Intraoral Injection of Trigger Points by Botox

Patients with orofacial pain lasting at least 3 months. The patients will be randomly assigned to one of the two groups according to the treatment method: group I (intraoral injection) and group II (transcutaneous injection) where each patient injected Botox at each trigger point according to the treatment group by the same operator. Patients will be examined by a blinded investigator at pre- and post-injections at the following intervals: during diagnosis, 1 week, 4, and 6 weeks post-injection. The patients will be assessed using a pain score measured on a 10-point visual analog scale (VAS). The secondary outcome assessed will be measuring the quality of life in an Oral Health Impact Profile questionnaire (OHIP-14).

The participated patients will be assessed using pain score measured on a 10-point visual analogue scale (VAS), the 0 indicating no pain and 10 indicating the worst pain ever.

OHIP-14 is used to measure patients' self-reported discomfort, disability, and functional limitation due to oral conditions with scores ranging from 0 to 56 (with 56 representing a subject answering ''very often'' to all 14 items

Inclusion Criteria: Definite diagnosis of myofascial pain with a referral the presence of one or more trigger points in the unilateral or bilateral masseter muscle - no history of any invasive procedures in the related masseter muscle Exclusion Criteria: Factors that can cause pain in the orofacial region other than trigger points (decayed tooth, temporomandibular joint internal disorder). Any systemic disease that possibly affects the masticatory system such as rheumatoid arthritis and epilepsy pregnancy and lactation.