Carolina Baratieri

Does rapid maxillary expansion have long-term effects on airway dimensions and breathing?

INTRODUCTION In this systematic review, we identified and qualified the evidence of long-term reports on the effects of rapid maxillary expansion (RME) on airway dimensions and functions. METHODS Electronic databases (Ovid, Scirus, Scopus, Virtual Health Library, and Cochrane Library) were searched from 1900 to September 2010. Clinical trials that assessed airway changes at least 6 months after RME in growing children with rhinomanometry, acoustic rhinometry, computed tomography, or posteroanterior and lateral radiographs were selected. Studies that used surgically assisted RME and evaluated other simultaneous treatments during expansion, systemically compromised subjects, or cleft patients were excluded. A methodologic-quality scoring process was used to identify which studies would be most valuable. RESULTS Fifteen articles fulfilled the inclusion criteria, and full texts were assessed. Three were excluded, and 12 were assessed for eligibility. Four articles with low methodologic quality were not considered. The remaining 8 were qualified as moderate. The posteroanterior radiographs showed that nasal cavity width increases; in the lateral radiographs, decreased craniocervical angulation was associated with increases of posterior nasal space. Cone-beam computed tomography did not show significant increases of nasal cavity volume. Rhinomanometry showed reduction of nasal airway resistance and increase of total nasal flow, and acoustic rhinometry detected increases of minimal cross-sectional area and nasal cavity volume. CONCLUSIONS There is moderate evidence that changes after RME in growing children improve the conditions for nasal breathing and the results can be expected to be stable for at least 11 months after therapy.

Evaluation of pharyngeal airway space amongst different skeletal patterns

The aim of the present study was to evaluate the dimensions of the pharyngeal airway space (PAS) in awake, upright children with different anteroposterior skeletal patterns using cone beam computed tomography (CBCT). The volume, area, minimum axial area and seven linear measurements of PAS were obtained from the CBCT images of 50 children (mean age 9.16 years). The patients were divided in two groups according to the ANB angle (group I 2° ≤ ANB ≤ 5°; group II ANB > 5°). Means and standard deviations of each variable were compared and correlated using independent t-test and Pearsons correlation test. There were statistically significant differences in the following parameters: angle formed by the intersection between NA and NB lines (p<0.001), angle formed by the intersection between SN and NB lines (p<0.05), Minimal pharyngeal airway space between the uvula and the posterior pharyngeal wall (p<0.05), airway volume (p<0.01), airway area (p<0.01) and minimum axial area (p<0.05). The anteroposterior cephalometric variable SNB had positive correlation with the variables PAS-UP (p<0.01), Minimal pharyngeal airway space between the uvula tip and the posterior pharyngeal wall (p<0.05), Pharyngeal airway space on mandibular line (p<0.05), Minimal pharyngeal airway space between the back of the tongue and the posterior pharyngeal wall (p<0.05), volume airway (p<0.05), airway area (p<0.05) and minimum axial area (p<0.05). The vertical cephalometric variables angle formed by the intersection between SN and GoGn lines (p<0.05) and angle formed by the intersection between FH and mandible plane (p<0.05) showed negative correlation with PAS-UT. These results showed that PAS was statistically larger in group I than group II, indicating that the dimensions of the PAS are affected by different anteroposterior skeletal patterns.

Is the airway volume being correctly analyzed

INTRODUCTION The aim of the study was to determine the most accurate threshold value for airway volume quantification based on specific experimental conditions. METHODS Ten scans from the airway prototype were obtained by using cone-beam computed tomography. The volume from each scan was measured with 8 values (25, 50, 70, 71, 72, 73, 74, and 75) of the threshold tool from the Dolphin software (Dolphin Imaging and Management Solutions, Chatsworth, Calif). The gold standard method used was the actual volume of the airway prototype, which was compared with the different threshold values. An intraclass correlation coefficient test was applied to evaluate the intraexaminer calibration and verify differences among the airway volumes measured in all cone-beam computed tomography scans. Analysis of variance with the Tukey post-hoc test was used to compare differences among the measurements with different threshold values with the gold standard. RESULTS The intraexaminer reliability was confirmed by the intraclass correlation coefficient, which was ≥0.99. The intraclass correlation coefficient used to verify the differences among the airway volume measurements in all cone-beam computed tomography scans was ≥0.98, showing that they were comparable. Analysis of variance and the Tukey post-hoc test showed that the volumes measured with the threshold values of the 25 and 50 filters had statistically significant differences from the gold standard. However, volumes measured with the threshold values of the 70, 71, 72, 73, 74, and 75 showed no statistically significant differences from the gold standard and among them. CONCLUSIONS In our study for the cone-beam machine and the acquisition parameters used, the threshold value of the 73 used in Dolphin 3D software was the most accurate to measure airway volume, but the threshold values of the 70, 71, 72, 74, and 75 had no statistically significant differences compared with the gold standard, showing they are also reliable.

