Effects of Rapid Maxillary Expansion on the Temporomandibular Joint: A Bone Scintigraphy Study.

OBJECTIVE: The purpose of this study is to assess the effects of rapid maxillary expansion on metabolic activity in the temporomandibular joints of young adult patients using scintigraphy. METHODS: The images belonging to temporomandibular joints were obtained from the retrospective scintigraphic records taken from 17 adult females (16.1 and 18.8 years of age and the mean age was 17.3±0.86 years) who had non-functional bilateral posterior crossbite, deep palatal vault and dental crowding, and had been treated with rapid maxillary expansion. Bone scintigraphy images were collected at three-time intervals: at the beginning of treatment (T1), during the opening of the mid palatal suture (T2), and at the end of screw activation (T3). Alteration in bone activity in the temporomandibular joint regions were evaluated in sagittal and transaxial slices. To determine the differences between the intervals, repeated analysis of variance and Bonferroni multiple comparison tests were applied. RESULTS: In the right and left temporomandibular joint regions, significantly increased metabolic activity was exhibited between T1-T2 (p<0.001). At the time of opening the maxillary mid-palatal suture, the metabolic activity increased approximately 60% compared to the initial status. At the end of the active expansion period (T3), the change in metabolic activity was approximately 20% reduced compared to T2. CONCLUSION: Metabolic activity intensification occurs in the regions of interest in the temporomandibular joint during rapid maxillary expansion. After mid-palatal suture opening, activity noticeably decreased (T2-T3). This decrease in bone activity suggests that the temporomandibular joint complex adapts to rapid maxillary expansion forces.

3D Evaluation of the Relationship between Different Vertical Growth Patterns and Cranial Base Angulations.

Objective This study aimed to compare cranial base angulations in subjects with high-angle, low-angle, and normal-angle vertical growth patterns using cone beam computed tomography (CBCT). Design This study is a retrospective clinical research. Settings This study was carried out at the Dentistry Faculty of Eskisehir Osmangazi University. Participants According to skeletal vertical face growth patterns, 78 subjects (48 females and 30 males, average age: 13.19 ± 1.73 years) were divided equally into three groups: high angle, low angle, and normal angle groups. Main Outcome Measures Cephalometric images were derived from CBCT, and patients were classified according to the SN-GoGn angle (sella-nasion, gonion gnathion angle). Sagittal, axial, and coronal cranial base angulations were measured in three-dimensional (3D) CBCT images. Data were analyzed using the Kolmogorov-Smirnov normality, Kruskal-Wallis, and Mann-Whitney U statistical tests. Results There were statistically significant differences between the low-angle and high-angle groups according to sagittal cranial base angulation parameters ( p = 0.01). Conversely, there were no statistically significant differences between vertical facial growth patterns according to coronal and axial cranial angle variables ( p > 0.05). Conclusion According to the study results, there were no effects of cranial base angulations in two planes (coronal and axial) on different vertical skeletal growth patterns. In the sagittal cranial base angulation parameter, the high-angle group showed greater angulation values than the low-angle group. CBCT may be helpful for evaluating, diagnosing, and predicting 3D cranial base differences.

Evaluation of the relationship between impacted canines and three-dimensional sella morphology.

PURPOSE: The purpose of this study was to assess the three-dimensional morphometric features of the sella turcica using cone beam computed tomography (CBCT) in subjects with unilateral and bilateral maxillary impacted canines and normal controls. METHODS: In this retrospective study, CBCT images captured with ultra-low dose protocol of 73 subjects (21 males, 52 females; mean age 20.01 ± 6.53 years) with unilateral or bilateral maxillary impacted canines (29 unilateral and 29 bilateral) and 15 controls were evaluated. Nineteen different measurements of the pituitary fossa were made on CBCT images. To evaluate the normality, the Kolmogorov-Smirnov test was used. The nonparametric statistical Kruskal-Wallis and Mann-Whitney U tests were applied to analyze the significant differences among and between the groups. Statistical significance was set at 5%. RESULTS: No measurement differed significantly among the groups (all p > 0.05) other than the right sella length, which differed between the unilateral and bilateral test groups and the unilateral test group and controls (both p < 0.05). The bilateral test group and control group did not differ significantly, but both exhibited greater right sella length than did the unilateral test group (p > 0.05). CONCLUSIONS: Other than the right sella length, there were no among-group differences in the mean pituitary fossa measurements of subjects with impacted unilateral and bilateral canines and normally erupted canines. The right sella length was lower in subjects with impacted unilateral canines than in those with bilateral impacted canines and normal controls.

