Ajuste oclusal na Ortodontia: Por que, quando e como?

Introduction: The knowledge of dental occlusion should be considered the basic foundation to an excellent orthodontic practice. The patient's diagnose without the centric relation assessment can take the orthodontist to an unpleasant surprises. The use of rectangular archwires requires occlusal contacts been checked to decide what kind of the dental movement will be necessary to achieve the dental equilibrium and mainly to investigate if the movement will be possible. Considering the occlusal surfaces complexity, the occlusal adjustment by selective grinding should be performed during the orthodontic treatment to allow vertical dental movements reducing treatment's time. Occlusal interferences are responsible not only for biomechanics adverse effects, producing undesirable dental movements, but also for potential side effects such as excessive forces (occlusal trauma), leading to roots reabsorption. The occlusal adjustment is a determinant point on dental balance after the end of orthodontics treatments, where each posterior occlusal tooth contacts A and B, or B and C on buccolingual aspect, as well as the stoppers and equalizers contacts on mesiodistal direction must be achieved and well established. The appropriate role of anterior teeth in mandibular movements must be determined, allowing immediate disclusion of posterior teeth, known as anterior guide, and promoting protecting muscle forces to the stomatognathic system. Selective grinding should not be used. in place of well planned and executed orthodontic movement. Aim: The aim of this article is to present the rationale use of occlusal adjustment in Orthodontics.

Occurrence, extension, and severity of gingival margin alterations after orthodontic treatment.

To assess the occurrence, extension, and severity of gingival margin alterations in a sample of youth after orthodontic treatment. Records from 209 Caucasian adolescents (118 female and 91 male) before and after orthodontic treatment were selected. Patients presented a mean age at the beginning of orthodontic treatment of 11.20 ± 1.86 years and a final mean age of 14.72 ± 1.83 years. Class I and II patients with mandibular incisors and canines that were completely erupted and with spacing or crowding not exceeding 4 mm were evaluated. The presence of gingival recession on the labial surface of the mandibular anterior teeth was evaluated in intraoral photographs and casts made before and after treatment. The proportion of patients with gingival recession after treatment was statistically higher than at the beginning (P<.001). After orthodontic treatment, gingival recession was not present in any of the teeth for 63.6% of the patients; in 29.2% of the patients, recession was present in at least 1 tooth. In terms of severity, the majority of affected teeth (47%) presented gingival recession less than 2 mm and in 2% more than 4 mm. It may be concluded that alterations in the gingival margin, especially gingival recession, occur in patients after orthodontic therapy, but the extent and severity of this finding are low. COPYRIGHT © 2007 BY QUINTESSENCE PUBLISHING CO, INC.

Orthognathic Surgery in the Young Cleft Patient: Preliminary Study on Subsequent Facial Growth

Purpose: This study evaluated the long-term effects of orthognathic surgery on subsequent growth of the maxillomandibular complex in the young cleft patient. Patients and Methods: We evaluated 12 young cleft patients (9 male and 3 female patients), with a mean age of 12 years 6 months (range, 9 years 8 months to 15 years 4 months), who underwent Le Fort I osteotomies, with maxillary advancement, expansion, and/or downgrafting, by use of autogenous bone or hydroxyapatite grafts, when indicated, for maxillary stabilization. Five patients had concomitant osteotomies of the mandibular ramus. All patients had presurgical and postsurgical orthodontic treatment to control the occlusion. Radiographs taken at initial evaluation (T1) and presurgery (T2) were compared to establish the facial growth vector before surgery, whereas radiographs taken immediately postsurgery (T3) and at longest follow-up (T4) were used to determine postsurgical growth. Each patient's lateral cephalograms were traced, and 16 landmarks were identified and used to compute 11 measurements describing presurgical and postsurgical growth. Results: Before surgery, all patients had relatively normal growth. After surgery, cephalograms showed statistically significant growth changes from T3 to T4, with the maxillary depth decreasing by -3.3° ± 1.8°, Sella-nasion-point A by -3.3° ± 1.8°, and point A-nasion-point B by -3.6° ± 2.8°. The angulation of the maxillary incisors increased by 9.2° ± 11.7°. Of 12 patients, 11 showed disproportionate postsurgical jaw growth. Maxillary growth occurred predominantly in a vertical vector with no anteroposterior growth, even though most patients had shown anteroposterior growth before surgery. The distance increased in the linear measurement from nasion to gnathion by 10.3 ± 7.9 mm. Four of 5 patients operated on during the mixed dentition phase had teeth that erupted through the cleft area. A variable impairment of postoperative growth was seen with the 2 types of grafting material used. No significant difference was noted in the effect on growth in patients with unilateral clefts versus those with bilateral clefts. The presence of a pharyngeal flap was noted to adversely affect growth, whereas simultaneous mandibular surgery did not. After surgery, 11 of 12 patients tended toward a Class III end-on occlusal relation. Conclusions: Orthognathic surgery may be performed on growing cleft patients when mandated by psychological and/or functional concerns. The surgeon must be cognizant of the adverse postsurgical growth outcomes when performing orthognathic surgery on growing cleft patients with the possibility for further surgery requirements. Performing maxillary osteotomies on cleft patients would be more predictable after completion of facial growth. © 2008 American Association of Oral and Maxillofacial Surgeons.

