Anterior open-bite and sucking habits in Italian preschool children.

AIM: To evaluate the consequences of prolonged sucking habits on the development of the orofacial complex in deciduous dentition. MATERIALS AND METHODS: A cross-sectional study was carried out involving 235 preschool children. A questionnaire for children parents and clinical examinations were carried out by calibrated blinded examiners. The chi-square test and the T-Student test were used for statistical analysis. RESULTS: The prevalence of non-nutritive sucking habits (NNSH) in the sample was 74%. Anterior open-bite (AOB) was detected in 18%, and it was significantly related to non-nutritive sucking habits, bottle-feeding (only in the 3-year-old group) and persistent use of pacifier (p<0.05). CONCLUSIONS: NNSH and type of feeding were important contributing factors in the development of anterior open-bite in deciduous dentition.

Denture-frame modifications in class III patients treated with rapid palatal expansion and facemask: a prospective controlled study.

AIM: The aim of this prospective controlled investigation was to analyze the short-term cephalometric treatment outcomes, according to the denture frame analysis proposed by Sato, of rapid palatal expansion (RPE) and facial mask (FM) therapy. METHODS: A group of 21 patients with Class III malocclusion treated with the RPE and FM (TG) was compared with untreated Class III controls (CG). The mean age of treatment group was 8.8 years; treatment consisted of 4 weeks of RPE activation (0.20 mm/die) followed by 14 hours wear of the FM for a mean of 333.1 days. As CG were used the data published by Tanaka and Sato. Pre- and post-treatment cephalometric values were compared and statistical analyzed with one-sample t-test. A P-value <0.05 was considered statistically significant. RESULTS: For almost all parameters the differences pre and post treatment values resulted significantly different compared to those observed in CG. Regarding conventional occlusal plane (POC) values some differences compared to control group were found but they were not statistically significant (P=0.067) while for aterior occlusal plane (POA) no differences where noticed. CONCLUSION: This study revealed an increase in inter-jaw angle during treatment with FM and RPE, an increase in the inclination of the posterior occlusal plane with respect to the Frankfurt plane and a posterior and lower adaptation of the mandible.

Evaluation of the cephalometrics modification of growing Class II Division I patients after treatment with the PUL appliance: a pilot study.

AIM: The aim of this preliminary study was to evaluate short-term dentoskeletal changes obtained with a functional appliance for Class II Division I malocclusions called propulsor universal light (PUL). METHODS: Fifteen Class II Division 1 patients (10.6±1.2 years) were consecutively treated by one expert operator with PUL appliance and they were compared with a longitudinal group of Class II Division I untreated patients (9.9±1.9 years) matched for pubertal growth spurt stage and sex. Lateral cephalograms were taken before PUL therapy and at the end of treatment. The mean duration of treatment was 11.2±0.3 months; t-test or Mann-Whitney U-test was used (P <0.05). RESULTS: Statistically significant reduction of the overjet, WITS and ANB was noticed in treated group as well as a significant improvement of CoGo and Ramus. CONCLUSION: Class II Division I malocclusion in the short term was efficiently treated by PUL appliance with both skeletal and dentoalveolar changes.

Do changes in spheno-occipital synchondrosis after rapid maxillary expansion affect the maxillomandibular complex?

AIM: This was to evaluate changes in spheno-occipital synchondrosis one year after rapid maxillary expansion (RME), in order to assess the influence that any change might have on sagittal and vertical skeletal cephalometric variables. MATERIALS AND METHODS: Patients were selected consecutively and grouped into: Group 1 comprised 30 Caucasian patients (13 m; 17 f) undergoing RME therapy; after active expansion therapy, the Haas expander was worn as passive retainer for an average of 7 months. Group 2 as control included 14 untreated subjects (6 m, 8 f), matched by age, sex and vertebral skeletal maturity (CVM method, stages 1-3). Six cephalometric variables concerning spheno-occipital synchondrosis were studied: N-S-Ba; SOS-Ba; SOS-S; S-Ba; Ba-N; S-N; nine skeletal variables for sagittal and vertical evaluation were also checked. T-test was used for comparing the 2 groups data. RESULTS: A statistically-significant opening of the spheno-occipital synchondrosis and increase of the posterior cranial base length (Ba-SOS) were found between group 1 and 2. After 1 year, these modifications in spheno-occipital syncondrosis produced no change in the anteroposterior or vertical skeletal parameters examined. CONCLUSION: After RME there were statistically significant effects on spheno-occipital synchondrosis length and cranial base angle; however, these changes in the mid-term did not affect the vertical or sagittal parameters of the skeletal maxillomandibular complex.

