No abstract

The aim of this study was to evaluate the preventive and/or reparative effects of low-level laser therapy (LLLT) on orthodontically induced inflammatory root resorption (OIIRR) in rats. Thirty rats were divided into four groups (short-term control (SC), short-term laser (SL), long-term control (LC), long-term laser (LL)). In all groups, the left first molar was moved mesially for 11 days. At the end of this period, the rats in groups SC and SL were killed in order to observe the resorption lacunas and to evaluate whether LLLT had any positive effect on root resorption. The groups LC and LL were remained for a healing period of 14 days in order to observe spontaneous repair of the resorption areas and investigate whether LLLT had reparative effects on root resorption. A Ga-Al-As diode laser (Doris, CTL-1106MX, Warsaw, Poland) with a wavelength of 820 nm was used. In SL group, the first molars were irradiated with the dose of 4.8 J/cm2 (50 mW, 12 s, 0.6 J) on every other day during force application. In LL group, the irradiation period was started on the day of appliance removal and the first molars were irradiated with the dose of 4.8 J/cm2 on every other day for the next 14 days. LLLT significantly increased the number of osteoblasts and fibroblasts, and inflammatory response in SL group in comparison with SC group (P = .001). The amount of resorption did not represent any difference between the two groups (P = .16). In LL group, LLLT significantly increased the number of fibroblasts and decreased the amount of resorption in comparison with LC group (P = .001; P = .02). Both parameters indicating the reparative and the resorptive processes were found to be increased by LLLT applied during orthodontic force load. LLLT applied after termination of the orthodontic force significantly alleyed resorption and enhanced/accelerated the healing of OIIRR. LLLT has significant reparative effects on OIIRR while it is not possible to say that it definitely has a preventive effect.

Good correlation was found between the degrees of TMM, fusion of SOS and CVM in young Turkish population.

The aim of this study was to investigate the effect that dosage has on the efficiency of low-level laser therapy (LLLT) in bone formation in a rat study model. Twenty-eight rats were divided into four groups as only expansion (OE), expansion + low dose (0.15 J) (LD), expansion + medium dose (0.65 J) (MD), and expansion + high dose (198 J) (HD) laser therapy groups. The midpalatal suture was expanded during 5 days. Afterwards, irradiations were started and performed with an 820 nm, continuous wave, Ga-Al-As diode laser (Doris, CTL-1106MX, Warsaw, Poland). At the end of experiment, the premaxillae of the animals were dissected. The sections were transferred into PC environment and analyzed by using Image Analysis program. Number of osteoblasts, osteoclasts, fibroblasts, vessels, transforming growth factor beta (TGF-β) expression, and new bone formation were evaluated with this program. Amount of expansion did not show any difference among the groups. All parameters except the number of osteoclasts were increased in all lased groups while that parameter was significantly decreased. Vessels, TGF-β expression, and new bone formation were mostly increased in LD group followed by HD group. Among the lased groups, a significant difference was observed only for the amount of new bone formation, which was between the LD and the MD groups. On the other hand, the difference in this parameter was insignificant between OE and MD groups. Low-level laser therapy with both 5 and 6,300 J/cm(2) doses was found to be significantly effective, while the 20 J/cm(2) dose did not show a significant effect in increasing new bone formation. This finding reveals that the efficiency of the therapy is affected by the dosage.

