Effects of casein phosphopeptide-amorphous calcium phosphate application after interproximal stripping on enamel surface: An in-vivo study.

INTRODUCTION: The aim of this study was to investigate the effects of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) application after interproximal stripping on enamel surface structures in vivo. METHODS: Fifteen patients with a mean age of 15.8 years participated in this study. For each patient, the extraction of 4 first premolars was part of the orthodontic treatment plan. The patients were randomly divided into 5 groups of 3 patients. With the exception of group 1, the mesial and distal surfaces of all first premolars were stripped with a stripping disc (Komet; Gebr Brasseler, Lemgo, Germany) under air cooling and then polished with Sof-Lex polishing discs (3M Dental Products, St Paul, Minn). In group 1, no stripping was performed, and the teeth were removed immediately. In group 2, the teeth were removed immediately after the stripping. In group 3, the stripped teeth were extracted after exposure to oral conditions for 3 months. In groups 4 and 5, CPP-ACP (Recaldent Tooth Mousse; GC Europe, Leuven, Belgium) or fluoride varnish (Bifluoride 12; Voco, Cuxhaven, Germany) was applied to the stripped surfaces for 3 months, respectively, before the teeth were extracted. Surface roughness and microhardness values were evaluated with 1-way analysis of variance and Tukey HSD tests. RESULTS: The CPP-ACP and the fluoride varnish applications increased the surface roughness and microhardness values that had been decreased by stripping. No statistically significant differences were found between groups 3, 4, and 5 for microhardness or between groups 4 and 5 for surface roughness (P > 0.5). CONCLUSIONS: The saliva and saliva plus remineralizing agents (fluoride varnish and CPP-ACP) increased the microhardness and surface roughness values of stripped enamel surfaces that had been decreased by stripping.

Effects of zygoma-gear appliance for unilateral maxillary molar distalization: A prospective clinical study.

INTRODUCTION: The aim of the study was to evaluate the dentoskeletal effects of the zygoma-gear appliance used for unilateral maxillary molar distalization in patients with Class II subdivision malocclusion. METHODS: This prospective clinical study consisted of 21 patients (9 boys, 12 girls; mean age, 15.68 ± 2.18 years) with unilateral Class II malocclusion treated using the unilateral zygoma-gear appliance supported by a zygomatic miniplate inserted on the Class II malocclusion side. The dentoskeletal effects of the system were evaluated using cephalometric lateral and panoramic films with a paired t test. RESULTS: The mean amount of distalization for the maxillary first molar was found to be 5.31 ± 2.46 mm (P <0.001) in 0.45 ± 0.12 years, showing an amount of 0.98 mm of distalization per month. It was also accompanied by a slight intrusion (0.76 ± 2.85 mm; P >0.05) and distal tipping (6.39° ± 5.39°; P <0.001) of the maxillary molars. The maxillary premolar also spontaneously moved distally 1.63 ± 1.90 mm (P <0.01) with distal tipping (4.05° ± 3.47°; P <0.001). Moreover, the inclination of the maxillary incisors and overjet were decreased (-1.59° ± 1.45°, P <0.001; and -0.29 ± 0.63 mm, P <0.05; respectively) showing no anchorage loss. No statistically significant changes were found for the skeletal and soft tissue measurements (P >0.05). CONCLUSIONS: The zygoma-gear appliance system is an effective method for unilateral maxillary molar distalization.

Mandibular changes during initial alignment with SmartClip self-ligating and conventional brackets: A single-center prospective randomized controlled clinical trial.

