Changes In Angulation Research Articles

Changes in mandibular incisor position and arch form resulting from Invisalign correction of the crowded dentition treated nonextraction.

To investigate changes in mandibular incisor position resulting from Invisalign correction of the crowded dentition without extraction. A retrospective chart review was completed on 61 adult White patients. Patients were categorized into three groups based on the value of pretreatment crowding of the lower dentition: 20 mild (2.0-3.9 mm), 22 moderate (4.0-5.9 mm), and 19 severe (>6.0 mm). Cephalometric radiographs were measured to determine lower incisor changes. Interproximal reduction and changes in arch width were also measured. Statistical evaluation of T0 and T1 values using paired t-tests and analysis of covariance were applied to evaluate mean value changes. Lower incisor position and angulation changes were statistically significant in the severe crowding group. There were no statistically significant differences in lower incisor position between the mild and moderate crowding groups. There was a statistically significant increase in buccal expansion in each of the three groups. Invisalign(®) treatment can successfully resolve mandibular arch crowding using a combination of buccal arch expansion, interproximal reduction, and lower incisor proclination. When there is <6 mm of crowding, lower incisor position remained relatively stable. The lower incisors proclined and protruded in the more severely crowded dentitions (>6 mm).

Endograft Shortening During Endovascular Repair of Abdominal Aortic Aneurysms in Severe Aortoiliac Tortuosity

Severely tortuous aortoiliac anatomy can influence the deployment of the endograft during endovascular abdominal aortic aneurysm repair (EVAR) and have a negative impact on distal fixation. The purpose of this study was to determine how severe aortoiliac tortuosity can change an aortic endograft's length and how it affects distal fixation. A retrospective review of a prospectively collected vascular surgery database at a university-affiliated medical center was used to identify the study patients. The goal was to identify patients who underwent EVAR with the main body device deployed to a severely tortuous iliac artery. Severe aortoiliac tortuosity was defined as aortoiliac or iliac angulation of <90°. Patients were excluded if more than one device was deployed distal to the main body device, which made accurate lengths measurements difficult. A total of 469 patients underwent EVAR between 2008 and 2014. Of the 171 patients with severe aortoiliac tortuosity, in only 18 patients was the main body placed on the side of severe tortuosity without an extension limb. The mean length of the main body for EVAR was 169 mm, and this length significantly shortened to 147 mm once it was placed in the severely tortuous AAA (P < .001). Treatment length of the main body side measured from the lowest renal artery to the iliac bifurcation also significantly shortened from 179 mm to 170 mm (P = .001). The most angulated portion of the artery on the main body side became significantly less post-EVAR, changing from 86° to 114° (P < .001). Analysis of the nontortuous side showed a nonsignificant change in treatment length (P = .859) and angulation (P = .195). Severe aortoiliac tortuosity can cause significant shortening of endografts, which can negatively impact distal fixation during EVAR. Consideration for a longer main body or an extension limb should be given in tortuous aneurysms.

Combined Coil Embolization and Foam Sclerotherapy for the Management of Varicose Veins: Description of a Novel Technique

Objectives: Severely tortuous aortoiliac anatomy can influence the deployment of the endograft during endovascular abdominal aortic aneurysm repair (EVAR) and have a negative impact on distal fixation. The purpose of this study was to determine how severe aortoiliac tortuosity can change an aortic endograft’s length and how it affects distal fixation. Methods: A retrospective review of a prospectively collected vascular surgery database at a university-affiliated medical center was used to identify the study patients. The goal was to identify patients who underwent EVAR with the main body device deployed to a severely tortuous iliac artery. Severe aortoiliac tortuosity was defined as aortoiliac or iliac angulation of <90 . Patients were excluded if more than one device was deployed distal to the main body device, which made accurate lengths measurements difficult. Results: A total of 469 patients underwent EVAR between 2008 and 2014. Of the 171 patients with severe aortoiliac tortuosity, in only 18 patients was the main body placed on the side of severe tortuosity without an extension limb. The mean length of the main body for EVAR was 169 mm, and this length significantly shortened to 147 mm once it was placed in the severely tortuous AAA (P < .001). Treatment length of the main body side measured from the lowest renal artery to the iliac bifurcation also significantly shortened from 179 mm to 170 mm (P 1⁄4 .001). The most angulated portion of the artery on the main body side became significantly less post-EVAR, changing from 86 to 114 (P < .001). Analysis of the nontortuous side showed a nonsignificant change in treatment length (P 1⁄4 .859) and angulation (P 1⁄4 .195). Conclusions: Severe aortoiliac tortuosity can cause significant shortening of endografts, which can negatively impact distal fixation during EVAR. Consideration for a longer main body or an extension limb should be given in tortuous aneurysms.

