Marcio José da Silva Campos

Salivary Alpha‐Amylase Activity: A Possible Indicator of Pain‐Induced Stress in Orthodontic Patients

INTRODUCTION Pain, a common experience reported by orthodontic patients, has its intensity assessed with the help of subjective scales, which have a limited and disputable value. Such unpleasant experience, which may raise stress levels, is reflected by an increase in the salivary concentration of alpha-amylase. OBJECTIVE Assess the correlation between the salivary levels of alpha-amylase and pain intensity reported by patients during orthodontic treatment. PATIENTS Twenty male patients (11-37 years of age) were assessed daily, before treatment, after bracket bonding, and after initial arch wire insertion. DESIGN Saliva was sampled for alpha-amylase analysis, and pain intensity was measured with the visual analog scale. RESULTS There was no correlation between alpha-amylase concentrations in the saliva and pain intensity, although the patients had a significant and progressive increase of alpha-amylase levels during the assessment period. CONCLUSIONS The findings may reflect the psychological stress caused by the presence and activation of the fixed appliance.

Bone mineral density in cone beam computed tomography: Only a few shades of gray

Cone beam computed tomography (CBCT) has often been used to determine the quality of craniofacial bone structures through the determination of mineral density, which is based on gray scales of the images obtained. However, there is no consensus regarding the accuracy of the determination of the gray scales in these exams. This study aims to provide a literature review concerning the reliability of CBCT to determine bone mineral density. The gray values obtained with CBCT show a linear relationship with the attenuation coefficients of the materials, Hounsfield Units values obtained with medical computed tomography, and density values from dual energy X-ray absorciometry. However, errors are expected when CBCT images are used to define the quality of the scanned structures because these images show inconsistencies and arbitrariness in the gray values, particularly when related to abrupt change in the density of the object, X-ray beam hardening effect, scattered radiation, projection data discontinuity-related effect, differences between CBCT devices, changes in the volume of the field of view (FOV), and changes in the relationships of size and position between the FOV and the object evaluated. A few methods of mathematical correction of the gray scales in CBCT have been proposed; however, they do not generate consistent values that are independent of the devices and their configurations or of the scanned objects. Thus, CBCT should not be considered the examination of choice for the determination of bone and soft tissue mineral density at the current stage, particularly when values obtained are to be compared to predetermined standard values. Comparisons between symmetrically positioned structures inside the FOV and in relation to the exomass of the object, as it occurs with the right and left sides of the skull, seem to be viable because the effects on the gray scale in the regions of interest are the same.

The null hypothesis

model to a random-effect model would generate no change in the conclusions. Second, owing to the commonly found considerable heterogeneity across studies and a chief aim to merely provide pooled prevalence, many MCPs reported subgroup differences only in a descriptive manner rather than ambitiously giving the statistical significance of the differences. According to Higgins and Green, nonoverlap (and even overlap to a small degree) of the confidence intervals of the summary estimates is an indication of statistical significance. To avoid exaggeration, we used this relatively conservative method to estimate the rough degree of differences while describing them. As for publication bias, previous MCPs either made no mention or provided only an overall value of relevant statistics for all included studies (same as what we did). Actually, the chief concern for publication bias was that studies with negative results are less likely to be published. However, results of epidemiologic surveys concerning prevalence could not be considered either positive or negative. Furthermore, a previous study has shown that study size was not consistently associated with the probability of publication. Thus, to MCPs, the importance of publication bias and the traditional methods to estimate it might not be absolutely applicable. Conversely, information bias, selection bias, and performance bias have been highlighted for MCPs, all of which we endeavoured to avoid and evaluate in our analysis. For the last 3 or 4 years, MCPs have been rapidly gaining the interest of researchers. The elimination of inconformity and the improvement of quality of future MCPs might be one task that the Cochrane Collaboration could undertake before its 25th anniversary! Fang Hua Hong He Wassim Bouzid Wuhan, China

Orthodontic distalization with rigid plate fixation for anchorage after bone grafting and maxillary sinus lifting

A 68-year-old woman was treated with an autogenous particulated bone graft from the anterior part of the mandible to elevate the right maxillary sinus floor, which was next to the alveolar ridge of an edentulous area, to facilitate dental implant placement. A rigid plate for anchorage was placed into the zygomatic bone. The maxillary right canine and the premolars were moved distally 6 months after the implant was placed and osteointegration of the bone graft had occurred. The Class II relationship was corrected. After tooth movement, the patient underwent multislice computed tomography to determine the mineral density of the bone graft and compare it with the opposite side of the maxilla. The mineral density showed values above normal for the posterior segment of the maxilla. Although the patient was taking bisphosphonate for treatment of osteoporosis, no related complications were noted during treatment.

