Join me for a summary looking at the use of botox for deep bite management and bruxism. This was an interesting lecture by Dr Nan Hatch from Seattle, which was presented at this year’s AAO 2023. She explored the use of Botox for masseter hypertrophy and the evidence around it.

Masseter hypertrophy when combined with bruxism can result in:

o  Long term changes in

o  Fixation breakages

o  Orofacial pain, tmd,

How does it work?

·        Injection of neurotoxin

·        Temporary partial paralysis

·        Most common Botulinum toxin

·        Mechanism of action

o  Block acetylcholine (neuromuscular

o  Also inhibit pain sensory

How to inject

·        Extra oral – use of facial

·        Intra-oral Use MRI / EMG

What are the effects

·        Anticipate change facial

·        Greater facial contouring

·        Last up to 180 days

·        Greater complications with

Anticipated change from botox

·        Treatment for masseteric

o  35 units to masseter , two

o  91% reported improvement

o  Duration 25 months

Decrease bite force Ahn 2007

·        25 units to each massenteric

·        Mean bite force 51kg /cm

o  Reduced to 30-36kg/cm for 8

o  After 41kg after 12 weeks ,

·        Significantly reduced bite

Potential adverse effects

·        Chewing weakness

·        Sunken cheeks – high volume

·        Headaches

·        Sagging skin

·        Asymmetry

·        Paradoxical Bulging – miss

·        Distant spread of toxin

·        Speech disturbance

·        Muscle fiber atrophy 4-6

Chemical denervation protocol

·        25 units per muscle, both

·        Interval 4-5 months and

·        3-5 serial injections

o  Some patients changes can