Relationship between palatally impacted canines and dimensions and morphology of sella turcica: A cone-beam computed tomography study.

INTRODUCTION: This study aimed to analyze the association of unilateral and bilateral palatal canine impaction with the dimensions and morphology of sella turcica from 3-dimensional cone-beam computed tomography (CBCT) images. METHODS: CBCT images of patients with bilateral (BPI) (n = 12; 9 female 3 male; 20.75 ± 5.88 years) and unilateral (UPI) (n = 35; 22 female 13 male; 19.28 ± 5.57 years) palatally impacted canines were compared with a control group (n = 56; 34 female 22 male; 20.82 ± 4.88 years). Linear measurements regarding sella turcica were made, and its morphologic variations were categorized. Two group comparisons were made with the Student t test or Mann-Whitney U-test, whereas one-way analysis of variance or Kruskal-Wallis tests were used for multiple group comparisons. Categorical variables were compared using the chi-square or Fisher exact test as appropriate. The binary logistic regression analyses and correlations using Spearman or Pearson correlation analyses were used to determine associations between variables (P <0.05). RESULTS: Sella diameter was significantly smaller in the BPI group compared to UPI and control groups. There was a significant association between sella diameter and BPI when compared with the control group (χ2[1] = 9.150; P = 0.008). There were no significant differences between groups in the distribution of sella turcica morphology. CONCLUSIONS: Despite the similar genetic origin of the sella turcica region and teeth, the association of palatal canine impaction with dimensions and morphology of sella turcica was weak. Both local and genetic factors might contribute to the ectopic position of the canine.

Effects of Tooth Brushing and MouthWashing on Leaching Bisphenol A Levels From an Orthodontic Adhesive: An In Vitro Study.

OBJECTIVE: To assess the levels of bisphenol A (BPA) released from an orthodontic adhesive with respect to the effects of tooth brushing and mouth washing. METHODS: Three groups, each containing fifteen adhesive samples were prepared. In Group 1, samples were polymerized according to manufacturer instructions. In Group 2, after the same polymerization protocol, each sample was brushed with a fluoride-containing toothpaste. For Group 3, samples were immersed in a mouth washing solution after polymerization. Later, all samples were placed into glass tubes containing 5 mL distilled water. High-performance liquid chromatography (HPLC) measurements were performed to assess the leaching amount of BPA. Intergroup comparison was performed by one way ANOVA test. RESULTS: Mean amounts of BPA were found to be 0.2674 µg/L, 0.2692 µg/L, and 0.2705 µg/L, respectively. Only a significant difference was found between Group 1 and 3 (P < .01), revealing higher BPA levels with the mouth washing solution. CONCLUSION: Measurable amounts of BPA release were observed in all groups of orthodontic adhesive samples, but the detected amounts were below the toxic levels. From a clinical point of view, alcohol-containing mouth washing solutions might increase the amount of leaching monomer, since alcohol is solvent of BPA.

Maxillary posterior intrusion with corticotomy-assisted approaches with zygomatic anchorage-a finite element stress analysis.

BACKGROUND: Anterior open bite is one of the most difficult malocclusions to treat and maintain in orthodontics. An effective treatment approach to correct anterior open bite is the intrusion of maxillary posterior teeth. The aim of this study was to evaluate the effects of corticotomy-assisted posterior maxillary intrusion with zygomatic anchorage by using finite element stress analysis. METHODS: An acrylic bite block on the posterior teeth including two transpalatal arches were modeled and 1.96 N intrusive force was loaded. Three scenarios were set, first with no subapical corticotomy, second with buccal, and third with both buccal and palatal corticotomies. The stress distributions along the cortical, cancellous bone surfaces, and dental structures were assessed by finite element stress analysis. RESULTS: Stress distributions over cortical and cancellous bones were commonly located at the inferior curvature of the zygomatic buttress area and posterior teeth for all scenarios. Stress values above the apices of anchor teeth were decreased for both corticotomy scenarios. Increased stress distributions were observed in cancellous bone around corticotomy regions. Despite the acrylic appliance and transpalatal arches, the stresses along the posterior teeth were not uniform. The apical third of the first molar mesiobuccal apex showed the highest stress values in all scenarios. CONCLUSIONS: Corticotomy-assistance effected biomechanical responses of dentoalveolar structures during maxillary posterior intrusion. There was no apparent difference for the stress levels of the root apices between corticotomy scenarios, pointing out that only buccal corticotomy may be a better option in corticotomy-assisted maxillary intrusion.

