Here is the design of a clinical trial:

Official Title: Efficacy and Safety of JHG002(Hominis Placenta, 紫河車) Therapy for Chronic Temporomandibular Joint Dysfunction: A Multicenter Randomized Controlled Trial)

Included conditions:
- Temporomandibular Disorder

Study Armgroups:
- {'label': 'Hominis placental pharmacopuncture', 'type': 'EXPERIMENTAL', 'description': 'The Hominis placental pharmacopuncture group will receive 10 sessions of Hominis placental pharmacopuncture at 2 sessions/week for 5 weeks. A trained doctor of Korean medicine with at least 2 years clinical experience will administer JHG002 pharmacopuncture with a disposable syringe (0.5ml) directly into the designated sites, using a standardized method.', 'interventionNames': ['Other: hominis placental pharmacopuncture']}
- {'label': 'Transcutaneous electrical nerve stimulation', 'type': 'ACTIVE_COMPARATOR', 'description': 'The control group will receive 2 sessions/week of TENS for 5 weeks. A high-frequency, low-intensity stimulus of 50-100Hz and up to 15mA will be used, such that the patients feel a current but do not feel pain. At each treatment visit, a physiotherapist will administer the treatment to the bilateral temporomandibular joint for 15 minutes. Both centres will use the same TENS device-a BioTron-DX (D.M.C, Osan, South Korea).', 'interventionNames': ['Other: hominis placental pharmacopuncture']}

Interventions:
- {'type': 'OTHER', 'name': 'hominis placental pharmacopuncture', 'description': "Hominis placental pharmacopuncture is human placental extract, which has been used in traditional Korean medicine to treat chronic diseases, including frailty, cough, anorexia, and fatigue, by enhancing the body's resistance.", 'armGroupLabels': ['Hominis placental pharmacopuncture', 'Transcutaneous electrical nerve stimulation']}

Primary Outcomes:
- {'measure': 'The difference in visual analogue scale (VAS) of temporomandibular pain', 'description': "The primary outcome is the difference in VAS for TMJ pain between baseline and the primary end point (Week 6). VAS is an assessment index in which the patient records their pain on a 100mm line from 'no pain' at one end, and 'the most severe pain imaginable' at the other end.", 'timeFrame': 'Week 6'}

Please estimate the sample size based on the assumption: 
Significance level (α) = 0.05 (two-tailed), type 2 error (β) = 0.2, power = 80%, and a dropout rate of 20%. The correlation between baseline and primary endpoint was assumed to be 0.4 for ANCOVA.
Sample size
        This is an investigator-initiated clinical trial, and we have calculated the required sample size with reference to similar studies and our clinical experience. First, we set a significance level of Î±â=â0.05 (two-tailed tests), a type 2 error (Î²) of 0.2, and a test power of 80%. Because there are no previous studies comparing pharmacopuncture with PT for the TMJ, we selected a moderate-to-high effect size for the comparison of mean VAS between the two groups based on our clinical experience, and used Cohenâs dâ=â0.65 [36]. Using these parameters, we calculated the sample size using G*Power 3.1.7. Based on an effect sizeâ=â0.65, the required sample size was estimated to be 39 persons/group (total 78 persons). However, as we plan to use an analysis of covariance (ANCOVA) correcting for the outcome at baseline for our main analysis, we calculated the sample size assuming the correlation between baseline and primary endpoint to be 0.4 [(1â0.4*0.4)*78], and found that the minimum required number of participants was a total of 65 persons [37]. Thus, to account for a dropout rate of 20%, we calculated that the number of participants we need to recruit is a total of 82 persons (41 persons/group).