Apical root resorption: the dark side of the root.

INTRODUCTION The diagnosis of apical root resorption is usually based on routine radiographs. However, these methods are limited because the images reflect the superimposition of the whole root structure and can lead to underestimation of the extent of apical root resorption. In this study, we aimed to determine the lengths of the labial and lingual surfaces of incisors with apical root resorption and compare them with the longest radicular length obtained on sagittal images of cone-beam computed tomography, and to create a qualitative visual scale of the different patterns of apical root resorption. METHODS Eighty-two incisors with apical root resorption from 25 patients had their labial and lingual root surfaces and the longest radicular lengths determined in the sagittal plane and compared. Five orthodontists, at 2 times, classified the images of each incisor according to a visual scale developed by the authors. RESULTS There was no significant difference between the labial and lingual surfaces; however, the longest radicular length was significantly greater than the shortest surface length. The visual scale showed intraobserver agreement of 0.615 and interobserver agreements of 0.74 and 0.52 at both times, respectively. CONCLUSIONS The difference between the longest and shortest root lengths suggests that radiographic superimposition underestimates the extent of the resorption lesion. The proposed visual scale showed a frequency of agreement above 65% and a coefficient of reproducibility varying from moderate to substantial.

Assessment of pain experience in adults and children after bracket bonding and initial archwire insertion

INTRODUCTION Ninety five percent of orthodontic patients routinely report pain, due to alterations in the periodontal ligament and surrounding soft tissues, with intensity and prevalence varying according to age. OBJECTIVE This study aimed to assess toothache and buccal mucosal pain in adults and children during two initial phases of the orthodontic treatment. METHODS The intensity of toothache and buccal mucosal pain reported by 20 patients, 10 children (11-13 years) and 10 adults (18-37 years) was recorded with the aid of a Visual Analog Scale (VAS), during 14 days--7 days with bonded brackets only and 7 days with the initial archwire inserted. RESULTS There was no significant difference in pain intensity among adults and children. After bracket bonding, 50% of the children and 70% of the adults reported pain. 70% of both groups reported pain after initial archwire insertion. While adults reported constant, low intensity, buccal mucosal pain, the children showed great variation of pain intensity, but with a trend towards decreasing pain during the assessment period. After initial archwire insertion the peaks of toothache intensity and prevalence occurred 24 hours in children and 48 hours in adults. CONCLUSIONS In general, children reported pain less frequently than adults did, though with greater intensity.

Anteroposterior condylar position: A comparative study between subjects with normal occlusion and patients with Class I, Class II Division 1, and Class III malocclusions

Background The present study aimed to determine and compare the anteroposterior position of the condyle in the mandibular fossa between groups of asymptomatic subjects with normal occlusion and asymptomatic subjects with Class I, Class II Division 1, and Class III malocclusions. Material/Methods Thirty persons with normal occlusion, 30 with Class I malocclusion, 30 with Class II Division 1, and 30 with Class III had computed tomography scans of their temporomandibular joints. The anterior joint space/posterior joint space (AJS/PJS) ratio was determined for the right and left joints. The paired t test was used to analyze the AJS/PJS ratio between both sides for each group. The ANOVA test was applied to verify the differences between the groups for the measurements of the right and left sides. In case the ANOVA test confirmed significance, the Dunnett’s t test was performed to compare the groups of malocclusion with that of normal occlusion. Results The paired t test between the AJS/PJS relationships in the right and left sides showed the following p values: Class I (0.168), Class II Division 1 (0.662), Class III (0.991), and normal occlusion (0.390). The ANOVA test showed a p value of 0.445 for the comparisons of the right side and 0.040 for the left side. The Dunnett’s t test demonstrated a statistically significant difference between the Class II group and the normal occlusion group (p value of 0.026) in the joints of the left side. Conclusions Bilateral symmetry and lack of condyle centralization were common characteristics among all groups. The greatest condylar decentralization was observed in the Class II group, whereas the least condylar decentralization was found in the normal occlusion group.