OBJECTIVE: To test the null hypothesis that SmartClip self-ligating brackets are more effective than conventional brackets for initial mandibular alignment and identify influential factors. METHODS: Fifty patients were randomly allocated to two equal treatment groups by using an online randomization program: self-ligating group (SmartClip brackets) and conventional group (Gemini brackets). The archwire sequence was standardized. Changes in anterior irregularity index, intercanine width, and intermolar width were assessed on plaster models at 8th and 16th weeks. Changes in incisor position and inclination were assessed on lateral cephalometric radiographs at 16 weeks. Intragroup and intergroup comparisons were performed with paired t-test and Student's t-test, respectively. Multiple linear regression was performed to identify variables affecting improvement in anterior ambiguity. RESULTS: Data of 46 patients were analyzed; those missing an appointment (n = 2) or showing bracket breakage (n = 2) were excluded. Incisor inclination (p < 0.05), intercanine width (p < 0.05), and intermolar width (p > 0.05) increased at 8 and 16 weeks in both the groups; no significant intergroup differences were noted (p > 0.05). Initial anterior irregularity index and intercanine width change were significantly associated with improvement in anterior irregularity (p < 0.001). CONCLUSIONS: The null hypothesis was rejected. Bracket type has little effect on improvement in anterior ambiguity during initial mandibular alignment.

Mesiodistal tooth dimensions and anterior and overall Bolton ratios evaluated by cone beam computed tomography.

AIM: The mesiodistal widths of the maxillary and mandibular teeth and anterior and overall tooth size ratios were measured by CBCT and conventional orthodontic plaster methods, compared, and correlation coefficients for both methods determined. MATERIAL AND METHODS: The records of 26 patients (14 males and 12 females) between the ages of 18 and 28 years were randomly selected from the archives of the Oral Diagnosis, Radiology and Orthodontic Departments at the Karadeniz Technical University. The mesiodistal diameters of the maxillary and mandibular permanent teeth from first molar to first molar were measured on the patient's plaster models and also on CBCT arch renditions. Anterior and overall Bolton ratios were calculated for each method. Comparisons were performed using Pearson's correlation coefficient (PCC). RESULTS: The measurements of the mesiodistal widths of most maxillary and mandibular teeth were similar and consistent between the conventional and CBCT methods. PCC values ranged from 0.637 (mandibular right second premolar) to 0.916 (maxillary right canine). PCC values for anterior and overall ratios were 0.756 and 0.781, respectively, indicating that correlations between conventional and CBCT methods were acceptable. CONCLUSION: Dental measurements and anterior and overall Bolton ratios calculated on CBCT showed acceptable PCC values indicating that CBCT measurements could be used instead of those obtained from conventional plaster models.

Unilateral maxillary molar distalization with zygoma-gear appliance.

The aim of this study was to present the orthodontic treatment of a 15-year-old boy with a unilateral maxillary molar distalization system, called the zygoma-gear appliance. It consisted of a zygomatic anchorage miniplate, an inner bow, and a Sentalloy closed coil spring (GAC International, Bohemia, NY). A distalizing force of 350 g was used during the distalization period. The unilateral Class II malocclusion was corrected in 5 months with the zygoma-gear appliance. The maxillary left first molar showed distalization of 4 mm with an inclination of 3°. The maxillary premolars moved distally with the help of the transseptal fibers. In addition, there were slight decreases in overjet (-0.5 mm) and maxillary incisor inclination (-1°), indicating no anchorage loss from the zygoma-gear appliance. Preadjusted fixed appliances (0.022 × 0.028-in, MBT system; 3M Unitek, Monrovia, Calif) were placed in both arches to achieve leveling and alignment. After 14 months of unilateral distalization with the zygoma-gear appliance and fixed appliances, Class I molar and canine relationships were established with satisfactory interdigitation of the posterior teeth. Acceptable overjet and overbite were also achieved. This article shows that this new system, the zygoma-gear appliance, can be used for unilateral maxillary molar distalization without anchorage loss.

Validity of demirjian and nolla methods for dental age estimation forNortheastern Turkish children aged 5-16 years old

Objective: To evaluate the applicability of Demirjian and Nolla methods for northeastern Turkish population. Material and Method: A retrospective study was performed on panoramic radiographs of 673 subjects aged 5-15.9 years. The mean dental age (DA) according to the Demirjian and Nolla methods were compared to the mean chronological age (CA).Results: The mean CA of the study sample was 10.37±2.90 and 10.03±2.81 years for females and males, respectively. Using the Demirjian method, the mean estimated DA was 11.26±3.02 years for females and 10.87±2.96 years for males. For Nolla method, the mean estimated DA was 9.80±3.41 and 9.53±3.14 years for females and males, respectively. The mean differences between the CA and DA according to the Demirjian and Nolla methods were 0.86 and -0.54 years for total study sample.Conclusion: Nolla method was found to be a more accurate method for estimating DA in northeastern Turkish population (AU)

Validity of demirjian and nolla methods for dental age estimation for Northeastern Turkish children aged 5-16 years old.

