In vitro enamel surface roughness analysis of 4 methods for removal of remaining orthodontic adhesive after bracket debonding.

OBJECTIVES: To perform an in vitro qualitative and quantitative evaluation of the enamel surface (by scanning electronic microscopy [SEM] and measuring polishing time and roughness analysis, respectively) among four methods to remove remaining orthodontic adhesive after bracket debonding. MATERIALS AND METHODS: Forty-one human premolars were randomly divided into four groups (n = 10) according to the adhesive remnant removal method and one tooth was used as control: Group 1 (G1): Enhance (Dentsply, Milford, USA); Group 2 (G2): Fiberglass (TDV, Pomerode, Brazil); Group 3 (G3): DU10CA-Ortho (Dian Fong Industrial, Shenzhen, China); Group 4 (G4): Sof-Lex Pop-On (3M ESPE, Seefeld, Germany). Roughness was measured before bonding and after complete removal of the remaining adhesive (Ra2). SEM analysis was performed on one sample of each group after adhesive removal and polishing. The time required for adhesive remnant removal and polishing was measured in all groups. Analysis of variance and Tukey post hoc for pairwise comparison was applied to compare polishing times among groups and analysis of covariance was used to compare Ra2 means. RESULTS: Comparison between groups show that G4 presented the lowest Ra2 mean (0.43 µm)c followed by G3 (0.71 µm)ac, G1 (1.06 µm)ab, and G2 (1.21 µm)b - different letters, statistically different at P ≤ 0,05. In addition, Fiberglass was more time-consuming for adhesive remnant removal than other methods (P ≤ .05). SEM analysis showed that some enamel damage occurred for all methods. CONCLUSIONS: All methods were able to remove the remaining adhesive and polish the enamel. The DU10CA-Ortho and Sof-Lex methods promoted better polishing of the enamel surface and exhibited a similar time-consuming process.

Dehiscence and buccal bone thickness after rapid maxillary expansion in young patients with unilateral cleft lip and palate.

INTRODUCTION: The present study aimed to evaluate the consequences of rapid maxillary expansion in the buccal bone thickness and dehiscence of subjects with unilateral cleft lip and palate. METHODS: This prospective cohort study consisted of 30 participants, 20 males and 10 females, between 8 and 15 years old. Participants were allocated into 3 groups, according to the type of maxillary constriction, and were treated with different types of expanders: G1, hyrax; G2, fan-type; G3, inverted mini-hyrax. Cone-beam computed tomography scans were performed immediately before treatment and after 90 days of retention. Linear measurements were obtained by the same calibrated and blinded examiner. RESULTS: An average of 0.8 mm decrease in buccal bone thickness (P <0.001) and a 0.5 mm increase in dehiscence (P <0.001) were observed. There was no significant difference between the cleft and noncleft side for all variables (P >0.05), as there was no significant difference between groups (P >0.05). CONCLUSION: The findings in this study allow the conclusion that the orthopedic forces of rapid maxillary expansion lead to a decrease in the posterior buccal bone volume in unilateral cleft lip and palate patients.

Evaluation of the three-dimensional (3D) position of cervical vertebrae in individuals with unilateral posterior crossbite.

OBJECTIVE: To evaluate the three-dimensional (3D) position of the cervical vertebrae of growing subjects with unilateral posterior crossbite (UPC). MATERIALS AND METHODS: In this cross-sectional study, cone beam computed tomography (CBCT) scans of 1455 patients were screened, and ultimately 58 scans (26 patients with UPC and 32 controls with normal occlusion) were included after imposing inclusion/exclusion criteria. Roll, yaw, and deviation of the geometric center of C1, C2, and C3 vertebrae were measured and compared between groups. A correlation between these parameters and different variables on mandibular positioning was also carried out. RESULTS: A statistically significant difference (p < 0.05) was observed between groups for the deviation of pogonium (Pog), mandibular plane roll, and C3 roll, and patients with UPC showed higher cant or deviation. A significant correlation was reported for the roll of C2 and C3 with the deviation of Pog, a roll of the occlusal plane, and roll of the mandibular plane (p < 0.05). The greater the deviation of the Pog to one side, the greater the roll of the vertebrae with this same side up. The same tendency was observed between the roll of the occlusal plane or the mandibular plane with the roll of these cervical vertebrae. CONCLUSIONS: There is a positive correlation between transverse occlusal changes and positional deviations of the cervical vertebrae, especially C2 and C3. CLINICAL RELEVANCE: The study results do not allow us to infer the clinical/functional consequences of these deviations, as well as if malocclusion's treatment would result in an improvement of intervertebral relationships.