Combined Coil Embolization and Foam Sclerotherapy for the Management of Varicose Veins: Description of a Novel Technique

Objectives: Severely tortuous aortoiliac anatomy can influence the deployment of the endograft during endovascular abdominal aortic aneurysm repair (EVAR) and have a negative impact on distal fixation. The purpose of this study was to determine how severe aortoiliac tortuosity can change an aortic endograft’s length and how it affects distal fixation. Methods: A retrospective review of a prospectively collected vascular surgery database at a university-affiliated medical center was used to identify the study patients. The goal was to identify patients who underwent EVAR with the main body device deployed to a severely tortuous iliac artery. Severe aortoiliac tortuosity was defined as aortoiliac or iliac angulation of <90 . Patients were excluded if more than one device was deployed distal to the main body device, which made accurate lengths measurements difficult. Results: A total of 469 patients underwent EVAR between 2008 and 2014. Of the 171 patients with severe aortoiliac tortuosity, in only 18 patients was the main body placed on the side of severe tortuosity without an extension limb. The mean length of the main body for EVAR was 169 mm, and this length significantly shortened to 147 mm once it was placed in the severely tortuous AAA (P < .001). Treatment length of the main body side measured from the lowest renal artery to the iliac bifurcation also significantly shortened from 179 mm to 170 mm (P 1⁄4 .001). The most angulated portion of the artery on the main body side became significantly less post-EVAR, changing from 86 to 114 (P < .001). Analysis of the nontortuous side showed a nonsignificant change in treatment length (P 1⁄4 .859) and angulation (P 1⁄4 .195). Conclusions: Severe aortoiliac tortuosity can cause significant shortening of endografts, which can negatively impact distal fixation during EVAR. Consideration for a longer main body or an extension limb should be given in tortuous aneurysms.

A Comparative Study of Canine Retraction by Distraction of the Periodontal Ligament and Dentoalveolar Distraction Methods.

Canine distraction was introduced as an alternative treatment to retract the canines in minimum possible period of 3weeks. It involved rapid canine retraction through distraction of the periodontal ligament. Another technique for rapid canine distalization involved osteotomies surrounding the canines to achieve rapid movement of the canines in the dentoalveolar segment known as dentoalveolar distraction. The present study is intended to assess and evaluate canine retraction by the above two mentioned methods of distraction osteogenesis. Eight orthodontic patients who required first premolar extractions were selected and 16 canines were distracted into the extraction space, using a distraction screw. The distraction procedure was completed in 15.38±1.51days on the side of periodontal ligament distraction while it took 14.50±2.45days on the side of dentoalveolar distraction. No significant anchorage loss was seen in both the sides. The distal displacement of the canines was 6.63±0.90mm on the periodontal distraction side at the rate of 0.43±0.05mm/day and 6.91±1.16mm on the side of dentoalveolar distraction at the rate of 0.48±0.08mm/day. An angulation change of 14.94°±7.58° was observed in canine inclination in periodontal distraction side while change of 14.88°±3.15° was seen in the dentoalveolar distraction side. No significant differences in the various parameters were found between both the techniques of canine retraction by distraction osteogenesis, while reducing orthodontic treatment duration by 6-9months without any unfavorable short-term effects on the periodontium.

Immediate Change in Suprarenal Neck Angulation After Endovascular Aneurysm Repair

