we have a 26 year old patient with mesoteric hypertrophy being larger on the right compared to the left hand side secondary to grind in the masteric hypertrophy contributes to the overall squareness to the lower third of the face and today we'll be injecting the masseters with botulinum toxin marking the left masseter again can I ask you to clench anterior border of the Masada along the mandible the ramus and again a line from oral commercial to tragus and the injection points will be in the lower half of a line that divides these can I please ask you to clinch relax clinch relax clench relax clench great now we can see that the right Masada is larger compared to the lift masseter I'll be injecting the right side with 40 units of on a botulinum toxin and on the left hand side 35 units of on a botulinum toxin and my Approach will be from posterior single entry dividing the doses 35 units divided by three in each of the bellies and then 40 units divided by three in each of the bellies on the right hand side the only muscle that I'm concerned about is the rhizorius because if I inadvertently uh strike the rhizorus I will shorten the patient's smile and injecting each of the three valleys of the masseters avoids the inadvertent paradoxical doubling up of Methodist if I don't equally distribute the botulinum toxin in each of the three bellies let's have a look at the masseters on ultrasound let's have a look at the left masseter I have the probe in the transverse position but let me have a look at rhizorius and here is the Masada and coming off the rhizor of the Masada aiming in a more anterior position lying around about 0.6 millimeters deep to the skin is a thin layer of muscle and that is rhizorius on ultrasound we can identify the intermediate head of Masada The Superficial head and the d-pad and I want to do one injection point so that I can Target all three muscles so little Sting coming your way ready one ready two and I'm now located my needle on ultrasound I can see the movement and there I have it and this is the intermediate head so I'll inject a third the dose into the intermediate head I'm now going to move my needle and reposition it so that I can Target The Superficial head of Masada and another one third of the dose and then I'm moving my needle again to Target the Deep head of Macedon and there it is and here is my third dose of on a botulinum toxin I'd like to visualize where the on a botulinum toxin is this is immediately post-injection and we can see volume within the intermediate head The Superficial head and the Deep head of Masada
