Comparison of different maxillary advancement protocols in patients with unilateral cleft lip and palate: a finite element analysis.

OBJECTIVES: The aim of this study was to evaluate the stress distributions and possible amount of movement in the maxillofacial region resulting from different maxillary advancement protocols in patients with unilateral cleft lip and palate. MATERIALS AND METHODS: A unilateral cleft lip and palate model (CLP model) with Goslon score 4 was created for finite element analysis. Three different protocols were compared: Group 1: usage of a face mask with elastics placed at a 30? angle to the occlusal plane over a conventional acrylic plate; Group 2: usage of a face mask with elastics placed at a 30? angle to the occlusal plane over miniplates placed in the infrazygomatic crest region; Group 3: usage of elastic from the menton plate placed in the mandible to the infrazygomatic plates in the maxilla. RESULTS: Dental effects were greater in the maxillary protraction protocol with a face mask over a conventional acrylic plate (Von Misses Stress Values; Group 1?=?cleft side:0.076, non-cleft side:0.077; Group 2?=?cleft side:0.004, non-cleft side: 0.003; Group 3?=?cleft side:0.0025; non-cleft side:0.0015), whereas skeletal effects were greater in maxillary protraction protocols with face mask using skeletal anchorage (Von Misses Stress Values; Group 1:0.008; Group 2:0.02; Group 3:0.0025). The maximum amount of counterclockwise rotation of the maxilla as a result of protraction was observed in traditional acrylic plate face mask protocol, and the minimum amount was observed by using elastics between infrazygomatic plates and menton plate. CONCLUSIONS: In individuals with unilateral cleft lip and palate with Goslon score 4, it was observed that the skeletally anchored face mask caused more skeletal impact and displacement than both the traditional acrylic plate face mask model and the pure skeletally supported maxillary protraction model. CLINICAL RELEVANCE: When planning maxillary protraction treatment in patients with cleft lip and palate, it should be considered that more movement in the sagittal plane might be expected on the cleft side than the non-cleft side, and miniplate and screws on the cleft side are exposed to more stress when using infrazygomatic plates as skeletal anchorage.

Age-related transversal changes in craniofacial sutures of the anterior viscerocranium in growing rats.

Objective: To evaluate the dimensional changes that occur in the internasal and nasopremaxillary sutures, and related transverse craniofacial dimensions, of rats from 4 to 38-weeks of age. Methods: Four groups of twelve male Wistar rats were sacrificed at different ages [4-weeks (immature), 16-weeks (adolescent), 26-weeks (young adult), 38-weeks (adult)]. The rats were scanned with a high-resolution micro-computed tomography imaging device with 90 µm voxel size and 45 mm × 45 mm field of view (FOV) to obtain images of the viscreocranium, and with 10 µm voxel size and 5 mm × 5 mm FOV to obtain images of the internasal and left nasopremaxillary sutures. The nasal bone width, transverse width between the nasopremaxillary sutures and interzygomatic width were measured as craniofacial measurements. The endocranial, ectocranial and mean suture widths (cross-sectional area between endocranial and ectocranial borders/suture height), and suture height were measured at 5 frontal planes with 1.2 mm intervals. Outcomes were compared at different ages, and correlation coefficients were used to assess the relationship between craniofacial and suture changes. Results: All transverse craniofacial dimensions increased significantly from 4-16 weeks of age (p < 0.001). After 16-weeks of age, the only significant increase was observed in interzygomatic width (p = 0.02), between 26 and 38 weeks. In both the internasal and nasopremaxillary sutures, the endocranial suture mean widths decreased from 4-16 weeks (p < 0.001 and p = 0.002, respectively), but did not show any significant change after 16-weeks of age. The ectocranial internasal suture width decreased from 4-16 weeks (p < 0.001), increased until 26-weeks (p = 0.035), and subsequently decreased (p < 0.001). The nasopremaxillary suture widths decreased from 4-38 weeks to varying degrees in different frontal planes. Except for the internasal ectocranial suture width, all suture measurements were found highly and negatively correlated with the transverse craniofacial dimensions. The height of the sutures increased with time, with the most significant changes occurring between 4 and 16 weeks of age (p < 0.001). Conclusion: Although the internasal and nasopremaxillary endocranial suture widths nearly reach their final widths during adolescence, the changes in the ectocranial and mean suture widths continue into early adulthood. These results may serve as a reference for future studies aiming to evaluate the effects of functional demands on suture development and dimensional changes of the viscerocranium.

