A three-dimensional comparison of a morphometric and conventional cephalometric midsagittal planes for craniofacial asymmetry

Morphometric methods are used in biology to study object symmetry in living organisms and to determine the true plane of symmetry. The aim of this study was to determine if there are clinical differences between three-dimensional (3D) cephalometric midsagittal planes used to describe craniofacial asymmetry and a true symmetry plane derived from a morphometric method based on visible facial features. The sample consisted of 14 dry skulls (9 symmetric and 5 asymmetric) with metallic markers which were imaged with cone-beam computed tomography. An error study and statistical analysis were performed to validate the morphometric method. The morphometric and conventional cephalometric planes were constructed and compared. The 3D cephalometric planes constructed as perpendiculars to the Frankfort horizontal plane resembled the morphometric plane the most in both the symmetric and asymmetric groups with mean differences of less than 1.00 mm for most variables. However, the standard deviations were often large and clinically significant for these variables. There were clinically relevant differences (>1.00 mm) between the different 3D cephalometric midsagittal planes and the true plane of symmetry determined by the visible facial features. The difference between 3D cephalometric midsagittal planes and the true plane of symmetry determined by the visible facial features were clinically relevant. Care has to be taken using cephalometric midsagittal planes for diagnosis and treatment planning of craniofacial asymmetry as they might differ from the true plane of symmetry as determined by morphometrics

Levels Of Interleukin-8 During Tooth Movement

A host-derived neutrophil-activating cytokine interleukin-8 (IL-8) is secreted mainly by monocytes and is considered to be important in regulating alveolar bone resorption during tooth movement. The aim of this study was to evaluate the levels of IL-8 during mechanical forces on periodontal tissues at different stages of orthodontic therapy. Ten canine teeth of patients having different Angle classifications were selected for the study. After the premolars were extracted, the maxillary/mandibular canines were tipped distally. Gingival crevicular fluid was sampled from mesial and distal gingival crevices of each canine separately at baseline and one hour, 24 hours, six days, 10 days, and 30 days after the application of the force. An enzyme-linked immunosorbent assay for quantitative detection of IL-8 was used. Although there was an increase in the concentration of IL-8 at tension (mesial) sites after one hour, 24 hours, six days, and 10 days, a decrease was observed at 30 days. Pressure (distal) sites did not demonstrate such an increase at any period except at 10 days. However, the concentration of IL-8 at both sites showed a similar decrease and approached each other at day 30. We concluded that local host response toward the orthodontic forces might lead an increase in IL-8 and neutrophil accumulation, and this may be one of the triggers for bone remodeling processes.Wo

Cytokines in crevicular fluid and orthodontic tooth movement

This review aimed to evaluate studies on cytokines in the gingival crevicular fluid (GCF) during orthodontic treatment, summarizing the regulation patterns of the most commonly studied cytokines and exploring their clinical implications. To achieve this, a number of key databases were searched using MESH terms and free text terms. An additional search was made by reference tracking. The procedures suggested by the QUOROM statement were followed. Data from the included studies were extracted into orthodontic mechanics, GCF sampling/handling methods, and cytokine measurements. From the 85 relevant studies identified, 23 studies could be included. Common drawbacks consisted mainly of inadequacies in the study design (e.g. short duration and small number of study subjects). The most consistent result was a peak of cytokine levels at 24 h. Associations existed between prostaglandin E-2 (PGE(2)) and interleukin-1 beta (IL-1 beta) and pain, velocity of tooth movement, and treatment mechanics. Interleukin-1 beta and PGE(2) showed different patterns of up-regulation, with IL-1 beta being more responsive to mechanical stress and PGE(2) more responsive to synergistic regulation of IL-1 beta and mechanical force. The results might be taken to support, at the cellular level, the use of light continuous forces for orthodontic treatment