José Rino Neto

Increase of condylar displacement between centric relation and maximal habitual intercuspation after occlusal splint therapy

The present study assessed condylar displacement between initial maximal habitual intercuspation (MHI) and centric relation (CR), recorded after using a deprogramming occlusal splint for an average period of 7.8 +/- 2.1 months prior to any orthodontic treatment. The sample consisted of 22 subjects, 11 male and 11 female, with an average age of 14.2 +/- 1.4 years, with Class II malocclusion and with no apparent signs or symptoms of temporomandibular dysfunction (TMD). Condylar displacement was measured using a Panadent axis position indicator in decimal fractions of a millimeter. The original mean vertical displacements and the corresponding standard deviations were 4.24 +/- 2.53 mm and 3.86 +/- 2.72 mm, respectively, for the right and left sides. Because a significant negative correlation was observed between original condylar displacements and age factors, the displacement values were statistically adjusted to 2.74 +/- 2.00 mm and 2.44 +/- 1.93 mm. On the horizontal plane, the mean displacements measured were -0.72 +/- 1.53 mm on the right side and -0.51 +/- 1.98 mm on the left. The mean displacement on the transversal plane was 0.03 +/- 0.87 mm. A comparison between these values and those observed in non-deprogrammed groups, as well as those published in the related literature, indicates that use of occlusal splints results in greater mean condylar displacement values, especially vertically, between CR and MHI positions, which contributed to a more accurate orthodontic diagnosis.

Low-level laser therapy effects on pain perception related to the use of orthodontic elastomeric separators

INTRODUCTION: Some patients refer to pre-banding orthodontic separation as a painful orthodontic procedure. Low-level laser therapy (LLLT) has been reported to have local analgesic effect. OBJECTIVE: The aim of this single-blind study was to investigate the perception of pain caused by orthodontic elastomeric separators with and without a single LLLT application (6J). METHODS: The sample comprised 79 individuals aged between 13 and 34 years old at orthodontic treatment onset. Elastomeric separators were placed in first maxillary molars at mesial and distal surfaces and kept in place for three days. The volunteers scored pain intensity on a visual analogue scale (VAS) after 6 and 12 hours, and after the first, second and third days. One third of patients received laser applications, whereas another third received placebo applications and the remaining ones were controls. Applications were performed in a split-mouth design. Thus, three groups (laser, placebo and control) were assessed. RESULTS: No differences were found among groups considering pain perception in all periods observed. CONCLUSION: The use of a single-dose of LLLT did not cause significant reduction in orthodontic pain perception. Overall pain perception due to orthodontic separator placement varied widely and was usually mild.

Avaliação das geometrias nasais de crianças empregando a rinometria acústica

UNLABELLED The area above the nasal cavity plays a role in respiratory physiology. AIM To analyze, during a period of growth, a possible change in the minimum cross sectional area (MCA) and nasal volume of the anterior nasal cavity. MATERIALS AND METHODS We evaluated 29 children (14 boys and 15 girls) with a mean age of 7.81 years at first examination (M1) and 11.27 years in the second examination (M2), without symptoms of nasal obstruction. The interval between examinations was 36-48 months. Children were subjected to the examination of acoustic rhinometry in which we recorded the minimum cross-sectional areas, volumes and their correlations with gender. STUDY DESIGN Cohort. RESULTS The mean cross-sectional area of the nasal cavity of MCA for girls was 0.30 +/- 0.09 cm2 (M1) and 0.30 +/- 0.14 cm2 (M2), while for boys was 0.24 +/- 0.12 cm2 (M1) and 0.32 +/- 0.10 cm2 (M2). The mean values of the total volumes found for the whole sample were 2.17 +/- 0.23 cm3 (MCA1-M1), 2.56 +/- 0.27 cm3 (MCA1-M2), 4.24 +/- 1.17 cm3 (MCA2- M2) and 4.63 +/- 1.10 cm3 (MCA2-M2). CONCLUSION There was no significant change in the minimum cross sectional area of the anterior nasal cavity. There was no significant difference between genders for both MCA and for the volume. There was a significant increase in MCA1.

