Thirty lower adult bovine incisors were selected and metallic brackets were bonded using the Concise adhesive system. Each bracket–adhesive–enamel interface was investigated according to torsion debonding. One-way analysis of variance was used for statistical evaluation. Finite element analysis was also undertaken. In order to assess if the technique was detrimental to the enamel, the mode of failure was determined using the Adhesive Remnant Index (ARI). The debonded surfaces were analysed using scanning electron microscopy (SEM) and electron dispersion spectrometry (EDS).

The R-system® provided a bond strength greater than that of the mesh-base bracket. EDS showed that the amount of calcium on the novel base was higher than that on the conventional base, which allowed transfer of torsional stress more uniformly to the substrate, resulting in higher bond values for the R-system®. On the other hand, as debonding of the R-system® occurred at the enamel–composite interface, lesions to the enamel substrate are possible.

On dry enamel, no significant differences between MC (58 ± 5 MPa) and MLS (64 ± 13 MPa) were noted. On wet enamel, the adherence of MC (6 ± 8 MPa) and MLS (37 ± 13 MPa) significantly decreased but to a lesser extent for MLS. The ARI scores corroborated these results.

In conclusion, MC did not tolerate moisture. MLS was also affected but maintained sufficient adherence.

The sample comprised 3196 children and adolescents (1593 males and 1603 females) aged 8–19 years (mean age 13.0 ± 3.6 years) from 24 randomly selected public schools in Zagreb, Croatia. Objective treatment need was assessed clinically using the Dental Aesthetic Index (DAI). Subjective treatment need was estimated separately by an orthodontic resident, the child/adolescent and his/her parent using the Standardized Continuum of Aesthetic Need (SCAN) procedure. The children/adolescents completed a questionnaire that had five questions with five-point Likert-type scale answers concerning satisfaction with dental appearance, importance of teeth for facial appearance, and malocclusion-related quality of life. Spearman correlation and logistic regression were used for statistical analysis.

Associations between objective and subjective orthodontic treatment need were weak but statistically significant (Rho from 0.20 to 0.50; P < 0.05). Malocclusion-related quality of life was poorly associated with treatment need. Satisfaction with tooth appearance showed the most frequent statistically significant correlation (Rho from –0.14 to –0.35; P < 0.05), while importance of aligned teeth for facial appearance and social contacts had the weakest correlation with treatment need. Perception of treatment need was greater in previously treated subjects. Parents’ perception had a low predictive value.

The findings of this study show that malocclusion has more impact on emotional well-being than on function or social contacts.

Little or no microleakage was observed between the composite–enamel interface for any of the three groups, and any difference was not statistically significant. The amount of microleakage at the wire–composite interface was higher than that at the enamel–composite interface. Multiple comparison testing showed statistically significant differences in microleakage between Transbond LR and the ACP-containing adhesive used with primer at the composite–enamel and composite–wire interfaces (P < 0.001). ACP-containing adhesive used with primer showed the highest microleakage scores at the composite–enamel (mean: 0.39 ± 0.42 mm) and composite–wire (mean: 1.66 ± 0.47 mm) interfaces. The hypothesis is rejected. The ACP-containing composite used with or without primer showed significantly higher leakage at the composite–wire interface, while conventional lingual retainer composite showed lower microleakage scores.

Little or no microleakage was observed between the composite–enamel interfaces for the three investigated composites, and any difference was not statistically significant. However, statistically significant differences were found between microleakage at the composite–wire interface for both the conventional and flowable composite groups (P < 0.001). Flowable composite showed the highest leakage (mean: 4.8 ± 0.8 mm), while Transbond XT (mean: 0.5 ± 0.3 mm) and Transbond LR (mean: 1.1 ± 1.2 mm) showed significantly lower and comparable results. The amount of microleakage at the wire–composite interface was significantly greater than that at the enamel–composite interface of flexible spiral wire retainers (FSWRs). The null hypothesis is therefore rejected. Flowable composites may not be appropriate for bonding FSWRs.

A nickel-titanium (Ni-Ti) closed coil spring delivering a force of 10 g was inserted between the upper anterior alveolar bone and the first molar in 8-week-old male C57BL/6 mice. Bisphosphonate (2 µg/20 µl) was injected daily into a local site adjacent to the upper molar. After 12 days, the distance the tooth had moved was measured. The number of tartrate-resistant acid phosphatase (TRAP)-positive cells was counted as osteoclasts in histological sections. Root resorption was assessed by scanning electron microscopy. The data were analysed with a Student’s t-test.

The orthodontic appliance increased the number of osteoclasts on the pressure side and mesial movement of the first molar. Bisphosphonates reduced the amount of tooth movement and the number of osteoclasts. In addition, they also reduced root resorption on the pressure side.

Bisphosphonates inhibit orthodontic tooth movement and prevent root resorption during orthodontic tooth movement in mice. These results suggest that bisphosphonates might have an inhibiting effect on root resorption during orthodontic tooth movement in humans and that they may interrupt tooth movement in orthodontic patients undergoing treatment, thus altering the outcome of treatment.