Symmetry of crown widths in subjects with unilateral maxillary lateral incisor agenesis.

PURPOSE: The aim of this study was to compare mesiodistal width and symmetry of maxillary and mandibular teeth in subjects with and without unilateral maxillary lateral incisor agenesis. PATIENTS AND METHODS: The study group consisted of 31 patients with unilateral maxillary lateral incisor agenesis (19 females, 12 males, mean age: 16.55 ± 5.24 years), and a control group of 31 patients (19 females, 12 males, mean age: 16.58 ± 4.41 years) without agenesis. Mesiodistal dimensions of all teeth except second molars were measured. Paired samples t­test and Wilcoxon signed-rank test were used for intragroup comparisons. Independent samples t­test was used for intergroup comparisons. RESULTS: In the study group, mesiodistal dimensions of maxillary canine, second premolar, first molar, mandibular second premolar and first molar teeth on the agenesis side were significantly smaller than on the contralateral side (p < 0.05). In the control group, no significant difference was seen in mesiodistal dimensions between right and left sides. In the study group, mesiodistal dimensions of all teeth on the lateral agenesis side were significantly smaller than on the control side (p < 0.05). On the side without lateral agenesis, all teeth except the maxillary and mandibular first molars and mandibular second premolar teeth were significantly smaller than on the control side (p < 0.05). Total mesiodistal dimensions of the maxillary teeth were significantly smaller on the lateral agenesis side than on the contralateral side (p = 0.001). Total tooth size of the study group was significantly smaller than for the control group (p < 0.05). CONCLUSION: Patients with unilateral maxillary lateral incisor agenesis might have asymmetries in tooth width and have smaller teeth than individuals without agenesis.

Assessment of food consumption changes in adolescents during orthodontic treatment.

INTRODUCTION: This study aimed to evaluate the changes in food consumption in adolescents during orthodontic treatment. METHODS: Twenty-five adolescents aged between 12 and 18 years participated in the study. Before the treatment, the participants were interviewed, and their food consumption frequency and 24-hour retrospective food consumption records were taken. Participants were followed up for 3 months, that is, in the first, fourth, and 12th week of the treatment. In the interviews, questions about food consumption changes and posttreatment pain were asked to the participants, and 24-hour retrospective food consumption records were obtained. RESULTS: When the food consumption records of the adolescents before the orthodontic treatment and at the first week, first month, and third month of the active orthodontic treatment were compared, there was no significant difference between total energy, protein, and carbohydrate intake. However, total fat intake decreased in the first week of treatment and increased significantly during the treatment period (P = 0.05). There was a significant decrease in the amount of fiber (P = 0.039), vitamin E (P = 0.043), and vitamin C (P = 0.048) intake of patients during the orthodontic treatment. CONCLUSIONS: Nutrition and feeding habits are important for growth and development in adolescence. In adolescents having orthodontic treatment, vitamin C, vitamin E, and fiber intake decreased significantly, especially in the first weeks of treatment. The intake of these nutrients did not return to their initial levels by the 12th week of the orthodontic treatment. It is thought that cooperation with dietitians and orthodontists might minimize the undesired nutritional effects of the orthodontic treatment.

Vertical Facial Skeletal Asymmetry and Occlusal Cant Relationship in Patients With Unilateral Cleft Lip and Palate.

