RESUMEN
OBJECTIVE: To compare the short-term treatment effects between two types of facemasks in skeletal Class III patients. MATERIALS AND METHODS: This retrospective study included 40 skeletal Class III subjects (mean age: 7.7 years) who had been treated with protraction facemasks with forehead straps (PFFS) or Petit type facemasks (PTF). Lateral cephalograms were analyzed at pretreatment (T1) and posttreatment (T2) with an average interval of 9 months. RESULTS: At T1, PFFS and PTF groups showed similar sagittal, vertical dentoskeletal patterns. From T1 to T2, both groups presented significant forward movement of the maxilla, posterior movement and clockwise rotation of the mandible (all p < .001), labioversion of the maxillary incisors, and linguoversion of the mandibular incisors. They showed increased overjet (p < .001). Although there were no significant differences in the number of changes in most dentoskeletal variables between the two groups, the PFFS group showed more anterior rotation of the palatal plane and backward rotation of the mandible compared to the PTF group, resulting in a significant decrease (-0.42 mm) in overbite (p < .05). CONCLUSIONS: Both PFFS and PTF showed no significant differences in most skeletal and dental changes, except for overbite. These findings might be helpful for clinicians in selecting the types of facemasks for growing Class III malocclusion patients.
Asunto(s)
Maloclusión Clase II de Angle , Sobremordida , Humanos , Niño , Estudios Retrospectivos , Máscaras , Cefalometría/métodos , MandíbulaRESUMEN
In this study, the formation of hydroxyapatite (HA) by a series of hydrothermal treatment and properties of the anodic oxide films and HA composite coatings were investigated. Based on the observations using EPMA, SEM, and X-ray diffraction, these needles were suggested to have a HA-like structure and were formed on the anodic oxide surfaces. The formation of these apatite-like needles were either oriented at an angle or formed on porous anodic oxide films. The concentration of Ca and P were enriched in apatite-like needles after hydrothermal treatments, whereas lower concentration of Ca and P were observed on anodic oxide film, particularly around the needles. In conclusion, HA-like needles were formed after hydrothermal treatment at 200 and 300 degrees C.