OBJECTIVE: To evaluate the applicability of Demirjian and Nolla methods for northeastern Turkish population. MATERIAL AND METHOD: A retrospective study was performed on panoramic radiographs of 673 subjects aged 5-15.9 years. The mean dental age (DA) according to the Demirjian and Nolla methods were compared to the mean chronological age (CA). RESULTS: The mean CA of the study sample was 10.37±2.90 and 10.03±2.81 years for females and males, respectively. Using the Demirjian method, the mean estimated DA was 11.26±3.02 years for females and 10.87±2.96 years for males. For Nolla method, the mean estimated DA was 9.80±3.41 and 9.53±3.14 years for females and males, respectively. The mean differences between the CA and DA according to the Demirjian and Nolla methods were 0.86 and -0.54 years for total study sample. CONCLUSION: Nolla method was found to be a more accurate method for estimating DA in northeastern Turkish population.

Reliability of four different computerized cephalometric analysis programs.

The aim of this investigation was to compare the traditional method of manual cephalometric tracing with four different computerized tracing programs, where the lateral cephalograms were scanned at 300 dpi and digitized onscreen. Thirty randomly selected cephalometric radiographs were used in this study. Four programs Dolphin Imaging, Vistadent, Nemoceph, and Quick Ceph were evaluated. Three dental, 11 skeletal, and 1 soft tissue parameters were measured that consisted of 5 linear and 10 angular measurements. Statistical analysis was carried out using multivariate analysis of variance and Box's and Levene's tests. No statistically significant difference was found between manual tracing and the computerized tracing programs. The measurements obtained with the cephalometric analysis programs used in the study were reliable.

Conventional frontal radiographs compared with frontal radiographs obtained from cone beam computed tomography.

AIM: To test the hypothesis that there is no difference between measurements performed on conventional frontal radiographs (FRs) and those performed on FRs obtained from cone beam computed tomography (CBCT) scans. MATERIALS AND METHODS: This study consisted of conventional FRs and CBCT-constructed FRs obtained from 30 young adult patients. Twenty-three landmarks were identified on both types of cephalometric radiographs. Twenty-one widely used cephalometric variables (14 linear distances, 4 angles, and 3 ratios) were calculated. Paired t-tests were performed to compare the means of corresponding measurements on two cephalometric radiographs of the same patient. RESULTS: Reproducibility of measurements ranged from 0.85 to 0.99 for CBCT-constructed FRs, and from 0.78 to 0.96 for conventional FRs. A statistically significant difference was observed between conventional FRs and CBCT-constructed FRs for all linear measurements (eurR-eurL, loR-loL, moR-moL, zygR-zygL, lapR-lapL, mxR-mxL, maR-maL, umR-umL, lmR-lmL, agR-agL, me-ans) (P < .05), except for the ans-cr measurement (P > .05). However, no statistically significant differences were noted between conventional FRs and CBCT-constructed FRs for ratios and angular measurements (P > .05). CONCLUSIONS: The hypothesis was rejected. A difference has been noted between measurements performed on conventional FRs and those performed on CBCT-constructed FRs, particularly in terms of linear measurements.

Effects of maxillary molar distalization with Zygoma-Gear Appliance.

OBJECTIVE: To evaluate the dentoalveolar, skeletal, and soft tissue effects of the Zygoma-Gear Appliance (ZGA) when used for bilateral distalization of the maxillary molars. MATERIALS AND METHODS: The study group included 15 patients (mean age, 15.87 ± 1.09 years; range: 14-18 years) treated with the ZGA system supported with zygomatic anchorage miniplates. The changes due to the distalization were evaluated from the lateral cephalometric films taken before and after distalization by means of a paired t-test. RESULTS: The mean treatment period required to achieve a Class I molar relationship was 5.21 months. The distalization amount of the maxillary molars was 4.37 ± 2.15 mm (P < .001), and, thus, the rate for the distal movement of the molars was 0.84 mm per month. Maxillary first molars showed a slight intrusion (0.50 mm) (P > .05), while distal tipping was only 3.30° ± 2.31° (P > .05). Furthermore, there was a decrease in overjet (-0.50 mm) (P > .05), indicating that there was no anchorage loss with use of the ZGA. CONCLUSIONS: Maxillary molar distalization without anchorage loss can be achieved in a short time with ZGA.

