Comparison of the Efficacy of Different Treatment Modalities in Masseteric Myofascial Pain: Masseteric Nerve Block, Local Anesthetic Injection and Dry-needling
Phase: NA
Conditions: Myofascial Pain - Dysfunction Syndrome of TMJ, Myofascial Trigger Point Pain, Local Anesthesia
Sponsor: Erzincan University

Comparison of the Efficacy of Different Treatment Modalities in Massateric Myofascial 
Pain: Masseteric Nerve Block, Local Anesthetic Injection and Dry-needling
Date: 06/03/2020
This document contains study design and statistical analysis plan of the study entitled
“Comparison of the Efficacy of Different Treatment Modalities in Masseteric Myofascial Pain:
Masseteric Nerve Block, Local Anesthetic Injection and Dry-needling”.

Study Design:
This is a 3-armed randomized, parallel, controlled, interventional clinical study enrolling 45
patients with myofascial pain originated from masseter muscle. 
Eligibility
•
Inclusion Criteria: Definite diagnosis of myofascial pain with a referral, based on the DC/
TMD criteria, presence of the myofascial pain for at least six months; the presence of one or
more trigger point in the unilateral or bilateral masseter muscle, no history of any invasive
procedures in the related masseter muscle in last two years;
•
Exclusion criteria: Factors that can cause pain in the orofacial region other than MTPs 
(decayed tooth, TMJ internal disorder, etc.), presence of any muscle disorders or neuropathy (e.g.
fibromyalgia), patients with a history of hypersensitivity to local anesthetics.
Patients were grouped according to the treatment they received: Masseteric nerve block
(MNB), TrP injections with local anesthetic (LA) and  dry-needling (DN).   Localization of the
MTPs  was  based  on  the  clinician’s  sense  and  patients’  expressions  of  pain.  Local  twitch
response  was  not  observable  in  all  cases.  This  procedure  was  completed  by  using  digital
palpation. Clinical examiner’s palpation was calibrated using a pressure algometer (1.5 Kg).
Sample size
The  sample  size  was  calculated  using  IBM  SPSS  22  (IBM  SPSS  Statistics  for  Windows,
Version 22.0. Armonk, NY: IBM Corp.). Based on a power of 0.80 and an alpha value of 0.05,
the sample size was calculated to be a total of 45 subjects with 15 in each group.
Outcome measures
The Rate of Pain on Function (PoF) assessed by Numerical pain Scale (NRS): Patients rated
their pain on function (pain during chewing or speaking etc.) on a Numeric Rating Scale (NRS)
(0–10 where 0 is no pain and 10 is the worst pain imaginable)

The Rate of Pain Intensity on Palpation (PoP): Patients rated their pain intensity on massater
muscle by a 4-point Likert-type scale (0 = no pain, 3 = as worst pain imaginable) while a
calibrated examiner palpating their masseter muscle.
The  measurement  of  pain-free  maximum  mouth  opening  (MMO)  in  milimeters.:  Pain-free
MMO was measured as the distance between the incisal edges of the upper and lower incisors
while patient’s mouth is open as possible without any assistance and without pain in massater
muscle. Three measurements were performed, and their average is recorded.
The patients were assessed before the injections (T0), and at one week (T1), 4 weeks (T2), and
12 weeks (T3) after the injections. Patient’s pain on palpation, pain on function and maximum
mouth opening values were reexamined and recorded on follow-up appointments. Treatment
protocol and the outcome measures were recorded in the patient’s form.
Statistical Analysis Plan: Descriptive statistics of variables were presented as mean ± standard
deviation for continuous variables and n (%) for categorical variables in statistical analysis.
IBM SPSS 22 was used to analyze the data (IBM SPSS Statistics for Windows, Version 22.0.
Armonk, NY: IBM Corp.). Pearson chi-square test was used in the analysis of categorical
variables. One-way ANOVA was used in the analysis of discontinuous variables (such as %
difference Baseline-T1). Bonferroni test was used as post hoc test after ANOVA. Repeated
Measures ANOVA test was used when testing group differences for repeated measurements.
Bonferroni  correction  was  used  in  multiple  comparisons  when  determining  the  differences
between the groups at each time point. The statistical significance level was accepted as p <
0.05.