Safe sites for orthodontic miniscrew insertion in the infrazygomatic crest area in different facial types: A tomographic study.

INTRODUCTION: Temporary skeletal anchorage devices (TSADs) are used to obtain skeletal anchorage for orthodontic treatment. Their insertion in the infrazygomatic crest (IZC) allows efficient orthodontic mechanics. Different facial types have different bone configurations. We aimed to evaluate the differences in bone thicknesses in the IZC area among patients of each facial type to determine a safe zone for TSAD insertion. METHODS: For this retrospective study, 86 cone-beam computed tomography (CBCT) scans were divided into 3 groups according to the facial type: group I, 24 CBCT scans of hyperdivergent patients; group II, 30 scans of neutral patients; and group III, 32 scans of hypodivergent patients. The buccal alveolar bone thickness was measured in 6 zones between the second premolar and distal root of the second molar, 5, 7, 9, and 11 mm apical to the alveolar crest. RESULTS: The IZC areas with minimum thickness for TSAD insertion follows: group I, between first and second molars at 11 mm from the alveolar crest, mesial root of the second molar at 9 mm from the crest, and distal root of the second molar at 11 mm from the crest; groups II and III, between first and second molars at 11 mm from the crest and mesial root of the second molar at 11 mm from the crest. CONCLUSIONS: The safe zones for IZC miniscrew insertion are located 11 mm from the alveolar crest between the maxillary first and second molars and on the mesial root of the second molar for all the 3 facial types.

A method to compute the effect of vertical mulching on the reduction of surface runoff.

Six plots (three as controls) were established in southern Brazil to assess the reduction in runoff by vertical mulching (vm). In the other three, ditches (0.08-m wide, 0.4-m deep) were cut perpendicular to the slope, 2-m and 12-m upslope from the bottom of the plot where a flume was installed to measure runoff. Three simulated rainfalls (80 mm h-1 for 120 min, 80 mm h-1 for 65 min, 97 mm h-1 for 65 min) were applied with a sprinkler system to generate runoff. Compared to the controls, vm delayed its beginning by 10 to 20 min and reduced its volume by 34 to 39%, because initially all and later some runoff was caught in the ditches from where it infiltrated into the surrounding soil. Based on the experimental results, we derived a method to compute the runoff reduction by vm as influenced by ditch spacing (ds), initial soil moisture content (θi), and rainfall rate and duration. Computations for a combination of four ds (5 to 20 m), five θi (16 to 32%-vol), and three rainfall regimes (124 mm h-1 for 20 min, 66 mm h-1 for 60 min, and 42 mm h-1 for 120 min) showed an increasing runoff reduction as ds or θi decreased. In some cases, runoff was even completely prevented. The reductions were larger in the 60-min than in the 20-min rainfall. For the 120-min rainfall, there was no runoff with any combination of ds and θi.

Micro-osteoperforation effectiveness on tooth movement rate and impact on oral health related quality of life.

OBJECTIVES: To investigate the effect of micro-osteoperforation (MOP) on the rate of tooth movement (RTM), space closure duration, and oral health-related quality of life (OHRQoL) during completion of anterior retraction in patients undergoing combined orthodontic-surgical treatment after premolar extraction and decompensation with sliding mechanics. MATERIALS AND METHODS: Twenty-four participants with indications for premolar extractions were randomly allocated to treatment with conventional sliding mechanics (control group; CG) or with to treatment in which three MOPs were performed every activation (experimental group; EG). Dental impressions were taken monthly until space closure was completed and dental casts were converted to three-dimensional models. After the anterior retraction procedure, Oral Health Impact Profile (OHIP-14) questionnaires were filled out at 4 and 72 hours. RESULTS: Eighteen patients (7 men and 11 women) remained in the trial until space closure was completed (mean follow-up period = 247 days). For full space closure RTM, no significant difference (P = .492) was found between groups (0.614 mm/month for the CG; 0.672 mm/month for the EG). The RTM for different time points, groups, time frames and their interaction were statistically different (P < .05). In multiple correlation analysis, the RTM significantly decreased over time for both groups (P < .05). The OHRQoL scores were significantly higher (worse) for the EG. The psychological, physical and social disabilities, and handicap domains displayed significant differences between the two groups. CONCLUSION: Use of MOPs did not change the full space closure RTM, while it had a negative impact on OHRQoL.

