3-D Evaluation of temporary skeletal anchorage sites in the maxilla.

BACKGROUND: The selection of temporary anchorage device (TAD) site can be a challenging task since one should not only consider the 2-D distances between roots, but also the entire 3-D space. Thus, the aim of this study was to evaluate the posterior maxillary region areas available for the insertion of temporary anchorage devices in reconstructed images from cone beam computed tomography (CBCT). MATERIAL AND METHODS: Sample consisted of 72 patients with indication for orthodontic treatment, grouped into three distinct age groups: 11 to 14 years (age group 1), 15 to 19 years (age group 2) and aged 20 years or older (age group 3), which were further subdivided as to the type of malocclusion (Angle Class I, II and III). Orthopantomographic reconstructions and cross sections were obtained with the Dolphin Imaging software. The distance between the roots of maxillary teeth (canines, premolars and first molars) was determined at 5 mm of the cementoenamel junction, as well as the depth of bone availability at different insertion angles (90°, 75°, 60°, 45°). The influence of different angulations, age, and malocclusion on bone availability was evaluated by ANOVA, followed by the Bonferroni post-test. For the evaluation of the interaction of these factors, 2-way ANOVA was used. RESULTS: Bone availability was found to be poor between roots in the molar region. There was a reduction in bone availability with increasing age. With regard to angulations, greater bone availability was found in depth for 45° angulation in the canine and first premolar regions and for angulation of 75° or 90° in the molar region. However, there was no difference between bone availability in the region of the second premolars. CONCLUSIONS: According to applied methodology it can be concluded that the region between canines and premolars accepts better vertical angular variations for TADs insertion. Key words:Cone-Beam Computed Tomography, Orthodontic Anchorage Procedures.

Importance of occlusion aspects in the completion of orthodontic treatment.

The purpose of this study was to address the therapeutic goals regarding the static and functional occlusion in the completion of orthodontic treatment. For such purpose, a study population comprising 20 female treated Class II malocclusion subjects with an initial mean age of 11 years underwent a two-phase treatment (orthopedics and orthodontics). The patients were diagnosed in centric relation and were treated according to the six keys for normal occlusion and functional occlusal parameters (centric relation, vertical dimension, lateral and anterior guidances, occlusal contacts and direction of forces applied on the teeth). After removal of fixed mechanics, retainers were installed and maintained for two years. Five years after orthodontic completion, the occlusal stability of the patients was evaluated regarding molar relationship and overjet, measured in dental casts. All subjects maintained the normal molar relationship and correct overjet achieved at the end of treatment, indicating a fair level of occlusal stability. The importance of the criteria of the ideal functional occlusion to ensure a better stability after completion orthodontic treatment will be discussed in detail in this paper. In addition, some clinical situations in which localized adjustments are indicated for occlusal refinement will be described.

Three-dimensional analysis of the pharyngeal airway space and hyoid bone position after orthognathic surgery.

PURPOSE: The aim of this study was to evaluate changes in the pharyngeal airway space (PAS) and hyoid bone position after orthognathic surgery with cone-beam computed tomography (CBCT). MATERIAL AND METHODS: This study was conducted with the tomographic records of 30 patients with skeletal class II or III deformities submitted to two different types of orthognathic surgery: Group 1 (n = 15), maxillary advancement, and mandibular setback; and Group 2 (n = 15), maxillomandibular advancement. CBCT scans were acquired preoperatively (T0); and at around 1.5 months (T1) and 6.7 months (T2) postoperatively. PAS volume, minimum cross-sectional area (min CSA), and hyoid bone position changes were assessed with Dolphin Imaging 3D software, and results analyzed with ANOVA and a Tukey-Kramer test (p < 0.05). RESULTS: The hyoid bone was significantly displaced in the horizontal dimension, moving posteriorly in Group 1, and anteriorly in Group 2. Although PAS volume and min CSA increased after both surgeries, these measurements were significantly larger only in Group 2. The significant differences that existed between groups preoperatively no longer existed after the surgeries. CONCLUSIONS: Both orthognathic surgeries assessed resulted in changes in hyoid bone position and increased PAS volume and min CSA, particularly after maxillomandibular advancement surgery.

