ABSTRACT
This study uses a cross-sectional design to examine the endothelial and inducible nitric oxide synthase (eNOS and iNOS, respectively) levels of gingival tissue. Fifteen subjects, 10 female and 5 male individuals (aged 14.6-21.2 years; mean 17.4 +/- 1.8 years), who needed extraction of the four first premolars for orthodontic reasons and who had indications for a gingivectomy were enrolled in the study. In each patient, two maxillary/mandibular premolars were extracted, and two months later an orthodontic appliance was placed in the same arch. A canine undergoing treatment for distal movement served as the test tooth (TT), whereas its contralateral canine was used as the control tooth (CT). The CT was included in the orthodontic appliance but was not subjected to the orthodontic force. Two weeks after the orthodontic appliance placement, clinical data consisting of the presence of supragingival plaque, bleeding on probing, and probing depth were collected from each experimental tooth. Immediately after, gingival tissue was collected from the distal aspect of each TT and CT for immunohistochemistry, messenger RNA reverse transcription by polymerase chain reaction, and Western blot analysis for both eNOS and iNOS. The results showed that no differences in clinical conditions occurred between the experimental teeth. On the contrary, both the eNOS and iNOS levels and the expression of the TTs were significantly greater than those of the CTs (all comparisons significant to P < .01). Our results indicate a role for gingival eNOS and iNOS during the early phases of orthodontic treatment in humans.
Subject(s)
Gingiva/enzymology , Nitric Oxide Synthase/analysis , Tooth Movement Techniques/methods , Adolescent , Adult , Bicuspid/surgery , Blotting, Western , Cross-Sectional Studies , Cuspid/pathology , Dental Plaque/enzymology , Female , Gingival Hemorrhage/enzymology , Gingivectomy , Humans , Image Processing, Computer-Assisted , Immunohistochemistry , Male , Nitric Oxide Synthase Type II , Nitric Oxide Synthase Type III , Periodontal Pocket/enzymology , RNA, Messenger/analysis , Reverse Transcriptase Polymerase Chain Reaction , Serial Extraction , Tooth Movement Techniques/instrumentationABSTRACT
Several published studies show a relationship between craniofacial morphology and head posture. The aim of this study was to evaluate the association between cervical lordosis angle and mandibular length from lateral skull radiographs, and to investigate the relationship between mandibular retrusion and cervical lordosis angle decreasing. The sample comprised 70 Caucasian adult women, average 27.4, in skeletal class II and Angle class II. Lateral skull radiographs were obtained in natural head position (mirror position). Ten morphological variables were individuated on tracings. In order to assess errors due to landmark identification, double measurements were made in ten randomly selected radiographs and were compared with Dahlberg's formula. A Sperman's rank correlation test showed a negative correlation (P < 0.01) between cervical lordosis and mandibular length (compensatory curvature of the cervical spine) and positive correlation between anterior cranial base and maxillary length (P < 0.05). Based upon the cross-sectional method, no conclusion was possible about the mechanism concerning these results. Future longitudinal studies in growing patients should be directed to understanding the extent of environmental and genotype influences on cervical lordosis angle.
