Bruxism An Orthodontist’s Perspective Mauro Farella. Episode 60. IOC 2020

Play episode
Hosted by
Farooq Ahmed

Day bruxism and sleep bruxism


Day bruxism

  • 20% of the population Lavigne 2008
  • Repetitive clenching (not grinding)
  • Risk factors – not fully understood, multifactorial


Normal clenching

  • 20 minutes of the day Grad 1969
  • Day bruxism = usually phychological factors and muscle pain


Sleep bruxism

  • Rhythmic masticatory muscle activity = grinding of teeth
  • Prevalence – children 18%, adults 8% Lavigne 2003
  • Aetiology – alcohol, stress, caffeine, smoking, anxiety, acid reflux


How frequent are the episodes of grinding

  • SB = 5/hours (non-SB 2/ hour)
    • SB grinding
      • 8 seconds per episode
      • Total grinding = 8 minutes at night (not long) Lavigne 1996
      • Force = 22.5 kgf, less than normal chewing force (normal chewing force = around 70kgf)
    • SB
      • OSA, Gastric reflux, dry mouth
    • SB = short duration, low intensity


Tooth wear

  • Not reliable marking of on going bruxism
  • Combination of attrition and erosion, overlapping aetiology
  • Tooth wear occurs more rapidly in erosive environment



  • Small reduction in PH during sleep Farella 2016
  • Intra oral PH varies significantly in the population




Orthodontics relevance

  • Bruxism and muscle forces reduce during orthodontic treatment Goldreich 1994, Michelotti 1999, 2005
  • RME reduces bruxism in children by 65% Bellerive 2015
  • Splint occlusal therapy – Cochrane review shows insufficient evidence to support
  • Twinblock improves sleep disorder breathing, but transient Idris 2018


Effects of wear on the dentition

  • Upper and lower anterior retroclination
  • Extrusion of upper and lower incisors
    • Treatment involves – decompensation –
      • Proclination of upper and lower incisors
      • Intrusion of upper and lower incisors
    • Avoid ceramic backets lower arch
    • Reduce risk factors – alcohol, caffeine, smoking, diet, stress
    • Restorations should be minimally invasive: Lommans
    • Exercises
      • Posturing the mandible 2mm = reduction in muscle force 40-50% Michelotti 1997


Orthodontic patients who have day bruxism

  • Greater effect of occlusal interference and develop jaw discomfort/ headaches RED FLAG FOR ORTHODONTIC TREATMENT Michelotti 2012
    • Types of orthodontic devices increase discomfort (anecdotal): Extra oral forces, Removable appliances, Mandibular advancement appliances, Clear aligners.
  • First onset of TMD can be successfully managed at home Michalotti 2005



  • Bruxism less severe during orthodontic treatment
  • Orthodontic appliances may retain acid

Orthodontics can be used to help manage heavily worn dentition


Join the discussion


More from this show

Your subscription could not be saved. Please try again.
Your subscription has been successful.

Never miss an episode or blog!

Subscribe now