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