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.

Dentoalveolar mandibular changes with self-ligating versus conventional bracket systems: A CBCT and dental cast study.

OBJECTIVE: The aim of the present study was to compare dentoalveolar changes in mandibular arch, regarding transversal measures and buccal bone thickness, in patients undergoing the initial phase of orthodontic treatment with self-ligating or conventional bracket systems. METHODS: A sample of 25 patients requiring orthodontic treatment was assessed based on the bracket type. Group 1 comprised 13 patients bonded with 0.022-in self-ligating brackets (SLB). Group 2 included 12 patients bonded with 0.022-in conventional brackets (CLB). Cone-beam computed tomography (CBCT) scans and a 3D program (Dolphin) assessed changes in transversal width of buccal bone (TWBB) and buccal bone thickness (BBT) before (T1) and 7 months after treatment onset (T2). Measurements on dental casts were performed using a digital caliper. Differences between and within groups were analyzed by Student's t-test; Pearson correlation coefficient was also calculated. RESULTS: Significant mandibular expansion was observed for both groups; however, no significant differences were found between groups. There was significant decrease in mandibular buccal bone thickness and transversal width of buccal bone in both groups. There was no significant correlation between buccal bone thickness and dental arch expansion. CONCLUSIONS: There were no significant differences between self-ligating brackets and conventional brackets systems regarding mandibular arch expansion and changes in buccal bone thickness or transversal width of buccal bone.

Assessment of cephalometric characteristics in the elderly.

This cross-sectional study aimed at assessing the cephalometric characteristics in the elderly, taking into account differences between genders, age ranges, ethnic groups and dental aspects. The sample consisted of 250 elderly subjects of both genders (163 female, mean age: 68 yr.; 87 male: 70.4 yr.). Conventional lateral cephalograms for cephalometric analysis were scanned and analyzed by Dolphin Imaging software 11.5. The statistical treatment of the data evaluated the influence of gender and age range variables (independent t test), as well as ethnic group, facial profile, and dental characteristics (one-way ANOVA), on cephalometric measurements. A confidence interval of 95% and level of significance of 5% were considered for all the tests performed. The results revealed: 1) The cephalometric measurements evaluated showed significantly lower values for the female gender; 2) a significant decrease in the cephalometric values was observed in relation to the growth pattern, with the advancement of age; 3) significant cephalometric differences were observed between the ethnic groups and the facial profiles; 3) dentulous patients had greater absolute values for all the components evaluated, followed by the individuals with partial dental losses and by those who were edentulous. It may be concluded that the cephalometric alterations observed in this study are inherent to facial maturity, and that they represent specific characteristics regarding each of the variables evaluated. These modifications must be taken into account when planning the treatment for younger patients, to minimize the modifications arising from the natural aging process.

Probable Correlation between Temporomandibular Dysfunction and Vertigo in the Elderly.

Introduction Temporomandibular disorder (TMD) covers a variety of clinical problems, and some epidemiologic studies have tried to indicate mechanisms of interaction and association between vertigo and TMD, but this topic still is controversial. Objective To assess the presence of vertigo in elderly patients associated with TMD. Methods A cross-sectional study was conducted with the inclusion of elderly individuals who lived independently. TMD was assessed by dental evaluation and vertigo was verified by medical history. Statistical analysis was performed using the chi-square and relative risk. Results There was a significant association (p = 0.0256) between the TMD and vertigo (odds ratio = 2.3793). Conclusion These results highlighted the importance of identifying risk factors for vertigo that can be modified through specific interventions, which is essential to prevent future episodes, as well as managing the process of rehabilitation of elderly patients in general.