Cephalometric assessment of soft tissue morphology of patients with acromegaly.

AIM: To assess the sagittal soft tissue morphology of patients with acromegaly in comparison with a healthy control group. METHODS: Twenty-seven patients with acromegaly (11 male, 16 female; mean age 47.3 ± 11.5 years) and 30 healthy subjects (15 male, 15 female; mean age 42.2 ± 17.4 years) were included in the study. Linear and angular measurements were made on lateral cephalograms to evaluate soft tissue and skeletal characteristics. The intergroup comparisons were analysed with the Student's t-test. RESULTS: Facial convexity (p < 0.01) and the nasolabial angle (p < 0.001) were reduced in patients with acromegaly, whereas nose prominence (p < 0.01), upper lip sulcus depth (p < 0.01), upper lip thickness (p < 0.01), basic upper lip thickness (p < 0.01), lower lip protrusion (p < 0.05), mentolabial sulcus depth (p < 0.05) and soft tissue chin thickness (p < 0.001) were increased. Anterior cranial base length (p < 0.05), the supraorbital ridge (p < 0.01), the length of the maxilla and mandible (p < 0.001, p < 0.01, respectively) were significantly increased, and mandibular prognathism was an acromegalic feature (p < 0.05). CONCLUSION: Acromegalic coarsening and thickening of the craniofacial soft tissues was identified from lateral cephalograms, which may therefore contribute to early diagnosis when evaluated together with other changes caused by the disease.

Changes in airway dimensions and hyoid bone position following class II correction with forsus fatigue resistant device.

OBJECTIVE: The objective of this study was to investigate the effects of fixed functional therapy on oropharyngeal airway dimensions and hyoid bone positions in Class II patients and make comparison with an untreated Class II group. MATERIALS AND METHODS: Eighteen patients (8 girls, 10 boys; mean age 13.62 ± 1.92 years) who were treated with Forsus Fatique Resistant Device (FFRD) and 19 patients (11 girls, 8 boys; mean age 12.74 ± 0.91 years) who served as control were enrolled. Cephalograms were used to assess linear, angular, and area measurements. Intragroup comparisons were made by paired t and Wilcoxon tests and intergroup comparisons were performed by independent t test. RESULTS: With respect to controls, FFRD group showed increased airway dimensions at soft palate (P < 0.05) and more forward positioning of the hyoid bone (P < 0.05). Dentoalveolar changes exhibited mesial movement of lower incisors and molars and reduction in overjet (P < 0.001) in FFRD group. CONCLUSIONS: Positive effects in oropharyngeal airway dimensions and increased values of hyoid bone displacement to a more forward position were found after fixed functional therapy. CLINICAL RELEVANCE: Treatment with fixed functional appliances is mostly based on mesial movement of mandibular dentition, which might influence changes in tongue posture. The present results might indicate that oropharyngeal airway dimensions may be affected by postural changes of the hyoid bone in consequence of dentoalveolar changes. Clinically, these may be considered especially in Class II cases with reduced airway dimensions.

Effects of reverse headgear on pharyngeal airway in patients with different vertical craniofacial features.

