Paula Vanessa Pedron Oltramari-Navarro

Comparison of root resorption between self-ligating and conventional preadjusted brackets using cone beam computed tomography.

OBJECTIVE To compare the magnitude of external apical root resorption (EARR) of incisors in patients undergoing the initial phase of orthodontic treatment with two sets of brackets. MATERIALS AND METHODS According to the results of the power analysis for sample size calculation, 19 Angle Class I patients (anterior crowding: 3 to 5 mm; mean age: 20.6 years) were included in the study and randomly divided into two groups: group I (n  =  11, self-ligating brackets) and group II (n  =  8, conventional preadjusted brackets). The degree of EARR was detected in 152 upper and lower incisors by using cone-beam computed tomography (CBCT) scans and a three-dimensional program (Dolphin 11.5, Dolphin Imaging & Management Solutions, Chatsworth, Calif) with 25% level of sensitivity. The CBCT scans were obtained before (T1) and 6 months after initiation of treatment (T2). Differences between and within groups were analyzed by nonpaired and paired t-test, respectively, with 5% significance level. RESULTS Significant differences were found for both groups between T1 and T2. However, no differences in the degree of EARR were detected between the groups studied. CONCLUSIONS Although EARR has occurred in all teeth evaluated, the bracket design (self-ligating or conventional) did not demonstrate any influence on the results observed.

Effectiveness of 0.50% and 0.75% chlorhexidine dentifrices in orthodontic patients: A double-blind and randomized controlled trial

INTRODUCTION In this double-blind and randomized controlled trial, we analyzed whether a lower concentration of chlorhexidine in dentifrices could reduce the risk of tooth staining without compromising its effectiveness in controlling gingivitis, bleeding, and dental plaque. METHODS Volunteers with fixed orthodontic appliances were randomly divided into 3 groups: control, 1100 ppm F, NaF (n = 27); experimental, chlorhexidine 0.50% (n = 27); and experimental, chlorhexidine 0.75% (n = 27). At baseline, and after 6 and 12 weeks, clinical examinations were carried out. Staining, calculus, gingivitis, bleeding, and dental plaque data were analyzed with Friedman tests to evaluate intragroup changes over time. To detect intergroup differences after 12 months, the data were evaluated with Kruskal-Wallis tests. Dunn tests were used in both situations for necessary post-hoc analyses. RESULTS The groups were statistically similar for the stain, calculus, and plaque indexes, but there were statistically significant differences for the gingival and bleeding indexes. During the experimental periods, gingivitis and bleeding scores improved in all 3 groups. Only the 0.75% chlorhexidine dentifrice significantly increased the stain index, although most patients did not notice the stains. The intergroup comparison showed a statistically significant better performance of the experimental groups regarding the gingival and bleeding indexes. CONCLUSIONS This study suggests that the use of dentifrices with lower concentration of chlorhexidine can reduce the risk of tooth staining without compromising its effectiveness in controlling gingivitis and bleeding in orthodontic patients.

Anti-inflammatory and analgesic effects of low-level laser therapy on the postoperative healing process

[Purpose] This study aimed to evaluate the anti-inflammatory and analgesic effects of intraoral application of low-level laser therapy (660 nm) to control pain, swelling and interincisal opening following the extraction of mandibular third molars. [Subjects and Methods] Ten patients underwent removal of lower third molars using the same surgical protocol and pharmacological approach. In the postoperative period, all patients received four consecutive daily sessions of low-level laser therapy, beginning 24 hours after the surgery. Intraoral applications using the diode laser with 660 nm wavelength in the continuous scan mode were performed covering the entire surgical area, which was divided into four quadrants, each of 1 cm2 area at a distance of 1 cm. The energy applied at each point was 5 J/cm2 during 8 seconds. [Results] The swelling and interincisal opening returned to normal 24 hours after the first low-level laser therapy application (Friedman test). Moreover, the pain intensity was reduced on the third postoperative day, according to the Friedman test. [Conclusion] Low-level laser therapy (660 nm), at the dosimetry used in this study, was effective in reducing postoperative pain and swelling following oral surgery.