Proximal retention grooves may increase early fracture strength of ART restorations / Sulcos de retenção proximal podem aumentar a resistência a fratura precoce de restaurações de ART

Objective: To evaluate the fracture resistance (RF) of Class II Glass-ionomer Cement (GIC) ART restorations with and without proximal retentions. Material and Methods: 20 freshly extracted human molars were used. Forty (40) standard Mesial-Occlusal (MO) and DistalOcclusal (DO) preparations (20 for each material) were performed with a 245 bur. The unprepared surfaces of the teeth were protected with nail polish and the specimens submerged in 0.5Mol EDTA solution, pH 7.4 for 8h under stirring. The preparations were finished with dentine spoons and 50% received proximal retention with # 3 excavators. 20 cavities were restored with Chemfil Rock (10 with retention and 10 without retention) and 20 cavities were restored with Equia Fil (10 with retention and 10 with no retention) and were stored in an oven at 37ºC and 100% relative humidity for 24h and submitted to axial compression loading in Test Machine - EMIC at a rate of 0.5 mm / minute, until restoration fracture occurred. The values were analyzed by two-way ANOVA (p<0.05). Results: ChemFil Rock presented 300.84 (69.20) (without retention) and 361.70 (81.08) (with retention) and Equia Fil showed 314.60 (69.97) (without retention) and 366.67 (103.38) (with retention). Data obtained with retention were statistically superior to those obtained with non-retained ART restorations (p=0.014). No statistical differences were detected between materials (p=0.761). Conclusion: Retentive grooves improved fracture resistance of Class II GIC ART restorations. (AU)

Objetivo: avaliar a resistência à fratura (FR) de restaurações de ART de Classe II de Cimento de ionômero de vidro (CIV) com e sem retenções proximais. Material e Métodos: Foram utilizados 20 molares humanos recém-extraídos. 40 cavidades padronizadas no sentido Mesial-Oclusal (MO) e Oclusal-Distal (OD) (20 para cada material) foram realizadas com uma broca 245. Os preparos cavitários foram submersos em solução 0,5 mol Mol EDTA, pH 7,4 por 8h sob agitação e foram finalizados com colheres de dentina, nos quais 50% receberam retenções proximais com escavadores #3. 20 cavidades foram restauradas com Chemfil Rock (10 com e 10 sem retenção) e 20 cavidades foram restauradas com Equia Fil (10 com e 10 sem retenção) e armazenadas em estufa a 37ºC e 100% de umidade relativa por 24h e submetidos a carga axial de compressão na máquina de ensaios EMIC a uma taxa de 0,5mm/min, até que a fratura de restauração ocorresse. Os valores foram analisados por ANOVA twoway (p<0,05). Resultados: ChemFil Rock apresentou 300.84 (69.20) (sem retenção) e 361.70 (81.08) (com retenção) e o Equia Fil apresentou 314.60 (69.97) (sem retenção) e 366.67 (103.38) (com retenção). Os dados obtidos com retenção foram estatisticamente superiores àqueles sem retenção (p=0.014). Não houve diferença estatística entre os materiais (p=0.761). Conclusão: Os sulcos retentivos melhoraram a resistência à fratura de restaurações de ART de Classe II de Cimento de ionômero de vidro (CIV).(AU)

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.

Associação entre disfunção temporomandibular e zumbido em idosos / Association between temporomandibular disorders and tinnitus in the elderly

RESUMO Objetivo Verificar a associação entre zumbido e disfunção temporomandibular em idosos. Métodos Estudo transversal realizado com a inclusão de idosos com vida independente. A disfunção temporomandibular foi avaliada por exame odontológico e o zumbido foi verificado pela história médica. A análise estatística foi realizada utilizando o teste Qui-quadrado, o risco relativo e a regressão logística. Resultados O zumbido foi observado em 82,9% dos indivíduos com disfunção temporomandibular e, através desta análise, observou-se que a disfunção temporomandibular é um fator de risco para o zumbido. Conclusão Houve associação entre zumbido e disfunção temporomandibular na população idosa. Ressalta-se a importância de identificar fatores de risco para o zumbido, que podem ser modificados por meio de intervenções específicas, uma vez que esta prática é essencial na prevenção de episódios futuros, bem como na gestão do processo de tratamento de pacientes idosos, em geral.