Maxillary protraction with rapid maxillary expansion and facemask versus skeletal anchorage with mini-implants in class III patients: a non-randomized clinical trial.

BACKGROUND: The use of skeletal anchorage devices for maxillary protraction in patients with class III malocclusion due to deficiency in the middle third of the face has been shown to be a promising approach to treatment of these patients. The aim of this study was to evaluate the treatment of class III patients with maxillary retrusion, using orthodontic mini-implants (MI) associated with intermaxillary elastics in comparison with the rapid maxillary expansion and facemask protocol (RME/FM). METHODS: In this prospective non-randomized clinical trial, the sample of 24 participants between 7 and 12 years of age (median age of 10.0 years and interquartile range = 3.0 years), at the stage prior to the pre-pubertal growth spurt, was divided in two groups. In group facemask (FM) (n = 12), the individuals received orthopedic treatment with RME/FM. In group MI (n = 12), two mini-implants were inserted in the region close to the maxillary first molar roots, and the other two in the region of the mandibular canines. Initial and final lateral teleradiographs were taken for cephalometric evaluation of all the cases. Statistical analysis included the Mann-Whitney, Wilcoxon, and Fisher's exact tests. The level of significance was 5% (α = 0.05). RESULTS: Improvement was verified in the facial profile and occlusion of the participants, showing advancement of the maxilla in the two groups, with significant differences (P ≤ 0.05) between T0 and T1 in the following measurements: SNA, ANB, Wits, Co-A, Co-Gn, NAP, A-Npog, overjet, and molar relationship. There was no statistically significant intergroup difference (P > 0.05) in the cephalometric measurements evaluated, but the time of treatment was significant, and was faster for group MI. CONCLUSIONS: The protocol with mini-implants may be an option for the correction of Class III due to maxillary deficiency.

An Oral Health-Related Quality of Life Comparison Between Adults With Unilateral Cleft Lip and Palate and Class III Malocclusion.

OBJECTIVE: To compare oral health-related quality of life (OHRQoL) before treatment of adults with unilateral cleft lip and palate (UCLP) and surgical Class III malocclusion, and to consider if clefts needing different orthodontic treatment protocols could influence people's self-perception. DESIGN: Cross sectional. SETTING: Cleft Lip and Palate Center and Clinic of Orthognathic Surgery from a School of Dentistry. PARTICIPANTS: A sample of adults with repaired nonsyndromic UCLP (n = 52) which was age- and sex-matched with a noncleft Class III malocclusion sample seeking orthognathic surgery (n = 51). In turn, the cleft group was subdivided according to treatment planning into nonsurgical orthodontic and surgical orthodontic approaches. MAIN OUTCOME MEASURE: The whole sample was assessed using the short-form oral health impact profile (OHIP-14), with higher scores indicating a poorer OHRQoL. Statistical comparisons were performed with Mann-Whitney U and Kruskal-Wallis tests, and effect size. Bonferroni adjustment was used for post hoc tests (P < .017). RESULTS: The OHIP-14 scores of the UCLP and Class III groups were significantly different (P = .001, η2 = 0.108), and higher in Class III. The largest commitment was in the physical disability, physical pain, and psychological disability domains. In addition, no differences were found when the UCLP treatment planning was considered. CONCLUSION: Surgical Class III malocclusion have a poorer OHRQoL when compared to patients with UCLP, irrespective of whether they are treated surgically or orthodontically. Therefore, the greater commitment of OHRQoL appears to be influenced by the etiology of Class III, and not by treatment plan.

Anterior crossbite treatment in the primary dentition: Three case reports.

Anterior crossbite is characterized by negative horizontal overjet between the jaws, and occurs due to skeletal, functional, and/or dental imbalances. It is often found in primary and mixed dentition stages and causes severe aesthetic, functional, and psychosocial impairment. We report the facial and occlusal effects of maxillary protraction associated with rapid maxillary expansion in three young patients with primary dentition. The proposed treatment plan consisted of protraction and rapid maxillary expansion. The mechanical device chosen was the facial mask combined with a McNamara rapid palatal expander. The anterior crossbite was corrected, and significant facial and cephalometric benefits were obtained. The treatment of maxillary protraction during the deciduous dentition stage, in cases where there is good acceptance and collaboration by patients, provides excellent clinical results and constitutes a viable treatment option.