Mandible protrusion and decrease of TMJ sounds: An electrovibratographic examination

This study quantified by, electrovibratography, the amount of mandible protrusion required to decrease significantly temporomandibular joint (TMJ) vibratory energy as an aid in the diagnosis of the recapture of anteriorly displaced disk. Eighteen patients diagnosed as having anterior disk displacement with reduction and TMJ clicking were submitted to electrovibratographic examination at the first appointment and treated with a stabilizing appliance and anterior positioning appliance with 1 to 5 mm protrusion. Vibratory energy was checked in each of these positions. Baseline data were used as control. At the first appointment, the patients had vibrations with more elevated intensities at the middle and late phases of the mouth opening cycle. At only one clinical step, mandible protrusion was obtained with the anterior repositioning appliance, ranging from 1 to 5 mm protusion. At each new position, a new electrovibratographic exam was made. After the 5-mm mandibular projection, only 2 patients presented vibration, with means between 0.6 and 2.8 Hz. Data were analyzed statistically by ANOVA and Tukey's test (α=0.05). The outcomes of this study indicate that 3 mm is the minimum amount of mandible protrusion to significantly decrease the TMJ vibratory energy and to recapture the displaced articular disk.

Avaliação da inclinação do incisivo inferior através da tomografia computadorizada

Introduction: Orthodontics has always used lateral cephalometric radiographs (LC) as the main examination in the orthodontic diagnosis and treatment plan. The determination of incisor position is part of most cephalometric analysis, including Tweed analysis. However, all radiographic images have limitations, since it is a bidimensional image of a tridimensional structure and overlapping of bone and dental structures often occurs. Computed tomography (CT) allows a trustworthy diagnostic, mainly for its tridimensional images possibility. In this situation it seems reasonable to question the classic cephalometric analysis, creating factors of comparison with computed tomography data. Aim: For this, it was considered the evaluation of the angle between the long axis of the inferior incisor and the mandibular plane (IMPA) in the lateral cephalograph and in the computed tomography. Methods: Nineteen patients, selected for orthodontic treatment, had constituted the sample of this study, 12 female and 7 male, with ages between 16 years and 4 months and 28 years and 2 months. After the collection of data made by two examiners, statistical analyses for the attainment of the errors intra and inter-examiners had been made, using level of significance of 5%. Results and Conclusion: It was concluded that IMPA can be measured in the lateral cephalometric radiographs with trustworthiness, even that its values were smaller when compared with the computed tomography.

Evaluation of temporomandibular joint noise in partially edentulous patients.

In order to evaluate the presence of TMD (temporomandibular disorder), dissatisfaction related to the use of removable partial dentures (RPD) and the effect of the treatment on temporomandibular joint noises, 13 female patients with Kennedy class I and II mandibular arch were selected. Another 13 young, asymptomatic, dentate patients, also female, were used as reference. After four years, 38.4% were found to have a moderate or severe degree of TMD. Over the four years, the degree of TMD increased in 46.15% of the patients, was not affected in 20.07%, while in 15.38% it decreased or the patients remained free from signs and symptoms. About 30% of the patients at the second year and 46% after the fourth year, had complaints regarding retention and stability. It was concluded that there is no relationship between TMD and the condition of partially edentulous Kennedy class I and II, but patient dissatisfaction increased after the second year and temporomandibular joint noise was reduced significantly with the replacement of the teeth.

Severe fracture of the maxillary alveolar process associated with extrusive luxation and tooth avulsion: A case report

Aim: The aim of this report is to present a case of severe fracture of the maxillary anterior alveolar process with substantial bone dislodgement associated with extrusive tooth luxation and avulsion. Background: Dentoalveolar trauma is a challenge to dentistry, especially in young patients, for it can lead to early tooth loss which compromises oral function, esthetics, self-esteem, and alter the long-term plan of care for the victim. Case Report: A 12-year-old girl with severe dentoalveolar trauma to the maxillary anterior region presented for emergency care for her injury. Treatment consisted of fracture reduction of the alveolar process, repositioning of the teeth that had suffered extrusive luxation, placement of a semi-rigid splint, and suturing of soft tissue lacerations. The traumatized teeth presented with pulpal necrosis and were treated endodontically. After 24 months of follow up, the fracture of the alveolar process was completely healed and the displaced teeth presented no signs of ankylosis or root resorption. Summary: First-aid care contributed remarkably to this case allowing the re-establishment of esthetics, function, and patient's self-esteem. In spite of trauma extension the treatment outcomes were favorable. Clinical Significance: Cases of dentoalveolar trauma should be evaluated on an individual basis. However, early emergency management and adequate follow-up can prevent further complications and contribute to treatment success.