The aim of this study was to investigate the effects of reverse headgear (RH) on pharyngeal airway morphology in two groups of Class III patients with different vertical craniofacial features in comparison with an untreated Class III group. Seventeen subjects (9 males, 8 females; mean age 11.3 ± 0.98 years) with optimum vertical growth and 17 subjects (10 males, 7 females, mean age 11.5 ± 1.1 years) with a vertical growth pattern treated with a removable intra-oral appliance and a Delaire type facemask were included. An untreated Class III control group of 11 subjects (8 males, 3 females, mean age 9.1 ± 1.1 years) was included to compare the treated groups. The paired t-test for intragroup and one-way ANOVA for intergroup comparisons were performed. The relationships between changes in the craniofacial morphology and airway were assessed by Spearman correlation analysis. The airway dimensions at the adenoid side and soft palate were increased in the treatment groups compared to the control group (p < 0.05). The nasopharyngeal area demonstrated a significant difference in normodivergent and control subjects (p < 0.05). No significant difference was found in the airway morphology due to different vertical features. The effect of RH treatment on the sagittal airway dimensions revealed no significant difference between different vertical craniofacial features in the short term.

Craniofacial and pharyngeal airway morphology in patients with acromegaly.

OBJECTIVE: The aim of this study was to assess differences in craniofacial characteristics, upper spine and pharyngeal airway morphology in patients with acromegaly compared with healthy individuals. MATERIALS AND METHODS: Twenty-one patients with acromegaly were compared with 22 controls by linear and angular measurements on cephalograms. The differences between the mean values of cephalometric parameters were analyzed with Mann-Whitney U-test. RESULTS: With respect to controls, anterior (p<0.05), middle (p<0.01) and posterior (p<0.05) cranial base lengths were increased, sella turcica was enlarged (p<0.001) and upper spine morphology demonstrated differences in the height of atlas (p<0.01) and axis (p<0.05) in patients with acromegaly. Craniofacial changes were predominantly found in the frontal bone (p<0.01) and the mandible (p<0.05). As for the airway, patients with acromegaly exhibited diminished dimensions at nasal (p<0.001), uvular (p<0.01), mandibular (p<0.01) pharyngeal levels and at the narrowest point of the pharyngeal airway space (p<0.001) compared to healthy controls. Soft palate width was significantly higher (p<0.001) and the hyoid bone was more vertically positioned (p<0.01) in patients with acromegaly. CONCLUSIONS: Current results point to the importance of the reduced airway dimensions and that dentists and/or orthodontists should be aware of the cranial or dental abnormalities in patients with acromegaly.

Effects of reverse headgear on pharyngeal airway in patients with different vertical craniofacial features

The aim of this study was to investigate the effects of reverse headgear (RH) on pharyngeal airway morphology in two groups of Class III patients with different vertical craniofacial features in comparison with an untreated Class III group. Seventeen subjects (9 males, 8 females; mean age 11.3 ± 0.98 years) with optimum vertical growth and 17 subjects (10 males, 7 females, mean age 11.5 ± 1.1 years) with a vertical growth pattern treated with a removable intra-oral appliance and a Delaire type facemask were included. An untreated Class III control group of 11 subjects (8 males, 3 females, mean age 9.1 ± 1.1 years) was included to compare the treated groups. The paired t-test for intragroup and one-way ANOVA for intergroup comparisons were performed. The relationships between changes in the craniofacial morphology and airway were assessed by Spearman correlation analysis. The airway dimensions at the adenoid side and soft palate were increased in the treatment groups compared to the control group (p < 0.05). The nasopharyngeal area demonstrated a significant difference in normodivergent and control subjects (p < 0.05). No significant difference was found in the airway morphology due to different vertical features. The effect of RH treatment on the sagittal airway dimensions revealed no significant difference between different vertical craniofacial features in the short term.

Evaluation of airway dimensions and changes in hyoid bone position following class II functional therapy with activator.

