Facemask therapy with miniplates for anchorage
Lee NK, Yang IH, Baek SH. The short-term treatment effects of face mask therapy in Class III patients based on the anchorage device: miniplates vs rapid maxillary expansion. Angle Orthod 2012;82:846-52
Traditionally, the treatment for growing patients with mild to moderate maxillary hypoplasia included some form of tooth-borne device with facemask therapy. Unfortunately, in addition to maxillary protraction, these treatment modalities tend to extrude and move the maxillary molars forward, increase crowding, and flare the maxillary incisors. The authors of this retrospective study compared the short-term skeletal and dental effects of facemask therapy with 2 anchorage systems: miniplates and rapid maxillary expanders. The study participants included 20 growing patients (9 boys, 11 girls) with cephalometrically diagnosed maxillary hypoplasia. The patients were divided into 2 groups: 10 with miniplates and 10 with rapid maxillary expanders. There were no significant differences in patient age or skeletal presentation between the 2 groups. Each group followed the same facemask protocol (elastic force of 400 g/side applied for 12-14 hours/day). Overall, the results showed that both modalities produced forward movement of A point, posterior repositioning of the mandible, opening rotation of the mandible, increased labioversion of the maxillary incisors, increased upper lip protrusion, increased ANB angle, increased Wits appraisal, and increased overjet. Significant differences between the groups included the following: the miniplates group showed greater forward displacement of the maxilla and significant protraction of orbitale, and the rapid maxillary expander group demonstrated greater backward and downward rotation of the mandible and greater labioversion of the maxillary incisors. There were no significant differences in soft-tissue change between the 2 groups. The study’s limitations included a small sample size, use of chronologic age, use of differing rapid maxillary expansion devices, and no controls. The authors concluded that facemask therapy with miniplates was more effective in advancing the maxilla with minimal flaring of the maxillary incisors, and less downward and backward rotation of the mandible.
Reviewed by Nathan Hawley
Calcitonin levels and pain intensity associated with orthodontic tooth movement
Alarcon JA, Linde D, Barbieri G, Solano P, Caba O, Rios-Lugo M, et al. Calcitonin gingival crevicular fluid levels and pain discomfort during early orthodontic tooth movement in young patients. Arch Oral Biol 2012 Oct 26 [Epub ahead of print]
Calcitonin, a 32-amino acid polypeptide hormone produced by the thyroid gland, has an inhibitory effect on osteoclasts and bone resorptive mechanisms. Calcitonin also has analgesic properties, especially on bone-related pain. The aims of this prospective longitudinal study were to assess the ability to detect calcitonin in the gingival crevicular fluid, measure calcitonin levels during orthodontic movement, and evaluate possible associations between calcitonin levels and patients’ perceived pain intensity. The subjects included 15 children (mean age, 12.6 years) requiring orthodontic closure of an upper midline diastema. Gingival crevicular fluid was collected from the compression and tension sites of the maxillary central incisor (experimental) and the first premolar (control) before treatment and after 1 hour, 24 hours, 7 days, and 15 days of treatment. Calcitonin levels were determined by Western blot. Pain intensity was assessed by using a visual analog scale. The results indicated that calcitonin levels were higher in the compression site than the control site at 7 days ( P = 0.014). No significant changes were found in the tension and control sites. Moreover, as the calcitonin levels increased, pain intensity decreased (r = −0.54; P = 0.05), suggesting an analgesic effect of calcitonin in orthodontic-induced pain. The observed rapid increase in the percentages of calcitonin levels at the compression site of the experimental teeth was probably due to bone calcium homeostasis induced by orthodontic forces. The authors concluded that calcitonin levels in the gingival crevicular fluid significantly increased in the compression site after the application of orthodontic forces, and these changes were negatively associated with corresponding pain intensity.
Reviewed by Lina Sharab