This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Dao, T.T.T. Articles by Lund, J.P. Search for Related Content PubMed PubMed Citation Articles by Dao, T.T.T. Articles by Lund, J.P. Pubmed/NCBI databases Medline Plus Health Information Clinical Trials Joint Disorders Social Bookmarking                         What's this?

Power and Sample Size Calculations for Clinical Trials of Myofascial Pain of Jaw Muscles

Faculté de medecine dentaire et Centre de recherche en sciences neurologiques, Université de Montreal, C.P. 6128, Succ. A, Montreal, PQ, Canada H3C 3J7

G.J. Lavigne

Faculté de medecine dentaire et Centre de recherche en sciences neurologiques, Université de Montreal, C.P. 6128, Succ. A, Montreal, PQ, Canada H3C 3J7

J.S. Feine

Faculté de medecine dentaire et Centre de recherche en sciences neurologiques, Université de Montreal, C.P. 6128, Succ. A, Montreal, PQ, Canada H3C 3J7

R. Tanguay

Faculté de medecine dentaire et Centre de recherche en sciences neurologiques, Université de Montreal, C.P. 6128, Succ. A, Montreal, PQ, Canada H3C 3J7

J.P. Lund

Faculté de medecine dentaire et Centre de recherche en sciences neurologiques, Université de Montreal, C.P. 6128, Succ. A, Montreal, PQ, Canada H3C 3J7

When a clinical trial is planned, the approximate number of subjects needed for significant differences between/among groups to be detected must be estimated. Sample-size calculations provide the investigator with this information.

This paper discusses the choice of outcome measures and describes the steps used to estimate the numbers of subjects necessary for a study that compares treatments for patients with chronic myofascial pain of jaw muscles. Within- and between-subject variances were estimated for the chosen variables, the subjects' pain ratings on visual analogue scales. Sample sizes were then calculated for theoretical differences between groups by pre-treatment means and overall standard deviations (Cohen, 1977).

The results of this analysis can be used by other researchers when planning studies involving these types of patients.