Three-dimensional evaluation of angular, linear, and resorption features of maxillary impacted canines on cone-beam computed tomography.

OBJECTIVES: The aim of this study was to evaluate the localization, angulation, and resorption features of maxillary impacted canines on cone-beam computed tomography (CBCT). METHODS: This retrospective study examined the CBCT scans of 140 maxillary impacted canines in 102 patients (43 males, 59 females; mean age: 16.25 ± 6.31 years). The following impacted canine-related parameters were analyzed on the CBCT images: impaction side; location; root resorption levels of adjacent teeth; occlusal plane and midline distances of impacted canines; and angulations of impacted canines to midline, lateral incisor, and occlusal plane. RESULTS: Bilateral canine impaction was found in 38 subjects, and unilateral canine impaction was present in 64 subjects. Severe resorption was found in 14 canines. There were no significant differences between the occlusal plane and midline distances to the impacted canine cusp tip and root apex (p > 0.05). The midline angulation of right maxillary impacted canines was significantly higher than that of left maxillary impacted canines (p < 0.05), while the occlusal plane angulation of left maxillary impacted canines was significantly higher than that of right maxillary impacted canines (p < 0.05). CONCLUSIONS: Maxillary canine impaction was more frequently seen in female subjects than in male subjects. Lateral incisors were more frequently affected than first premolars, and slight resorption was more frequently seen in adjacent teeth. CBCT assessment of maxillary impacted canines can provide accurate measurements of angular, linear, and resorption parameters.

The Relationship between Dental Follicle Width and Maxillary Impacted Canines' Descriptive and Resorptive Features Using Cone-Beam Computed Tomography.

OBJECTIVES: To assess the relationship between dental follicle width and maxillary impacted canines' descriptive and resorptive features with three-dimensional (3D) cone-beam computed tomography (CBCT). METHODS: The study comprised 102 patients with cone-beam computed tomography 3D images and a total of 140 impacted canines. The association between maxillary impacted canine dental follicle width and the variables of gender, impaction side (right and left), localization of impacted canine (buccal, central, and palatal), and resorption of the adjacent laterals was compared. Measurements were analyzed with Student's t-test, Kruskal-Wallis test, and Mann-Whitney U statistical test. RESULTS: According to gender, no statistically significant differences were found in the follicle size of the maxillary impacted canine between males and females (p > 0.05). Widths of the follicles were determined for the right and left impaction sides, and no statistically significant relation was found (p > 0.05). There were statistically significant differences between root resorption degrees of lateral incisors and maxillary impacted canine follicle width (p < 0.05). Statistically significant higher follicle width values were present in degree 2 (mild) resorption than in degree 1 (no) and degree 3 (moderate) resorption samples (p < 0.05). CONCLUSIONS: No significant correlation was found between follicle width and the variables of gender, impaction side, and localization of maxillary impacted canines. Our study could not confirm that increased dental follicle width of the maxillary impacted canines exhibited more resorption risk for the adjacent lateral incisors.

Evaluation of oxidative stress biomarkers in patients with fixed orthodontic appliances.

AIM: The aim of this study was to examine the changes in the levels of interleukine-1 beta (IL-1 ß ), tumor necrosis factor alpha (TNF- α ), malondialdehyde (MDA), nitric oxide (NO), and 8-hydroxydeoxyguanosine (8-OHdG) in saliva and IL-1 ß , TNF- α , and NO in gingival crevicular fluid (GCF) samples of patients with fixed orthodontic appliances. MATERIAL AND METHOD: The subject population consisted of 50 volunteers who were in need of orthodontic treatment with fixed orthodontic appliances. GCF and saliva samples were obtained from all individuals before treatment, at 1st month of treatment and at 6th month of treatment. Periodontal clinical parameters were measured. Samples were investigated to detect IL-1 ß , TNF- α , and 8-OHdG levels using ELISA method and NO and MDA levels using spectrophotometric method. RESULTS: Since IL-1 ß level detected in GCF at the 6th month of orthodontic treatment is statistically significant according to baseline (P < 0.05), all other biochemical parameters detected both in saliva and in GCF did not show any significant change at any measurement periods. CONCLUSION: Orthodontic tooth movement and orthodontic materials used in orthodontic treatment do not lead to a change above the physiological limits that is suggestive of oxidative damage in both GCF and saliva.