The prevalence of hypodontia was 6.3 per cent (39.4 per cent males and 60.6 per cent females) with no statistically significant difference between the genders. One case of oligodontia was observed. The maxillary lateral incisor was the most frequently missing tooth, followed by the mandibular second premolar. All cases of hypodontia, except one, were associated with at least one other dental anomaly. These associated dental anomalies were retained primary teeth (30.3 per cent), ectopic canine eruption (25.8 per cent), taurodontism (21.2 per cent), and peg-shaped maxillary lateral incisors (16.7 per cent).

A 2 year parallel study was conducted of 184 patients scheduled to receive bonded retainers in the upper and lower anterior segments. In three centres, the patients (mean age 14 years; 90 males and 94 females) were sequentially assigned to receive GFR retainers containing 500 unidirectional glass fibres (GFR500), 1000 unidirectional glass fibres (GFR1000), or multistranded retainers (gold standard). Retainer failures and periodontal conditions were monitored every 6 months. In a control group of 90 subjects without retainers, periodontal conditions were examined (negative control). Of the 274 recruited patients, 15 dropped out during the 2 year study period. Kaplan–Meier plots were drawn to assess survival of the different retainers. The Mantel–Cox log-rank test was used to identify significant differences in survival functions among the groups. Repeated measures analysis of variance and appropriate post hoc tests were adopted to evaluate periodontal conditions over time.

GFR retainers showed unacceptably high failure rates in comparison with multistranded retainers (51 versus 12 per cent). The most significant periodontal conditions were found in patients with GFR retainers with no significant differences between the GFR500 and the GFR1000 group for any parameter at any time point. Subjects without retainers showed significantly lower levels of gingival inflammation and plaque accumulation when compared with patients in any retainer group.

Multistranded retainers should remain the gold standard for orthodontic retention, although periodontal complications are common. The use of GFR retainers should be discouraged in daily practice.

Each patient was assigned to one of the groups by random number generation. Clinical records in the form of study models were taken at the start of active treatment (T1), at debond (T2), 6 months into the retention phase (T3), and 1 year post-debond (T4). The irregularity index, intercanine width, intermolar width, arch length, overbite, overjet, and Peer Assessment Rating (PAR) scores were measured on study models using digital callipers. A Mann–Whitney test was used to evaluate the treatment changes within each group.

The only statistically significant difference was found to be at T3 and T4 for overbite (P = 0.05 and P = 0.02, respectively). PAR scoring showed more variable changes in group 2. There was good correlation for the measurement method. There was no statistical difference for the two groups for overjet, arch length, intermolar width, intercanine width, and irregularity index at any time point.

The results showed that there was no significant elevation of any of the three inflammatory markers at any of the time points. This research provides evidence that conventional orthodontic treatment is not associated with a systemic immune response in the factors investigated.

Of the 12-year-olds, 23.5 per cent (n = 121) and of the 15- to 16-year-olds, 26.6 per cent (n = 108) were receiving or had previously received orthodontic treatment. The observed agreement between the two indices on the need for treatment among the 12-year-olds (n = 363) was 83.4 per cent and Kappa for diagnostic agreement was 0.52 [95 per cent confidence interval (CI): 0.42–0.63]. For the 15- to 16-year-olds (n = 292), the figures were 82.5 per cent and 0.38 (95 per cent CI: 0.24–0.52), respectively. For the total sample (n = 655), the observed agreement was 83 per cent and the diagnostic agreement was 0.47 (95 per cent CI: 0.39–0.55).

For this population, there was only moderate agreement between the two indices. This means that, when one of these indices is used to measure or prioritize orthodontic treatment in a determined population, the individuals selected with an obvious treatment need are going to be different in 17 per cent of the cases depending on which index is used, DAI or IOTN. This difference has to be taken in consideration when measuring, recording, or quantifying orthodontic treatment need.

This review summarizes the adaptive response of jaw muscles to various stimuli or perturbations in the orofacial system and addresses general changes in muscles as they adapt, specific adaptive changes in jaw muscles under various physiologic and pathologic conditions, and their adaptive response to non-surgical and surgical therapeutic interventions.

Although the jaw muscles are used concertedly in the masticatory system, their adaptive changes are not always uniform and vary with the nature, intensity, and duration of the stimulus. In general, stretch, increases neuromuscular activity, and resistance training result in hypertrophy, elicits increases in mitochondrial content and cross-sectional area of the fibres, and may change the fibre-type composition of the muscle towards a larger percentage of slow-type fibres. In contrast, changes in the opposite direction occur when neuromuscular activity is reduced, the muscle is immobilized in a shortened position, or paralysed. The broad range of stimuli that affect the properties of jaw muscles might help explain the large variability in the anatomical and physiological characteristics found among individuals, muscles, and muscle portions.

Comparison of the two major intrusion techniques for the maxillary anterior teeth, segmented and bioprogressive, revealed that the Burstone TMA 0.017 x 0.025 inch intrusion arch exerted the lowest force on the incisors (0.99 N), followed by the TMA utility 0.017 x 0.025 inch (1.33 N) and the blue Elgiloy 0.016 x 0.016 inch utility (1.43 N). The highest force was recorded for the reverse curve of Spee NiTi and exceeded the value of 9 N. The lowest buccolingual moments were recorded with the Burstone intrusion arch (2.47 Nmm), whereas the highest was registered for the utility arch constructed with a 0.017 x 0.025 inch TMA wire (7.31 Nmm).

