A Novel Analysis via Micro-CT Imaging Indicates That Chemically Modified Tetracycline-3 (CMT-3) Inhibits Tooth Relapse after Orthodontic Movement: A Pilot Experimental Study.

OBJECTIVE: To evaluate the effect of chemically modified tetracycline-3 (CMT-3) and simvastatin on tooth relapse after orthodontic movement in rats using a novel analysis method employing high-resolution micro-CT (Micro-CT) images. In addition, the correlation between bone density and orthodontic relapse was also evaluated for each experimental group. METHODS: Forty adult male Wistar rats had stainless steel springs installed on their left upper first molars in order to generate tooth movement for 18 days. After this initial period, the animals were divided into three groups: (1) 30 mg/kg of CMT-3; (2) 5 mg/kg of simvastatin; and (3) 0.5% carboxymethylcellulose, and each group was treated for 20 days. Micro-CT images were analyzed (conventional method and 3D reconstruction) on the 7th and 18th days following spring fixation and finally, 20 days after treatment either with CMT-3 or simvastatin (38th day). Bone mineral density (BMD) of the mesial and distal roots of the upper first molar was also analyzed. RESULTS: The difference was statistically significant between the groups as to recurrence (p=0.048), and the post hoc test identified the value of p=0.007 between the control group and the CMT-3 group. Simvastatin was not able to inhibit tooth relapse. The bone mineral densities of both the mesial and distal roots were different between the three groups, after the 20th day of drug use (p=0001 and p < 0001). CONCLUSION: Our findings support the initial evidence that CMT-3 is able to prevent relapse after tooth movement. Future trials in humans should evaluate such treatment as a promising approach to preventing this common phenomenon. CLINICAL RELEVANCE: Considering the results obtained, CMT-3 can be used to avoid relapse after tooth movement.

Oral lichen planus and malignant transformation: The role of p16, Ki-67, Bub-3 and SOX4 in assessing precancerous potential.

The association of oral lichen planus (OLP) lesions with malignant transformation risk has remained a controversial topic and is of clinical importance. Therefore, the present study evaluated the expression levels of p16, Ki-67, budding uninhibited by benzimidazoles 3 (Bub-3) and sex-determining region Y-related high mobility group box 4 (SOX4), and their roles as precancerous biomarkers in OLP. A retrospective study was performed, in which tissue blocks of OLP, oral dysplasia (OD), cutaneous lichen planus (CLP) and oral fibrous hyperplasia (OFH) were used (n=120). A positivity index (PI) for p16, BUB3, Ki-67 and SOX4 expression was calculated in each group. The PI for p16 was 20.65% for OLP, 7.85% for OD, 86.59% for CLP and 11.8% for OFH, and the difference between these groups was statistically significant (P<0.001). PIs of Ki-67 were indicated as 11.6% for OLP, 14.4% for OD, 8.24% for CLP and 5.5% for OFH, and a statistically significant difference was observed between the groups (P<0.001). Notably, the expression levels of BUB3 were not statistically different among groups. The highest expression levels of SOX4 were identified in CLP (P<0.001 vs. OLP/CLP; P=0,001 vs. CLP/OD). The determined expression levels of p16 and Ki-67 suggest that specific OLP lesions may have an intermediate malignant potential and should be carefully followed up. The intense SOX4 staining in CLP indicated a different proliferation pattern of epithelium compared with oral mucosa cells. These findings suggest that SOX4 expression may also be associated with the different clinical courses of OLP and CLP.

Two-stage surgical treatment of severe cherubism.

Cherubism is an autosomal-dominant syndrome characterized by excessive bilateral maxillomandibular bony degeneration followed by fibrous tissue hyperplasia. Eight patients (age, 6-15 years; mean, 11 years) with severe cherubism were treated with a 2-stage operation by the same senior surgeon (C.M.R.-A.) over an 18-year period, 1987 through 2005. Severity was based on a modified Motamedi classification system. The diagnosis was established clinically, radiographically, and histologically. Postoperative follow up ranged from 2 to 18 years (mean, 5.1 years). All patients underwent 2-stage surgical treatment. In the first stage, the anterior wall of the maxilla was osteotomized and removed (n = 5). The cherubic lesion was curetted from the maxilla and orbits. The maxilla was recontoured on the back table and then fixed orthotopically with wires. Alternatively, cortical bone windows were created, the maxillary and orbital lesions were curetted, and the maxilla was infractured and recontoured in situ with manual pressure (n = 3). Six months after the maxillary/orbital procedure, all patients underwent second-stage curettage and recontouring of the mandible using bony access windows and manual infracture. Satisfactory esthetic results were achieved in all patients. The patients remained clinically and radiographically disease-free throughout the follow-up period. The most profoundly affected patient sustained bilateral lower eyelid ectropion that resolved with full-thickness skin grafting. Although cherubism tends to abate by the fourth decade of life, early 2-stage surgical curettage provides a simple and reliable treatment that not only delivers immediate results, but also seems to arrest the growth of any remaining cherubic tissue.