Evaluation of the Effect of Different Rapid Maxillary Expansion Appliances on Airway by Acoustic Rhinometry

Evaluation of the Effect of Different Rapid Maxillary Expansion Appliances on Airway by Acoustic Rhinometry

Evaluation of the Effect of Different Rapid Maxillary Expansion Appliances on Airway by Acoustic Rhinometry: A Randomized Clinical Trial

Rapid maxillary expansion (RME) is an orthodontic treatment based on the principle of opening the midpalatal suture with the effect of orthopedic forces. The aim of this randomized clinical study was to evaluate and compare the effects of tooth-borne, tooth-tissue borne, and bone-borne rapid maxillary expanders on nasal airway by using AR. The null hypothesis was that there is no difference for the effect on nasal airway between the appliances.

Introduction: The aim of this 3-arm parallel trial was to compare the effects of tooth-borne (Hyrax), tooth tissue-borne (KBME) and bone-borne (MIDME) rapid maxillary expansion (RME) appliances on nasal airway with acoustic rhinometry (AR). Methods: Fourty-six 12- to 14-years-old patients with narrow maxilla were randomly allocated into 3 study groups according to the type of RME appliance: tooth-borne, tooth tissue-borne and bone-borne. Participants were recruited from the Department of Orthodontics, Faculty of Dentistry, Izmir Katip Celebi University, Turkey. During the RME treatment, the same protocol was applied to all patients and the expansion screws were activated twice a day (0.4 mm/day). Computer-generated randomization was used with group allocation concealed using opaque, sealed envelopes. The outcome assessor was blinded; however, it was not feasible to blind either operator or patients. The primary outcome of this study was the correction of posterior crossbite. Secondary outcomes included AR assessment of nasal airway dimensions as nasal volume, the minimal cross-sectional area (MCA) 1 and 2. AR measurements were obtained before treatment (T0), after active expansion (T1), and at 3 months-follow-up (T2). One-way analysis of variance (ANOVA) and a Bonferroni test was used for inter-group comparison and two-way ANOVA was used for intra-group evalaution.

The patients were treated with KBME, Hyrax and MIDME maxillary expansion appliances, respectively. All expansion appliances containing a Hyrax expansion screw positioned parallel to the second premolars and were used to correct the posterior crossbite. In the MIDME group, two mini-screws with a diameter of 1.6 mm and a length of 10 mm are located on the right and left sides between the roots of the 2nd premolar and 1st molar teeth with 60-70° angle. KBME and Hyrax expansion appliances were cemented with glass ionomer cement and MIDME was cemented with using the light-cured composite. Same protocol was applied to all patients during RME treatment. Expansion screws in all groups were activated by two turns a day.

The palatal cusps of the maxillary posterior teeth approximated the lingual cusps of the mandibular posterior teeth.

At baseline (T0), after active expansion (up to 3 weeks) (T1) and after 3 months retention period (T2)

At baseline (T0), after active expansion (up to 3 weeks) (T1) and after 3 months retention period (T2)

At baseline (T0), after active expansion (up to 3 weeks) (T1) and after 3 months retention period (T2)

Inclusion Criteria: no previous tonsillar, nasal or adenoid surgery and orthodontic treatment, Bilateral crossbite and need for RME, maxillary and mandibular permanent teeth fully erupted, willingness to participate in the study Exclusion Criteria: the presence of adenotonsillectomy due to tonsillar hypertrophy or adenoidal hypertrophy having nasal/nasopharyngeal /oropharyngeal pathologies, craniofacial syndromes, systemic disease, poor oral hygiene, history of previous orthodontic treatment.

Gokce G, Gode S, Ozturk A, Kirazli T, Veli I. Evaluation of the effects of different rapid maxillary expansion appliances on airway by acoustic rhinometry: A randomized clinical trial. Int J Pediatr Otorhinolaryngol. 2022 Apr;155:111074. doi: 10.1016/j.ijporl.2022.111074. Epub 2022 Feb 15.