There were no statistically significant differences between the two retention regimens at T2 for labial segment irregularity or crowding (P > 0.05). Since both retention regimens were equally effective during the 1 year retention period, it would seem clinically acceptable to ask patients to wear their retainers at night only.

For both groups, the maxillary base, nasal cavity width and upper intercanine and intermolar distances were increased, and the upper molars tipped buccally. The only statistically significant (P < 0.05) difference between two groups was in inferior movement of posterior nasal spine (PNS) relative to the SN plane (SNPNS). This measurement increased in both groups yet significantly more in the RME group. The results suggest that RME and SRME have similar effects on dentofacial structures both in the transverse, vertical, and sagittal planes.

Forty ceramic discs (15 mm in diameter and 1.5 mm thick) of each ceramic were prepared and divided into four equal groups. Ten pieces of each group of different bracket bases (beads, Inspire Ice; large round pits, Crystalline IV; and irregular base, Clarity) and one group of stainless steel brackets (Optimesh XRT, control) were bonded to glazed ceramics under a 200 g load. All specimens were then subjected to SBS evaluation using a universal testing machine at a crosshead speed of 0.2 mm per minute. The data were analysed using analysis of variance and Tukey’s test at a significance level of 0.05. The mode of failure was examined under a stereomicroscope.

The results demonstrated that for Vitadur Alpha and IPS e.max Ceram, the highest SBS were found with Inspire Ice (25.1 ± 2.6 and 24.9 ± 2.1 MPa) and were significantly different than Crystalline IV (21.6 ± 1.1 and 20.9 ± 1.5 MPa), Clarity (19.6 ± 1.5 and 19.3 ± 2.3 MPa), and Optimesh XRT (14.9 ± 1.3 and 15.3 ± 2.2 MPa; P < 0.05). Inspire Ice and Crystalline IV had 100 per cent adhesive failure while Clarity and Optimesh XRT had combination failure. The various base designs gave different SBS, but the SBS of all base designs could withstand normal orthodontic force.

One-way analysis of variance showed a significant effect of ligation mode on the frictional properties of the three-bracket set-ups (P < 0.001). Post hoc pairwise comparison showed that the frictional forces arising from passive self-ligation were significantly lower (P < 0.01) than those resulting from elastic ligation. The same result was achieved when comparing self-ligation and metallic ligation (P < 0.01). No significant difference was found when comparing elastic and metallic ligation.

The SBS values were 24.7 ± 9.2 and 10.2 ± 5.5 MPa and the mean WPO values 19.8 ± 4.6 and 11.1 ± 5.7 N for Transbond-LR and Fuji Ortho-LC, respectively. Statistical analysis showed that the SBS and WPO values of Transbond-LR and Fuji Ortho-LC were significantly different (P < 0.001). No significant differences were present among the groups in terms of fracture mode. However, the RMGIC resulted in a significant decrease in SBS and WPO; it produced sufficient SBS values on the etched enamel surfaces, when used as a bonded orthodontic retainer adhesive.

The history of orthodontic treatment decreased the odds for acceptability of morphology [odds ratio (OR) = 0.719, 95 per cent confidence limit (CL), P = 0.016] and acceptability of function (OR = 0.724, 95 per cent CL, P = 0.018). The early timing of treatment increased the odds for acceptability of morphology (OR = 1.370, 95 per cent CL, P = 0.042) and of function (OR = 1.420, 95 per cent CL, P = 0.023). No substantial differences were observed in the acceptability of occlusion between the early and late timing health centres. However, the proportion of subjects with acceptable occlusion was slightly higher in the early than in the late timing group. These findings suggest that when examining the effect of timing on treatment outcome, factors other than acceptability of occlusion should be concomitantly evaluated. Consequently, in this context, the duration and cost of treatment need to be investigated.

Significant favourable skeletal changes in the maxilla and mandible were observed in the treated group both after Ts2 and T3. No significant short- or long-term changes in the sagittal oropharyngeal and nasopharyngeal airway dimensions were induced by maxillary protraction in subjects with a Class III malocclusion when compared with untreated controls.

The gingival sides of group 1 displayed a higher median microleakage score than the occlusal side at the enamel–composite interface but this was not statistically significant (P > 0.05). All occlusal margins in both groups showed no microleakage under orthodontic brackets at the enamel–composite or composite–bracket interfaces. Comparisons of the microleakage scores between the direct and the indirect bonding groups at the enamel–composite and composite–bracket interfaces indicated no statistically significant microleakage differences at the gingival and occlusal margins (P > 0.05). The type of bonding method (direct versus indirect) did not significantly affect the amount of microleakage at the enamel–composite–bracket complex.

In a multicentre retrospective study, 400 pre-treatment lateral cephalograms of adult patients (over 17 years of age) with a skeletal Class III (n = 250, 132 females and 118 males) or a skeletal Class I (n = 150, 94 females and 56 males) malocclusion were analysed. The morphology, length, depth, and diameter of the sella turcica were investigated. For statistical analysis, chi-square and t-tests were used.

Skeletal Class III patients presented a significantly higher rate of sella turcica bridging, 16.8 per cent (P = 0.031), in comparison with skeletal Class I patients, whose rate was 9.4 per cent. No differences between females and males were detected for the length, depth, and diameter of the sella turcica. Bridging of the sella turcica could be seen radiographically in skeletal Class III subjects.

