No abstract

Retention procedures for stabilising tooth position after treatment with orthodontic bracesLittlewood, Simon J.; Millett, Declan T.; Doubleday, Bridget; Bearn, David R.; Worthington, Helen V.

Objective To summarize speech outcomes in children born with unilateral cleft lip and palate (UCLP) throughout the United Kingdom. Design Prospective descriptive study on a cross-sectional sample of children. Patients/Participants Data were collected for 238 5-year-olds (born between April 1, 1989, and March 31, 1991) and 218 12-year-olds (born between April 1, 1982, and March 31, 1984) with complete UCLP. Main Outcomes Ratings of intelligibility, nasality, “speech cleft type characteristics” and speech therapy intervention. Conclusions Nineteen percent of 5-year-olds and 4% of 12-year-olds were judged to be impossible to understand or just intelligible to strangers. Thirty-four percent of 5-year-olds and 17% of 12-year-olds had at least one serious error of consonant production. Eighteen percent of 5-year-olds and 12-year-olds had consistent hypernasality of mild, moderate, or severe degree. Approximately two-thirds of both age groups had undergone speech therapy.

This study examined the mechanical and physical properties of retrieved coated nickel-titanium (NiTi) archwires compared with unused samples. Ultraesthetic 0.016 inch coated archwires (G&H(R) Wire Company) were investigated. Ten as-received wires were subjected to a three-point bending test using conventional and self-ligating bracket systems. Surface roughness of the coating was measured with a contact stylus profilometer. Optical and scanning electron microscopes were used to assess surface topography. Ten archwires were used in vivo for a period of between 4 and 6 weeks. Retrieved archwires were subjected to the same tests. The percentage of the remaining coating was calculated using digital photography. Coated archwires were used in vivo for a mean period of 33 days. Differences between the mean values of the as-received and retrieved archwires were determined using t-tests. In the three-point bending test, with conventional elastomeric ligation, retrieved wires produced a lower unloading force (P < 0.001). Both retrieved and as-received coated archwires produced zero values of unloading force when deflected for 4 mm. When tested using a self-ligating bracket system, retrieved and as-received coated archwires produced the same amount of force (P > 0.05). With surface profilometry, all measured roughness parameters (except R(sm)) had greater surface roughness for the retrieved coated archwires (P < 0.05). Under microscopy, retrieved coated archwires showed discolouration, ditching, and delamination. Only 75 per cent of the coating was present in retrieved coated archwires. Retrieved coated archwires produced lower unloading force values than as-received coated archwires with conventional ligation. Surface roughness of coated archwires increased after use. Coated archwires have a low aesthetic value, with 25 per cent of the coating lost within 33 days in vivo.