OBJECTIVE: To evaluate the maxillary and mandibular vertical skeletal asymmetries, and the correlation between these asymmetries and occlusal cant in patients with unilateral cleft lip-palate (UCLP). METHODS: Anteroposterior radiographs of 25 patients with UCLP (UCLP group, mean age: 20.98 ± 4.88 years) and 25 subjects without cleft (control group, mean age: 19 ± 2.86 years) were included. Independent samples t test, Mann-Whitney U test and Pearson correlation analysis were performed based on linear and angular measurements. RESULTS: Lower facial horizontal asymmetry did not show statistically significant difference between the UCLP and control groups. However, vertical asymmetry of (a) the lateral cranial base (P = .014), (b) the nasomaxillary region (P < .001), (c) the maxillary dentoalveolus (P = .001), and (d) the lower face (P = .038) were all found to be significantly greater in UCLP group. The occlusal cant angle was also significantly greater in patients with UCLP compared to the controls (P = .016). While the occlusal cant angle was found to be correlated with the vertical asymmetry of the occlusal cant (r = 0.931, P < .001), maxillary cant angle was found to be correlated with the vertical asymmetry of the maxillary dentoalveolus (r = 0.655, P < .001). CONCLUSIONS: There was no correlation between the occlusal cant and the vertical and horizontal skeletal asymmetries. Vertical asymmetries of the lower face and the medial cranial base were negatively correlated with the horizontal lower facial asymmetry.

Comparison of Transverse Craniofacial Dimensions Between Growing Individuals With Unilateral Cleft Lip and Palate and Age-and Sex-Matched Noncleft Controls.

OBJECTIVE: The study aimed to assess the transverse craniofacial dimensions of patients (age, 7-14 years) with unilateral cleft lip and palate (UCLP), compare these dimensions with those of noncleft individuals, and identify the correlations between the nasal and maxillary transverse widths of patients with UCLP. DESIGN: A cross-sectional study. PARTICIPANTS: Eighty patients operated on for complete UCLP (UCLP group; 35 girls, 45 boys; median age: 10.7 [7.9-14] years) and 80 age- and sex-matched noncleft individuals (control group; 35 girls, 45 boys; median age: 10.7 [7.3-14] years). INTERVENTIONS: Interorbital, bizygomatic, nasal, maxillary skeletal, maxillary molar, mandibular molar, and antegonial width measurements were performed using posteroanterior cephalometric radiographs. Intergroup comparisons were conducted by using the independent samples t-test and Mann-Whitney U test. Correlation between the variables was examined using Pearson correlation analysis. RESULTS: The bizygomatic, maxillary skeletal and molar, mandibular molar, and antegonial widths in the UCLP group were significantly less than those in the control group (P < .05). A positive correlation was found between the maxillary skeletal and nasal widths (r = 0.550, P < .001) and between the maxillary molar and nasal widths (r = 0.560, P < .001). CONCLUSIONS: In individuals with UCLP, the bizygomatic, maxillary skeletal and molar, mandibular molar, and antegonial widths were significantly less than those in noncleft individuals. As the maxillary skeletal and dental widths presented a positive correlation with the nasal width, a decrease in nasal width must be considered when maxillary constriction is noted.

The Effect of Live-Video Demonstration on Dental Students' Orthodontic Bending Performance.

The aims of this study were to evaluate the effects of a live-video teaching tool on the performance of dental students in bending an orthodontic vestibular arch and to assess the students' perceptions of the technology. All 135 fourth-year dental students in the 2018 academic year at Hacettepe Dental School, Ankara, Turkey, were invited to participate in the study; after exclusions, the remaining 116 were randomly divided into two demonstration cohorts. These students had no prior experience bending an orthodontic wire. Cohort 1 (control, N=58) was shown a conventional live demonstration of the orthodontic bending of a vestibular arch, and Cohort 2 (experimental, N=58) was shown a live-video demonstration of the same procedure. Both cohorts saw the demonstration before beginning the exercise and were evaluated afterwards on their performance of the procedure. In addition, the students' perceptions of the demonstration techniques were collected with a questionnaire. The results did not show any significant differences in the students' bending scores between the control and experimental cohorts (p=0.767). The median values on the questionnaire indicated almost no statistically significant difference in responses between the cohorts. The only significant difference was that Cohort 1 had a higher percentage who answered "yes" they would like to rewatch the demonstration than did Cohort 2 (p=0.024). In this study, the live-video technique was found to be as effective as a conventional live demonstration for orthodontic practical education, suggesting that either technique could be used as an appropriate method for training in orthodontic wire bending.