Ten patients (seven males and three females; aged 22.0 ± 3.4 years), who required orthodontic treatment with extraction of all four premolar teeth, participated in the study. Twenty miniscrew implants (used as orthodontic anchorage) were placed, two in each patient, buccally and bilaterally in the alveolar bone between the roots of the maxillary posterior teeth. Sentalloy closed-coil springs (50 g) were used to load the miniscrew implants and to move the maxillary canines distally. During the unloaded period, PMICF samples were collected on days 1, 3, 5, and 7 after miniscrew implant placement and on days 14, 21, 28, and 35 during the loaded period. Clinical mobility assessments of the miniscrew implants were recorded at each visit. The competitive enzyme-linked immunosorbent assay with monoclonal antibody WF6 was used to detect CS (WF6 epitope) levels in the PMICF samples. The differences between the CS (WF6 epitope) levels during the unloaded and loaded periods were determined by a Mann–Whitney U-test.

During the loaded period, two miniscrew implants were considered to have failed. The CS (WF6 epitope) levels during the unloaded period ranged from 0.00 to 758.03 ng/ml and those during the loaded period from 0.00 to 1025.11 ng/ml. Medians of CS (WF6 epitope) levels, around ‘immobile’ miniscrew implants, between the unloaded and loaded periods were not significantly different (P = 0.07).

CS (WF6 epitope) levels in PMICF can be detected and may be used as biomarkers for assessing alveolar bone remodelling around miniscrew implants during orthodontic loading.

A total of 30 subjects (15 females and 15 males) with an Angle Class I occlusal relationship and normal antero-posterior (ANB, 2–4 degrees) skeletal relationships were selected from the archive of Dicle University. All subjects were of Anatolian Turkish heritage, and none had any apparent facial disharmony or had undergone orthodontic therapy. Lateral cephalometric radiographs taken at T1 (mean age 8.8 years), T2 (mean age 13.8 years), and T3 (mean age 17.8 years) were separately investigated. Non-gender-specific research was also carried out at the same time periods. In total, 24 measurements were analysed longitudinally. Differences between the genders were determined using independent t-tests. Repeated measures analysis of variance tests were used to evaluate repeated measurements, and paired sample t-tests to compare inside effects between the genders.

Significant increases (P < 0.05) were found with age for both females and males. Generally, the increases were greater in males than in females. Nasal prominence increased more than chin prominence, resulting in a tendency to have convex profiles.

A one-way analysis of variance test conducted at a 95 per cent confidence level (CL) demonstrated that there was a significant difference (P < 0.01) with respect to the four methods of preparation of the enamel surface. An unpaired t-test was then applied at a 95 per cent CL. There was no statistically significant difference between groups 1 and 2. There was, however, a statistically significant difference between groups 1 and 3 (P < 0.01), as well as between groups 1 and 4 (P < 0.01). In addition, there was significant difference found between groups 2 and 3 (P < 0.05), groups 2 and 4 (P < 0.01), and groups 3 and 4 (P < 0.05).

The results of this study revealed that unerupted incisors were more frequent in males than in females. A statistically significant association (P = 0.006) was found between unerupted incisors and other inherited dental anomalies, namely ectopic teeth, hyperdontia, and enamel hypoplasia.

Unerupted incisors may be considered part of a spectrum of inheritable dental anomalies.

The distance between the teeth in group II was significantly greater than that in group I during the first 3 days. Between days 4 and 14, no significant difference was observed. During the last 6 days, except for day 19, tooth movement in group II again increased, resulting in the distance between the teeth being greater in group II. The mean total opening was 3.98 ± 0.59 mm in group I and 4.82 ± 0.82 mm in group II, and the mean difference was approximately 0.8 mm.

The results of this study show that there was a close relationship between tooth movement and force magnitude. However, higher forces did not produce force-equal tooth movements.

The aim of this study was to compare, retrospectively, two orthodontic treatment approaches in patients treated by a BSSO. In one group (4 males, 20 females; mean age pre-surgery 29.3 years), the deep bite was maintained (deep bite group) while in the other (3 males, 10 females; mean age pre-surgery 27.1 years) the overbite was normal prior to surgery (level group). Lateral skull radiographs were taken before orthodontic treatment (T0), prior to surgery (T1), and at the end of treatment (T2). Differences between the groups as measured on lateral skull radiographs at T1 and T2 were analysed and quantified using an independent t-test.

The results showed that soft tissue pogonion moved significantly further forward in the level than in the deep bite group (P < 0.05). Lower anterior face height and the cranial base-mandibular plane angle increased more in the deep bite than in the level group (P < 0.05 and P = 0.001, respectively).

The maintenance of a deep bite prior to mandibular advancement surgery induces an opening rotation of the mandible reducing chin prominence and increasing lower anterior face height post-surgically.

The mandibular third and maxillary second premolars of five skeletally mature male foxhounds, approximately 2 years of age, were extracted. One randomly selected mandibular quadrant had buccal and lingual flaps and corticotomies performed around the second premolar; the other quadrant served as the control. Both maxillary quadrants had initial buccal flaps and corticotomies; one randomly selected quadrant had a second buccal flap surgery and corticotomy after 28 days. Coil springs (200 g force), along with a 0.045 mm diameter tube on a 0.040 mm diameter guiding wire, were used to move the mandibular second and maxillary third premolars. Records, including digital calliper measurements and radiographs, were taken on days 0, 10, 14, 28, 42, and 56. Multilevel statistical procedures were used to model longitudinal tooth movements.