Is there an asymmetry of the condylar and coronoid processes of the mandible in individuals with unilateral crossbite?

OBJECTIVES: To evaluate if there is a true skeletal asymmetry of the condylar and coronoid processes of the mandible in growing individuals with unilateral posterior crossbite (UPC) either functional or not. MATERIALS AND METHODS: This cross-sectional study screened a total of 1120 cone beam computed tomography (CBCT) scans based on inclusion and exclusion criteria. The final sample comprised 20 CBCT images of individuals with UPC and 19 CBCT images of individuals without transverse malocclusion. The lengths of the condylar and coronoid processes were measured to evaluate asymmetry, as well as the magnitude of the mandibular lateral deviation in the UPC group. RESULTS: There was a significant difference between the lengths of the affected and nonaffected sides of the coronoid processes in the UPC group (P < .01). The same was not observed in the condyle in the UPC group (P > .05). There were no significant differences between the groups (P > .05). CONCLUSIONS: Although no differences in the condyle were observed, the coronoid process was asymmetric in individuals with UPC. However, this asymmetry was not considered to be clinically significant.

Compensations in Bone Morphology and the Dentition in Patients With Untreated Unilateral Cleft Lip and Palate: A Cone-Beam Computed Tomographic Analysis.

OBJECTIVE: The purpose of this study was to quantitatively assess dentoalveolar and skeletal compensations in patients with untreated unilateral cleft lip and palate (UCLP). We hypothesized that there are significant skeletal and dental adaptations in UCLP cases compared to a comparison maxillary crossbite group. DESIGN: A convenience retrospective sample of 30 patients with UCLP and a comparison group of 30 patients with unilateral posterior crossbite without CLP. Cone-beam computed tomography scans (CBCTs) were used to evaluate dental and skeletal compensations. In addition, alveolar bone thickness was measured at 2-mm increments in mesiodistal and faciolingual cross-sectional views along the long axis of the central incisors. Alveolar bone height was measured, and the percentage of root length supported by bone was calculated. RESULTS: Compensations for unilateral cleft lip and palate were restricted to the cleft site and adjacent structures. Dental compensations include alteration in the position of cleft-adjacent maxillary incisors and maxillary canines. No gross skeletal compensations were found. Alveolar support of cleft adjacent incisors was similar to controls except for measurements in the most coronal and apical regions. The cleft group contralateral incisors exhibited buttressing effects and had significantly higher alveolar thickness in the coronal half of the tooth. There was less (5%) alveolar coverage of the cleft-facing aspect of the central incisor root than all other incisors. CONCLUSION: The bone adaptation to the presence of a cleft was localized in the vicinity of the cleft, and adaptations in the mandible were not apparent.

The impact of rapid maxillary expansion on maxillary first molar root morphology of cleft subjects.

OBJECTIVES: The aim of this prospective cohort study was to determine the effects of rapid maxillary expansion (RME) on the first molar roots of cleft lip and palate subjects along different root development stages. MATERIALS AND METHODS: Thirty participants with unilateral cleft lip and palate were divided into three groups (n = 10), according to the type of expander used: Hyrax, iMini and Fan-type. A cone beam CT scan was performed before (T1) and 3 months after stabilization of the appliance (T2). Measurements of root lengths of the first permanent maxillary molars were taken to evaluate root development and external apical root resorption (EARR). RESULTS: Roots presenting open apexes before treatment exhibited a statistically significant increase in root length after treatment (P < .001). Conversely, there were no significant changes in the root length of roots that had closed apexes at the beginning of treatment (P > .05). Furthermore, there were no differences among groups, or correlation between cleft side and gender was found vis-à-vis to changes in the root length (p > .05). CONCLUSIONS: Orthopaedic forces of RME were neither able to interrupt the root development process nor to cause EARR in cleft subjects. CLINICAL RELEVANCE: As the RME is the most common orthodontic procedure in patients with cleft lip and palate, understanding its impact on dental structures is of fundamental importance.

Effects of rapid maxillary expansion in cleft patients resulting from the use of two different expanders

ABSTRACT Objective: The aim of this study was to evaluate the skeletal and dental effects of rapid maxillary expansion (RME) in cleft patients using two types of expanders. Methods: Twenty unilateral cleft lip and palate patients were randomly divided into two groups, according to the type of expander used: (I) modified Hyrax and (II) inverted Mini-Hyrax. A pretreatment cone-beam computed tomographic image (T0) was taken as part of the initial orthodontic records and three months after RME, for bone graft planning (T1). Results: In general, there was no significant difference among groups (p > 0.05). Both showed a significant transverse maxillary expansion (p < 0.05) and no significant forward and/or downward movement of the maxilla (p > 0.05). There was greater dental crown than apical expansion. Maxillary posterior expansion tended to be larger than anterior opening (p < 0.05). Cleft and non-cleft sides were symmetrically expanded and there was no difference in dental tipping between both sides (p > 0.05). Conclusions: The appliances tested are effective in the transverse expansion of the maxilla. However, these appliances should be better indicated to cleft cases also presenting posterior transverse discrepancy, since there was greater expansion in the posterior maxillary region than in the anterior one.