Comparison of Live-Video and Video Demonstration Methods in Clinical Orthodontics Education.

The aim of this study was to compare the effectiveness of live-video and video demonstration methods in training dental students in orthodontic emergency applications. A total of 105 fifth-year dental students at a dental school in Turkey participated in the study in 2018. A pretest was given to the students to evaluate their level of knowledge about band cementing and re-bonding of brackets. Subsequently, two clinical applications were demonstrated with either live-video or video demonstration. During the live-video demonstration, the lecturer gave information about the steps of the procedure while performing the clinical application on the patient using a camera attached to the loupes. The students were able to see the process on the screens. During the video demonstration, previously recorded videos of those clinical applications were shown, and information was given to students in a classroom. On the next day, posttests were given to the students. The posttest also asked students to give their opinions about both methods. The results showed that the mean posttest scores on the video demonstration were significantly higher than on the live-video demonstration. However, no significant difference between the demonstration methods was found with regard to increase of scores from pre- to posttest. Most students preferred use of the two demonstrations together for education in the clinical orthodontics lecture. This study found that the two demonstration methods had comparable effects on increasing students' level of knowledge. However, from the students' perspective, the two should be used together to achieve the highest effect.

Comparison of Positive Screening for Obstructive Sleep Apnea in Patients With and Without Cleft Lip and Palate.

OBJECTIVE: To compare the prevalence of increased risk of obstructive sleep apnea (OSA) in children with and without cleft lip and/or palate using a previously validated questionnaire and to examine the clinical and demographic variables that may lead to increased OSA risk. DESIGN: Prospective, cross-sectional study. PARTICIPANTS: One hundred fifty-five cleft lip palate and 155 noncleft children between 2 and 18 years old. INTERVENTIONS: The Pediatric Sleep Questionnaire (PSQ): Sleep Related Breathing Disorder Scale was used for screening of increased OSA risk. Age, body mass index (BMI), gender, breast-feeding, and bottle-feeding durations were recorded for all patients. Cleft type, lip and palate operation times, nasoalveolar molding, or nutrition plaque usage was documented for the cleft lip palate group. Pearson χ2 or Fisher exact test was used for the evaluation of the qualitative variables and independent samples t test or Mann Whitney U test for quantitative variables. P < .05 was accepted as statistically significant. RESULTS: The mean ages were 7.52 ± 3.91 and 7.50 ± 3.89 years for cleft lip palate and control groups, respectively. No significant differences were observed between the groups for age, gender, or BMI. Breast-feeding duration was significantly higher, and bottle-feeding duration was lower in the control group (P < .05). Mean PSQ score was significantly higher in cleft lip palate group (0.18 ± 0.12) than in control group (0.13 ± 0.1, P < .001); and prevalence of increased OSA risk was significantly higher in patients with both cleft lip and palate (P = .020). CONCLUSIONS: Positive OSA screening ratio of children with cleft lip and palate (12.2%) was significantly higher than the controls (4.5%).

A comparative assessment of clinical efficiency between premium heat-activated copper nickel-titanium and superelastic nickel-titanium archwires during initial orthodontic alignment in adolescents: a randomized clinical trial.

