The purpose of this study was to evaluate nasal airway resistance (NAR) during rapid maxillary expansion (RME) using acoustic rhinometry (AR). The sample comprised 22 children (13 girls and nine boys) with maxillary constriction. The mean age was 12.9 +/- 1.54 years and all patients were found to have normal nasal cavities following anterior rhinoscopic examination. A modified bonded splint type RME appliance was used for expansion. AR was used to measure NAR before (T1), during (T2) and after (T3) expansion, and at the end of retention (T4). Each AR recording was performed, for each patient, with and without the use of a decongestant. Subjective evaluation of reported changes in nasal breathing were also undertaken at T3. The results showed that NAR was significantly reduced with the use of RME, with the main decrease observed during expansion (P < 0.05). The use of a decongestant was not found to have any effect on the results. Subjective evaluation showed that 59 per cent of patients considered that their nasal breathing had improved following RME.

Objective: To determine the pulpal blood flow (PBF) changes in anchorage teeth associated with the high forces of a rapid maxillary expansion (RME) appliance. Materials and Methods: The study was performed with 14 girls and 7 boys for a total of 21 patients between 10 and 15 years of age (mean, 13.1 6 1.39 years). A modified acrylic bonded RME appliance was used as an expansion appliance. Laser Doppler flowmetry was used for the pulpal perfusion measurements. Records were taken from 42 upper central incisors, 28 canines, and 42 first molars at the following time intervals: just before expansion (T1); at the first week of expansion (T2); at the end of the expansion process (T3); and at the third (T4), seventh (T5), and 12th weeks of retention (T6). The data gained were statistically evaluated by parametric tests. Results: PBF values of the anchorage teeth were doubled at the first week of expansion; however, these values began to decrease because of separation of the median palatal suture. PBF values tended to reach their initial values during the retention period. Pulpal perfusion changes of all examined anchorage teeth were similar to each other from the beginning to the end of the evaluation. Conclusion: PBF changes that occur with RME are reversible. (Angle Orthod. 2010;80:1136-1140

The purpose of this study was to compare nasal volume changes using acoustic rhinometry (AR) and computed tomography (CT). The subjects were 10 children (6 girls and 4 boys, with an age range of 12-14 years) who required rapid maxillary expansion (RME) on the basis of their individual malocclusion. All patients were found to have normal nasal cavities following anterior rhinoscopic examination. AR and CT were undertaken at the start of treatment (t(1)) and 6 months after expansion (t(2)). Volume changes due to expansion were evaluated using Wilcoxon's test, and the correlation between the two methods was assessed with correlation analyses. Both methods demonstrated that nasal volume significantly increased following the use of RME (P<0.05). Correlation analyses showed no difference in volume (P>0.05) using either of the two methods.

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The aim of this study was to identify the role of psycho-social factors in headgear compliance. Fifty-one patients, with an Angle Class II division 1 malocclusion comprised the study sample. The treatment plan aimed to correct the malocclusion using cervical pull headgear. An electronic module timer was attached to the neckstrap to evaluate the number of hours the patients wore the headgear. One of their parents was asked to answer the Child Behaviour Checklist (CBCL), which defines a patient's behaviour. The patients were monitored for 6 months and the modules were measured at the end of each 2 month period. Mann-Whitney U and Chi square tests were used to analyse the data. The patients were separated into groups according to their compliance. The results showed that although there were significant differences in the use of headgear between the groups (P < or = 0.001), age, gender, and CBCL subgroup scores were not statistically significant (P > 0.05).