Three-dimensional assessment of pharyngeal airway in nasal- and mouth-breathing children

OBJECTIVES The aim of this study was to assess the pharyngeal airway space (PAS) in nasal and mouth-breathing children using cone beam computed tomography (CBCT). METHODS Volume, area, minimum axial area and linear measurements (PAS-NL, PAS-UP, PAS-OccL, PAS-UT, PAS-Bgo, PAS-ML, PAS-TP) of the pharyngeal airway of 50 children (mean age 9.16 years) were obtained from the CBCT images. The means and standard deviations were compared according to sexes (28 male and 22 female) and breathers patterns (25 nasal breathers and 25 mouth breathers). RESULTS There were no statistically significant differences (p>0.05) between all variables when compared by sexes. Comparisons between nasal and mouth breathers showed significant differences only in two linear measurements: PAS-OccL (p<0.001) and PAS-UP (P<0.05). Airway volume (p<0.001), area (p<0.001) and minimum axial area (p<0.01) had significant differences between the groups. CONCLUSIONS The CBCT evaluation showed that pharyngeal airway dimensions were significantly greater in nasal-breathers than in mouth-breathers.

Efeitos transversais da expansão rápida da maxila em pacientes com má oclusão de Classe II: avaliação por Tomografia Computadorizada Cone-Beam

OBJECTIVE: The aim of this study was to evaluate by Cone-Beam Computed Tomography (CBCT) transversal responses, immediately and after the retention period, to rapid maxillary expansion (RME), in Class II malocclusion patients. METHODS: Seventeen children (mean initial age of 10.36 years), with Class II malocclusion and skeletal constricted maxilla, underwent Haas´ protocol for RME. CBCT scans were taken before treatment (T1), at the end of the active expansion phase (T2) and after the retention period of six months (T3). The scans were managed in Dolphin software, where landmarks were marked and measured, on a coronal slice passing through the upper first molar. The paired Student´s t-test was used to identify significant differences (p<0.05) between T2 and T1, T3 and T2, and T3 and T1. RESULTS: Immediately after RME, the mean increase in maxillary basal, alveolar and dental width was 1.95 mm, 4.30 mm and 6.89 mm, respectively. This was accompanied by buccal inclination of the right (7.31°) and left (6.46°) first molars. At the end of the retention period, the entire transverse dimension increased was maintained and the dentoalveolar inclination resumed. CONCLUSIONS: The RME therapy was an effective procedure to increase transverse maxillary dimensions, at both skeletal and dentoalveolar levels, without causing inclination on anchorage molars in Class II malocclusion patients with skeletal constricted maxilla.

Root damage associated with intermaxillary screws: a systematic review

This systematic review examined the literature for evidence of dental root damage after contact with intermaxillary screws (IMS). Electronic databases, including the Cochrane Library, Ovid, Scirus, Scopus and Virtual Health Library, were used to search for original articles from 1980 to January 2011. Prospective and retrospective studies that assessed the association of root damage and contact with IMS were selected. Two authors independently reviewed and extracted the data from the included studies. A methodological quality scoring process was used to classify whether the articles presented low, moderate or high evidence. The search retrieved 795 citations. Nine studies fulfilled the initial selection criteria. Of these studies, 3 were excluded. Two studies did not note any iatrogenic injuries of the dental roots; the other study was a case report. Of the 6 included articles, 2 were ranked as having low and four as having moderate evidence. The moderate evidence found suggested that the roots did not exhibit clinical changes after coming into contact with the IMS, but this situation depends on the root damage level. To obtain reliable scientific evidence, studies with an adequate sample size and diagnostic methods are required to confirm the effects of IMS on the dental root.