Photoelastic analysis of stress distribution in mandibular second molar roots caused by several uprighting mechanics.

INTRODUCTION: Mandibular molar uprighting is indicated when mesial inclination of the second molars occurs because of missing first molars. There are many methodologies to perform such movement. In this study, we aimed to analyze and compare the stress distributions in different molar uprighting techniques. METHODS: Four photoelastic models were designed to evaluate different mandibular second molar uprighting techniques: a miniscrew positioned in the retromolar region, a beta-titanium alloy cantilever spring, a beta-titanium alloy wire with a T-loop spring, and an 0.018-in stainless steel archwire with an open-coil spring between the second premolar and the second molar. RESULTS: On the miniscrew test specimen, the greatest concentration of strains was observed in the cervical zone of the distal root. The cantilever spring had many strains in the cervical zone of the mesial root. On the T-loop spring test specimen, mainly the observed strains were in the apical zone of the mesial root. The open-coil spring specimen showed fringes in the cervical zone and the apical zone of the mesial root without formation of large sequences of strains. CONCLUSIONS: The miniscrew mechanical action had the least and the cantilever spring mechanical action had the greatest strain means on the roots of mandibular second molars.

Correlation between buccolingual tooth inclination and alveolar bone thickness in subjects with Class III dentofacial deformities.

INTRODUCTION: The purposes of this study were to identify buccolingual inclinations and alveolar bone thickness in patients with Class III dentofacial deformities and to compare these measurements with those from subjects with normal occlusions to verify, based on the correlation between these 2 variables, whether the natural process of bone remodeling provides uniformity of bone thickness or whether it varies around the roots due to tooth inclination. METHODS: The sample consisted of 35 adults with normal occlusions and 35 adults with Class III dentofacial deformities with no previous orthodontic treatment. Buccolingual inclinations and alveolar bone thickness were measured at 3 heights from the cementoenamel junction from 3-dimensional images generated by cone-beam computed tomography. RESULTS: The region corresponding to the maxillary canines appeared to be thinner, and the palatal area of the maxillary central incisors and the distobuccal region of the mandibular second molars appeared to be thicker. Greater tooth inclinations were observed in the maxillary incisors and mandibular canines, and smaller tooth inclinations were observed on the buccal roots of the mandibular second molars. CONCLUSIONS: In subjects with Class III deformities, more statistically significant correlations were found between inclination and thickness in the mandibular teeth, whereas in subjects with normal occlusion, few statistically significant correlations were found between these 2 variables.

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.

Orthodontic movement of teeth with short root anomaly: Should it be avoided, faced or ignored?

INTRODUCTION: Short Root Anomaly (SRA) is an uncommon disease and a challenge for orthodontic treatment as it tends to increase the risk of root resorption. OBJECTIVE: Assess the current status of the diagnosis, etiology and orthodontic management of teeth with SRA, and present case reports. METHODS: A literature review was carried out in PubMed, SciELO, LILACS, Scopus and Web of Science databases. RESULTS: A differential diagnosis of SRA should be conducted for teeth with incomplete root formation, external apical root resorption, dentin dysplasia type I and post dental trauma root hypoplasia. SRA is genetically determined and orthodontic movement requires changes in clinical and radiographic management in order to restrict damage. CONCLUSIONS: Orthodontic movement of teeth with SRA is contraindicated in extreme cases, only. Caution at all stages could minimize attachment loss and lead to long-term stability.

Muscular activity in class III dentofacial deformity.

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.

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).

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 Tukey's 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.

Iatrogenic absence of maxillary canines: Bolton discrepancy treated with mandibular incisor extraction.

This case report describes the orthodontic treatment of an adult patient with iatrogenic absence of the maxillary canines, moderate maxillary and severe mandibular dental crowding, a Bolton discrepancy with a large mandibular anterior excess, a maxillary right lateral incisor crossbite, and Angle Class II molar relationships. The treatment consisted of fixed appliance therapy, mandibular incisor extraction, tooth bleaching, and dental recontouring. This method of treatment maintained the patient's good facial appearance, improved the dental esthetics, and provided a good functional occlusion, eliminating the arch length and Bolton discrepancies and providing a good outcome with minimal undesirable effects.