BACKGROUND: To compare the clinical efficiency of premium heat-activated copper nickel-titanium (Tanzo Cu-NiTi) and NT3 superelastic NiTi during initial orthodontic alignment. SUBJECT AND METHODS: A total of 50 patients were randomly allocated to 1 of 2 different archwire types (group 1, Tanzo Cu-NiTi; group 2, NT3 superelastic NiTi). Eligibility criteria included Class I or Class II malocclusion, moderate maxillary anterior crowding, and healthy periodontal condition. Impressions of the upper arches were taken before archwire placement (T0) and at every 4 weeks (T1, T2, T3, and T4). For T1 and T2 stages, 0.014-in., and for T3 and T4 stages, 0.018-in. archwires were used. The primary outcome was the alignment efficiency assessed using Little's irregularity index. The secondary outcomes were arch width and incisor inclination changes. Data were analyzed using independent samples t test, repeated measures ANOVA, and Mann-Whitney U test. Marginal models were established for the estimation of coefficients. RESULTS: The anterior irregularity index reduction was mostly observed between T0 and T2 periods, which were respectively - 7.40 ± 0.50 mm (p < 0.001; 95% CI, - 8.94, - 5.85) and - 6.80 ± 0.55 mm (p < 0.001; 95% CI, - 8.49, - 5.12) for groups 1 and 2 (p < 0.001). With both wires, Little's irregularity index decreased over time, and the difference between the groups was not significant (p = 0.581; estimated effect size, 0.011). No statistically significant difference was found between the groups in terms of intercanine and intermolar width and incisor inclination changes. CONCLUSION: There were no significant between-group differences in alignment efficiency, arch width, and incisor inclination change. There was an increased alignment with 0.014-in. compared with 0.018-in. diameter archwire.

Reliability of cone-beam computed tomography for temporomandibular joint analysis.

OBJECTIVE: The aim was to assess the intraobserver and interobserver reliabilities of temporomandibular joint linear measurements and condylar shape classifications performed with cone-beam computed tomography (CBCT). METHODS: CBCT images of 30 patients were measured at two different time points by two orthodontists using the Dolphin 3D program (n = 60). Anterior, posterior, and superior joint space measurements and sagittal joint morphology classification in the sagittal view and medial and lateral joint space and mediolateral width measurements and coronal joint morphology classification in the coronal view were recorded. Intraclass-interclass correlation coefficients (ICC) and kappa statistics were used to assess intraobserver and interobserver reliability for the measurements and morphology classifications, respectively. RESULTS: The ICC values were good for measurements of the posterior joint space by observer I and for measurements of the posterior, medial, and lateral joint spaces by observer II, while the other intraobserver measurements were excellent. Only the mediolateral width measurements showed excellent interobserver ICC values, while the other measurements showed good interobserver ICC values. Intraobserver agreement for the sagittal morphology classifications was moderate (κ = 0.479) and almost perfect (κ = 0.858) for observers I and II, respectively, while the corresponding agreement for the coronal morphology classifications was substantial for both observers. The interobserver agreement values for sagittal and coronal morphology classifications were slight (κ = 0.181) and fair (κ = 0.265), respectively. CONCLUSIONS: Linear temporomandibular joint measurements were reproducible and reliable in both intraobserver and interobserver evaluations. However, interobserver agreement for assessments of condylar shape was low.

Clinical performance of precoated brackets and self-etch bonding technique: a prospective comparative study.

OBJECTIVE: The aim was to compare the clinical performance of uncoated and adhesive precoated brackets bonded with either self-etching primer (SEP) or conventional two-step etch and primer method (CEM). SUBJECTS AND METHODS: The sample consisted of 63 patients with a mean age of 15.20 ± 1.6 years. In group I (n = 15), uncoated brackets and CEM; in group II (n = 16), precoated brackets and CEM; in group III (n = 16), uncoated brackets and SEP; in group IV (n = 16), precoated brackets and SEP were used for bonding. Bonding time, bracket failure rate, and adhesive remnant index (ARI) scores were measured. The mean orthodontic treatment time was 1.13 ± 0.18 years. One-way variance ANOVA was used to determine bonding time differences and the chi-square test was used to determine differences in bracket failure rates and ARI scores. RESULTS: The bonding time was significantly lower for Groups III and IV, when compared to Groups I and II (p < 0.001). The bond failure rates were not different between the groups. Significant difference was observed between the procedures in relation to ARI scores (p < 0.001), which were higher in group IV. CONCLUSIONS: Precoated brackets with SEP application significantly reduced chair time without compromising bracket failure rate. CLINICAL RELEVANCE: Precoated brackets with SEP application can be safely used for bonding. Regarding the mode of failure, this group can be thought as favorable with a reduced risk of enamel tear.