The role of orthodontic tooth movement in bone and root mineral density: A study of patients submitted and not submitted to orthodontic treatment

Summary Background Orthodontic force application to the teeth is responsible for a series of biological responses in the bone and dentin, which lead to some alterations of the mineral density of the tissues. Our objective was determine, through cone-beam computed tomography (CBCT), the mineral density of the apical third of the roots of the upper central incisors and of the periapical bone portion surrounding these teeth, in patients submitted to orthodontic treated and untreated individuals. Material/Methods 30 untreated individuals and 15 treated ones (treatment cessation at least 1 year before the study) underwent CBCT. Mineral density was assessed in the apical third of the root of the upper central incisors and in the alveolar bone in the periapical region of these teeth. In order to reduce CBCT-related mineral density variability, we standardized the cone-beam tomography device, the image-acquisition settings and the field of view positioning and size. Student’s t test was used for the analyses. Results bone mineral density (BMD) and root mineral density (RMD), in Hounsfield Units, were 674.84 and 1282.26 for the untreated group and 630.28 and 1370.29 for the treated group, respectively. The differences between the group means were statistically significant for RMD (p<0.05). Conclusions untreated individuals had a significant lower mean RMD in comparison with those submitted to orthodontic treatment.

Multiple hyperdontia: Report of an unusual case

Supernumerary teeth are an infrequent developmental anomaly that can appear in any area of the dental arch and can affect any dental organ. Multiple supernumerary teeth, or hyperdontia, is rare in people with no other associated diseases or syndromes. Conditions commonly associated with hyperdontia include cleft lip and palate, trichorhinophalangeal syndrome, cleidocranial dysplasia, and Gardners syndrome. A black girl, aged 11 years 8 months, came for consultation; radiographs showed 81 teeth: 18 deciduous, 32 permanent, and 31 supernumerary. The main concern initially was to determine whether she was syndromic, and she was referred to a geneticist. G banding analysis showed pericentric inversion of chromosome 9; the chromosome formula was 46, XX, inv (9) (p13q21). Orthodontic treatment for this patient will be a clinical challenge because of the great number of teeth to be extracted and the alterations in the shapes of the teeth. Treatment goals should be established by a multidisciplinary team, where oral surgeon, orthodontist, periodontist, and prosthodontist come together to solve a medical and dental puzzle, eliminating the pieces that do not fit and searching for new ones to obtain an occlusion that will give the patient physiologic conditions of normality and esthetic satisfaction.

Shear bond resistance and enamel surface comparison after the bonding and debonding of ceramic and metallic brackets

Objective To evaluate, in vitro, the shear bond strength presented by three brands of polycrystalline ceramic brackets and one brand of metallic bracket; verify the adhesive remnant index (ARI) after the tests, and analyze, through scanning electron microscopy (SEM) the enamel surface topography after debonding, detecting the release of mineral particles. Methods Sixty bovine lower incisors were used. Three ceramic brackets (Allure®, InVu®, and Clarity®) and one metallic bracket (Geneus®) were bonded with Transbond XT®. Kruskal-Walliss test (significance level set at 5%) was applied to the results of share bond and ARI. Mann Whitneys test was performed to compare the pairs of brackets in relation to their ARI. Brown-Forsythes test (significance level set at 5%) was applied to the results of enamel chemical composition. Comparisons between groups were made with Games-Howells and the Post-hoc tests. Results No statistically significant difference was observed in relation to the shear bond strength loads. Clarity® brackets were the most affected in relation to the surface topography and to the release of mineral particles of enamel (calcium ions). Conclusion With regard to the ARI, there was a prevalence of score 4 (40.4%). As for enamel surface topography, the Geneus® bracket was the only one which did not show superficial tissue loss. The InVu® and Clarity® ones showed cohesive fractures in 33.3% and the Allure® in 50%, the latter being the one that presented most fractures during removal.