Reliability of a method to conduct upper airway analysis in cone-beam computed tomography

The aim of this study was to assess the reliability of a method to measure the following upper airway dimensions: total volume (TV), the nasopharyngeal narrowest areas (NNA), and the oropharyngeal narrowest areas (ONA). The sample consisted of 60 cone-beam computed tomography (CBCT) scans, evaluated by two observers twice, using the Dolphin 3D software (Dolphin Imaging & Management solutions, Chatsworth, California, USA), which afforded image reconstruction, and measurement of the aforementioned dimensions. The data was submitted to reliability tests, by the intraclass correlation coefficient (ICC), and the Bland & Altman agreement tests, with their respective confidence intervals (CI) set at 95%. Excellent intra- and interobserver reliability values were found for all variables assessed (TV, NNA and ONA), with ICC values ranging from 0.88 to 0.99. The data demonstrated an agreement between the two assessments of each observer and between the first evaluations of both observers, thus confirming the reliability of this methodology. The results suggest that this methodology can be used in further studies to investigate upper airway dimensions (TV, NNA, and ONA), thereby contributing to the diagnosis of upper airway obstructions.

Comparison of manual, digital and lateral CBCT cephalometric analyses

Objective: The aim of this study was to compare the reliability of three different methods of cephalometric analysis. Material and Methods: Conventional pretreatment lateral cephalograms and cone beam computed tomography (CBCT) scans from 50 subjects from a radiological clinic were selected in order to test the three methods: manual tracings (MT), digitized lateral cephalograms (DLC), and lateral cephalograms from CBCT (LC-CBCT). The lateral cephalograms were manually analyzed through the Dolphin Imaging 11.0(tm) software. Twenty measurements were performed under the same conditions, and retraced after a 30-day period. Paired t tests and the Dahlberg formula were used to evaluate the intra-examiner errors. The Pearsons correlation coefficient and one-way analysis of variance (ANOVA) tests were used to compare the differences between the methods. Results: Intra-examiner reliability occurred for all methods for most of the measurements. Only six measurements were different between the methods and an agreement was observed in the analyses among the 3 methods. Conclusions: The results demonstrated that all evaluated methodologies are reliable and valid for scientific research, however, the method used in the lateral cephalograms from the CBCT proved the most reliable.

Tooth-wear patterns in adolescents with normal occlusion and Class II Division 2 malocclusion

INTRODUCTION In this study, we investigated tooth-wear patterns in adolescents with either normal occlusion or Class II Division 2 malocclusion. METHODS The sample consisted of dental casts from 165 subjects that were divided into 2 groups: 115 normal occlusion subjects (mean age, 14.3 years) and 50 complete Class II Division 2 subjects (mean age, 13.9 years). Dental wear was assessed by using a modified version of the tooth wear index. The 2 groups were compared with the Mann-Whitney test for the frequency and severity of wear on each surface of each group of teeth. The level of statistical significance was set at 5%. RESULTS The normal occlusion group statistically had greater tooth wear on the incisal surfaces of the maxillary lateral incisors and the incisal surfaces of the maxillary canines than did the Class II Division 2 malocclusion group. The malocclusion group showed statistically greater tooth wear on the labial surfaces of the mandibular lateral incisors, the occlusal surfaces of the maxillary premolars and first molars, the occlusal surfaces of the mandibular premolars, the palatal surfaces of the maxillary second premolars, and the buccal surfaces of the mandibular premolars and first molars than did the normal occlusion group. CONCLUSIONS Subjects with normal occlusion and those with complete Class II Division 2 malocclusions have different tooth-wear patterns. Tooth wear on the malocclusion subjects should not be considered pathologic but, rather, the consequence of different interocclusal arrangements.

Tooth-wear patterns in subjects with Class II Division 1 malocclusion and normal occlusion.

INTRODUCTION The aim of this study was to investigate the prevalence of tooth wear in adolescents with Class II malocclusion, compared with those with normal occlusion. METHODS The sample consisted of dental casts obtained from 310 subjects, divided into 3 groups: group 1, 110 subjects with normal occlusion (mean age, 13.51 years); group 2, 100 complete Class II Division 1 patients (mean age, 13.44 years); and group 3, 100 half-cusp Class II Division 1 patients (mean age, 13.17 years). Dental wear was assessed by using a modified version of the tooth-wear index. The 3 groups were compared by means of the Kruskal-Wallis and Dunn tests, considering the frequency and the severity of wear on each surface of each group of teeth. The level of statistical significance was set at 5%. RESULTS The normal occlusion group had statistically greater tooth wear on the palatal surfaces of the maxillary central incisors and the incisal surfaces of the maxillary canines than the corresponding surfaces in both Class II malocclusion groups. The complete and half-cusp Class II Division 1 malocclusion groups had statistically greater tooth wear on the occlusal surfaces of the maxillary second premolar and first molar, the occlusal surfaces of the mandibular premolars, and the buccal surfaces of the mandibular posterior teeth compared with the normal occlusion group. The half-cusp Class II Division 1 malocclusion group had significantly greater tooth wear on the incisal surfaces of the mandibular incisors compared with the complete Class II Division 1 malocclusion group. CONCLUSIONS Subjects with normal occlusion and complete or half-cusp Class II Division 1 malocclusions have different tooth-wear patterns. Tooth wear on the malocclusion subjects should not be considered pathologic but rather consequent to the different interocclusal tooth arrangement.