ABSTRACT Purpose To verify the association between tinnitus and temporomandibular dysfunction in the elderly. Methods A cross sectional study was conducted with the inclusion of elderly individuals with independent living. Temporomandibular dysfunction was assessed by odontological evaluation and tinnitus was verified by medical history. Statistical analysis was performed using the chi-square test, relative risk and logistic regression. Results Tinnitus was observed in 82.9% of individuals with temporomandibular dysfunction and through this analysis is shown that temporomandibular dysfunction as a risk factor for tinnitus. Conclusion The results showed that there was association between tinnitus and temporomandibular dysfunction in the elderly population and emphasizes the importance of identifying risk factors for tinnitus that can be modified through specific interventions, since it is essential in the prevention of future episodes, as well as managing the process of treatment of elderly patients in general.

Posterior crossbite--treatment and stability.

Posterior crossbite is defined as an inadequate transversal relationship of maxillary and mandibular teeth. Even when eliminating the etiologic factors, this malocclusion does not have a spontaneous correction, and should be treated with maxillary expansion as early as possible. This treatment aims at providing a better tooth/skeletal relationship, thereby improving masticatory function, and establishing a symmetrical condyle/fossa relationship. Should posterior crossbite not be treated early, it may result in skeletal changes, demanding a more complex approach. Additionally, an overcorrection expansion protocol should be applied in order to improve the treatment stability. Although the literature has reported a high rate of relapse after maxillary expansion, the goal of this study was to demonstrate excellent stability of the posterior crossbite correction 21 years post treatment.

Serial extraction: 20 years of follow-up.

This paper reports a case treated by a serial extraction program at the mixed dentition stage followed by a corrective orthodontic treatment, with a long-term follow-up period. Twenty years after the interceptive treatment, a harmonious face was observed along with treatment stability in the anterior posterior direction, deep overbite (which has been mentioned as a disadvantage of the serial extraction program), and a small relapse of anterior tooth crowding. All these conditions have been regarded as normal occurrences for most orthodontic treatments with a long-term follow-up period. This case report demonstrated that the establishment of a serial extraction protocol determined relevant esthetic changes that afforded an improvement of the patient's self-esteem, with a positive social impact. Furthermore, the low cost of this protocol permits the use of this therapy with underprivileged populations. It is important to emphasize that an early correction of tooth crowding by this protocol does not guarantee stability, but small relapses do not invalidate its accomplishment.

Avaliação do Seio Maxilar: Radiografia Panorâmica Versus Tomografia Computadorizada de Feixe Cônico / Evaluation of the Maxillary Sinus: Panoramic Radiography Versus Cone Beam Computed Tomography

O objetivo deste estudo retrospectivo implica em comparar a presença de velamento, o espessamento de mucosa e a presença de septo no seio maxilar em radiografias panorâmicas e tomografias computadorizadas de feixe cônico (TCFC). A amostra foi composta por 100 pacientes do arquivo, que apresentavam as radiografias panorâmicas e as TCFC antes do início do tratamento ortodôntico, sendo 57 mulheres e 43 homens, com média de idade de 19,08 anos. Foram incluídas nesta pesquisa apenas os exames que apresentavam boa qualidade e bom posicionamento do paciente. A avaliação do velamento, espessamento de mucosa e presença de septo no seio maxilar foi realizada por um único examinador calibrado, de forma independente, nas radiografias e nas TCFC. A concordância entre os exames foi avaliada por meio do teste Kappa. Os resultados demonstraram boa concordância entre as radiografias panorâmicas e TCFC (Kappa entre 0,62 a 0,72), com -90, -88 e 89% de convergência entre os métodos, para velamento do seio maxilar; espessamento de mucosa e presença de septo no seio maxilar, respectivamente. Pode-se concluir que foi encontrada concordância satisfatória na avaliação do velamento, espessamento de mucosa e presença de septo no seio maxilar entre as radiografias panorâmica e TCFC. Dessa forma, as características do seio maxilar foram identificadas, de maneira semelhante, na radiografia panorâmica e na TCFC. (AU).