Therapeutic effects of alpha lipoic acid and vitamin C on alveolar bone resorption after experimental periodontitis in rats: a biochemical, histochemical, and stereologic study.

BACKGROUND: Alpha lipoic acid (ALA) and vitamin C (Vit-C) are very important and powerful antioxidants that have been used for the treatment of many diseases. The present study aims to investigate the role of ALA and Vit-C substances in the treatment of alveolar bone resorption in periodontal diseases. METHODS: Thirty-six male Wistar albino rats were randomly divided into four groups as follows: 1) control rats; 2) rats with experimental periodontitis (PED); 3) rats with PED treated with ALA (ALA); and 4) rats with PED treated with ALA+Vit-C (ALA+Vit-C). PED was simulated by placing ligatures around the neck of teeth for 5 weeks. After ligature removal, the PED group was given a single intragastric dose of 1 mL saline, and the ALA and ALA+Vit-C groups were treated with an intragastric dose of 50 mg/kg ALA and ALA+Vit-C for 15 days, respectively. Levels of serum bone alkaline phosphatase (B-ALP) and myeloperoxidase (MPO) activity in gingival tissues were analyzed. To evaluate the osteoclast activation, expression of activated receptor activator nuclear factor-kappa B ligand (RANKL) and bone density index (BDI) were determined stereologically in the bone sections obtained from the mandibles of the rats. RESULTS: The results showed statistically significant differences between the PED group and groups treated with antioxidant according to B-ALP, MPO, RANKL, and BDI values (P <0.05). ALA and ALA+Vit-C treatments showed beneficial effects on the mesial/distal periodontal bone support at the ligature-induced periodontitis tooth areas. CONCLUSION: This study shows that ALA and Vit-C treatment provides therapeutic effects on inhibition of alveolar bone resorption and periodontal tissue destruction.

The effects of face mask therapy with and without rapid maxillary expansion in adolescent patients.

OBJECTIVE: To examine the effects of face mask therapy with and without associated rapid maxillary expansion (RME) in adolescent patients presenting with skeletal Class III malocclusion characterised by maxillary retrognathism. METHODS: Case records consisting of lateral cephalograms and hand-wrist films of 43 patients with hypoplastic maxillary Class III malocclusions treated using a face mask with and without an RME were analysed. The patients were divided into two groups; Group A (N = 27) were treated with a face mask coupled with rapid maxillary expansion and patients in Group B (N = 16) were treated with a face mask appliance only. Ten cephalometric linear and 9 angular variables were measured to assess the dentofacial changes. Within group and between groups comparisons were determined by a paired t-test and Student's t-test, respectively. RESULTS: Forward displacement of the maxilla and a clockwise rotation of the mandible occurred in both groups. The maxillary-mandibular relationship improved and soft-tissue changes resulted in a more convex profile. The maxillary incisors moved forward only in Group B subjects but the mandibular incisors moved backward in both groups. CONCLUSIONS: Face mask therapy with and without an associated RME improved skeletal Class III malocclusion by a combination of skeletal and dental changes. These results suggested that the use of an RME should be based on clinical criteria rather than assisting the Class III correction.

Evaluation of volumetry and density of mandibular symphysis bone grafts by three-dimensional computed tomography.

PURPOSE: Bone grafting before implant placing can improve the treatment in traumatized or regular implant patients. The aim of this study was to evaluate the density and maximum amount of harvestable bone graft in the mandibular symphysis. MATERIALS AND METHODS: Data from 15 CT-scans were obtained from 15 adult patients (10 male/five female) for the purposes of this study. The CT data, in DICOM format, were read into Mimics software from Materialize (Leuven, Belgium), with a slice thickness of 0.5 mm. The volume, density, and dimensions based on Hounsfield units (HU) were measured on the 3D symphyseal bone graft using Mimics software. RESULTS: The average bone volume calculated from the mandibular symphysis was 3491.08 +/- 772.12 mm(3). The average sized corticocancellous block that was measured was 38.75 x 11.05 x 7.80 mm. The mean bone density was 958.95 +/- 98.11 HU. CONCLUSION: The use of three-dimensional computed tomography (3D CT) in combination with a software program is a reliable means of determining the density of graft, evaluating maximal volume and dimensions of the graft that can be harvested from the mandibular symphysis region.