AIM: The aim of this study was to evaluate the long-term effects of Class 2 functional treatment on airway dimensions and positional changes in hyoid bone and compare it with that of an untreated Class 2 control group. METHODS: Lateral cephalograms of 16 patients (eight girls, eight boys, mean chronological age = 11.36 ± 0.77 years) who were treated with activator and 19 patients (11 girls, eight boys, mean chronological age = 12.14 ± 0.65 years) who served as control were used for linear, angular and area measurements regarding airway track and hyoid bone. Statistics. Intra-group comparisons were performed by paired t-test and Wilcoxon test, whereas independent t-test and Mann Whitney-U were used for inter-group comparisons. RESULTS: During treatment (T2-T1), nasopharyngeal height and nasopharyngeal area increased (p < 0.05) and hyoid bone moved downward (H-SN; p < 0.001) and forward (H-C3; p < 0.01). During retention period (T3-T2); nasopharyngeal (p < 0.01) and oropharyngeal area increased (p < 0.05). H-SN (p < 0.01) and C3-H distances (p < 0.05) increased. Hyoid bone position exhibited significant changes (H-SN, p < 0.001; C3-H, p < 0.01). The increases in C3-H in long-term was more in the activator group than control (p < 0.05). CONCLUSIONS: In growing Class 2 patients with mandibular deficiency and airway track without obstructions, functional appliance treatment provided favorable effects on nasopharyngeal and oropharyngeal area throughout the retention period.

The effect of drill-free and drilling methods on the stability of mini-implants under early orthodontic loading in adolescent patients.

The aim of this study was to compare the stability of mini-implants using drill-free and drilling methods, both before and after early force loading. Sixty-two adolescent patients (24 males and 38 females, mean age 15.7 ± 4.2 years) were randomly assigned to three groups and 112 titanium mini-implants were placed between the upper first molars and second premolars to achieve molar distalization. Groups I (n = 22) and II (n = 20) received pilot drilling with diameters of 1.1 and 0.9 mm, respectively, while the drill-free method was used in group III (n = 20). Distalization forces of up to 200 g were applied with nickel-titanium (NiTi) open coil springs. The Z-test was used for statistical analyses to compare the success rates of the groups with each other. The overall success rate was 77.7 per cent. There was no significant difference between groups I and II either before or after loading. Significant differences were found between groups I and III (P = 0.0002) and between groups II and III (P = 0.045) both before and after loading. Mini-implants using the drill-free method provided the highest success rate before orthodontic force application and also maintained their stability after early loading for 1 month during orthodontic treatment. Smaller drill diameters can contribute to clinical stability of mini-implants in the short-term, however long-term evaluations are needed to clarify the stability of temporary skeletal anchorage devices throughout orthodontic loading.

Tensile bond strength of lingual orthodontic brackets with adhesive systems.

AIM: To study in vitro the bond strength of three adhesive systems on lingual brackets. METHODS: Forty-five extracted human mandibular premolars were randomly divided into three groups of 15 specimens each. All brackets (Stealth lingual brackets) were bonded with Transbond XT Light Cure Adhesive. In group 1, the conventional primer was used; in group 2, Transbond Moisture Insensitive Primer was employed; and in group 3, an antimicrobial self-etching primer (Clearfil Protect Bond) was used. RESULTS: The highest mean bond strength values were observed when Clearfil Protect Bond (13.54 ± 0.58 MPa) was used and the lowest after applying the conventional Transbond XT primer (6.41 ± 0.43 MPa). The mean bond strength in group 2 was 8.20 ± 0.50 MPa, which was significantly higher than that of group 1. CONCLUSION: Besides its antimicrobial effect, Clearfil Protect Bond results in high bond strength values. Therefore, this product might be preferable when bonding lingual brackets.

Effects of maxillary protraction and fixed appliance therapy on the pharyngeal airway.

OBJECTIVE: To evaluate the long-term outcome of treatment with reverse headgear in patients with skeletal Class III malocclusion diagnosed as maxillary deficient. MATERIALS AND METHODS: Twenty-five patients (11 girls, 14 boys; mean age, 11.32 years) treated with a reverse headgear appliance were included in this study. Pretreatment, posttreatment, and 4-year follow-up cephalometric radiographs were obtained; linear, angular, and area measurements were performed. Comparison of treatment and observation changes was performed using a paired t-test. RESULTS: A significant increase was found in the forward movement of the maxilla, which was maintained 4 years after reverse headgear treatment. Treatment changes revealed significant increases in the sagittal dimensions and area of nasopharyngeal airway and remained significant at the end of the 4-year follow-up period. The oropharyngeal airway area increased nonsignificantly after the treatment, but significant increases occurred during the follow-up period. CONCLUSIONS: In young individuals diagnosed with maxillary deficiency treated with reverse headgear, the nasopharyngeal airway dimensions were improved after the treatment, and favorable effects of the treatment remained over the posttreatment period of 4 years.