Purpose: To compare the immediate suprarenal neck angulation change between the Ovation stent-graft, with its inflatable sealing rings, and a stent-graft with a conventional sealing mechanism. Methods: A case-control study was conducted in which 30 consecutive patients (mean age 67 years; all men) with abdominal aortic aneurysm (AAA) treated with the Ovation stent-graft (group O) were retrospectively compared with 24 patients (mean age 77 years; all men) contemporaneously treated with the Endurant stent-graft (group E) at 3 high-volume tertiary vascular centers. The variables recorded were the aortic neck length, preoperative and postoperative angulation, minimum and maximum diameters of the infrarenal neck, as well as the maximum AAA diameter. All patients had undergone preoperative and postoperative (within 30 days) computed tomographic angiography. Multiple regression analysis compared the relative contribution to neck angulation change of each geometric parameter and the type of endograft. Data are presented as the mean ± standard deviation. Results: The mean preoperative suprarenal neck angulation in group O was 23.2°±18.0° compared with 23.8°±22.9° in group E (t test, p=0.91). The neck lengths were 29.2±14.6 and 23.2±11.0 mm in groups O and E, respectively (p=0.1). Similarly, the minimum and maximum neck diameters were 22.4±2.6 and 25±3.5 mm, respectively, in group O vs 23.3±3.6 mm and 27.0±5.7 mm, respectively, in group E (p=0.3 and 0.12, respectively). The maximum transverse diameters of the AAA in the 2 groups were comparable, that is, 57.0±9.0 mm in group O vs 53.2±11.1 mm in group E (p=0.17). The Ovation stent-graft caused greater decrease in the aortic neck angulation postoperatively compared with the Endurant device (13.2°±16.1° vs 6.1°±5.9°, p=0.04). Multiple regression analysis revealed that preoperative neck angulation (β coefficient 0.37, p<0.001) and the type of endograft (β coefficient −7.91, p=0.01) had significant influence on the postoperative neck angulation change. The intraclass correlation coefficient ranged from 0.951 to 0.990 for the preoperative measurements and from 0.911 to 0.999 for the postoperative measurements for each examiner or the total of estimates at the measurement time points. Conclusion: The Ovation stent-graft induces greater postoperative reduction in the AAA neck angulation compared to an endograft with stent-supported graft seal. Expanded research to infrarenal angle as well to greater angles and correlation to clinical events is justified.

Secondary Improvement in Static Facial Reanimation Surgeries: Increase of Nasal Function.

The aim of this study was to measure the effect of the static reanimation operation administered to patients with facial paralysis on nasal function area by comparing patients' preoperative and postoperative subjective perception of the nasal airflow. We applied the Nasal Obstruction Symptom Evaluation (NOSE) scale to 13 patients who underwent static reanimation because of facial palsies, both preoperatively and postoperatively, and results were compared statistically. The changes in nasal base angulation were recorded and compared based on the photographs of patients taken before and after the surgery. Following the static reanimation operation, 76% (10/13) of the patients reported a subjective improvement in the nasal airflow, whereas 24% (3/13) did not report any change. Mean preoperative and postoperative NOSE scale scores were 66.92 ± 9.90 and 36.15 ± 9.61, respectively. The change in mean NOSE scale score was statistically significant (P < 0.001). In the preoperative and postoperative comparison of the photographs taken from the front view of the patients, a decreased nasal base angulation compared with preoperative period was detected in 8 (61.6%) patients. A statistically significant increase in subjective perception about nasal function was observed after the static facial reanimation; however, it is not certain whether this effect can be considered persistent. Long-term studies conducted on a larger patient population will provide beneficial results.

Response of the maxillary dentition to a statically determinate one-couple system with tip-back mechanics: A prospective clinical trial

To quantify the effects of tip-back mechanics on the maxillary first molars and incisors. Sixteen subjects with Class II end-on malocclusion were treated with an intrusion arch to achieve distalization of the maxillary molar through tip-back mechanics. Lateral cephalograms were taken prior to molar tip-back (T1), after molar tip-back (T2), and after molar root uprighting (T3). Data were analyzed using the Friedman's and Wilcoxon signed rank tests to evaluate differences in time points (P ≤ .016). The maxillary first molar distalized 1.53 mm (P = .001) with 6.65° (P = .001) of distal tipping and 0.86 mm (P = .001) of extrusion at T2. Minor relapse of the first molar (mesial direction) was seen at T3. The maxillary incisors flared labially 0.4 mm, and the incisor root apex moved palatally 1.19 mm (P = .005) at T2. At T3, the incisor root apex moved palatally 1.5 mm (P = .003) from T1. An angular change from T1 of 3.31° (P = .008) and 3.53° (P = .014) was seen at T2 and T3, respectively, as a result of palatal root movement of the maxillary incisors. A significant amount of distalization of maxillary molars was attained at the crown level with tip-back mechanics. Palatal root angulation change was significant in the incisors with minimal anteroposterior movement of the incisal edge.