The radiographic measurements initially showed increasing mandibular tooth movement rates, peaking between 22 and 25 days, and then decelerating. Total mandibular tooth movements were significantly (P < 0.05) greater on the experimental (2.4 mm) than on the control (1.3 mm) side. The rates of maxillary tooth movement slowed over time, with significantly (P < 0.05) more overall tooth movement on the side that had two (2.3 mm) than one (2.0 mm) corticotomy procedure.

Alveolar corticotomy significantly increases orthodontic tooth movement. Performing a second corticotomy procedure after 4 weeks maintained higher rates of tooth movement over a longer duration and produced greater overall tooth movement than performing just one initial corticotomy, but the difference was small.

None of the investigated groups showed statistically significant gender differences for posterior vertical height measurements (P > 0.05). Asymmetry indices were similar, with no statistically significant differences found in any of the groups. However, gonial angle showed statistically significant differences (P < 0.05) in the UCLP group and condylar height (CH) in the BCLP patients (P < 0.001). Except for CH measurement in the BCLP group, CLP patients have symmetrical mandibles when compared with a normal occlusion sample.

A significant gender difference was found only for posterior ratio in all groups (P < 0.01). There was no significant difference among the malocclusion groups in anterior ratio, but the differences for overall and posterior ratios were significant (P < 0.05 and P < 0.001, respectively). A large number of subjects had discrepancies greater than 2 SD from Bolton's mean. In addition, the means and SDs in this investigation were found to be larger than those of Bolton. Intermaxillary tooth size ratios may vary in different malocclusion types and may, to some degree, contribute to the severity of a malocclusion.

The study comprised 151 adult patients who were referred for orthodontic or surgical-orthodontic treatment to the Oral and Maxillofacial Department, Oulu University Hospital, Finland during the years 2001–2004. The study group consisted of 92 females and 59 males with a mean age of 35.5 years [standard deviation (SD) 11.5 years, range 16–64 years]. A self-completed Oral Health Impact Profile (OHIP)-14 questionnaire was used to measure oral impacts during a 1 month reference period. The prevalence, extent, and severity scores were calculated from the OHIP-14. Malocclusions were registered at clinical examination. The prevalence and mean extent and severity scores were compared among malocclusion groups and between genders. Statistical significance was evaluated with Mann–Whitney, Kruskall–Wallis, Chi-squared, and Fisher’s exact tests.

The prevalence of oral impacts perceived fairly or very often was 70.2 per cent. The mean severity and extent scores were 17.2 (SD 10.5, range 0–45) and 2.5 (SD 2.6, range 0–10), respectively. Physical pain as well as psychological discomfort and disability were the most commonly perceived oral impacts. Being self-conscious, feeling tense, having difficulties in relaxing, and being somewhat irritable with other people were more common in females than in males. No differences were observed in oral impacts among the malocclusion groups.

Compared with a ‘normal’ population, patients with severe malocclusions report high levels of oral impacts. Females reported oral impacts more often than males.

No significant change was observed in the number of posterior contacts during T1, whereas a significant increase was found at T2 (P < 0.01) for the second premolars (P < 0.01) and second molars (P < 0.05). Both ‘ideal’ and ‘non-ideal’ contacts increased significantly but only at T2 (P < 0.05). The number of ideally located contacts on the posterior teeth at all three periods were lower than normal values (P < 0.01); while non-ideal contacts at T1 (P < 0.05) and T2 (P < 0.01) were found more often when compared with the values of normal subjects. Only the increased number of premolar contacts at T2 was more than normal values (P < 0.01). There was no expected increase in occlusal contacts at T2; however, posterior occlusal contacts were increased at T3.

The highest KHN was obtained with the QTH at 30 (25.19 KHN) and 20 (24.01) seconds, which did not differ statistically, and in the LED 15 second (21.86) group. The QTH 10 second group (20.53) did not differ statistically from the QTH 20 second or the LED 5 (19.96) and 15, or 10 second (18.95) groups. According to FTIR, there was no statistical difference for the degree of conversion among the groups, QTH 10 (43.42 per cent), QTH 20 (46.12 per cent), QTH 30 (45.30 per cent), LED 10 (47.02 per cent), or LED 15 (47.24 per cent) seconds. The lowest degree of conversion was obtained for the LED 5 second group (38.97 per cent), which did not differ statistically from the QTH 10 second group.

Light curing with the LED resulted in a reduction of 50 per cent in the time recommended for use of the QTH light with the composite resin, Transbond XT.

The findings indicated that this southern Italian school population showed a rather low prevalence rate for objective need for treatment (grades 4 and 5; 27.3 per cent of the total sample). This prevalence rate is generally lower than those reported in northern and central European countries (Sweden, Germany, and UK) but slightly greater than those in France. No significant differences in the DHC grades of the IOTN were found between genders. Among the occlusal features diagnosed in the subjects examined, a high prevalence rate was found for crowding (45.9 per cent). Moreover, posterior crossbites and Class III malocclusions, which would presumably have benefited from early orthodontic intervention, were still present in 14.2 and 4.3 per cent of the students, respectively.