Early Treatment Protocol for Skeletal Class III Malocclusion

Skeletal Class III malocclusion, with its unpredictable and unfavorable nature, has been characterized by a growth pattern with doubtful prognosis regarding orthodontic mechanics, even when performed early. For a long time, Class III malocclusion was regarded as a synonym of mandibular prognathism, regardless of the affected skeletal structures. Mandibular growth, essentially determined by genetic factors, could barely be controlled by early orthodontic interventions. Therefore, the treatment choice was to wait for the patient to grow, and then make an orthodontic intervention associated with an orthognathic surgery. Maxillary involvement in the etiology of Class III malocclusion was conclusive to change orthodontic therapeutics. Maxillary intramembranous growth has a better response to orthopedic treatment, based on growth control and redirection, thus contributing for early intervention success. In several cases, excellent results have been achieved with rapid maxillary expansion and protraction. The aim of this study was to describe and discuss the treatment of a patient with Class III malocclusion, whose treatment planning comprised two phases: interceptive (mechanical orthopedic appliances) and comprehensive (fixed orthodontic appliance). The results of this case showed that Class III malocclusion should be intercepted as early as possible to permit growth redirection, mainly when the maxilla is the primary etiologic factor or dental and/or functional factors are involved. Diagnosis, treatment planning and prognosis depend on patient age, growth potential and severity of malocclusion. Early intervention, adequate indication of appliances, and patient compliance are key factors for good outcomes.

Early treatment of Class III malocclusion: 10-year clinical follow-up

Angle Class III malocclusion has been a challenge for researchers concerning diagnosis, prognosis and treatment. It has a prevalence of 5% in the Brazilian population, and may have a genetic or environmental etiology. This malocclusion can be classified as dentoalveolar, skeletal or functional, which will determine the prognosis. Considering these topics, the aim of this study was to describe and discuss a clinical case with functional Class III malocclusion treated by a two-stage approach (interceptive and corrective), with a long-term follow-up. In this case, the patient was treated with a chincup and an Eschler arch, used simultaneously during 14 months, followed by corrective orthodontics. It should be noticed that, in this case, initial diagnosis at the centric relation allowed visualizing the anterior teeth in an edge-to-edge relationship, thereby favoring the prognosis. After completion of the treatment, the patient was followed for a 10-year period, and stability was observed. The clinical treatment results showed that it is possible to achieve favorable outcomes with early management in functional Class III malocclusion patients.

Tomographic evaluation of the temporomandibular joint in malocclusion subjects: condylar morphology and position

The aim of this study was to investigate condyle concentricity and morphology, and their association with Class I and II malocclusions (Angle). The sample consisted of 49 individuals of both genders, between 11 and 35 years old, divided into two groups, G1: 26 patients with Class I malocclusion, and G2: 23 patients with Class II malocclusion, selected for orthodontic treatment. Evaluation of the condyle morphology and position was performed by the same previously calibrated examiner using cone-beam computed tomography (CBCT) images of the subjects. The CBCT scans were analyzed by means of a 3D program (Dolphin 11.5, Dolphin Imaging & Management Solutions, Chatsworth, CA, USA), with a 25% level of sensitivity. The images obtained from the coronal slices were employed for the condyle morphology analysis, which classified the condyle form as rounded, as flat or convex, and as triangular or angled. The sagittal slices were used to classify further the condyles as concentric and displaced anteriorly or posteriorly. A clinical examination was also performed, including TMJ and muscle palpation. The kappa test was used to evaluate investigator calibration; the Chi-square and paired t-tests were used for analysis. The convex and anteriorly positioned condyles were found most frequently, regardless of the type of malocclusion. No association was observed between the groups regarding condylar characteristics.