Evaluation of the load system produced by a single intrusion bend in a maxillary lateral incisor bracket with different alloys.

OBJECTIVES: To evaluate if a 0.5-mm vertical bend applied on an incisor bracket produces movements in other planes and if different wires influence these effects. MATERIALS AND METHODS: An acrylic model of a treated patient with brackets passively bonded was attached to an Orthodontic Force Tester, and a load cell was attached to the left lateral incisor. Thirty 0.019 × 0.025-inch archwires were divided into three groups according to their alloy: SS (stainless steel), B-Ti (beta-titanium), and MF (beta-titanium wire coated with nickel-titanium). Step-bends of 0.5 mm high were placed on the lateral incisor bracket using a universal plier, and the forces and moments in three dimensions were statistically analyzed by analysis of variance and Tukey post hoc test. RESULTS: SS produced a larger force (3.4 N) than the B-Ti (1.41 N) and the MF (0.53 N; P < .001). Lingual forces were produced by the SS (0.82 N) and B-Ti (0.31 N) groups, while in the MF group, the force was insignificant. SS produced a mesial force of 0.24 N, while the B-Ti force was insignificant and MF produced 0.09 N. Groups produced different crown-distal tipping moments (SS = 31.48 N-mm, B-Ti = 11.7 N-mm, and MF = 4.55 N-mm) and different crown-buccal tipping moments. SS produced larger moments (3.63 N-mm) than B-Ti (1.02 N-mm) and MF (0.36 N-mm) wires. A mesial-out rotational moment was observed in all groups (SS = 7.17 N-mm, B-Ti = 3.46 N-mm, and MF = 0.86 N-mm). CONCLUSIONS: A 0.5-mm intrusion bend produced lingual and mesial side effects. In addition to the distal and buccal crown-tipping moments, there was a mesial-out moment. Compared with SS, B-Ti and MF wires produced lower forces. These more flexible wires showed side effects with lesser intensity.

Molecular diagnostic dilemmas in Rett syndrome.

Rett syndrome (OMIM 312750) is a progressive, X-linked neurodevelopmental disorder caused by mutations in the MECP2 gene located on chromosome Xq28. The disorder is characterized by a period of normal development during the first 6-18months of life, followed by gradual loss of skills already gained, such as speech and purposeful movement of the hands. The majority of cases are sporadic and represent "de novo" mutations. In this study we summarize the results of diagnostic testing of 30 patients with Rett syndrome (RTT) or mental retardation of unknown etiology using bidirectional sequencing of the open reading frame of the MECP2 gene. Twenty different variants were identified in those patients including 12 missense (R133C, P152R, T158M, V300I, I303M, R306C, T311M, R344W, A358T, P384L, A443T, V481M), four nonsense (R168X, K192X, R255X, R270X), two deletion (E137_L386del, I293_S350del), and two frameshift (S291QfsX26, G343AfsX6) mutations. Seven of the twenty variants identified were novel mutations (E137_L386del, K192X, S291QfsX26, G343AfsX6, I293_S350del, P384L, and A443T). In the cases with novel or non-recurrent missense mutations, family studies were performed to investigate genotype-phenotype correlations. Our results demonstrate the importance of family studies and highlight the complexity of interpretation of MECP2 alterations, which may or may not be disease-associated.

Composite pontics for orthodontic patients with extraction spaces.

Esthetic orthodontic appliances continue to appeal to more patients, which results in objections to extraction spaces that remain for several months during orthodontic therapy. This has led orthodontists to design temporary pontics that fill extraction sites and that can be reduced as the spaces close. This report describes a simple, efficient, and expeditious technique for making such pontics.

The use of parallel imaging for MRI assessment of knees in children and adolescents.

BACKGROUND: Parallel imaging provides faster scanning at the cost of reduced signal-to-noise ratio (SNR) and increased artifacts. OBJECTIVE: To compare the diagnostic performance of two parallel MRI protocols (PPs) for assessment of pathologic knees using an 8-channel knee coil (reference standard, conventional protocol [CP]) and to characterize the SNR losses associated with parallel imaging. MATERIALS AND METHODS: Two radiologists blindly interpreted 1.5 Tesla knee MRI images in 21 children (mean 13 years, range 9-18 years) with clinical indications for an MRI scan. Sagittal proton density, T2-W fat-saturated FSE, axial T2-W fat-saturated FSE, and coronal T1-W (NEX of 1,1,1) images were obtained with both CP and PP. Images were read for soft tissue and osteochondral findings. RESULTS: There was a 75% decrease in acquisition time using PP in comparison to CP. The CP and PP protocols fell within excellent or upper limits of substantial agreement: CP, kappa coefficient, 0.81 (95% CIs, 0.73-0.89); PP, 0.80-0.81 (0.73-0.89). The sensitivity of the two PPs was similar for assessment of soft (0.98-1.00) and osteochondral (0.89-0.94) tissues. Phantom data indicated an SNR of 1.67, 1.6, and 1.51 (axial, sagittal and coronal planes) between CP and PP scans. CONCLUSION: Parallel MRI provides a reliable assessment for pediatric knees in a significantly reduced scan time without affecting the diagnostic performance of MRI.

Creating certainty and confidence with indirect bonding.