In vivo assessment of zinc deficiency on craniofacial growth in a rat model.

OBJECTIVES: The aim of this study was to investigate the effects of low levels of zinc intake on the rat mandible and maxilla during growth and to compare these results with those of zinc-containing rats. METHODS: The study was carried out on 14 Sprague-Dawley rats. The rats were randomly divided into two groups. Group I rats were fed with a Zn-deficient diet, and Group II rats with a Zn-containing diet. At the end of the fourth week on the experimental diet, all the rats were killed and blood samples were taken. Serum Zn levels were measured by atomic absorption spectrophotometry. Then, the skulls and mandibles were freed from soft tissues and measurements were made on the dry skulls, the mandibles, and teeth in both of the two groups. RESULTS: The zinc-deficient group showed a significantly lower value in dry skull, mandible, and teeth measurements when compared with those of the Group II. CONCLUSIONS: Changes in zinc intake might exert an effect on the growth of craniofacial structures. A low-zinc diet during adolescence might slow bone and teeth growth and enhance the risk of oral, periodontal, and orthodontic problems in later years.

Effects of early loss of permanent first molars on the development of third molars.

INTRODUCTION: The aim of this study was to evaluate whether early loss of the permanent first molars has an effect on the developmental stages and eruptive conditions of the third molars. METHODS: Panoramic radiographs and dental casts of 165 adolescent patients (103 boys, 62 girls) with unilateral early loss of a permanent first molar were used to assess the developmental stages of the third molars. The formation stages of third molars on the extraction sides were evaluated, and the formative conditions of the contralateral teeth were used as controls. The Mann-Whitney U test was used to assess sex differences in formation stages of the third molars. The Kruskal-Wallis analysis of variance (ANOVA) was used to determine whether there were significant differences in the developmental stages of the third molars between the various extraction quadrants. In addition, the Wilcoxon signed rank test and the paired t test were used to compare the differences in the developmental stages and eruptive conditions of the third molars between the extraction and control sides. RESULTS: The Mann-Whitney U test showed no significant sex differences for the formation stage of the third molars. Therefore, the data from both sexes were pooled. No statistically significant differences were found in the developmental stages of the third molars between the various extraction quadrants in the same jaw and between those in the mandible and maxilla. However, statistically significant differences were found in developmental stages (P <.001) and eruptive conditions (P <.05) of the third molars between the extraction and control sides. The development of the third molars on the extraction side was significantly accelerated compared with the contralateral teeth. CONCLUSIONS: Early loss of the permanent first molars might have an accelerating effect on the development of the third molar on the extraction side compared with the contralateral teeth. Therefore, emergence of the third molars on the extraction side might be hastened, and these teeth might erupt earlier than the contralateral teeth.

Nonsurgical rapid maxillary expansion effects on craniofacial structures in young adult females. A bone scintigraphy study.

OBJECTIVE: To evaluate the skeletal effects of nonsurgical rapid maxillary expansion (RME) on craniofacial structures with bone scintigraphy in young adult female subjects. MATERIALS AND METHODS: The material of the present study consists of scintigraphic records taken from 17 early adult females treated with RME. All patients had a bilateral posterior crossbite, transverse maxillary deficiency, deep palatal vault, and dental crowding at the beginning of the treatment. The age range of the patients was 16.1 to 18.8 years, and the mean age was 17.3 +/- 0.86 years. Bone scintigraphy records were obtained before RME (T1), during the splitting of the midpalatal suture (T2), and after the end of active widening period (T3). Repeated measure analysis of variance was used to assess the differences between the periods. In addition, Bonferroni multiple comparison tests were applied to the measurements at which F values were found to be statistically significant. RESULTS: According to the statistical analysis, significant activity changes were found in all regions studied and in all slices. The metabolic activity in all regions showed significant increases up to the separation of the midpalatal suture (T1-T2), whereas the metabolic activity exhibited a remarkable decrease (T2-T3) after the opening of the midpalatal suture. CONCLUSIONS: Scintigraphic records revealed an increase in the regions of interest scores during RME in all regions and all slices. Therefore, it can be speculated that RME has had not only dental effects but also skeletal effects on young adult patients.

