measurements (55 mm, 43 mm, and 47 mm, respectively), with the others in the case series being considerably lower.
VAS measurements were also seen to improve in each of the 7 cases that had both VAS measurements. The median decrease was 45 mm on a 100-mm scale, with a range of 21 mm to 71 mm. Inasmuch as Kelly12 reports that 9 mm is the minimum clinically significant difference on a scale of 100 mm, the VAS results of this case series indicate a marked decrease in pain for the participants.
A limitation of this study is that there was no control group, which is inherent in a case-series type study. Therefore, any participant improvement noted over the course of the study may not be due specifically to the treatment given. This study was based on observing and documenting the condition of the participants before and after the clinician's regimen of treatment in his normal practice. However, it is of interest to note that the median duration of symptoms before beginning treatment was 8 years. Consequently, improvement seen over the course of the 3 to 8 weeks of care seen in this study may indicate an actual therapeutic effect. Future studies should include a control group.
One of the lessons learned in this preliminary study was the difficulty in obtaining follow-up for patients in ambulatory settings. The intent was to collect data at baseline and again at the last visit prior to treatment. However, that was not always possible. Fortunately, the clinician also collected data on some intermediate visits for most participants. Noting that 5 of 8 outcome assessments in this study were made before the last visit of the participant, we feel that the improvement reported here may actually be a conservative estimate of the overall effect.
The patients who were asked by the clinician and subsequently volunteered to become participants in this case series seem to be representative of the typical TMD sufferer seeking treatment, as described by Shimshak et al.  However, eligibility criteria will need to be more rigorous and verified in future studies.
The quantified results of both outcome measures used in this prospective case series indicate that the TMD symptoms of participants in this study improved following a course of treatment using the Activator Methods, International protocol for adjusting the TMJ. Consequently, further investigation of this type of chiropractic treatment for patients with the articular type of TMD is warranted.