RESUMO Objetivo: o objetivo deste estudo foi avaliar os efeitos esqueléticos e dentários da expansão rápida da maxila (ERM) em pacientes fissurados, utilizando dois tipos de disjuntores. Métodos: vinte pacientes com fissura labiopalatal unilateral foram aleatoriamente divididos em dois grupos, de acordo com o tipo de aparelho utilizado: (1) Hyrax modificado e (2) Mini-Hyrax invertido. Tomografias computadorizadas de feixe cônico foram obtidas antes do tratamento (T0), como parte da documentação ortodôntica inicial, e três meses após a ERM, para o planejamento de enxertia óssea (T1). Resultados: não houve diferença significativa entre os grupos (p>0,05). Ambos apresentaram significativa expansão transversal da maxila (p<0,05), sem significativa movimentação anterior e/ou inferior da maxila (p>0,05). Houve uma maior expansão transversal das coroas em relação à expansão nos ápices. A tendência observada foi uma maior expansão na região posterior da maxila, em comparação à anterior (p<0,05). Avaliando o deslocamento dos lados fissurado e não fissurado, a expansão ocorreu de maneira simétrica e não houve diferença na inclinação dentária entre os lados (p>0,05). Conclusões: os aparelhos testados são eficazes na expansão transversal da maxila em pacientes fissurados. Porém, esses aparelhos seriam melhor indicados para casos de fissura labiopalatal com atresia transversal posterior, uma vez que a expansão foi maior na região posterior da maxila do que na região anterior.

Effects of rapid maxillary expansion in cleft patients resulting from the use of two different expanders.

OBJECTIVE:: The aim of this study was to evaluate the skeletal and dental effects of rapid maxillary expansion (RME) in cleft patients using two types of expanders. METHODS:: Twenty unilateral cleft lip and palate patients were randomly divided into two groups, according to the type of expander used: (I) modified Hyrax and (II) inverted Mini-Hyrax. A pretreatment cone-beam computed tomographic image (T0) was taken as part of the initial orthodontic records and three months after RME, for bone graft planning (T1). RESULTS:: In general, there was no significant difference among groups (p > 0.05). Both showed a significant transverse maxillary expansion (p < 0.05) and no significant forward and/or downward movement of the maxilla (p > 0.05). There was greater dental crown than apical expansion. Maxillary posterior expansion tended to be larger than anterior opening (p < 0.05). Cleft and non-cleft sides were symmetrically expanded and there was no difference in dental tipping between both sides (p > 0.05). CONCLUSIONS:: The appliances tested are effective in the transverse expansion of the maxilla. However, these appliances should be better indicated to cleft cases also presenting posterior transverse discrepancy, since there was greater expansion in the posterior maxillary region than in the anterior one.

Unusual Spontaneous Mandibular Regeneration of a Large Defect Followed by Orthodontics, Alveolar Distraction, and Dental Implant Rehabilitation: A 10-Year Follow-Up.

This report describes an atypical case of spontaneous mandibular regeneration of a large size bony defect after resection of an aseptic osteonecrotic area near the symphysis and parasymphyseal area. The patient underwent orthodontic therapy, vertical osteogenic distraction of the alveolar bone, and oral rehabilitation with an implant borne prosthesis. This case study also describes the 10-year follow-up of comprehensive multidisciplinary treatment and successful recovery of a patient's esthetic and functional aspects.

Cone Beam CT Analysis of Tempora Bone Pneumatizatioi in Subjects with Unilateral Cleft Lip and Palate.

OBJECTIVES: To evaluate the pneumatization pattern in the temporal bone in patients with cleft lip and palate. METHODS: A retrospective observational analysis of cone beam computed tomography (CBCT) scans of patients with cleft lip and palate was done. The patients were referred for orthodontic treatment and had a unilateral cleft lip and palate and anterior maxillary constriction. Four reference structures were identified to evaluate the extension of pneumatization in the cleft vs non-cleft side temporal bones. RESULTS: Twenty patients had cleft on the left side and nine patients had cleft on the right side, This study found reduced temporal bone pneumatization on the side of the cleft. The mean score of temporal bone pneumatization on the cleft side was 4.7±1.47 while mean score of pneumatization on the non-cleft side was 6.7±1.80 (P<0.001). CONCLUSIONS: Pneumatization of the temporal bone was significantly lower on the side of the cleft and an identification of this change can help in early diagnosis and management of any ear-related conditions in this vulnerable group of patients to make appropriate referrals for specialized care.