Indirect bonding offers a superior method of adhering brackets to teeth, but few orthodontists use it. The neglect of this procedure has many origins, including expense, lack of expertise, and inconsistent results. This paper presents an indirect-bonding method that can be used to expedite bonding appointments and make them more pleasant for patients and clinicians alike.

Digital versus conventional templating techniques in preoperative planning for total hip arthroplasty.

BACKGROUND: The purpose of our investigation was to compare a digital templating system to conventional templating techniques when preoperatively planning for total hip arthroplasty. METHODS: We included 18 consecutive patients with primary osteoarthritis undergoing uncemented total hip arthroplasty in our study. At separate sittings, we independently conducted preoperative templating. They performed the templating using hard-copy radiographic films and traditional hard-copy prosthetic overlays on a radiograph view box. They then repeated templating using a digital technique at a computer workstation with specially developed software. We used kappa statistical analysis to evaluate intra-and interobserver variability of both techniques. We also examined correlation of template measurements with final component selection. RESULTS: Intra-and interobserver variability was satisfactory for both templating techniques. There was no significant difference in the performance of the 2 techniques in predicting final component selection during surgery. CONCLUSION: Digital preoperative templating is as reliable as conventional templating techniques.

Treatment of a mutilated dentition with the mandibular protraction appliance: a patient report.

A 35-year-old female presented missing her maxillary right first premolar, left central and lateral incisors, and left second premolar and mandibular left first molar. The referring dentist had requested that only the maxillary left first molar be intruded to facilitate the prosthodontic replacement of the missing mandibular left first molar. After clinical examination and consultation with her dentist, it was decided to protract the mandibular left second and third molars, intrude the maxillary left first molar, replace the missing incisors with a temporary partial denture, and restore the missing maxillary right first premolar with an implant.

Proinflammatory cytokine-receptor interaction model improves the predictability of cerebral white matter injury in preterm infants.

Proinflammatory cytokines have been variably linked to development of cerebral white matter injury (WMI) in preterm infants. Because soluble receptors tightly control cytokine bioactivity, we modeled cytokine-receptor interaction as a predictor of WMI. Plasma from 100 preterm infants was assayed for cytokines (tumor necrosis factor alpha, interleukin (IL-1beta, IL-6) and their soluble receptors (sTNF-RI), sTNF-RII, sIL-1RA, and sIL-6R). Cranial ultrasound (US) results were correlated with cytokine and receptor concentrations individually and with cytokine-receptor interaction models (PROC LOGISTIC; SAS Software). Receiver operating characteristic curves were constructed to determine the predictability of WMI. Fifty-two infants with normal US exams were compared with 21 infants with evidence of WMI. There was no association between individual cytokine or receptor concentrations and the development of WMI. However, modeling cytokines with their soluble receptors significantly improved the predictability of WMI. We concluded that consideration of cytokine-receptor interaction may be more important than individual cytokine concentrations alone in determining the role of inflammation in the pathogenesis of WMI in preterm infants.

Early tooth extraction in the treatment of anterior open bite in hyperdivergent patients.

AIM: To describe the treatment of a 7-year-old patient with a hyperdivergent (dolichofacial) pattern, Class II Division 1 malocclusion, and anterior open bite. METHODS: Treatment was performed in 2 stages following the principles of the Ricketts bioprogressive technique and comprised early extraction of the maxillary permanent first molars and primary second molars. RESULTS: The treatment plan established for correction of the initial malocclusion reached the orthodontic goals, providing optimal esthetics and normal function. CONCLUSION: Posterior dentoalveolar height, which is fundamental in diagnosis and treatment planning, should be investigated in cases with excessive vertical dimension. In addition, extraction of permanent or primary maxillary posterior teeth at an early age may be a good option for hyperdivergent patients with excessive posterior dentoalveolar height.

O aparelho de protração mandibular no fechamento dos espaços dos primeiros molares permanentes ausentes em adultos / The mandibular protraction appliance in closing absent mandibular first molar spaces in adult patients

A crescente tendência de pacientes adultos procurarem tratamento ortodôntico coincide com a detecção bastante frequente de más oclusões mutiladas por ausência dos primeiros molares inferiores. Isto gera a necessidade da decisão, por parte do profissional, entre fechar os espaços existentes ortodonticamente ou preenchê-los proteticamente. Enquanto a opção ortodôntica apresenta o risco de resultados comprometidos por inclinação lingual dos incisivos inferiores, a opção protética com a utilização de pontes fixas ou implantes apresenta a desvantagem do envolvimento de dentes vizinhos, da utilização de elementos artificiais e de custos elevados. O aparelho de Protração Mandibular tem sido usado com frequência na resolução de tais casos, constituindo uma solução segura, de resultados previsíveis e custo reduzido, já que seu emprego está integrado ao tratamento ortodôntico que geralmente se faz necessário para atender outros aspectos de má oclusão

Closing mandibular first molar spaces in adults.

Adult orthodontic patients with missing mandibular first molars and large spaces to close have challenged orthodontists for many decades. Most of the techniques previously used to close such spaces have rendered equivocal results that typically result in compromised treatment. The mandibular protraction appliance offers orthodontic clinicians a method to close those spaces by bringing the mandibular second molars forward without retracting the mandibular incisors. This presents a method for managing large mandibular spaces without resorting to prosthetic replacements.