Evaluation of changes in the maxillary alveolar bone after incisor intrusion.

OBJECTIVE: This study was performed to investigate the changes in alveolar bone after maxillary incisor intrusion and to determine the related factors in deep-bite patients. METHODS: Fifty maxillary central incisors of 25 patients were evaluated retrospectively. The maxillary incisors in Group I (12 patients; mean age, 16.51 ± 1.32 years) were intruded with a base-arch, while those in Group II (13 patients; mean age, 17.47 ± 2.71 years) were intruded with miniscrews. Changes in the alveolar envelope were assessed using pre-intrusion and post-intrusion cone-beam computed tomography images. Labial, palatal, and total bone thicknesses were evaluated at the crestal (3 mm), midroot (6 mm), and apical (9 mm) levels. Buccal and palatal alveolar crestal height, buccal bone height, and the prevalence of dehiscence were evaluated. Two-way repeated measure ANOVA was used to determine the significance of the changes. Pearson's correlation coefficient analysis was performed to assess the relationship between dental and alveolar bone measurement changes. RESULTS: Upper incisor inclination and intrusion changes were significantly greater in Group II than in Group I. With treatment, the alveolar bone thickness at the labial bone thickness (LBT, 3 and 6 mm) decreased significantly in Group II (p < 0.001) as compared to Group I. The LBT change at 3 mm was strongly and positively correlated with the amount of upper incisor intrusion (r = 0.539; p = 0.005). CONCLUSIONS: Change in the labial inclination and the amount of intrusion should be considered during upper incisor intrusion, as these factors increase the risk of alveolar bone loss.

Tooth color change due to different etching and debonding procedures.

OBJECTIVES:: To compare the effects of different etching techniques, 12-, 24-bladed tungsten carbide burs, and polishing discs on tooth color changes during orthodontic treatment. MATERIALS AND METHODS:: 59 individuals (mean age: 15.20 ± 1.59 years) were divided into four groups: 37% phosphoric acid and adhesive primer was used in Groups I and II whereas self-etch primer was used in Groups III and IV for enamel preparation. After orthodontic treatment, residual adhesives were cleaned with 12-bladed tungsten carbide burs in Groups I and III, while 24-bladed tungsten carbide burs were used in Groups II and IV. All teeth were polished with medium and fine Sof-Lex XT discs (3M ESPE, St Paul, Minnesota). Color measurements were taken from upper incisors and canines at pretreatment (T0), after cleaning with tungsten carbide burs (T1) and polishing with discs (T2). Wilcoxon test was used for evaluation of L*, a*, b* changes and Kruskal-Wallis for intergroup comparison of color changes. RESULTS:: L*, a*, b* values, except a* at Groups I, II, IV, and b* at Group III, changed significantly ( P < .05). Groups III and IV showed significantly different color alterations from T0 to T1 ( P < .05). After polishing, tooth color alterations were not significantly different among the groups. CONCLUSIONS:: In self-etch bonding groups, a 12-bladed tungsten carbide bur caused less color change than the 24-bladed tungsten carbide bur. Orthodontic treatment resulted with visible and clinically unacceptable tooth color alterations regardless of the enamel preparation and clean-up techniques. Polishing reduced the effect of tungsten carbide burs, but did not affect the total influence of orthodontic treatment on the tooth color.

Effects of Three Different Orthodontic Treatment Methods on the Stability of Mandibular Incisor Alignment.