Root repair after contact with mini-implants: systematic review of the literature

This systematic review identified and qualified the current evidence of dental root damage and repair after contact with mini-implants. The electronic databases Cochrane library, Ovid, Scirus, Scopus, and Virtual Health Library were used to search original articles from 1980 to December 2011. The inclusion criteria to select the articles were 1. randomized controlled trials and prospective clinical studies based on trials involving humans, 2. randomized controlled studies in animals, 3. use of mini-implants with a diameter less than 2.5 mm, and 4. root contact evaluation associated with the use of orthodontic mini-implants. Two authors independently reviewed and extracted data from the selected studies and a methodological quality assessment process was used to rank the studies classifying them as low moderate or high quality. The searches retrieved 579 citations. After initial selection, 17 studies were considered eligible and their full texts were assessed. Four of those were excluded because root damage was not evaluated and two were excluded because of overlapping samples. Eleven articles, nine in animals and two in humans, fulfilled the inclusion criteria. From these, two studies were ranked as presenting high methodological quality, eight were judged to be of moderate, and one of low quality. The evidence found suggested that the quality of root repair depends on the amount of damage caused by the mini-implant. When the damage is limited to the cementum or dentin, healing and almost complete and repair of the periodontal structure can occur. Mini-implants that injured the pulp were less likely to result in complete repair of the periodontal tissues.

Angle Class III malocclusion treated with mandibular first molar extractions

A Class III malocclusion associated with dental asymmetry is a complex diagnostic and treatment problem in orthodontics. The goals of maintaining or improving the facial profile and achieving good function are decisive factors when considering whether to plan a surgical or a nonsurgical treatment approach. A fixed appliance in combination with extractions could be considered for nonsurgical management of this type of malocclusion in the permanent dentition. This article presents the results of an orthodontic approach to a Class III subdivision malocclusion in an adult treated with mandibular first molar extractions. The extractions provided the space needed to correct the overjet and overbite and to improve the intercuspation.

Tomographic mapping of the hard palate and overlying mucosa

The aim of this study was to measure the thickness of the hard palate and its overlying mucosa using cone-beam computed tomography (CBCT), for purposes of miniscrew placement. The sample comprised 36 CBCT scans of patients aged 12 to 52 years from a database of the Orthodontics Department of the Federal University of Rio de Janeiro. Paracoronal views of the palatal region were reconstructed at 4, 8, 16 and 24 mm posterior to the incisive foramen. In each reconstruction measurements were taken at the suture, 3 mm and 6 mm bilaterally to it. Wilcoxons test verified the differences between the selected regions. Total bone height decreased from the anterior to the posterior region. In cross sections 4, 16 and 24, bone height decreased from the suture laterally to the 3 mm region and then increased in the 6 mm region. The cortical thickness does not seem to be a concern because it presented a mean thickness of at least 1 mm at all sites evaluated. The measurements of the mucosa thickness decreased from lateral to median and from anterior to posterior regions. The most suitable areas for miniscrew placement in the palate are located 4 mm posterior to the incisive foramen, in the median or paramedian regions 3 mm adjacent to the suture.

Relationship between maxillary canine intra-alveolar position and maxillary incisor angulation: a cone beam computed tomography study

The aims of the present study were to evaluate the angulation and inclination of permanent maxillary incisors and to correlate the results to the intra-alveolar permanent maxillary canine position during mixed dentition, using cone beam computed tomography (CBCT). The subjects were 30 children aged 7 to 10 years in the inter-transitory period of mixed dentition (permanent incisors and first molars erupted; primary canines, first and second molars erupted; and permanent canines intraosseous). The CBCT scans were obtained and, using the Dolphin Imaging(®) software - version 11.0, 3D images were reconstructed and the measurements were performed. The angulation of the right and left lateral and central maxillary incisors was measured in relation to the sagittal plane and their inclination was measured in relation to the coronal plane. The intra-alveolar height of the right and left maxillary canines was measured from the cusp tip to the axial plane. Pearsons correlation at 5% significance level showed positive correlation between the canine height and the lateral incisor angulation. It was concluded that the intra-alveolar position of the maxillary canines has a direct influence on the angulation of maxillary incisors, especially the lateral incisors.