ABSTRACT
AIM: The aim of the study was to find a relationship between anatomic porion (PoA) and machine porion (PoM) and to construct PoA with the help of machine porion. METHODOLOGY: About 200 pretreatment lateral roentgenic cephalograms were used for the study. Perpendicular distances of PoA and PoM were measured from Sella-Nasion (SN) plane and SN perpendicular plane. The results were tabulated. With the help of statistical analysis, predictive equation was derived to construct PoA and PoM. p-value was set at p < 0.05. RESULTS: Anatomic porion distance from SN was 24.35 ± 3.96 and from SN perpendicular was 12.89 ± 4.56. Distance of PoM from SN was 22.46 ± 4.20 and from SN perpendicular was 16.76 ± 4.89. Sexual dimorphism was also seen. CONCLUSION: There is a relationship between the PoM and PoA, thus, PoA, which is more reliable, can be constructed with the help of PoM, which is easy to reproduce. CLINICAL SIGNIFICANCE: To overcome the inherent limitations of PoA and PoM, the present study aimed to find a relationship between the two so as to easily construct PoA that is more reliable while taking advantage of the ease of reproducibility of PoM.
Subject(s)
Imaging, Three-Dimensional , Cephalometry/methods , Reproducibility of Results , Radiography , Imaging, Three-Dimensional/methodsABSTRACT
AIMS AND OBJECTIVES: To derive a new horizontal plane which can be a suitable alternative to Frankfurt horizontal plane (FH plane). MATERIALS AND METHODS: 200 pre-treatment lateral roentogenic cephalograms from patient records in the department of orthodontics and dentofacial orthopaedics were traced. The landmarks were identified and marked and the measurements were carried out. Patients with all skeletal relationships were included in the study. The angle formed between the lines connecting anatomic porion, orbitale and machine porion was measured and tabulated. Dimorphism between the genders if any was also evaluated. RESULTS: The mean angulation between the planes from the anatomic porion to orbitale to machine porion (PoA-Or-PoM) in our sample is 3.14 ± 2.17°. PoA to Or to PoM angulation for males is 2.57° and for females is 3.4°. CONCLUSIONS: SIDS plane also called as derived FH plane given here is a reliable and easily reproducible alternative to the FH plane.
ABSTRACT
BACKGROUND: Fixed orthodontic appliances can release metal ions such as nickel, chromium, and zinc into saliva and blood, which can cause contact dermatitis, hypersensitivity, and cytotoxicity. This study was undertaken to assess the release of nickel, chromium, and zinc in saliva and serum of patients undergoing fixed orthodontic treatment. MATERIALS AND METHODS: This in vivo study was conducted on 80 participants with an age range of 15-40 years. Thirty were included as controls and 50 participants were treated with fixed orthodontic appliances. Saliva and blood samples were collected at five different periods, before insertion of fixed orthodontic appliance and at 1 week, 3 months, 1 year, and 1.5 years after insertion of appliance, respectively. The metal ion content in the samples were analyzed by atomic absorption spectrophotometry. Mean levels of nickel, chromium, and zinc in saliva and serum were compared between groups using independent sample t-test and before and after results using paired t-test. P < 0.05 was considered as statistically significant. RESULTS: At the end of 1.5 years, the mean salivary levels of nickel, chromium, and zinc in controls were 5.02 ppb, 1.27 ppb, and 10.24 ppb, respectively, as compared to 67 ppb, 30.8 ppb, and 164.7 ppb at the end of 1.5 years. This was statistically significant with P < 0.001. A significant increase in the metal ion levels were seen in participants with before and after insertion of appliance (P < 0.001). CONCLUSION: Orthodontic appliances do release considerable amounts of metal ions such as nickel, chromium, and zinc in saliva and serum. However, it was within permissible levels and did not reach toxic levels.