An investigation of maxillary and mandibular morphology in different overjet groups.

BACKGROUND: It has been suggested that overjet may be related to the form of the maxilla and mandible. AIMS: The aims of this study were to compare the gender differences in the maxillary and mandibular morphology in different overjet groups, and to determine the associations between overjet and craniofacial morphology in the same subjects. METHODS: The material consisted of lateral cephalometric radiographs of 80 untreated subjects 140 boys, 40 girls), aged 13 to 15 years, selected from records held in the Orthodontic Department, Atatürk University. The subjects were divided into four overjet groups. Thirteen linear, one angular, and three area measurements were used to assess maxillary and mandibular form in the male and female subjects. RESULTS: The results showed that there were statistically significant differences in the maxillary anterior and posterior dentoalveolar heights (MxAABH, MxPABH), effective mandibular length (Cd-Gn), corpus length (Go-Gn), and ramus width (RW) between the overjet groups. In 15 out of 17 measurements the males were significantly larger than the females. There were no gender differences in antegonial notch depth (AND) and the gonial angle. Furthermore, significant negative correlations were found between overjet and Cd-Gn, and between overjet and Go-Gn in the girls. Significant positive correlations were found between overjet and MxAABH, and overjet and RW in the boys. CONCLUSIONS: Evaluation of the maxillary dentoalveolar heights and some mandibular parameters, such as Cd-Gn, Go-Gn and RW, in different overjet patterns may be useful in the analysis of the malocclusion, and prediction of treatment success.

Investigation of the changes in the positions of upper and lower incisors, overjet, overbite, and irregularity index in subjects with different depths of curve of Spee.

The aim of this study was to investigate the relationship between the depth of the curve of Spee and positions of upper and lower incisors, overjet, overbite, and anterior lower crowding. The material consisted of lateral head films and dental casts of 137 untreated adolescent subjects, 76 girls and 61 boys, aged 13 to 16 years. The subjects were divided into three groups with normal Spee, flat Spee, and deep Spee and were compared with one another. Differences between the Spee groups and between sexes were assessed by means of analysis of variance and a post hoc multiple comparison test. In addition, correlation coefficients between the depth of curve of Spee and other variables were calculated. Finally, cephalometric measurements for all subjects were subjected to a multiple regression analysis, with the depth of curve of Spee as the dependent variable. The results showed that there were no statistically significant differences in the positions of upper and lower incisors and anterior lower crowding among the Spee groups. However, overjet and overbite demonstrated significant differences among the groups. Statistically significant correlations were found between the depth of curve of Spee and overjet and overbite. Multiple linear regression analysis revealed that chronological age and all other variables used in the study could account for only 28.7% of the total variance of the curve of Spee. The overbite alone explained 17.3% of the total variance of the curvature.

Gingival enlargement in children treated with antiepileptics.

This study was conducted to determine the occurrence, severity, and risk factors of gingival enlargement in children treated with valproate and other nonvalproate antiepileptic drugs. A cross-sectional study was carried out in which data obtained from 68 epileptic children under treatment were compared with those from 50 controls. A structured questionnaire was used to collect data on patients' demographics, dental and oral hygiene practices, and medication history. Gingival enlargement, gingival index, plaque index, and probing depth were measured to assess periodontal health. The chi-square and Fisher exact tests were used in statistical analysis. In case of significance, a detailed chi-square analysis was carried out to determine the origin of the difference. Patients in both the valproate and nonvalproate groups showed significantly higher gingival enlargement, gingival index, plaque scores, and pocketing (P < .001 and P < .01, respectively) than the control group. In the valproate group, the duration of the treatment had a significant effect on gingival enlargement (P < .001) but not on gingival index, plaque index, and probing depth values (P > .05). Toothbrushing was most frequent in the control group (P = .000) and more frequent in the valproate group than the nonvalproate group (P = .024). Our study showed significant differences regarding gingival enlargement in children treated with valproate. These findings illustrate that epileptic children on valproate are at risk of periodontal problems.