Physiological responses to shuttle repeated-sprint running.

This study investigated the influence of 180 degrees changes of direction during a repeated-sprint running test on performance, cardiorespiratory variables, muscle deoxygenation and post-exercise blood lactate ([La] (b)) levels. Thirteen team-sport athletes (22+/-3 yr) performed 6 repeated maximal sprints with (RSS, 6 x[2 x 12.5 m]) or without (RS, 6 x 25 m) changes of direction. Best and mean running time, percentage speed decrement (%Dec), pulmonary oxygen uptake ( V O (2)), vastus lateralis deoxygenation (Hb (diff)) and [La] (b) were calculated for each condition. Best and mean times for both protocols were largely correlated (r =0.63 and r =0.78, respectively), and were 'ALMOST CERTAINLY' higher for RSS compared with RS (e. g., 5.30+/-0.17 vs. 4.09+/-0.17 s for mean time, with the qualitative analysis revealing a 100% chance of RSS time being greater than RS). In contrast, %Dec was 'POSSIBLY' lower for RSS (2.6+/-1.2 vs. 3.2+/-1.3%, with a 79% chance of a real difference). Compared with RS, V O (2) (40.4+/-4.2 vs. 38.9+/-3.8 mL x min (-1) x kg (-1), with a 90% chance of a real difference) and [La] (b) (10.0+/-1.7 vs. 9.3+/-2.4 mmol.L (-1), with a 70% chance of a real difference) were 'POSSIBLY' higher. Conversely, there were no differences in Hb (diff) (11.5+/-3.2 vs. 10.9+/-3.0 microM, with the comparison rated as 'UNCLEAR'). To conclude, the present results suggest that the ability to repeat sprints can be considered as a general quality. They also suggest that repeated shuttle sprints might be an effective training practice for eliciting a greater systemic physiological load, but perhaps not a greater loading of the vastus lateralis.

Delayed tooth formation in low birthweight African-American children.

Low birthweight (LBW) infants are susceptible to several developmental problems (e.g., pulmonary diseases, hyperbilirubinemia, hypocalcemia) with potentially long-lasting effects that slow growth during infancy and childhood. Dental age (DA), judged from stages of permanent tooth mineralization, was scored in 4- to 7-year-old LBW African-American children (N = 66; x = 5.5 years) to test whether they were delayed due to LBW and its consequences. Data were matched in a case-control fashion to African-American children with normal birth-weights (N = 76). Only the early-forming teeth (incisors, first molars) were delayed significantly in their formation. Children with the lowest height-for-age centiles were the most delayed dentally which suggests that height status would improve as dental age caught up with chronological age (CA). Older children were more delayed because there is a proportionately greater opportunity for DA to diverge from CA as children grow older. Since only those teeth undergoing rapid differentiation neonatally were affected systematically, it was speculated that perinatal insults may have an enduring impact on developing primordia, while leaving later-forming teeth unaffected.

Comparison of shear bond strength of three bonding agents with metal and ceramic brackets.

Shear bond strengths of a light-cured composite resin, a light-cured glass ionomer cement, and a light-cured compomer used with metal and ceramic brackets were compared, and ARI scores were evaluated. Ceramic brackets showed statistically higher shear bond strengths than metal brackets when bonded with all test materials (p<0.001). When used with metal brackets, the light-cured glass ionomer cement (LCGIC) and compomer materials demonstrated statistically lower shear bond strengths than the light-cured composite (p<0.01 and p<0.001, respectively). When used with ceramic brackets, LCGIC was found to have significantly lower shear bond strength than the composite material (p<0.001). Despite its relatively low shear bond strength, LCGIC demonstrated optimal bonding values (8.39+/-3.24 MPa) with ceramic brackets. Bond failures within the LCGIC groups occurred at the adhesive-tooth interface, whereas in the compomer and composite groups, failures were detected at the adhesive-bracket interface. In the metal bracket group, clinically acceptable shear bond strength was obtained only with the composite resin (7.06+/-1.65 MPa). Compomer and LCGIC demonstrated values well below the accepted standard for metal brackets (4.32+/-1.75 MPa and 4.45+/-1.06, respectively), while in the ceramic bracket group, values for composite and compomer were above the desired level (14.40+/-5.88 MPa and 12.31+/-6.09, respectively). LCGIC showed reasonably good bond strength with ceramic brackets, suggesting that this material may be considered suitable for use with ceramic brackets in clinical situations where moisture cannot be controlled.

[Sterilization and disinfection in clinical orthodontics]. / Klinik ortodontide sterilizasyon ve dezenfeksiyon.

Recently a great deal of attention has been devoted to the spread of hepatitis b and aids viruses and the high risk of contamination of these viruses during the dental operations has made orthodontists more aware of the necessity of sterilization and disinfection. This article discusses the methods of sterilization and disinfection. Avoidance of corrosion of instruments and the use of a ultrasonic cleaner to avoid contamination has been explained. In the conclusion the measures that the orthodontist has to take in order to protect himself is discussed.

Functional regulator therapy in treatment of skeletal open-bite.