The objective of this retrospective study was to compare the presence of filled maxillary sinus, mucosal thickening and the presence of septum in the maxillary sinus on panoramic radiographs and concomitant computed tomography (CBCT) scans. The sample consisted of 100 patients from the archive who presented the panoramic radiographs and the CBCT before the beginning of the orthodontic treatment, being 57 women and 43 men, with a mean age of 19.08 years. Only the exams that presented good quality and good positioning of the patient were included in this study. The evaluation of the presence of filled maxillary sinus, mucosal thickening and the presence of septum in the maxillary sinus was performed by a single examiner, regardless of who was calibrated on panoramic radiograph and CBCT. The agreement among the exams was assessed by means of Kappa test. The results showed good agreement between panoramic radiograph and CBCT (Kappa between 0.62 and 0.72), with -90, -88 and 89% convergence between the methods, for the presence of filled maxillary sinus, mucosal thickening and presence of septum in the maxillary sinus, respectively. It can be concluded that satisfactory agreement was found in the evaluation of the the presence of filled maxillary sinus, mucosal thickening and presence of septum in the maxillary sinus between the panoramic and CBCT radiographs. Thus, the characteristics of the maxillary sinus were similarly identified in panoramic radiography and CBCT. (AU).

The nance lingual arch: an auxiliary device in solving lower anterior crowding.

After exfoliation of the primary incisors and eruption of the permanent incisors, the dentist has the opportunity of observing closely the beginning of occlusal changes. In several cases, alterations, such as lower anterior crowding, can be prevented and treated with proper follow-up. In the mixed dentition, one of the mechanisms for maintaining space and favoring dental alignment is to preserve leeway space before permanent second molar irruption. Among the devices with this function, the Nance lingual arch helps maintaining the position of the permanent mandibular molars and incisors after a premature loss of the primary canines. This paper describes the applicability of Nance lingual arch for preserving leeway space, thus contributing for correction of lower anterior crowding.

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

Abstract 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.

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.

Assessment of cephalometric characteristics in the elderly

This cross-sectional study aimed at assessing the cephalometric characteristics in the elderly, taking into account differences between genders, age ranges, ethnic groups and dental aspects. The sample consisted of 250 elderly subjects of both genders (163 female, mean age: 68 yr.; 87 male: 70.4 yr.). Conventional lateral cephalograms for cephalometric analysis were scanned and analyzed by Dolphin Imaging software 11.5. The statistical treatment of the data evaluated the influence of gender and age range variables (independent ttest), as well as ethnic group, facial profile, and dental characteristics (one-way ANOVA), on cephalometric measurements. A confidence interval of 95% and level of significance of 5% were considered for all the tests performed. The results revealed: 1) The cephalometric measurements evaluated showed significantly lower values for the female gender; 2) a significant decrease in the cephalometric values was observed in relation to the growth pattern, with the advancement of age; 3) significant cephalometric differences were observed between the ethnic groups and the facial profiles; 3) dentulous patients had greater absolute values for all the components evaluated, followed by the individuals with partial dental losses and by those who were edentulous. It may be concluded that the cephalometric alterations observed in this study are inherent to facial maturity, and that they represent specific characteristics regarding each of the variables evaluated. These modifications must be taken into account when planning the treatment for younger patients, to minimize the modifications arising from the natural aging process.

