Mandibular advancement devices in obstructive sleep apnoea: side effects


Obstructive sleep apnoea is thought to affect about 6% of women and 12.5% of men. It is characterised by a relaxing and narrowing of the upper airway during sleep which determines snoring, cessation of breathing, fragmented sleep, increased heart rate and fluctuations in heart rate. Nasal continuous positive airway pressure (CPAP) is the standard treatment for obstructive sleep apnoea (OSA) studies have demonstrated benefits using oral appliances.

 The aim of this review was to assess the dental and skeletal effects of mandibular advancement devices (MAD) in treatment of OSA patients.


Searches were conducted in the Medline, Cochrane Database, Google Scholar Beta, Scopus, and LILACS and Web of Science databases with no language restrictions. Randomised controlled trials (RCTs)  and cohort studies investigating dental and/or skeletal side effects on adult patients wearing MAD for the treatment of OSA or snoring  with at least 2 years follow up were considered.

Two reviewers independently selected studies and assessed risk of bias. Risk of bias was assessed using the Cochrane tool for RCTs and the Risk Of Bias In Non- randomized Studies of Interventions (ROBINS-I) tool for cohort studies.  The quality of the overall body of evidence was assessed using (GRADE) Grading of Recommendations Assessment, Development, and Evaluation.


  • 21 studies (3 RCTs, 8 prospective cohorts, 10 retrospective cohorts) were included.
  • Follow up periods ranged from 2 to 11 years.
  • Only the 3 RCTS were considered to have a good study design and only 1 of these was at low risk of bias on all of the domains of the Cochrane tool.
  • The studies did not control for possible confounders.
  • Sample sizes ranged from 19-103.
  • Side effects reported were a reduction in overjet, overbite, and in the upper incisor inclination, and an increase in lower incisor inclination, A point-Nasion-B point, and anterior facial height.
  • The meta-regression analysis showed that the side effects were influenced by the therapy duration for all parameters (P < 0.05).
  • The quality of evidence was low/moderate.


The authors concluded: –

MAD therapy produces time-related dental and skeletal side effects. After a long period of treatment, the dental side effects are clinically relevant and therefore the clinician should inform the patients about this issue. Since the side effects are progressive, patients need to be continuously monitored over time.


The reviews have undertaken a broad database search for evidence with no language restrictions. However, just under 50% of the included studies are retrospective, a study design that is at a higher risk of bias. The authors also highlight than none of the included studies provided or considered any information on potential confounders. The included studies are all relatively small. So while a this review helpfully summarises the current evidence and a number of potential adverse dental outcomes are suggested, the available evidence is currently of low quality. Further well designed and conducted prospective studies with larger sample sizes and longer follow up periods are required.


Primary Paper

Bartolucci ML, Bortolotti F, Martina S, Corazza G, Michelotti A, Alessandri-Bonetti G. Dental and skeletal long-term side effects of mandibular advancement devices in obstructive sleep apnea patients: a systematic review with meta-regression analysis. Eur J Orthod. 2018 Jun 13. doi: 10.1093/ejo/cjy036. [Epub ahead of print] PubMed PMID: 29901715.

Other references

Dental Elf Sleep Apnoea Blogs



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