Patterns of third-molar agenesis and associated dental anomalies in an orthodontic population.

INTRODUCTION: The aim of this study was to investigate the frequency of dental anomalies in orthodontic patients with different patterns of third-molar agenesis, comparing them with patients without third-molar agenesis. METHODS: A sample of 374 patients with agenesis of at least 1 third molar was divided into 4 groups according to the third-molar agenesis pattern, and a control group of 98 patients without third-molar agenesis was randomly selected from the patient archives. Panoramic radiographs and cast models were used to determine the associated dental anomalies, such as hypodontia, hyperdontia, impaction, dilaceration, microdontia, ectopic eruption, transposition, and transmigration. The Pearson chi-square and Fisher exact tests were used to determine the differences in the distribution of the associated dental anomalies among the groups. RESULTS: The prevalence of agenesis of other teeth (11.2%, n = 42) was significantly greater in our study sample (groups 1-4) than in the control group (group 5) (4.1%, n = 4; P <0.05). When we compared the groups according to the various third-molar agenesis patterns, we found that agenesis of other teeth was more common in patients with agenesis of 3 and 4 third molars. In addition, the patients with agenesis of 4 third molars exhibited maxillary lateral-incisor microdontia more frequently. Another important finding was a higher prevalence of total dental anomalies in patients with agenesis of 3 and 4 third molars compared with the control group. CONCLUSIONS: Permanent tooth agenesis, microdontia of maxillary lateral incisors, and total dental anomalies are more frequently associated with agenesis of 4 third molars than with the presence of third molars.

Maxillary and mandibular mesiodistal tooth sizes among different malocclusions in a sample of the Turkish population.

The purpose of this study was to establish normative data for mesiodistal tooth crown dimensions with respect to malocclusions and gender differences in Turkish sample. The subjects were randomly selected and assigned to three malocclusion groups according to Angle's classification. Each group consisted of 100 individuals between the ages of 13 and 18 years with the following distribution: Class I, 42 males and 58 females; Class II, 52 males and 48 females; and Class III, 51 males and 49 females. An electronic digital calliper was used to measure the mesiodistal tooth width from the right second permanent molar to the left second permanent molar on both upper and lower study casts. For statistical evaluation, one- and two-way analyses of variance and post hoc Tukey's honestly significant difference (HSD) tests were performed. There were statistically significant differences for the maxillary canine (P < 0.001), first premolar (P < 0.05), second molar (P < 0.05), and mandibular canine (P < 0.01) for males, and for all maxillary teeth and the mandibular central (P < 0.05), canine (P < 0.001), and first premolar (P < 0.05) teeth in females among the malocclusion groups. When Angle's classification was evaluated, significant differences were determined, except for the first and second mandibular molars. All mesiodistal widths were also found to be statistically different according to gender dimorphism. A significant relationship was found between mesiodistal tooth size, Angle's classification, and gender. Therefore, tooth dimensions may play a crucial role in treatment planning and in achieving satisfactory interdigitation of the upper and lower dentition following the completion of orthodontic treatment.

Shear bond strength of orthodontic brackets to aged resin composite surfaces: effect of surface conditioning.

The aim of this study was to investigate the effects of surface conditioning protocols on the shear bond strength (SBS) of metal brackets to aged composite resin surfaces in vitro. Ninety composite resin discs, 6 mm in diameter and 2 mm in height, were prepared and treated with an ageing procedure. After ageing, the specimens were randomly assigned to one of the following groups: (1) control with no surface treatment, (2) 38 per cent phosphoric acid gel, (3) 9.6 per cent hydrofluoric acid gel, (4) airborne aluminium trioxide particle abrasion, (5) sodium bicarbonate particle abrasion, and (6) diamond bur. The metal brackets were bonded to composite surfaces by means of an orthodontic adhesive (Transbond XT). All specimens were stored in water for 1 week at 37°C and then thermocycled (1000 cycles, 5-55°C) prior to SBS testing. SBS values and residual adhesive on the composite surface were evaluated. Analysis of variance showed a significant difference (P = 0.000) between the groups. Group 6 had the highest mean SBS (10.61 MPa), followed by group 4 (10.29 MPa). The results of this study suggest that a clinically acceptable bond strength can be achieved by surface conditioning of aged resin composite via the application of hydrofluoric acid, aluminium trioxide particle abrasion, sodium bicarbonate particle abrasion, or a diamond bur.