Hallazgos clínico-radiológicos de la articulación temporomandibular en pacientes con artritis reumatoide

Aim of present paper is to describe and to assess the Clinicoradiological findings of the temporomandibular joint (TMJ) in a group of patients diagnosed with rheumatoid arthritis (RA). Sample included 61 patients with a mean age of 54 years and 5 months. All of them were interrogated and clinically examined and then underwent to a radiographic examination of both TMJs, using the transcranial projection technique, with the closed mouth and in maximal opening. Study includes the TMJ syndrome founded such as pain, tumefaction, luxation, clicking, and a limited oral opening. The study of radiographic features showed the presence of changes in condyle surface and temporal fossa, in condylar motility, and articulation space. We conclude that in patients presenting with rheumatoid arthritis is frequent the presence of clinicoradiological findings in the TMJ, and that patient's age and gender and the activity level and the RA course time, are factors influencing in TMJs general status.

Transformação cística como consequência de terceiro molar inferior incluso

The permanence of impacted third molar in the jaws can cause many pathological alterations, amongst them the appearance of odontogenic cysts. The paradental cyst appearance and evolution next to a mandibular included third molar was diagnosised in radiograph routine follow-up, and its evolution and treatment are described. Are discussed the aspects related with the preventive removal to the impacted third molars and the necessity to institution a plan of treatment based in clinical history and radiograph in order to establish a preventive protocol the alterations caused by these impactions. The indication of extraction of impacted third enclosed can be a way to preventing the appearance of these and otherspathologies associates to these lesions.

Osteologia craniana de Nyctibiidae (Aves, Caprimulgiformes)

The Potoos form an exclusively neotropical family of nocturnal birds distributed throughout Central and South America, except Chile, and reaching their highest diversity in the Amazon region. The seven currently recognized species are certainly among the most poorly known birds of this region. They are characterized by a distinctive mimicry of vegetal trunks, where they remain almost motionless during daytime. For this reason, their nocturnal and cryptic habits make them exceedingly difficult to study. Published accounts on behavior and natural history of the family are scarce and contributions regarding its anatomy are rare. Here we sample six of the seven currently recognized species of Nyctibiidae, including Nyctibius grandis, N. aethereus, N. griseus, N. jamaicensis, N. leucopterus and N. bracteatus, in order to conduct a detailed and illustrated description of the skull and jaw osteology. High interspecific variation in skull osteology was observed in the family. Species of this family possess a highly modified skull, adapted to their life habits, which shelters their well developed eyes and permits a large mouth opening. The bones that form the palate structure exhibit a dorsoventral flattening, particularly in the pterigoid and parasphenoid bones, with the palatine bone being a broadly developed, wing-shaped structure. In the maxilar region, near the jugal arch, there is a tooth-like projection, unique among birds, which may assist in the retention of prey upon capture. The vomer bone is highly variable within the family, showing varying numbers of rostral projections amongst species. The broad occipital region exhibits large spacing between the quadrate bones, which are vertically disposed and possess a reduced processus orbitalis. The mandible, which is flexible and elastic, has an extremely short symphyseal region and sindesmotic joints in both mandibular rami. As a family, potoos possess a highly specialized skull which provides insight into the relationship between the form of the structures and the feeding habits of the species. Furthermore, the large interspecific variation in skull morphology emphasizes the needs for taxonomic revision within the family, which at present is lumped into a single genus.

Influence of diltiazem in combination with a sucrose-rich diet on gingival alterations in rats

The aim of this study was to evaluate the influence of diltiazem in combination with a sucrose-rich diet on gingival alterations in rats. One hundred and twenty male Holtzman rats were randomly assigned to 10 groups (n = 12), being 2 control groups treated with saline and 8 test groups treated with diltiazem in daily doses of 5, 25, 50 and 100 mg/kg during 40 or 60 days. Afterwards, the mandibles were removed for macroscopic, histologic and histometric analyses of the buccal gingiva of the mandibular right first molar. No macroscopic characteristic of gingival overgrowth was observed in any of the groups. The microscopic analysis showed characteristics of normality with inflammatory cells only adjacent to the crevicular epithelium in all groups for both periods. The histometric analysis showed significant differences only for the epithelial tissue area in the 40-day period (Kruskal-Wallis; P = 0.032). Comparing the periods, significant differences regarding the connective and epithelial tissue areas were observed only in the group treated with a 25 mg/kg dose (Mann-Whitney; P = 0.004 and P = 0.007, respectively). Oral administration of diltiazem in combination with a sucrose-rich diet did not induce gingival alterations in rats. © 2009 Sociedade Brasileira de Pesquisa Odontológica.