Thread shape factor: evaluation of three different orthodontic miniscrews stability.

The thread shape factor (TSF) to evaluate the relationships between geometrical characteristics and mechanical properties of the temporary anchorage devices (TADs) has recently been introduced. This in vitro experimental study evaluated in 30 different tests with three TADs: ORTHOImplant (1.8 mm diameter and 10 mm length; 3M Unitek), Tomas (1.6 mm diameter and 10 mm length; Dentaurum), and Orthoeasy (1.7 mm diameter and 10 mm length; Forestadent). Scanning electron microscopy images were acquired for each TAD to measure the TSF; afterwards, the maximum insertion torque (MIT) was evaluated and thereafter pull-out tests on two differently designed organic bone analogs were carried out using a testing machine with a crosshead speed of 2 mm/minute being applied. One-way analysis of variance with group as factor was performed. Post hoc multiple comparisons Bonferroni test was used. Rank-transformed data were used when asymmetry of data was shown. To assess correlation between characteristics, load, and MIT, Spearman's rank correlation coefficient was used. A P-value of 0.05 was considered statistically significant. Significant direct correlations were found between TSF and depth and both load and MIT. Particularly, a correlation of 0.90 (P < 0.001) was found between depth and MIT for 2.2 mm cortical thickness. The authors conclude that MIT and maximum load values of pull-out test are statistically related to depth of the thread of the screw and to TSF.

Early functional treatment in Class II division 1 subjects with mandibular retrognathia using Fränkel II appliance. A prospective controlled study.

AIM: This was to clarify dentoalveolar, skeletal and facial profile modifications induced by Fränkel II functional treatment in Class II division 1 subjects in prepubertal stages CS1-2. MATERIALS AND METHODS: Evaluation of 25 caucasian subjects (15 males, 10 females), mean age 8y 11m, in vertebral stages CS1-2. The mean duration of functional treatment was 1y 11m. STUDY DESIGN: Prospective controlled study. The sample was evaluated at T0, start of treatment, and T1, end of Fränkel II therapy. Untreated subjects in Class II division 1 were the control group. STATISTICS: T-test for paired data was calculated before and after treatment (P< 0.05). RESULTS: A statistically significant increase between T0 and T1 was obtained for SNB (p = 0.022), ANB (p <0.001), Mx/Mn differential (p = 0.001), Co-Go-Me (p = 0.014), OJ (p < 0.001), OB (p = 0.042), IMPA (p = 0.021) . OJ (p < 0.001) and OB (p = 0.003) showed a higher significant change in the Fränkel group compared to control group. CONCLUSION: The Fränkel II appliance produced, in CS1-2 subiects, significant effects in teeth position, skeletal modifications and soft tissue changes, although the pubertal growth spurt would occur at least two years later.

Temporary anchorage device stability: an evaluation of thread shape factor.

The resistance to extraction of temporary anchorage devices (TADs) depends on various factors, including miniscrew design, shear strength, and bone density. This research introduces the thread shape factor (TSF) as a new factor for the evaluation of TAD mechanical properties. The authors evaluated three TADs for a total of 27 tests: Mini-impianto autoforante (Leone, 1.75 mm diameter and 8 mm length), Orthoscrew (Leader Ortodonzia, 1.65 mm diameter and 9 mm length), and MAS (Miniscrew Anchorage System, 1.3 mm diameter and 11 mm length). For each TAD, the images were acquired via a 20.00 kV scanning electron microscopy to measure their respective mean depth of thread (D), pitch (P), and the relationship between the two (TSF). Subsequently, pullout tests on organic bone analogue were carried out using a testing machine; a crosshead speed of 2 mm/minutes was applied. A two-way analysis of variance was performed to evaluate the interaction between the type of miniscrew and the cortical thickness. A post hoc analysis for single comparisons was subsequently employed. In addition, if homogeneity of variances was not rejected, Scheffè's test was performed, while Tamhane's test was carried out if the homogeneity of variance assumption was not met. Univariate linear regression models were fitted to evaluate the relationship between the outcomes and TSF, D, and P separately. A P value of 0.05 was considered statistically significant. From univariate linear regression, TSF, D, and P were statistically significant predictors of 'peak load'. The tests showed that TSF has a statistical significance for describing the mechanical competency of TADs.