Oral focal mucinosis associated with surgically assisted rapid maxillary expansion

Oral focal mucinosis is a rare soft-tissue lesion that might result from the overproduction of hyaluronic acid by fibroblasts. The lesions are commonly found on the gingiva and palate; however, other sites, such as the tongue, have also been reported. The diagnosis of oral focal mucinosis is based on histologic analysis, and treatment involves surgical excision. Recurrences of lesions have not been reported. This article presents a patient with oral focal mucinosis that might be associated with surgically assisted rapid maxillary expansion.

Comparative study of classic friction among different archwire ligation systems

OBJECTIVE: To describe and compare three alternative methods for controlling classical friction: Self-ligating brackets (SLB), special brackets (SB) and special elastomeric ligatures (SEB). METHODS: The study compared Damon MX, Smart Clip, In-Ovation and Easy Clip self-ligating bracket systems, the special Synergy brackets and Morellis twin bracket with special 8-shaped elastomeric ligatures. New and used Morelli brackets with new and used elastomeric ligatures were used as control. All brackets had 0.022 x 0.028-in slots. 0.014-in nickel-titanium and stainless steel 0.019 x 0.025-in wires were tied to first premolar steel brackets using each archwire ligation method and pulled by an Instron machine at a speed of 0.5 mm/minute. Prior to the mechanical tests the absence of binding in the device was ruled out. Statistical analysis consisted of the Kruskal-Wallis test and multiple non-parametric analyses at a 1% significance level. RESULTS: When a 0.014-in archwire was employed, all ligation methods exhibited classical friction forces close to zero, except Morelli brackets with new and old elastomeric ligatures, which displayed 64 and 44 centiNewtons, respectively. When a 0.019 x 0.025-in archwire was employed, all ligation methods exhibited values close to zero, except the In-Ovation brackets, which yielded 45 cN, and the Morelli brackets with new and old elastomeric ligatures, which displayed 82 and 49 centiNewtons, respectively. CONCLUSIONS: Damon MX, Easy Clip, Smart Clip, Synergy bracket systems and 8-shaped ligatures proved to be equally effective alternatives for controlling classical friction using 0.014-in nickel-titanium archwires and 0.019 x 0.025-in steel archwires, while the In-Ovation was efficient with 0.014-in archwires but with 0.019 x 0.025-in archwires it exhibited friction that was similar to conventional brackets with used elastomeric ligatures.

Muscular activity in class III dentofacial deformity.

Abstract Individuals with Class III dentofacial deformities exhibit morphological changes and myofunctional adaptations, and an accurate diagnosis is essential for treatment planning. The purpose of this study was to evaluate the electrical activity of the masseter, temporal, and suprahyoid muscles in subjects with Class III dentofacial deformities, assessing electromyographic characteristics using functional tests. The research group consisted of 20 subjects with Class III dentofacial deformities and indications for surgical-orthodontic treatment. The control group consisted of 10 individuals presenting a good maxilla and mandible relationship. Electrical activities of the masseter and temporal were recorded during isometric contraction and maximal isometric contraction. The suprahyoid and masseter were assessed during maximal mouth opening and swallowing of saliva. Isometric contraction and maximal isometric contraction analysis showed less potential in the research group, with a significant difference regarding the masseter muscle in isometric contraction. In maximal isometric contraction, an increase in electrical activity in both groups was observed; it remained lower for the research group, but with no significant difference. With regard to symmetry, significant differences among the groups were observed only for the left masseter in the research group, as well as during isometric contraction. There was no significant difference found regarding maximal mouth opening. During swallowing of saliva, there was a high percentage of abnormal electromyographic tracings for both groups. This finding was not expected for the control group. The study found some changes in muscular activity in Class III dentofacial deformities, characterized by lower potential in the masseter muscle during isometric contractions. No other peculiarities were found that could contrast either group.

Does self-ligating brackets type influence the hysteresis, activation and deactivation forces of superelastic NiTi archwires?