A study was performed on the functional regulator, Fränkel appliance (FR4) in order to test its efficiency in the treatment of patients with skeletal open-bite. Pretreatment and post-treatment cephalometric evaluation was done on 11 patients and 10 untreated patients with skeletal open-bite. The results showed that the FR4 appliance was mainly effective on changes in dentoalveolar structures and produced no significant skeletal changes. The degree of anterior open-bite was decreased significantly in the treatment group in comparison with the controls (p < 0.01), due to vertical eruption of upper and lower incisors and retraction of maxillary incisors.

Occlusal contact changes after the active phase of orthodontic treatment.

Occlusal contacts in maximum intercuspidation were recorded at the end of active orthodontic treatment and 3 months into the retention period. Hawley retainer, tooth positioner, and nontreated normal occlusion groups of 10 subjects were examined for change in the number and location of occlusal contacts. Soft silicone-base impression materials were used to make interocclusal registrations. The contacts were then transferred onto the study models, and standard photographs of each model were taken. To determine any locational changes, superimposition of the first registration photograph on the second one was done. Significant difference in the number of total contacts between the treated groups and the control sample was recorded at both time periods. Use of a tooth positioner as a retainer did not show any additional gain of contacts in the positioner group when compared with the Hawley retainer group. No significant change in the location of contacts occurred during the period of observation.

Orthodontic intervention in adult patients as an adjunct to prosthetic and restorative dentistry.

Combined orthodontic-prosthodontic procedures will enhance the results of restorative treatment in adult patients. Restoration of malposed teeth using prostheses alone will fail both esthetically and functionally. Rotation, spacing or crowding and tipped teeth will compromise the final restoration if left untreated. Correction of axial inclination will prevent pulp exposure during preparation, as well as improving the periodontal status of the involved teeth. Cooperation between the orthodontist and the prosthodontist will ensure a more favorable final result. Cases treated in this manner are presented, illustrating the orthodontic treatment and the successful end results.

Short-term effects of fiberotomy on relapse of anterior crowding.

The effects of fiberotomy were evaluated in alleviating dental relapse of incisors after orthodontic treatment. The study sample consisted of 23 patients with crowded maxillary and mandibular incisors before orthodontic treatment. The amount of initial crowding was determined according to Little's irregularity index. Fiberotomy procedures were performed on 11 of the patients 1 week before debonding. The other 12 subjects served as the control group. All patients wore Hawley retainers. Lateral cephalometric headfilms and dental casts of the patients were taken at the beginning (T1) and at the end (T2) of treatment, 6 months into the retention phase (T3), and 1 year after orthodontic treatment (T4). Significant increase of irregularity index was noted in the control group at T3 and T4 for both maxillary and mandibular anterior segments (P <.05, P <.01). Meanwhile, in the group where circumferential supracrestal fiberotomy was performed, no significant increase of the irregularity index was noted.

Effects of retainers on the articulation of speech.

Articulation abilities of 15 patients were evaluated at the end of orthodontic treatment with the initiation of removable upper and lower retainer wear. A test of articulation, based on consonants and vowels (cv), (vcv), (vc), (cvc) nonsense syllables, was used to evaluate the articulatory distortions with no retainers and with maxillary and mandibular retainers worn respectively and together. The test was performed (a) on the first day, (b) 24 hours later, and (c) 1 week later. Statistically significant articulatory distortions with the /t/ and /d/ sounds on the first day with upper retainer only and with both retainers worn together were noted. Also significant distortion of the /k/ sound with both retainers worn was observed. These distortions, due to the wearing of retainers, decreased to an insignificant level or disappeared completely on the seventh day showing the ability of tongue adaptation in a very short period of time.

Changes in hypopharyngeal airway space and in tongue and hyoid bone positions following the surgical correction of mandibular prognathism.

This study was aimed at measuring the changes in the hyoid bone position, tongue position, and hypopharyngeal airway space in subjects with mandibular setback osteotomies. Lateral cephalometric radiographs of 15 patients were taken preoperatively, 6 weeks postoperatively, and at the follow-up with a mean of 1.5 +/- 0.4 years. A significant decrease in the hypopharyngeal airway space following mandibular setback surgery was found (P < .01). This change sustained during the follow-up period. The hyoid bone moved down (P < .001), and the lower tongue point also moved down (P < .05) postoperatively. Results of the study suggest that narrowing of the hypopharyngeal airway space due to the posterior and inferior movement of the tongue can be permanent.

Epicondilitis lateral de húmero / Lateral epicondylitis of the humerus

La epicondilitis lateral de codo constituye una controversia actual respecto a su definición, etiología y tratamiento. El constituir una patología de frecuente presentación en trabajadores manuales la hace relevante en nuestra realidad. El presente trabajo explora la literatura reciente respecto a los aspectos mencionados en cuanto a epidemiología, fisiopatología y tratamiento, demostrando la falta de evidencia científica que avale los conocimientos actuales en el tema. Se efectúa además una revisión de la casuística en la Clínica del Trabajador de Valdivia y se efectúa una propuesta de tratamiento a la luz de los conocimientos actuales del tema