Compensatory canine angulation in angle class II and III patients

Abstract: The aim of this study was to evaluate the occurence of compensation in mesiodistal axial inclinations of canines in skeletal malocclusions patients. The sample consisted of 25 Angle Class II, division 1 malocclusion (group 1) and 19 Angle Class III malocclusion patients (group 2). After measurement of dental angulations through a method that associates plaster model photography and AutoCad software, comparisons between the groups were performed by T-test for independent samples. Results showed that there was no statistically significant difference (p ≤ 0.05) between groups, when maxillary canine angulations were compared. Regarding the mandibular canines, there was a statistically significant difference in dental angulation, expressed by 3.2° for group 1 and 0.15° for group 2. An upright position tendency for mandibular canines was observed in the Angle Class III sample. This configures a pattern of compensatory coronary positioning, since the angulation of these teeth makes them occupy less space in the dental arch and consequently mandibular incisors can be in a more retracted position in the sagittal plane.

Conservative approach to the treatment of keratocystic odontogenic tumor

The odontogenic keratocyst, also known as the keratocystic odontogenic tumor, is an aggressive, intraosseous lesion of odontogenic origin that presents a high rate of recurrence. Treatment modalities include aggressive surgical procedures and more conservative approaches that significantly influence the lesion's recurrence potential. The purpose of this case report was to demonstrate a conservative approach in the treatment of an extensive keratocystic odontogenic tumor, located in the mandible's posterior region, using decompression and enucleation.

Avaliação das dimensões transversas na maxila e mandíbula em pacientes na fase da dentição mista tratados com aparelho ortodôntico removível superior

Objeti vo: Avaliar os efeitos da expansão lenta na maxila e na mandíbula com o aparelho ortodônti co removível superior com torno de expansão simétrico e mediano, nas regiões oclusal, gengival e alveolar de pacientes jovens com atresia maxilar. Método: A amostra compreendeu 18 indivíduos leucodermas (11 meninas e 7 meninos; idade média: 8 anos e 10 meses no início do tratamento) que apresentavam atresia da maxila, acompanhadas ou não de mordida cruzada posterior uni ou bilateral na fase de denti ção mista. Todos os pacientes foram tratados com aparelho ortodônti co removível superior com torno de expansão simétrico e mediano, sendo o tempo médio de tratamento de 15,4 meses (± 7,6). Para avaliar a infl uência do tratamento nas mensurações dos pontos demarcados nas regiões oclusal, gengival e alveolar, foram uti lizados os modelos de gesso dos arcos superior e inferior (36 pares) obti dos em dois tempos: T1: início do tratamento e T2: ao fi nal do tratamento. Para cada paciente em ambos os tempos, foram mensuradas as distâncias transversas na região oclusal entre caninos decíduos, 1o molares decíduos ou 1o pré-molares permanentes e entre 1o molares permanentes, superiores e inferiores. Para verifi car se a movimentação ocorreu por inclinação ou por movimento de corpo, foram uti lizadas também medidas nas regiões gengival e alveolar. Os dados foram avaliados estati sti camente pelo teste “t student para amostras pareadas (5%). Resultados: Observou-se que em T2, todas as distâncias mensuradas para as regiões oclusal, gengival e alveolar apresentaram valores estati sti camente superiores às mesmas medidas em T1 (p<0,05). Conclusão: O aparelho ortodônti co removível superior é efeti vo nos casos de expansão lenta da maxila, agindo também indiretamente nas dimensões transversas do arco inferior.

Scanning electron microscopy analysis of RinsEndo system and conventional irrigation for debris removal

A new device for irrigation, which presents hydrodynamic activation based on the pressure-suction technology, has recently been introduced to the market: the Rinsendo system. This study compared the efficacy of the Rinsendo system and conventional (manualdynamic) irrigation in the removal of debris from the root canal walls, using scanning electron microscopy (SEM). Twenty mandibular premolars with completely formed roots were selected and randomly divided into group 1 (irrigation with the Rinsendo system) and group 2 (conventional irrigation). The canals were irrigated with 1 ml of saline at each change of instrument. instrumentation started with a #15 K file and continued up to a #40 K file, which was standardized as the working length instrument. Then, the teeth were sectioned in buccolingual direction and the halves were sputter-coated with gold and examined by SEM. The apical, middle and cervical root canal thirds were evaluated, and the results were analyzed statistically by the Mann-Whitney test for comparison between methods, Kruskal-Wallis test for comparison among thirds, and Miller test for individual comparisons. A significance level of 5% was set for all analyses. The results did not show significant differences (p>0.05) between methods at each third and among thirds for each technique analyzed individually. in conclusion, there was no difference in the cleaning ability of the Rinsendo system and conventional irrigation.