Effects of craniofacial manual therapy on the masseter muscle morphology and postural stability in healthy adults

Participants in each group (arm 1, 2 an 3) will deliver face to face intervention in 3 sets of 10 minutes manual therapy technics in 7 days interval (10 minutes session once a week for a 3 weeks). Each session will be performed by the same physiotherapist (early stage physiotherapist who passed some courses in craniofacial therapy). Interventions will occur at Musculoskeletal Elastography and Ultrasonography Laboratory, Institute of Physiotherapy and Health Sciences, The Jerzy Kukuczka Academy of Physical Education in Katowice. POLAND. Arm 1 - Extraoral Therapy - 30 finger movements along the fibers of the masseter muscle from the outside – along the belly of the masseter muscle from the zygomatic arch to the angle and lateral surface of ramus of mandible. - 15 finger movements along the zygomatic arch (from nose to lateral) - 15 finger movements along the fibers of musculus temporalis - 15 finger movements along the ramus of mandible- submandibular region Arm 2 - Intraoral Therapy - 30 finger movements along the fibers of the masseter muscle from the inside- The therapist's thumb inside the patient's mouth, the rest of the fingers on the outside of the cheek. Therapist in disposable gloves. - 15 seconds pressure of the Lateral Pterygoid muscle at 4 different angles (15 seconds each)- the index finger upward and backward past the upper last mollar x 2 Arm 3 - Extraoral and intraoral Therapy - 15 finger movements along the fibers of the masseter muscle from the outside – along the belly of the masseter muscle from the zygomatic arch to the angle and lateral surface of ramus of mandible. - 15 finger movements along the zygomatic arch (from nose to lateral) - 15 finger movements along the fibers of musculus temporalis - 15 finger movements along the ramus of mandible- submandibular region - 15 finger movements along the fibers of the masseter muscle from the inside- The therapist's thumb inside the patient's mouth, the rest of the fingers on the outside of the cheek. Therapist in disposable gloves. - 15 seconds pressure of the Lateral Pterygoid muscle at 4 different angles (10 seconds each)- the index finger upward and backward past the upper last mollar