Bleeding on probing (BOP), plaque index (PI), and pocket probing depth (PPD) were measured in 10 adults (8 females and 2 males, aged 29.0 ± 4.7 years) who received treatment with custom-made lingual appliances (Incognito/iBraces) before (T₀) and 3 months after beginning of treatment (T₁). No supportive dental prophylaxis was undertaken. In addition, a 16S rRNA-based polymerase chain reaction (PCR) method was used to detect Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) in the crevicular fluid. A Wilcoxon test was used to compare clinical parameters at the buccal (control) and lingual sites between T₀ and T₁.

At T₀, BOP was 12.4 ± 8.2 per cent, PPD 2.1 ± 0.3 mm, and PI 0.1 ± 0.2 at the buccal sites and at T₁ 14.3 ± 8.1 per cent, 2.1 ± 0.2 mm and 0.1 ± 0.2, respectively. At the lingual sites, BOP was 22.2 ± 19.0 per cent, PPD 2.3 ± 0.3 mm, and PI 0.1 ± 0.2 at T₀ and at T₁ 56.2 ± 31.6 per cent, 2.9 ± 0.3 mm, and 1.2 ± 1.1, respectively. Differences between T₀ and T₁ were significant for clinical parameters only at the lingual sites. Aa was found in five patients at baseline and in four at T₁, whereas Pg was found in one patient at T₀ and in two at T₁.

Insertion of fixed lingual appliances without supportive dental prophylaxis induced a worsening of clinical parameters restricted to the lingual sites, whereas the relative prevalence of Aa and Pg remained unchanged.

The average MBF in Jordanian adults was 573.42 ± 140.18 N. Those with a short face had the highest MBF (679.60 ± 117.46 N) while the long-face types had the lowest MBF (453.57 ± 98.30 N; P < 0.001). The average MBF was 599.02 ± 145.91 in males and 546.97 ± 131.18 in females (P = 0.149). No gender differences were observed. The average MBF was higher in patients with premature contacts than those without, while it did not differ in subjects with different types of functional occlusion or in the presence of parafunctional habits.

A questionnaire-based study was carried out at Bristol Dental Hospital between November 2005 and March 2006. Questionnaires were distributed within the dental hospital and at local meetings in order to obtain a mixed sample of hospital and practice-based orthodontists. The clinicians asked to complete the questionnaire were consultant orthodontists (n = 37), specialist practitioners (n = 36), senior specialist registrars in orthodontics (n = 10), and dentists with a special interest in orthodontics (n = 17). The questionnaire consisted of two parts: the first was concerned with the initial alignment phase of treatment and the second with the space-closing phase of treatment in premolar extraction cases. The choice of archwires, significance of arch form, and intra-arch dimensions considered important at both stages were assessed. The clinicians were also asked about their usual practice with regard to adaptation of working archwires and the use of study models and symmetry charts.

One hundred questionnaires were returned, giving a response rate of 92.6 per cent. The majority of clinicians felt that preservation of the pre-treatment arch form was essential in the latter but not in the early stages of treatment. In particular, conservation of the original intercanine width was considered important. However, there was no uniformity in how arch form should be preserved. Some respondents used study models and symmetry charts as an aid, but even then they were used in different ways. There was no uniformity in the landmarks used when adapting stainless steel archwires to arch form. Therefore, even when clinicians do adapt their archwires carefully with the intention of preserving arch form, are they choosing the correct arch form?

µCT analysis showed that the condylar width was significantly greater in the HD group than in the SD group after 1 week. After 4 weeks, mandibular length was significantly longer and ramus height was greater in the HSD group than in the other two groups. Bone volume was significantly less in the SD group than in the other two groups after 4 weeks. These findings suggest that changes in mastication markedly affect mandibular condylar cartilage growth and mandibular morphology. It is considered that dietary education at an early age is important in order to prevent disruption of the development of the mandible.

The fields described cover all areas seen on profile, frontal, and panoramic radiographs. The fields are the theca, frontonasal, maxillary, palatine, and mandibular together with the cerebellar field and cervical spine. Regional fields in the dentition are described according to the pattern of peripheral nerve innervation. Studies on severely malformed foetuses show that the malformation can occur solely within a single field or in several fields. This is the background for these personal views on craniofacial patterning. These new views may assist in the diagnosis and interpretation of malformations in the cranium and dentition.

The right upper first molars of 25 twelve-week-old male Wistar anaesthetized rats were loaded with forces in order to be moved mesially. Constant forces for 4 hours of 0.25 and 0.5 N were applied in five animals each. Furthermore, constant forces for 2 hours of 0.1 N were applied in 10 animals and afterwards, the first and second molars were permanently separated with composite. In these animals, the antagonists were sliced and five rats were killed after 1 day and five after 2 days. As a last experiment, intermittent forces of 0.1 N and 0.25 Hz were applied in five different animals for 4 hours. The untreated contralateral sides served as the control. Paraffin-embedded sections were analysed by immunohistochemistry for proliferating cell nuclear antigen (PCNA), runt-related transcription factor 2 (Runx2/Cbfa1), and phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2). Statistical analysis to determine differences between the groups was carried out using a Student's t-test.