Dentoalveolar mandibular changes with self-ligating versus conventional bracket systems: A CBCT and dental cast study

OBJECTIVE: The aim of the present study was to compare dentoalveolar changes in mandibular arch, regarding transversal measures and buccal bone thickness, in patients undergoing the initial phase of orthodontic treatment with self-ligating or conventional bracket systems. METHODS: A sample of 25 patients requiring orthodontic treatment was assessed based on the bracket type. Group 1 comprised 13 patients bonded with 0.022-in self-ligating brackets (SLB). Group 2 included 12 patients bonded with 0.022-in conventional brackets (CLB). Cone-beam computed tomography (CBCT) scans and a 3D program (Dolphin) assessed changes in transversal width of buccal bone (TWBB) and buccal bone thickness (BBT) before (T1) and 7 months after treatment onset (T2). Measurements on dental casts were performed using a digital caliper. Differences between and within groups were analyzed by Student's t-test; Pearson correlation coefficient was also calculated. RESULTS: Significant mandibular expansion was observed for both groups; however, no significant differences were found between groups. There was significant decrease in mandibular buccal bone thickness and transversal width of buccal bone in both groups. There was no significant correlation between buccal bone thickness and dental arch expansion. CONCLUSIONS: There were no significant differences between self-ligating brackets and conventional brackets systems regarding mandibular arch expansion and changes in buccal bone thickness or transversal width of buccal bone. .

OBJETIVO: o objetivo do presente estudo foi comparar as alterações dentoalveolares transversais e a espessura óssea da arcada inferior em pacientes submetidos ao tratamento ortodôntico utilizando sistemas de braquetes autoligáveis ou convencionais. MÉTODOS: uma amostra de 25 pacientes requerendo tratamento ortodôntico foi recrutada com base no tipo de braquete. No Grupo 1, 13 pacientes foram tratados com braquetes autoligáveis (SLB, slot 0,022"); o Grupo 2 incluiu 12 pacientes, nos quais foram colados braquetes convencionais (CLB, slot 0,022"). Utilizou-se tomografia computadorizada de feixe cônico e um programa 3D (Dolphin) para avaliar as alterações pré-tratamento (T1) e 7 meses após o início desse (T2). As medições em modelos de gesso foram realizadas com o auxílio de um paquímetro digital. As diferenças intergrupos, bem como intragrupo, foram analisadas por meio de teste t de Student. Além disso, o coeficiente de correlação de Pearson foi utilizado. RESULTADOS: alterações dentoalveolares significativas foram observadas em ambos os grupos. Entretanto, não houve diferenças significativas entre os grupos. Houve uma diminuição da espessura óssea na região posterior e das medidas transversais em ambos os grupos. Não houve uma correlação significativa entre a espessura óssea posterior e a expansão da arcada dentária, em nenhum dos dois sistemas de braquetes utilizados. CONCLUSÕES: comparando-se o uso dos aparelhos autoligáveis e convencionais, concluiu-se que não houve diferenças dentoalveolares significativas quanto à expansão da arcada inferior e quanto à espessura óssea posterior. .

Histologic and tomographic analyses of the temporomandibular joint after mandibular advancement surgery: study in minipigs.

OBJECTIVE: The aim was to elucidate the changes occurring in temporomandibular joint (TMJ) after surgical mandibular advancement with different fixation materials: bicortical screws and miniplates. STUDY DESIGN: Eighteen minipigs were randomly divided into 3 groups: group I (control), nonoperated animals; group II, animals submitted to surgical advancement surgery and osteosynthesis by bicortical screws; and group III, animals submitted to surgical advancement surgery and osteosynthesis by miniplates. Four months after the surgeries, TMJs were collected and histologically prepared after computerized tomography (CT) scanning for the blind detection of erosion, flattening, and osteophyte. RESULTS: The CT analysis revealed significant alterations in the shape of the condyles (erosion: P = .0010; flattening: P < .0001) for group II compared with groups I and III. Descriptive histologic analysis was compatible with the CT findings. CONCLUSIONS: The results indicated that bicortical screw fixation resulted in more pronounced condylar alterations in the shape of the condyles than miniplate osteosynthesis. However, further clinical studies are necessary to confirm these data.