REFERENCES

• Altman, D.G. (1980): Statistics and Ethics in Medical Research. III. How Large a Sample?, Br Med J 281:1336-1338.[Free Full Text]
• Bell, W.D. (1982): Classification of TM Disorders. In: The President's Conference on the Examination, Diagnosis and Management of Temporomandibular Disorders, D. Laskin, W. Greenfield, E. Gale, J. Rugh, P. Neff, C. Alling, and W.A. Ayer, Eds., Chicago: American Dental Association, pp. 24-29.
• Bell, W.D. (1990): Temporomandibular Disorders. Classification, Diagnosis, Management, 3rd ed., Chicago: Yearbook Medical Publishers.
• Clark, G.T.; Lanham, F.; and Flack, V.F. (1988): Treatment Outcome Results for Consecutive TMJ Clinic Patients, J Craniomandib Disord 2:87-95.[Medline] [Order article via Infotrieve]
• Cohen, J. (1977): Statistical Power Analysis for the Behavioral Sciences, New York: Academic Press.
• Cooper, B.C. and Rabuzzi, D.D. (1984): Myofacial (sic) Pain Dysfunction Syndrome: A Clinical Study of Asymptomatic Subjects, Laryngoscope 94:68-75.[Medline] [Order article via Infotrieve]
• Dao, T.T.T.; Charbonneau, A.; Feine, J.S.; Tanguay, R.; Lund, J.P.; and Lavigne, G.J. (1989): Sample Size Estimation in a Myofascial Pain (MPD) Study, J Dent Res 68 (Sp Iss): 1017, Abst. No. 1206.
• Duncan, G.H.; Bushnell, M.C.; and Lavigne, G.J. (1989): Comparison of Verbal and Visual Analogue Scales for Measuring the Intensity and Unpleasantness of Experimental Pain, Pain 37:295-303.[CrossRef][Medline] [Order article via Infotrieve]
• Ekblom, A. and Hansson, P. (1988): Pain Intensity Measurements in Patients with Acute Pain Receiving Afferent Stimulation, J Neurol Neurosurg Psychiat 51:481-486.[Abstract/Free Full Text]
• Feine, J.S.; Dao, T.T.T.; Lavigne, G.J.; and Lund, J.P. (1989): Is Treatment Success due to Faulty Memory of Chronic Pain?, J Dent Res 68 (Sp Iss):1018, Abst. No. 1207.
• Freiman, J.A.; Chalmers, T.C.; Smith, H.; and Kuebler, R.R. (1978): The Importance of Beta, the Type II Error and Sample Size in the Design and Interpretation of the Randomized Control Trial, N Engl J Med 299:690-694.[Abstract]
• Friedman, L.M.; Furberg, C.D.; and Demets, D.L. (1985): Fundamentals of Clinical Trials, Littleton: PSG Publishing Company.
• Goldstein, H. (1979): The Design and Analysis of Longitudinal Studies, London: Academic Press.
• Goldstein, H. (1987): Multilevel Models in Educational and Social Research, London: Griffin.
• Gore, S.M. (1981): Assessing Clinical Trial Size, Br Med J 282:1687-1689.[Free Full Text]
• Greene, C.S. and Laskin, D.M. (1983): Long-term Evaluation of Treatment for Myofascial Pain-Dysfunction Syndrome: a Comparative Analysis, J Am Dent Assoc 107:235-238.[Abstract]
• Griffiths, R.H. (1983): Report of the President's Conference on the Examination, Diagnosis, Management of Temporomandibular Disorders, J Am Dent Assoc 106:75-77.[Medline] [Order article via Infotrieve]
• Harkins, R.; Marteney, J.L.; Cueva, O.; and Cueva, L. (1988): Application of Soft Occlusal Splints in Patients Suffering From Clicking Temporal Mandibular Joints, Cranio 6:72-76.
• Hulley, S.B. and Cummings, S.R. (1988): Designing Clinical Research, Baltimore: Williams and Wilkins.
• Jamison, R.N.; Sbrocco, T.; and Parris, W.C.V. (1989): The Influence of Physical and Psychosocial Factors on Accuracy of Memory for Pain in Chronic Pain Patients, Pain 37:289-294.[CrossRef][Medline] [Order article via Infotrieve]
• Jankelson, R. and Pulley, M.L. (1984): Electromyography in Clinical Dentistry, Seattle: Myotronics Research, Inc.
• Lachin, J.M. (1981): Introduction to Sample Size Determination and Power Analysis for Clinical Trials, Controlled Clin Trials 2:93-113.[CrossRef][Medline] [Order article via Infotrieve]
• Linton, S.J. and Gotestam, K.G. (1983): A Clinical Comparison of Two Pain Scales: Correlation, Remembering Chronic Pain, and a Measure of Compliance, Pain 17:57-65.[CrossRef][Medline] [Order article via Infotrieve]
• Linton, S.J. and Melin, L. (1982): The Accuracy of Remembering Chronic Pain, Pain 13:281-285.[CrossRef][Medline] [Order article via Infotrieve]
• Lund, J.P.; Widmer, C.G.; and Schwartz, G. (1989): What is the Link Between Myofascial Pain and Dysfunction? In: Electromyography of Jaw Reflexes in Man, D. van Steenberghe and A. DeLaat, Eds., Leuven: Leuven University Press, pp. 427-444.
• McNeill, C. (1990): Craniomandibular Disorders-Guidelines for Evaluation, Diagnosis, and Management, Chicago: Quintessence.