No abstract

In the literature, some studies show a relation between tooth agenesis and craniofacial morphology, whereas other authors conclude that dental agenesis exerts little influence on dent facial structures. The objective of this study was to determine the existence of any relation between bilateral agenesis of the maxillary and/or mandibular third molars and the anteroposterior dimensions and vertical growth pattern of the jaws. Subjects and Methods: Sixty-eight subjects between the ages of 13 and 17 years with bilateral agenesis of maxillary third molars (group I, n=37), bilateral agenesis of the mandibular third molars (group II, n=19), and agenesis of all third molars (group III, n=12) as well as 33 subjects without third molar agenesis (group IV) were selected from the radiology archive. A before and after treatment orthopantomograph and the pretreatment cephalometric radiograph of the subjects were used. Several angular and linear parameters representing the anteroposterior dimensions and vertical growth pattern of the jaws were measured on cephalometric radiographs. The data were analyzed by Kolmogorov-Smirnov test, analysis of variance for 1 factor, and independent-samples t test. Statistical significance was set at p,0.05. Results: When the agenesis groups (groups I, II, and III) were compared with the control group, it was found that all parameters representing the anteroposterior dimensions of both jaws (A-Ptm, CoA, ANS-PNS, CoB, CoGn, CoPog, and ABRB) were significantly smaller in all agenesis groups (p,0.05). The parameters reflecting the vertical growth pattern did not represent any difference among the groups (p.0.05). Conclusion: In subjects with bilateral or total third molar agenesis, the anteroposterior dimensions of both jaws were smaller in comparison with subjects without tooth agenesis. Vertical growth pattern of the jaws did not differ among the groups.

The aim of this study was to evaluate the effect of the Er:YAG laser and acidulated phosphate fluoride application on enamel solubility around orthodontic brackets via atomic absorption spectrometry. Materials and Methods: Twenty freshly extracted upper premolar teeth were divided into 2 halves. Each half was covered with a nail varnish, excluding 1 mm (width) of space around each side of the bracket base. Orthodontic brackets were bonded in the center of the isolated area. Four groups were generated. The first group was the control group, and no treatment was performed. In group II (F), only fluoride was applied. Groups III and IV were laser and fluoride combination groups. In Group III (LF), fluoride was applied to the laser-irradiated surface, whereas laser irradiation was performed on the fluoridated enamel surface in Group IV (FL group). Afterwards, samples were demineralized in an acidic solution for 96 hours, and calcium assessment was performed using atomic absorption spectrometry. Comparisons of the calcium ion release values of the groups were performed with Kruskal-Wallis and Tukey honestly significant difference post hoc tests. The statistical significance level was set at p , 0.05. Results: The least amount of calcium release was observed in the LF group (median, 112.7 ppm), while the parameter of the control group was the highest (median, 217.9 ppm). The differences between the control and F groups, control and LF groups, and LF and FL groups were statistically significant. No difference was recorded between the control and FL groups. Conclusion: Laser treatment followed by topical application of acidulated phosphate fluoride gel resulted in the lowest calcium dissolution from the enamel surface.

Objective: The literature indicates a correlation between vertebral morphologic anomalies and some orthodontic malocclusions. The aim of this study was to examine the occurrence of the types of cervical vertebral anomalies (CVAs) in subjects with transverse maxillary deficiency (TMD) and to compare this with the occurrence of CVA in a control group without TMD. Materials and Method: A sample of 47 Turkish patients (17 boys, 30 girls) with TMD and another sample of 47 Turkish patients (15 boys, 32 girls) with adequate maxillary transversal dimensions was studied. A visual assessment of the cervical column was made using lateral cephalometric films. Characteristics of the cervical column were classified according to Sandham as fusions and posterior arch deficiencies of C1 (PADs). Clinically normal appearance was determined when the first 4 vertebrae could be traced as separate entities with all anatomic components present. Differences in occurrence of CVA between the groups and between genders were assessed by v 2 independence test. Results: In the TMD group, 10,6% of the subjects had fusion in the cervical column, and 14,9% had PAD. In the control group, 17% of the subjects had fusion of the cervical column, and 8,5% had PAD. The occurrence of PAD was significantly increased in the TMD group (p,0.05), while no significant difference was found between the groups for occurrence of fusion (p.0.05). No statistically significant gender differences were found in the occurrence of CVA in the TMD group and the control group (p.0.05). Conclusion: No difference was found in the occurrence of fusion between the subjects with TMD and the subjects without TMD, and the occurrence of PAD was significantly increased in subjects with TMD. (Turkish J Orthod. 2015;27:136-142)