OBJECTIVE: To compare the effects of extraction, non-extraction and air-rotor stripping treatments on mandibular dental arch dimensions, lower incisor positions and evaluate their effects on the stability of the treatment. STUDY DESIGN: The sample consisted of 44 patients with Class I malocclusion and moderate crowding including 15 patients treated with extraction, 13 with air-rotor stripping (ARS), and 16 with non-extraction treatment. The records were taken at pretreatment (T0), end of active orthodontic treatment (T1), minimum 3 years post-treatment (T2). The model and cephalometric measurements were evaluated. For statistical analyses ANOVA and Welch test was applied. RESULTS: At post-retention period Little's irregularity indices were increased to 1.96 mm, 2.38 mm and 3.59 mm for extraction, ARS and non-extraction groups respectively (p<0.05). At T1-T2, intercanine widths were decreased significantly at all groups (p<0.05). The arch length and arch depth decreased significantly at extraction group (p<0.05) from T0 to T1 and remained the same at T2 (p>0.05). The lower incisors were retroclined with treatment and slightly proclined at post-retention period in extraction group. In ARS and non-extraction group, lower incisors proclined with treatment and remained the same at post-retention. CONCLUSION: At all groups the irregularity indices relapsed but did not return to pretreatment values. Although significant increase at intercanine width was only observed in non-extraction treatment, at post-retention phase, intercanine widths were significantly decreased at all groups. The changes at lower incisor inclinations relapsed slightly in extraction group but remained the same in the other groups.

Assessment of upper airway size after orthopedic treatment for maxillary protrusion or mandibular retrusion.

INTRODUCTION: The aim of this retrospective study was to find out whether different Class II treatments would affect the airway sizes of patients having maxillary protrusion or mandibular retrusion. METHODS: The study sample comprised 57 Class II patients whose upper airway sizes were not significantly different at the start of treatment and whose sagittal skeletal jaw relationships showed that they had maxillary protrusion or mandibular retrusion. Twenty-two of them were treated with cervical headgear, 16 with activator, and 19 were selected as a control. Lateral cephalograms at the start of treatment and the end of orthopedic treatment were assessed. The intragroup comparisons were performed by using the paired-samples t test, and intergroup comparisons of the skeletal features and upper airways were performed with 1-way analysis of variance, with the Tukey test as a second step, at P < 0.05. RESULTS: The ANB angle decreased significantly in the treatment groups. The middle airway space and the SNB angle were significantly increased after the activator therapy (P < 0.05). The SNB angle increased and SN-1 decreased in the mandibular retrusion group when compared with both maxillary protrusion and control groups. No statistically significant difference between the maxillary protrusion and the mandibular retrusion groups was found regarding the upper airway sizes after cervical headgear or activator treatments, respectively (P > 0.05). The only significant differences observed in airway variables were at the middle airway space of the activator and control groups with an increase of 1.6 ± 2.5 mm and a decrease of 1.5 ± 2.3 mm, respectively. CONCLUSIONS: Orthopedic treatment with either cervical headgear or activator did not result in different upper airway changes, but activator treatment resulted in increased middle airway space with regard to the Class II control group.

Computed tomography assessment of temporomandibular joint position and dimensions in patients with class II division 1 and division 2 malocclusions.

BACKGROUND: This study aimed to investigate and compare the positions and dimensions of the temporomandibular joint and its components, respectively, in patients with Class II division 1 and division 2 malocclusions. MATERIAL AND METHODS: Computed tomography images of 14 patients with Class II division 1 and 14 patients with Class II division 2 malocclusion were included with a mean age of 11.4 ± 1.2 years. The following temporomandibular joint measurements were made with OsiriX medical imaging software program. From the sagittal images, the anterior, superior, and posterior joint spaces and the mandibular fossa depths were measured. From the axial images, the greatest anteroposterior and mediolateral diameters of the mandibular condyles, angles between the long axis of the mandibular condyle and midsagittal plane, and vertical distances from the geometric centers of the condyles to midsagittal plane were measured. The independent samples t-test was used for comparing the measurements between the two sides and between the Class II division 1 and 2 groups. RESULTS: No statistically significant differences were observed between the right and left temporomandibular joints; therefore, the data were pooled. There were statistically significant differences between the Class II division 1 and 2 groups with regard to mandibular fossa depth and anterior joint space measurements. CONCLUSIONS: In Class II patients, the right and left temporomandibular joints were symmetrical. In the Class II division 1 group, the anterior joint space was wider than that in Class II division 2 group, and the mandibular fossa was deeper and wider in the Class II division 1 group. Key words:Temporomandibular joint, Class II malocclusion, Cone beam computed tomography.