• Medical Research Council Of Canada (1987): MRC Guidelines on Research Involving Human Subjects, Ottawa: Supply and Services Canada (MR 21-5/1987).
• Mohl, N.D.; Lund, J.P.; Widmer, C.G.; and McCall, W.D. (1990a): Devices for the Diagnosis and Treatment of Temporomandibular Disorders. Part II: Electromyography and Sonography, J Prosthet Dent 63:332-336.[CrossRef][Medline] [Order article via Infotrieve]
• Mohl, N.D.; McCall, W.D.; Lund, J.P.; and Plesh, O. (1990b): Devices for the Diagnosis and Treatment of Temporomandibular Disorders. Part I: Introduction, Scientific Evidence, and Jaw Tracking, J Prosthet Dent 63:198-201.
• Moller, E.; Sheikholeslam, A.; and Lous, I. (1984): Response of Elevator Activity During Mastication to Treatment of Functional Disorders, Scand J Dent Res 92:64-83.[Medline] [Order article via Infotrieve]
• Moore, P.A.; Duncan, G.H.; Scott, D.S.; Gregg, J.M.; and Ghia, J.N. (1979): The Submaximal Effort Tourniquet Test: its Use in Evaluating Experimental and Chronic Pain, Pain 6:375-382.[CrossRef][Medline] [Order article via Infotrieve]
• Ohnhaus, E.E. and Adler, R. (1975): Methodological Problems in the Measurement of Pain: a Comparison Between the Verbal Rating Scale and the Visual Analogue Scale, Pain 1:379-384.[CrossRef][Medline] [Order article via Infotrieve]
• Price, D.D.; McGrath, P.A.; Rafii, A.; and Buckingham, B. (1983): The Validation of Visual Analogue Scales as Ratio Scale Measures for Chronic and Experimental Pain, Pain 17:45-56.[CrossRef][Medline] [Order article via Infotrieve]
• Reed, J.F. and Slaichert, W. (1981): Statistical Proof in Inconclusive "Negative" Trials, Arch Intern Med 141:1307-1310.[Abstract/Free Full Text]
• Revill, S.I.; Robinson, J.O.; Rosen, M.; and Hogg, M.I.J. (1976): The Reliability of a Linear Analogue for Evaluating Pain, Anesthesia 31:1191-1198.[Medline] [Order article via Infotrieve]
• Rothman, K.J. (1986): Modern Epidemiology, Boston: Little, Brown.
• Rubinoff, M.S.; Gross, A.; and McCall, W.D. (1987): Conventional and Nonoccluding Splint Therapy Compared for Patients with Myofascial Pain Dysfunction Syndrome, Gen Dent (November-December):502-506.
• Rugh, J.D. and Solberg, W.K. (1985): Oral Health Status in the United States: Temporomandibular Disorders, J Dent Educ 49:398-405.[Medline] [Order article via Infotrieve]
• Schneiderman, M.A. (1964): The Proper Size of a Clinical Trial: "Grandma's Strudel" Method, J New Drug (Jan.-Feb.):3-11.
• Scott, J. and Huskisson, E.C. (1976): Graphic Representation of Pain, Pain 2:174-184.
• Shields, J.M.; Clayton, J.A.; and Sindledecker, L.D. (1978): Using Pantographic Tracings to Detect TMJ and Muscle Dysfunctions, J Prosthet Dent 39:80-87.[CrossRef][Medline] [Order article via Infotrieve]
• Spriet, A. and Simon, P. (1985): Methodology of Clinical Drug Trials, New York: Karger.
• Sriwatanakul, K.; Kelvie, W.; Lasagna, L.; Calim-Lim, J.F.; Weis, O.F.; and Mehta, G.I. (1983): Studies with Different Types of Visual Analog Scales for Measurement of Pain, Clin Pharmacol Ther 34:234-239.[Medline] [Order article via Infotrieve]
• Van Willigen, J. (1979): The Sagittal Condylar Movements of the Clicking Temporomandibular Joint, J Oral Rehabil 6:167-175.[CrossRef][Medline] [Order article via Infotrieve]
• Widmer, C.G.; Lund, J.P.; and Feine, J.S. (1990): Evaluation of Diagnostic Tests for TMD, Calif Dent J 18:53-60.
• Woodforde, J.M. and Merskey, H. (1972): Some Relationships between Subjective Measures of Pain, J Psychosom Res 16:173-178.[CrossRef][Medline] [Order article via Infotrieve]
• Young, M.J.; Bresnitz, E.A.; and Strom, B.L. (1983): Sample Size Nomograms for Interpreting Negative Clinical Studies, Ann Intern Med 99:248-251.[Abstract/Free Full Text]

Journal of Dental Research, Vol. 70, No. 2, 118-122 (1991)
DOI: 10.1177/00220345910700020401


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				N.D. Mohl Reliability and Validity of Diagnostic Modalities for Temporomandibular Disorders Advances in Dental Research, August 1, 1993; 7(2): 113 - 119. [Abstract] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Dao, T.T.T. Articles by Lund, J.P. Search for Related Content PubMed PubMed Citation Articles by Dao, T.T.T. Articles by Lund, J.P. Pubmed/NCBI databases Medline Plus Health Information Clinical Trials Joint Disorders Social Bookmarking                         What's this?