In selected areas under tension, the proportion of pERK1/2-positive cells was increased compared with those in control teeth under all types of loading, whereas these proportions in selected areas under pressure were increased only after the application of intermittent forces. In representative areas, both under tension and pressure, the proportion of Runx2-positive cells decreased after the application of constant forces. After the application of constant forces for 4 hours in representative areas, both under tension and pressure, the proportion of PCNA-positive cells was lower than those in control teeth.

The involvement of pERK1/2, Runx2/cbfa-1, and PCNA in the reaction of PDL cells to different load regimens was verified.

Anterior coronoid marginal depth correlated negatively (r = 0.71) with gonial angle, SNA, and overjet. The coronoid angle also correlated negatively (r = 0.86) with both the vertical and horizontal lengths from sella to the coronoid tip as well as with the horizontal length from sella to the posterior ramus margin. Furthermore, the coronoid length correlated positively (r = 0.61) with the coronoid angle and the anterior coronoid marginal depth. The coronoid width was also positively (r = 0.69) correlated with overbite.

Coronoid process morphology is related not only to mandibular morphology and position but also to maxillary position and the dental relationship in the anterior region. It therefore seems clear that coronoid process morphology might be related to temporal muscle functioning and its associated craniofacial morphological measurements.

Single or multiple hypodontia was diagnosed in 137 patients (6.5 per cent), 62 males and 75 females. One or more supernumerary teeth were found in 42 patients (2 per cent), 22 males and 20 females. CHH was diagnosed in seven subjects (0.33 per cent), four males and three females. In the CHH subpopulation, the total number of absent and supernumerary teeth was nine and eight, respectively. Hypodontia always occurred in the permanent dentition and was more frequent in the mandible than in the maxilla (four versus three teeth). Supernumerary teeth were more frequent in the permanent than in the primary dentition (six versus two teeth). Five supernumeraries were located in the maxilla and three in the mandible.

Four patients (2.6 per cent) were found to have secondary ossicles in close relationship to the first cervical vertebra, while in 7.4 per cent, the vertebral arteries of the atlas were surrounded by a complete ring-shaped osseous structure. Three cephalograms showed atlas posterior arch dehiscence. After visual examination, 14 patients were provisionally identified as presenting fusion between the second and third cervical vertebrae. However, growth-based superimposition of the radiographs disclosed that no patient showed actual fusion, even though the lateral cephalometric analysis revealed sufficient extreme skeletal patterns, which have been previously related to vertebral fusion.

The findings of this study demonstrated a low percentage of atlas anomalies. It was not possible to correlate skeletal pattern to fusion of cervical vertebrae because no fusions were found. Subjective visual examination of a single cephalogram may result in false-positive findings of fusion and growth-based superimposition is recommended.

Five identical appliances were manufactured from three different materials all with a thickness of 1.0 mm (Ideal Clear®, Erkodur®, and Biolon®). For measuring the forces, an isolated measuring tooth, as part of a standardized resin model incorporated in a newly developed measuring device, was tipped in nine arc minute ( degree) steps, from 0 to degrees in the vestibular and palatal directions around a rotational axis through the virtual apex, after positioning an appliance on the model. For statistical analysis, the force components Fx/tipping and Fz/intrusion at a displacement of ±0.151 mm from the incisor edge were determined. Means and standard deviations (SDs) were calculated. The Kruskal–Wallis test for overall effects and the Wilcoxon two-sample test for individual group pairings were used (P < 0.05 significance level).

The mean Fx forces ranged from –2.82 N (SD 0.62) to 5.42 N (SD 0.56). The mean Fz forces were between –0.14 N (SD 0.52) and –2.3 N (SD 0.43). The highest intrusive forces were measured during vestibular displacement of the measuring tooth. The forces delivered by the Biolon® appliance were found to be much greater (P < 0.01) than those of the other materials.

The forces delivered by the materials investigated were mostly higher than those stated in the literature.

The bond strength of group 3 (mean: 36.7 ± 11.8 MPa) was significantly higher than group 4 (mean: 26.6 ± 8.9 MPa; P < 0.05), group 1 (mean: 25.5 ± 5.1 MPa; P < 0.01), and group 2 (mean: 22.9 ± 7.3 MPa; P < 0.001). No significant differences in debond locations were found among the groups (P > 0.05). Compared with conventional acid etching, SEPs significantly decreased the SBS of ceramic orthodontic brackets.

The experimental connector is easily constructed, inexpensive, and small enough for use as an intraoral MAS. To evaluate durability, the axial and diagonal tensile breaking strengths of the MAS, using high- or low-density polyethylene (HDPE or LDPE) lateral toothed belts, were compared with those of a conventional mobile MAS (Silensor). The values were compared by factorial analysis of variances and post hoc Scheffe's S multiple comparison intervals, with the value of statistical significance set at alpha = 0.05. In addition, the experimental LDPE connectors were clinically tested in 30 patients (23 males and 7 females aged 19–71 years) and evaluated.

Compared with the Silensor, the experimental MAS exhibited sufficient breaking strength, especially when a diagonal tensile load was applied to mimic mandibular lateral translation. When examining the clinical evaluation between 3 and 4 months after insertion, no damage or failure was observed.