OBJECTIVE To compare hysteresis, activation and deactivation forces produced by first-order deformation of Contour 0.014-in NiTi wire (Aditek, Brazil) in four brands of self-ligating brackets: Damon MX, Easy Clip, Smart Clip and In-Ovation. METHODS Activation and deactivation forces were measured in an Instron universal tensile machine at 3 mm/minute speed to a total displacement of 4 mm. Tests were repeated eight times for each bracket/wire combination. Statistical analysis comprised ANOVA and Tukeys multiple comparisons test. RESULTS Using a 4-mm deformation, mean activation forces increased in the following order: Damon = 222 gf, Easy Clip = 228 gf, In-Ovation = 240 gf and Smart Clip = 306 gf. The same order was observed for mean hysteresis values, i.e., 128 gf, 140 gf, 150 gf and 206 gf, respectively. The respective values of deactivation forces for the Damon, Easy Clip, In-Ovation and Smart Clip brackets were 94 gf, 88 gf, 90 gf and 100 gf. CONCLUSIONS Brackets with higher activation forces were accompanied by higher hysteresis values, which resulted in clinically similar deactivation forces, regardless of the type of self-ligating brackets used.

Evaluation of radiographic magnification in lateral cephalograms obtained with different X-ray devices: experimental study in human dry skull

OBJECTIVE The purpose of this study was to evaluate the influence of the magnification factor of the radiographic image in angular, linear and proportional measurements. METHODS From a dried human skull where metallic spheres with predetermined size were fixed (1.0 mm), 14 radiographs were obtained in devices from three different manufacturers: Panoura, Instrumentarium and Tomeceph. The Pearson correlation test was used to investigate the relationship between the rate of radiographic magnification and the cephalometric measurements assessed. RESULTS According to the results, the linear measurements showed a high positive correlation, pointing out great influence of the magnification factor, while the angular and proportional measurements did not correlate. CONCLUSIONS Comparisons between linear cephalometric measurements obtained with different devices from the same manufacturer showed maximum rates of expansion of 0.6%, 1.25% and 2.3%, respectively, for the devices from Instrumentarium (OP-100, Instrumentarium, Finland), Panoura (10CSU, Yoshida, Japan) and Satelec/Tomeceph (XMind, Satelec/Tomeceph Orion Corporation, Finland).

Rhinometric evaluation of nasal cavity geometry and its relation to the upper arch transverse distance

The objective of this study was to evaluate childrens respiratory patterns in the mixed dentition, by means of acoustic rhinometry, and its relation to the upper arch width development. Fifty patients were examined, 25 females and 25 males with mean age of eight years and seven months. All of them were submitted to acoustic rhinometry and upper and lower arch impressions to obtain plaster models. The upper arch analysis was accomplished by measuring the interdental transverse distance of the upper teeth, deciduous canines (measurement 1), deciduous first molars (measurement 2), deciduous second molars (measurement 3) and the first molars (measurement 4). The results showed that an increased left nasal cavity area in females means an increased interdental distance of the deciduous first molars and deciduous second molars and an increased interdental distance of the deciduous canines, deciduous first and second molars in males. It was concluded that there is a correlation between the nasal cavity area and the upper arch transverse distance in the anterior and mid maxillary regions for both genders.

Avaliação cefalométrica radiográfica da posição craniocervical de pacientes orientados em posição natural da cabeça pré e pós-expansão rápida da maxila

The aim of this study was to evaluate the eventual alteration in the craniocervical position of patients, oriented in the Natural Head Position (NHP), after the rapid maxillary expansion (RME) procedure. We have used lateral radiographs, selected from the documentation file of the Preventive Orthodontics Clinic, School of Dentistry, University of Sao Paulo. Our sample consisted of 20 patients (7M:13F), with ages ranging from 5.08 up to 11.08 years (mean of 9,0). The cephalometric radiographs were obtained in the beginning of the treatment and immediately after the active phase of the maxilla expansion. All patients showed constrictions of the maxilla, and were treated with modified Biederman appliance. Craniocervical cephalometric analysis was carried out by evaluating the craniovertical (SN.VER), craniocervical (OPT.SN e CVT.SN), cervicohorizontal (OPT.HOR e CVT.HOR) and the cervical curve (OPT. CVT) angles. On the basis of the statistical analysis of the data, we conclude that the head position did not show significant alteration. Statistically significant differences were not detected between the sexes, when the phases pre and post RME were compared for the measurements studied. In the sample studied, the method of obtaining cephalometric radiographs in the Natural Head Orientation showed to be trustworthy and reproducible, even in the presence of orthodontic-orthopedic intervention between the series of radiographs.