Finite element analysis of mandibular molar protraction mechanics using miniscrews.

BACKGROUND/OBJECTIVES: The aim of this study was to determine the most desirable force system to achieve molar protraction from an interdental miniscrew minimizing side-effects. Several iterations of force delivery were simulated through variations in the height of a miniscrew, length of a molar extension arm, and incorporation of a lingual force. MATERIALS/METHODS: A three-dimensional mesh model of the right posterior segment of the mandible was developed from cone beam computed tomography data from a patient missing a first molar. Protraction appliances were constructed using computer-aided design software and integrated with finite element software. After mesh generation, a total of 80 loading conditions were simulated by altering the extension arm length (2-10mm), miniscrew height (0-8mm), and magnitude of protraction force from the lingual side (0-1.5 N). A constant labial force of 1 N was used in all models. RESULTS: As the length of the extension arm increased, mesial tipping decreased, rotation decreased, and buccolingual inclination remained the same without lingual traction force. Lingual traction reduced rotation but increased tipping. Similar trends were observed in all situations despite of the height of the miniscrew. CONCLUSIONS: The height of the miniscrew is not as critical in affecting tooth movement during mandibular second molar protraction as the length of the extension arm. The most ideal force system in the model appeared to be the longest extension arm (10mm) with the addition of a lingual force of half or equal magnitude of the labial force.

An alternative clinical approach to achieve greater anterior than posterior maxillary expansion in cleft lip and palate patients.

Cleft lip and palate patients commonly present maxillary constriction, particularly in the anterior region. The aim of this case report was to describe an alternative clinical approach that used a smaller Hyrax screw unconventionally positioned to achieve greater anterior than posterior expansion in patients with complete unilateral cleft lip and palate. The idea presented here is to take advantage of a reduced dimension screw to position it anteriorly. When only anterior expansion was needed (patient 1), the appliance was soldered to the first premolar bands and associated to a transpalatal arch cemented to the first molars. However, when overall expansion was required (patient 2), the screw was positioned anteriorly, but soldered to the first molar bands. Intercanine, premolar, and first molar widths were measured on dental casts with a digital caliper. Pre-expansion and postexpansion radiographs and tomographies were also evaluated. A significant anterior expansion and no intermolar width increase were registered in the first patient. Although patient 2 also presented a greater anterior than posterior expansion, a noteworthy expansion occurred at the molar region. The alternative approach to expand the maxilla in cleft patients reported here caused greater anterior than posterior expansion when the Mini-Hyrax was associated to a transpalatal arch, and its reduced dimension also minimized discomfort and facilitated hygiene.

Clinical treatment of a ruptured temporomandibular joint disc: morphological changes at 5-year follow-up.

Osteoarthrosis is a disease that affects the temporomandibular joint (TMJ). This case report chronicles the diagnosis and treatment of a patient for whom this pathological condition was accompanied by a rupture of the articular disc. The patient presented with loud sounds in the left TMJ and an irregular mandibular occlusal plane due to condylar intrusion in the glenoid fossa on the ipsilateral side. A noninvasive treatment was selected. A 4-month follow-up revealed remission of the articular sounds, and tissue regeneration was noted. These improvements remained visible at 5-year follow-up.

Utilização de pinos biológicos em reconstrução de raízes debilitadas / Utilization of biological posts to reconstruct weakened roots

A adequada reconstrução de dentes endodonticamente tratados e com grande perda de tecido dentinário é um dos desafios da Odontologia Restauradora. Nenhum dos pinos intra-radiculares pré-fabricados encontrados no mercado preenche todas as propriedades biológicas e mecânicas ideais. Recentemente, tem sido indicada uma técnica com múltiplas vantagens para reconstrução de dentes despolpados com raízes enfraquecidas, consistindo na utilização de pinos dentários obtidos a partir de dentes naturais. Este artigo apresenta, através de um caso clínico, todos os detalhes necessários para execução da técnica.

Adequate reconstruction of endodontically treated teeth with severe loss of dentine tissue is one of the challenges of Restorative Dentistry. None of the commercially available pre-fabricated intraradicular posts meets all ideal biological and mechanical properties. Recently, a technique for the reconstruction of pulpless teeth with weakened roots has been indicated - the use of dental posts obtained from natural teeth. This article presents, through a clinical case, important details for the execution of the technique.