The experimental connecting system may have clinical applications. To make the connector stronger for clinical use, HDPE should be used.

Statistical analysis showed that the bond strengths of the control (Transbond LR, mean: 24.77 ± 9.25 MPa) and Clearfil Protect Bond with etching, (mean: 20.24 ± 8.5 MPa) were significantly higher than Clearfil Protect Bond without etching, (mean: 12.56 ± 6.93 MPa). In general, a greater percentage of the fractures were adhesive, at the tooth–composite interface (60–65 per cent). No statistically significant difference was found among the groups. The hypothesis is thus rejected. Within the limits of this in vitro model, antibacterial monomer-containing self-etch adhesive with acid etching did not significantly affect shear bond strength when compared with the control. However, the same adhesive used without acid etching resulted in a significant decrease in bond strength.

The results showed that most of the marginal ridge points studied deteriorated during digitized treatment prediction compared with T1. Statistical and clinically significant changes (P < 0.05) were found for upper premolar and lower molar marginal ridge points. Variability in the facial contour of the teeth seemed to play an important role.

At T1, the majority of the cephalometric measurements showed statistically significant changes. ANB was significantly reduced by 2.3 degrees due to a significant increase in SNB, but only small changes were observed in SNA. The interincisal angle increased as a result of significant retroclination of both maxillary and mandibular incisors. All patients achieved a Class I molar relationship and a significant reduction in overjet and overbite. At T2, the results showed only slight relapse from T1. However, the relapse did not compromise the significant improvement in almost all the cephalometric and dental variables. Combined activator–headgear treatment improved the skeletal and dental conditions and the results remained stable in the long term.

No difference was found in the demographics and oral hygiene indices between the two groups, verifying the random assignment of brackets to the population sample. The levels of S. mutans in whole saliva of orthodontically treated patients do not seem to be significantly different between conventional and self-ligating brackets. The pre-treatment levels of S. mutans are significant predictors of the levels of S. mutans after placement of orthodontic appliances, while this was not the case for total bacterial counts.

The results demonstrated that group 1 (Transbond XT, mean: 12.60 ± 4.48 MPa) had a higher SBS than that of group 2 (nano-composite, mean: 8.33 ± 5.16 MPa; P < 0.05) and group 3 (nano-ionomer, mean: 6.14 ± 2.12 MPa; P < 0.001). No significant differences in debond locations were found among the three groups. Nano-composites and nano-ionomers may be suitable for bonding since they fulfil the previously suggested SBS ranges for clinical acceptability, but they are inferior to a conventional orthodontic composite.

The lingually inclined, crowded lateral incisor presented an extrusive and buccal movement and showed the lowest force in the vertical direction, whereas the self-ligating group of brackets generated the highest force in the buccolingual direction. The moments applied by the three bracket systems followed the general trend shown for forces; in the vertical axis, the self-ligating brackets exerted lower forces than their conventional counterpart. This was modified in the buccolingual direction where, in most instances, the self-ligating appliances applied higher moments compared with the conventional bracket. In most cases, the magnitude of forces and moments ranged between 30–70 cN and 2–6 N mm, respectively. However, maximum forces and moments developed at the lateral incisor were almost four times higher than the average.

The dental casts and lateral cephalometric radiographs of 301 Croatian subjects (127 males and 174 females, mean age 16.86 ± 2.93 years) were selected from a larger sample of records of the archives of the Orthodontic Department, School of Dental Medicine, University of Zagreb, Croatia. The subjects were from malocclusion groups according to Angle classification, with the corresponding skeletal characteristics. The MD dimensions of all teeth from first molar to first molar were measured on the dental casts using digital callipers. Statistical analysis was undertaken using Kolmogorov–Smirnov, t, and Scheffé’s tests and one-way analysis of variance.

A statistically significant gender difference was found in anterior ratio (P = 0.017). A significant difference in the overall and posterior ratio was observed between Class II and Class III subjects. There was a tendency for mandibular tooth size excess in subjects with an Angle Class III malocclusion and for maxillary tooth size excess in those with an Angle Class II malocclusion. The percentage of subjects more than 2 standard deviations from Bolton's means for anterior and overall ratios was 16.28 and 4.32, respectively.

The Milan sample comprised 88 UCLP patients (60 males, 28 females) at 5 years of age and 26 patients (17 males, 9 females) at 10 years of age all operated on by the same surgeon. The Oslo sample consisted of 48 UCLP patients (26 males, 22 females) aged 5 years and 29 patients (20 males, 9 females) aged 10 years treated by four different surgeons. Lateral cephalometric radiographs obtained for both samples were analysed and angular measurements and ratios were calculated both for the hard and soft tissues. Statistical analysis was undertaken with an unpaired t-test.

At 5 years of age, there were neither sagittal nor vertical hard tissue differences between the two groups. With regard to the soft tissues, only the naso-labial angle showed a statistically significant difference (Milan greater than Oslo by 5 degrees, P < 0.01). At 10 years of age, both SNA and ANB differences were larger in the Oslo group than in the Milan group, >2.6 degrees, P < 0.01 and >2.9 degrees, P < 0.001, respectively.

At 5 years of age, the Milan UCLP sample had the same maxillary protrusion as the Oslo group, while at 10 years of age, the Milan sample were slightly less protruded than the Oslo group.