Effects of thermocycling on the degree of cure of two lingual retainer composites.

The aim of this study was to evaluate the effects of thermocycling on the degree of cure (DC) and water sorption behavior of two lingual retainer composites. A total of 50 composite specimens, 5 mm diameter and 2 mm height, were prepared using Light Cure Retainer (LCR) (Reliance) and Transbond Lingual Retainer (TLR) (3M Unitek). After 40-second curing with a halogen light and after 24-hour water storage, the composite specimens were subjected to different thermocycling regimes. Absorbance peaks to monitor the DC were recorded using Fourier transform infrared (FTIR) spectroscopy, while water sorption was calculated in microg/mm(3). On DC, significant differences among the different thermocycling regimes were observed only for the TLR specimens (p<0.05). On water sorption behavior, an increase in the number of thermal cycles resulted in increased water sorption for both composites, but the statistical differences in these groups were not significant. On the effect of thermocycling up to 20,000 cycles, present findings showed that LCR was less affected than TLR. Further, LCR exhibited higher DC and lower water sorption values than TLR after thermal cycling.

Bond strength of ceramic brackets bonded to enamel with amorphous calcium phosphate-containing orthodontic composite.

The aim of this in vitro study was to compare the shear bond strength (SBS) and failure modes of a conventional resin-based composite with a recently developed amorphous calcium phosphate (ACP)-containing orthodontic composite system. Forty freshly extracted human maxillary premolar teeth were randomly divided into two equal groups. Conventional composite (group 1; Transbond-XT; 3M Unitek) and ACP-containing orthodontic composite (group 2; Aegis-Ortho; Harry J. Bosworth Co.) were used for bonding ceramic orthodontic brackets. The SBS of these brackets were measured and recorded in megapascals (MPa). Adhesive remnant index (ARI) scores were determined after bracket failure. Data were analysed with a Student's t-test for two independent variables and Pearson's chi-square tests. Statistical analysis showed that the bond strength of group 1 (mean: 36.7 +/- 6.8 MPa) was significantly higher than group 2 (mean: 24.2 +/- 5.4 MPa; P < 0.01). Although a greater percentage of the fractures were cohesive at the composite interface (Score 1 + Score 2 = 70 per cent in group 1 and 90 per cent in group 2), statistically significant differences were observed between the groups (P < 0.05). The ACP system is suitable for bonding ceramic orthodontic brackets due to the lower SBS values compared with conventional composite. The ACP-containing composite is recommended for use in clinical orthodontic practice in order to achieve lower decalcification scores under ceramic orthodontic brackets.

Reproducibility of airway dimensions and tongue and hyoid positions on lateral cephalograms.

INTRODUCTION: The aim of this study was to evaluate the reproducibility of airway dimensions and tongue and hyoid positions on lateral cephalometric radiographs. METHODS: Three lateral cephalograms each of 30 patients were obtained in natural head positions at 30-minute intervals. Twelve measurements, including pharyngeal airway dimensions and tongue and hyoid positions, were taken. The relationships between 3 sets of measurements were evaluated by using repeated analysis of variance, Dahlberg's method error formula, and correlation coefficient. RESULTS: No statistically significant differences were found between the 3 sets of measurements with the repeated analysis of variance (P > .05). Correlation coefficient values ranged between 0.964 (vertical position of the hyoid) and 0.683 (hypopharyngeal airway width). The average method error was 1.22 mm. CONCLUSIONS: The results suggest that airway dimension and tongue- and hyoid-position measurements are highly reproducible on natural-head-position cephalograms.