References

Hershey HG, Stewart BL, Warren DW Changes in nasal airway resistance associated with rapid maxillary expansion. Am J Orthod. 1976; 69:274-284
Timms DJ The effect of rapid maxillary expansion on nasal airway resistance. Br J Orthod. 1986; 13:221-228
Hartgerink DV, Vig PS, Abbot DW The effect of rapid maxillary expansion on nasal airway resistance. Am J Orthod Dentofacial Orthop. 1987; 92:381-389
Timms DJ Rapid maxillary expansion in the treatment of nasal obstruction and respiratory disease. Ear Nose Throat J. 1987; 66:242-247
White BC, Woodside DG, Cole P The effect of rapid maxillary expansion on nasal airway resistance. J Otolaryngol. 1989; 18:137-143
Warren DW, Hershey HG, Turvey TA, Hinton VA, Hairfield WM The nasal airway following maxillary expansion. Am J Orthod Dentofacial Orthop. 1987; 91:111-116

Dear editor

From Volume 43, Issue 5, June 2016 | Page 493

Authors

MJ Trenouth

Consultant Orthodontist (Retired)

Articles by MJ Trenouth

Article

I should like to thank the authors for their reply to my letter (Dent Update 2016; 43: 193) regarding their article ‘Extra-oral appliances in orthodontic treatment’ Almuzian M, Alharbi F, McIntyre G (Dent Update 2016; 43: 74–82).

They cite the publication ‘Upper airway dimension in Class II malocclusion: effects of headgear treatment’ Kirjavainen M, Kirjavainen T Angle Orthod 2007; 77: 1046–1053. They correctly quote these authors findings that ‘The retropalatal area was widened by treatment, whereas the rest of the oropharynx and hypopharynx remained narrower than in controls’. This by itself is misleading and requires additional comment. To quote from these authors again ‘The important feature of the headgear used was a 10 mm expanded inner bow’. The increase in retropalatal airway space was more likely to be due to the upper arch expansion and the observed increase in lateronasal width rather than the distalizing effect of the headgear on the maxilla. The authors recognize this by the fact that they quote six references on the effects of rapid maxillary expansion on the nasal airway.1,2,3,4,5