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.

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.

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.

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.

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.

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.

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.

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.

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.

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?

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.

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 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.

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 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.

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.

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 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.

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.