RESUMO
Idiopathic osteosclerosis (IO) is described as a localized radiopacity of unknown etiology. Also known as dense bone islands, enostoses, bone scar, or focal periapical osteopetrosis, it is generally clinically asymptomatic and appears round, elliptical, or irregular in shape on a radiograph. The internal structure is usually homogenous. It should be distinguished from condensing osteitis and other alveolar bone-related radiopacities. This condition may cause changes in tooth position or interfere with orthodontic treatment. Two cases of IO involving the maxilla and mandible are highlighted. Both patients were females and presented with complaints of malocclusion and desired orthodontic correction. One case was detected incidentally on routine radiographic examination of the patient. In contrast, the other case presented as an expansile lesion lingual to the left mandibular first molar and second premolar. Radiographically, both lesions appeared as well-defined radiopaque masses with no surrounding radiolucent rim; the maxillary lesion was irregular in shape, while the mandibular lesion was elliptical. Both patients underwent orthodontic treatment without any adverse sequelae. The clinical and radiographic findings are discussed to facilitate the diagnosis of radiopacities of jaws. Usually asymptomatic and of no clinical significance, IO may occasionally induce root resorption, traumatic occlusion, traumatic/pathologic migration of teeth, and inhibit eruption of teeth. Though orthodontic tooth movement through areas of IO can be undertaken, the rate of tooth movement may be slower due to higher trabecular bone density. Lower force levels are warranted to avoid adverse effects like root resorption and bone hyalinization.
RESUMO
Objective: This study investigated torque expression in maxillary incisors using two passive self-ligating bracket types (Damon Q and Pitts 21) placed at different heights using the Finite element method. Materials and methods: Two passive self-ligating brackets, Damon Q (Ormco, USA) and Pitts 21 (OC Orthodontics, USA) were 3D modeled using micro-computed tomography. Damon Q (0.022Ë® x 0.028â³ slot size) and Pitts 21 (0.021Ë® x 0.021â³ slot size) brackets were placed on a maxillary central incisor at predetermined vertical heights. Arch wires of size 0.019Ë® x 0.025â³ stainless steel (Damon Q) and 0.020Ë® x 0.020" Titanium Molybdenum (Pitts 21) were placed in the bracket slots. Results: Pitts 21 brackets showed higher torquing moments at all bonding heights as compared to Damon Q brackets. The minimum torquing moment was 9.03Nmm at 5 mm for Damon Q and the maximum torquing moment was 14.92Nmm for Pitts 21 at a bracket bonding height of 8 mm. Total deformation for Pitts 21 at a height of 5 mm from the incisal edge was 0.61 × 10-6mm as compared to that of Damon Q which was 0.41 × 10-6mm. Lowest Von Mises stress values were at 27.07 MPa in Damon Q brackets at a bracket height of 5 mm from the incisal edge. Highest Von Mises stress values were 36.80 MPa for Pitts 21 brackets at a bracket height of 8 mm from the incisal edge. Conclusion: Pitts 21 brackets exhibited superior torquing characteristics compared to Damon Q. Total deformation in Pitts 21 was higher than Damon Q at all tested bracket bonding heights.
RESUMO
INTRODUCTION: Current orthodontic literature reveals a lack of studies on bacterial colonization of orthodontic miniscrew implants (MSI) and their role in the stability of MSI. This study aimed to determine the pattern of microbiological colonization of miniscrew implants in 2 major age groups, to compare it with the microbial flora of gingival sulci in the same group of patients and to compare microbial flora in successful and failed miniscrews. METHODS: The study involved 102 MSI placed in 32 orthodontic subjects in 2 age groups: (1) aged ≤14 years and (2) aged >14 years. Gingival and peri-mini implant crevicular fluid samples were collected using sterile paper points (International Organization for Standardization no. 35) >3 months and processed by conventional microbiologic culture and biochemical techniques. A microbiologist characterized and identified the bacteria, and the results were subjected to statistical analysis. RESULTS: Initial colonization was reported within 24 hours, with Streptococci being the dominant colonizer. The relative proportion of anaerobic bacteria over aerobic bacteria increased over time in peri-mini implant crevicular fluid. Group 1 had greater Citrobacter (P = 0.036) and Parvimonas micra (P = 0.016) colonizing MSI than group 2. Failed MSI showed a significantly higher presence of Parvimonas micra (P = 0.008) in group 1 and Staphylococci (P = 0.008), Enterococci (P = 0.011), and Parvimonas micra (P <0.001) in group 2. CONCLUSIONS: Microbial colonization around MSI is established within 24 hours. Compared to gingival crevicular fluid, peri-mini implant crevicular fluid is colonized by a higher proportion of Staphylococci, facultative enteric commensals and anaerobic cocci. The failed miniscrews showed a higher proportion of Staphylococci, Enterobacter, and Parvimonas micra, suggesting their possible role in the stability of MSI. The bacterial profile of MSI varies with age.