Incidence and distribution of deciduous molar ankylosis, a longitudinal study.

AIM: To study incidence and distribution of deciduous molar ankylosis. MATERIALS AND METHODS: study design: longitudinal retrospective study. A total of 512 consecutive subjects (aged 5 to 15 years) were examined at the Orthodontics and Paediatric Dentistry Department of the Genoa University School of Dentistry; for each subject an ortopantomography x-ray was taken. RESULTS: Thirty-four children were affected by deciduous molars ankylosis (6.6%). A statistically significant difference was revealed between the distributions: the lower deciduous molars were ankylosed more frequently than the upper ones (P < 0.001); the second deciduous molars were ankylosed more frequently than the first molars (P < 0.001). No statistical significance was found between sex and number of infraoccluded teeth (P = 0.74). CONCLUSION: This study found an incidence of deciduous molar ankylosis of about 6.6%; the lower deciduous molars and second deciduous molars were ankylosed more frequently (P < 0.001).

Three-dimensional tomographic mapping related to primary stability and structural miniscrew characteristics.

OBJECTIVES: To evaluate the maxilla, mandible, and cortical plates on computerized tomographic (CT) scans to achieve accurate three-dimensional bone thickness measurements. SETTING AND SAMPLE POPULATION: We selected the CT scans of 25 subjects (among 102), aged 18-58 years (10 men, 15 women), with nearly complete dentition. MATERIAL AND METHODS: We performed interradicular and bucco-lingual (including cortical plate thickness) measurements in dental areas distal to the canines in both alveolar arches, at three levels (5, 8, and 11 mm) from the alveolar ridge. RESULTS: The mean thicknesses of the cortical plates in the maxilla were 1.10 mm buccally and 1.27 mm on the palatal side (p < 0.05). In the mandible, cortical plates were 2.23 mm buccally and 2.02 mm lingually. Mandibular buccal and lingual cortical plates became thicker distally in the second and third molar areas. There was considerable variation in cortical thickness (from 0.25 to 5.50 mm). Based on interradicular distances, only 13% of measured sites in the maxilla were suitable for miniscrew insertion (≥3.3 mm), but 63% of sites were suitable in the mandible. CONCLUSION: This study showed considerable individual variation in bone thickness. Our data suggested that the palatal/lingual side may provide greater primary stability for miniscrews. The palatal area, between the second upper bicuspid and the first molar, appeared to be the most suitable area for tapered 7- to 9-mm miniscrews, starting at 1.5-2 mm from the alveolar crest.

Manual orthodontic vs. oscillating-rotating electric toothbrush in orthodontic patients: a randomised clinical trial.

AIM: To compare the efficacy of manual and oscillating-rotating electric toothbrushes in removing plaque and reducing gingivitis in patients with fixed orthodontic appliances. STUDY DESIGN: Randomised clinical trial. MATERIALS AND METHODS: 20 subjects aged 10 to 14 years (8 males; 12 females) scheduled for fixed orthodontic treatment were enrolled, randomly divided into two groups, A and B, and later assigned electric or manual toothbrushes, respectively. Three months after orthodontic appliance bonding (T1), and again after a further 4 (T2) and 8 (T3) weeks, plaque levels (PI), gingival bleeding (GBI) and hypertrophy were assessed. RESULTS: Between the two toothbrush types, statistically significant differences in PI were detected from T2 to T3 (P value 0.010), but not from T1 to T2. In contrast, the GBI was significantly different from T1 to T2 (P value 0.025), but not from T2 to T3. CONCLUSION: With respect to the manual orthodontic toothbrush, the electric oscillating-rotating toothbrush was found to better improve both PI and GBI.