Effects of first premolar extraction on airway dimensions in young adolescents: A retrospective cephalometric appraisal

Abstract

Objective:To evaluate the upper airway dimensions in adolescents treated for bimaxillary proclination with first premolar extraction.Materials and Methods:A retrospective cephalometric evaluation was carried out on the available pre and post orthodontic treatment records of 150 patients (12-18 years of age) who had bimaxillary proclination and were treated with fixed orthodontic therapy. Cephalometric landmarks for sagittal airway measurements and hyoid bone were identified; linear and angular measurements were obtained. Descriptive statistics using paired t-test was used to assess changes in pre and post treatment values and Pearson's correlation coefficient was calculated to evaluate the reliability of observations. The method error calculations were performed using the Dahlberg formula.Results:It was observed that the mean values of nasopharyngeal dimension and Total Airway Length (TAL) showed no statistically significant difference in pre and post treatment groups. All other airway and hyoid parameters showed statistically significant difference. Pearson's correlation coefficient showed statistically significant correlations in all the airway and hyoid parameters.Conclusions:In the present study, the nasopharyngeal dimension and TAL were not found to be directly affected by the retraction of anterior teeth, This can be attributed to the fact that nasopharyngeal dimension and TAL are not under direct influence of tongue position. The other findings also indicated direct correlation of tongue position to oropharynx and hypopharynx. Consequently, we emphasize clinically relevant anatomic risk factors that should be given prime importance and serious consideration on the decision whether to extract or not in growing patients.

Effects of bicuspid extractions and incisor retraction on upper airway of Asian adults and late adolescents: A systematic review

“…After full‐text appraisal, 12 articles were excluded due to the following reasons: Full text not in English Treatment group below 16 years old Single‐arch extraction …”

Reviewing the Evidence: Do Orthodontic Premolar Extractions Directly Cause Obstructive Sleep Apnea?

“…No statistical significance was evident between the pre-and post-treatment groups [7]. A speculated reason for this could be due to the fact that the tongue position during total retraction of anterior teeth during orthodontic treatment does not affect the TAL or nasopharyngeal dimensions.…”

“…A speculated reason for this could be due to the fact that the tongue position during total retraction of anterior teeth during orthodontic treatment does not affect the TAL or nasopharyngeal dimensions. But it was observed that after extraction treatment, the velopharyngeal, glossopharyngeal, and hypopharyngeal airways became narrower following orthodontic therapy [7]. Another study also reported a decrease in velopharyngeal and glossopharyngeal airway spaces after full retraction of the incisors [12].…”

“…Previously within the literature, it has been questioned whether orthodontic treatment with the extraction of 4 premolars causes a reduction of dental arch length with a subsequent reduction or crowding of the resting tongue space, promotion of upper airway collapse during sleep and subsequently, could contribute to OSA [5][6][7][8][9]. Due to the fact that there is an abundance of sleep medicine practitioners or "non-extraction" orthodontists who believe that the use of extraction therapy in orthodontic treatment causes obstructive sleep apnea, it is important to discuss the evidence available to ensure that patients receive appropriate and suitable treatment based on their needs [5].…”

Impact on the airway

“…Two audit papers 2,3 show that clinical assistant (CA) training produced good quality outcomes very similar to consultants and specialists in both hospital and general practice. The volume of cases treated was not found to be an indicator of the quality of outcome.…”