Effect of fluoride-releasing light-cured resin on shear bond strength of orthodontic brackets.

INTRODUCTION: The aim of this study was to analyze the effect of an enamel-protective resin on the shear bond strength (SBS) of orthodontic brackets bonded with self-etching primer. METHODS: Eighty extracted premolars were randomly divided into 4 groups of 20, and metal brackets were bonded. Group 1 specimens were bonded with Transbond Plus self-etching primer (3M Unitek, Monrovia, Calif) and no fluoride resin; in group 2, a fluoride-releasing resin (Ortho-Coat, Pulpdent, Watertown, Mass) was used with the Transbond Plus self-etching primer; group 3 teeth were bonded with a new antimicrobial self-etching primer (Clearfil Protect Bond, Kuraray Medical, Osaka, Japan) with no fluoride resin; and the same protocol was used in group 4 with an application of Ortho-Coat. A universal testing machine was used to determine the SBS, and the adhesive remaining after debonding was assessed. RESULTS: There was no difference in SBS whether fluoride-releasing resin was used. Groups 3 and 4 had higher SBS values than the other groups (P <0.001). The Kruskal-Wallis test showed no significant differences in the adhesive remnant index (chi-square = 0.019, P = 0.990). CONCLUSIONS: The application of enamel-protective resin did not affect the bond strength of orthodontic brackets to enamel with self-etching primer systems.

Osteotomy assisted maxillary posterior impaction with miniplate anchorage.

This case report presents orthodontic treatment with miniplate anchorage accelerated by osteotomy-assisted maxillary posterior impaction in a severe open bite case. A 14-year-old girl with a severe anterior open bite was treated by intrusion of the maxillary posterior teeth. A segmental osteotomy was applied, and the miniplates were fixed to the zygomatic buttress area. The intrusive force was applied with nickel-titanium closed coil springs using a force of 250 g between the miniplates and the upper first and second molar buccal tubes. The intrusion was completed 2.5 months after osteotomy. The treatment was continued with the fixed orthodontic appliances and completed after 12 months. At the end of treatment, optimal occlusion and the correction of the anterior open bite were achieved. The maxillary molars were impacted 4.0 mm, and the mandibular plane showed a counterclockwise autorotation of 3.0 degrees . The results showed that osteotomy-facilitated orthodontic treatment clearly reduced the treatment time and had no adverse effects. In conclusion, this one-stage osteotomy technique can be an effective option to help molar intrusion in severe open bite cases.

Effects of a magnetic appliance in functional Class III patients.

The aim of this study was to determine the effects of a magnetic appliance in functional Class III patients. Standardized lateral head cephalograms and hand-wrist films of 10 subjects (mean age nine years seven months) were taken. These records were repeated after a period of one year, and the serial films were compared to determine the direction of facial growth as the control group. After this observation period, the magnetic appliance was placed in the 10 patients for approximately 9.4 months. The significant findings showed a posterior rotation of the mandible (x = 2.1 +/- 0.7 degrees), increased overjet (x = 4.8 +/- 0.3 mm), decreased overbite (x = -3.7 +/- 0.7 mm), protrusion of the upper incisors (x = 6.2 +/- 1.2 degrees), retrusion in the lower incisors (x = -0.6 +/- 0.3 degrees), reduced SNB angle (x = -1.8 +/- 0.8 degrees), increased ANB angle (x = 1.9 +/- 0.3 degrees), and an increased mandibular plane angle (x = 2.1 +/- 0.7 degrees). The results of this study indicate that the primary effect of magnetic appliance was the increase in the posterior rotation of the mandible.

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.