Myofunctionals & airways – separating myth from reality: Peter Miles

orthodontics In summary

Join me as I summarise Pater Miles lecture exploring myofunctional appliances and the literature of the appliance

Claims by some manufacturers of myofunctional appliances:

· incorrect breathing from 2 years of age

· Incompetent lips & mouth breathing – aesthetic effects

· Crooked teeth

· Long face

· Behavioural changes, tired / hyperactive

Claimed effects of appliances treatment

· Improve facial growth

· Skeletal growth

· Better alignment

· Stable

Myofunctional Appliances what are they?

Design – off the shelf design

· Monoblock Kesling positioner type appliance 1945:

· Double mouthguard postured into edge to edge position

· Postured edge to edge

· Example Occlus-o-guide, LM activator, Myobrace

Effects:

· Retrocline uppers, procline lowers

· Disocclusion posterior teeth = overeruption of posterior teeth, overbite improvement

Evidence

Occlusal changes with appliances

· Eruption Guidance Appliance, T4K, LM activator AJODO 2008 Angle 2019

· Overjet 2mm improvement

· Overbite 2mm improvement

· Crowding reduction 2mm

· Relapse towards baseline Janson, significant for OB crowding and 25% for OJ 2007

· Time 13-43 months

o Small changes over a long period, options to treat later Obrien 2003

Myobrace Vs Activator EJO 2015

· Poor compliance: PFA 70% non-compliance, 53% Activator non-compliance (Twinblock 84% compliance AJODO 2003)

· 2018 cost benefit analysis: PFA minimised costs

Airway evidence

Difficult to show direct changes, so related parameters are used.

Claimed issues with narrow airway and mouth breathing:

1. Dental: Crooked teeth and arches

2. Lip incompetence

3. Skeletal: long face

4. Behaviour tired and hyperactive

1: Crooked teeth and narrow arches

o Prevalence of malocclusion similar in Paediatric sleep disorder breathing in the population J den Sleep Medicine 2017

2: Lip incompetence

· Vig 1979

o Lip growth accelerate sand overtakes facial height 9-13

o Lip incompetence will improve with age

· Vig 1881

o Lip incompetence no difference in nasal airflow

§ Cannot conclude lip incompetence = mouth breather

o Proffit – long face still use nose to breath, but less than normal face type

3: Skeletal: long face

· Craniofacial morphology metal analysis: AJODO 2013

o Paediatric OSA statistically significant in class 2, 1.5-1.6o – NOT clinically significant or diagnostically useful

§ Direct casual relationship of craniofacial structure and paediatric sleep disorder is unsupported in meta analsysis

Myofunctional therapy

Oropharyngeal exercises

· Aim to improve tone of surrounding muscles, phalangeal muscles, soft palate, airway – increase patency

o Reduce AHI index by half short term studies 3 months Am J resp Crit Car Med 2009, Sleep Med 2013

Orthodontists role in SDB

· We are not the primary care giver

· Main role: Screening / Assessment, questionnaire

o Paediatric sleep questionnaire

§ Effective ruling out OSA / SDB