Comparative study of frictional forces generated by NiTi archwire deformation in different orthodontic brackets: In vitro evaluation / Estudo comparativo da força de atrito produzida pela deformação de arco NiTi em diferentes braquetes ortodônticos: avaliação in vitro

INTRODUCTION: The purpose of this study was to compare the frictional forces between 0.014-in NiTi wires (Aditek) with 4 mm horizontal deflection and brackets with different archwire ligation systems. METHODS: Four types of self-ligating brackets (Damon MX, Easy Clip, Smart Clip and In-Ovation), a triple bracket (Synergy) and a twin bracket with 8-shaped ligature (Tecnident) were tested. Twin brackets with conventional elastomeric ligatures (Morelli) were used as control group. Tests were repeated 10 times for each bracket/archwire combination. Frictional forces were measured in an Instron universal tensile machine at 3 mm/minute speed and a total displacement of 6 mm. Statistical analysis comprised ANOVA and Dunnett's multiple comparison post hoc test. RESULTS: Deflection-induced frictional (DIF) forces increased in the following order: Synergy, Damon, 8-shaped Ligature, Easy Clip, In-Ovation, Smart-Clip and conventional ligatures. The differences among groups were significant, with the exception of the 8-shaped ligature groups which was equal to the Damon and Easy Clip groups. CONCLUSIONS: Compared to conventional ligatures, all ligation systems tested reduced frictional forces. However, such reduction varied according to the ligation system employed.

OBJETIVO: o objetivo desse trabalho foi comparar as forças de atrito entre fios NiTi 0,014" (Aditek) com deformações horizontais de 4mm, e braquetes com diferentes sistemas de ligação dos arcos. MÉTODOS: foram testados 4 tipos de braquetes autoligáveis (Damon MX, Easy Clip, Smart Clip e In-Ovation), um braquete triplo (Synergy) e um braquete gêmeo com amarrilho 8 (Tecnident). Como grupo controle, foi utilizado braquete gêmeo com ligadura elástica convencional (Morelli). Foram executadas 10 repetições em cada combinação arco/braquete. As forças de atrito foram medidas em máquina de tração universal Instron, com velocidade de 3mm/minuto e deslocamento total de 6mm. Para análise estatística, usou-se a ANOVA e o Teste de Comparações Múltiplas de Dunnett. RESULTADOS: as forças de atrito por deformação do fio se mostraram crescentes na seguinte ordem: Synergy, Damon, amarrilho 8, Easy Clip, In-Ovation, Smart-Clip e ligadura convencional. As diferenças entre todos os grupos foram estatisticamente significantes, com exceção do Amarrilho 8 em relação aos grupos Damon e Easy Clip. CONCLUSÃO: em relação à ligadura convencional, todos os sistemas de fechamento das canaletas testados são eficientes em reduzir a força de atrito, porém, tal redução varia significativamente de acordo com o sistema de fechamento da canaleta selecionado.

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 Morelli's 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.

Upper airway expansion after rapid maxillary expansion evaluated with cone beam computed tomography.

OBJECTIVE: Cone-beam computed tomography (CBCT) is a reliable method of assessing the oral cavity and upper airways. We conducted this study to examine the changes introduced by rapid maxillary expansion in the nasal cavity, nasopharynx, and oropharynx as seen with images obtained by CBCT. MATERIALS AND METHODS: We evaluated 15 patients with maxillary width deficiency treated with RME. Patients were subjected to CBCT at the beginning of RME and after the retention period of 4 months. RESULTS: The nasal cavity presented a significant transverse increase in the lower third, in the anterior (1.08 mm ± 0.15), medium (1.28 mm ± 0.15), and posterior regions (0.77 mm ± 0.12). No significant change occurred in the nasopharynx in volume (P  =  .11), median sagittal area (P  =  .33), or lower axial area (P  =  .29) resulting from the RME. A significant change was noted in the oropharynx in volume (P  =  .05), median sagittal area (P  =  .01), and lower axial area (P  =  .04) before and immediately after the RME. CONCLUSIONS: RME is able to increase the transverse width of the nasal cavity, but it does not have the same effect in the nasopharynx. Changes noted in the oropharynx may be due to the lack of a standardized position of the head and tongue at the time of image acquisition.