Injecting Lateral Pterygoid Muscle by Botulinum Toxin Type A With 2 Different Methods : 3D Guided Appliance and Electromyography (EMG) .

"* Needle insertion guide will be placed on upper teeth.~* Needle will be inserted from needle insertion sleeve and 25-30 units of botulinum toxin type A will be injected.~* Aspiration will be done before injection, and then, the patient will be asked to manipulate the mandible to activate the lateral pterygoid muscle."

"* A 27- gauge needle electrode will be inserted lateral to the maxillary tuberosity, just above the maxillary molars to inject 25-30 units of botulinum toxin type A under electromyographic guidance.~* Aspiration will be done before injection, and then the patient will be asked to manipulate the mandible to activate the lateral pterygoid muscle.~* The intramuscular injection will be confirmed when the electromyographic device produces a distinct loud sound."