Effect of premolar extractions on third molar angulation changes: a meta-analysis

To assess the effect of premolar extractions on third molar angulation changes in orthodontic patients. The Cochrane library, PubMed, Embase, China Science and Technology Periodical Database, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM) and Wanfang database were searched from January 1, 1990 to May 20, 2014 to identify all the studies about third molar angulation changes in orthodontic patients with or without premolars extraction, which was assigned as a extraction group and a control group. Th e extraction group was further divided into a fi rst premolar extraction subgroup and a second premolar extraction subgroup. Literature filtering, data extraction and methodological quality evaluation were finished independently by two researchers. After cross checking, the disagreements were solved by discussion. Meta-analysis was carried out by RevMan 5.3.3 software. Ten studies involving 712 patients were included. Meta-analysis revealed that: compared with the control group, the changes of third molar angulation in maxillary and mandible in the extraction group were statistically significantly different (all P<0.05); the difference in angulation between the two groups was about 5.19° in maxillary and 3.55° in mandibul. As for the premolar extraction subgroups, there was no significant difference in mandibular third molar angulation between them (P>0.05). The orthodontic treatment involving first or second premolar extractions can improve the maxillary third molar angulation, and the second premolar extraction is the best option.

Eruption Pattern in Madibular Premolars Associated with Dentigerous Cysts after Marsupialization

The purpose of this study was to evaluate the eruption patterns of mandibular premolars associated with dentigerous cysts after marsupialization regarding the depth, angulation and root development of impacted teeth. Spontaneous eruption was found in 93% of mandibular premolars after marsupialization. Eruption speed and rate of angulation change were greater in mandibular premolars associated with a cyst than those on the non-cyst side. The group with less matured roots tended to have greater eruption speed and angulation change. The eruption speed and angulation change declined rapidly during the first 6 months after marsupialization. Based on the results of this study, it might be possible to predict the eruption pattern of mandibular premolars associated with a cyst after marsupialization, which would be useful for treatment planning.

Displacement pattern of the anterior segment using antero-posterior lingual retractor combined with a palatal plate.

ObjectiveTo evaluate and compare the effects of two appliances on the en masse retraction of the anterior teeth anchored by temporary skeletal anchorage devices (TSADs).MethodsThe sample comprised 46 nongrowing hyperdivergent adult patients who planned to undergo upper first premolar extraction using lingual retractors. They were divided into three groups, based on the lingual appliance used: the C-lingual retractor (CLR) group (group 1, n = 16) and two antero-posterior lingual retractor (APLR) groups (n = 30, groups 2 and 3). The APLR group was divided by the posterior tube angulation; posterior tube parallel to the occlusal plane (group 2, n = 15) and distally tipped tube (group 3, n = 15). A retrospective clinical investigation of the skeletal, dental, and soft tissue relationships was performed using lateral cephalometric radiographs obtained pretreatment and post en masse retraction of the anterior teeth.ResultsAll groups achieved significant incisor and canine retraction. The upper posterior teeth did not drift significantly during the retraction period. The APLR group had less angulation change in the anterior dentition, compared to the CLR group. By changing the tube angulation in the APLR, the intrusive force significantly increased in the distally tipped tube of group 3 patients and remarkably reduced the occlusal plane angle.ConclusionsCompared to the CLR, the APLR provides better anterior torque control and canine tipping while achieving bodily translation. Furthermore, changing the tube angulation will affect the amount of incisor intrusion, even in patients with similar palatal vault depth, without the need for additional TSADs.

Radiographic Assessment for Predicting the Mandibular Third Molar Eruption after Orthodontic Treatment in First Premolar Extraction Group and Non-Extraction Group: A-retrospective Study

Introduction: The third molars are the most congenitally missing teeth. If present, they might follow ectopic eruption path and become impacted. Because it is the last tooth erupt in the arch, and usually there is no space in the arch. Effects of orthodontic treatment may also affect the position of third molar after treatment and may changes the eruption pattern of third molar. Materials and Methods: 30 patient’s pre-treatment and post-treatment lateral cephalogram and orthopantomogram (OPG) were taken out of which 15 patients were treated with first pre-molar extraction, and 15 patients were treated with non-extraction approach. Cephalomatric and OPG tracing were done at T1 (pre-treatment) and T2 (post-treatment). Distance from Xi-point to distal surface of second molar, distance from anterior border of ramus to the distal surface of second molar, angulation of third molar in relation with second molar and mesio-distal width of third molar were checked. Descriptive analysis was perform for both the groups and paired t-test and un-paired t-test were performed for first pre-molar extraction and nonextraction group with two different methods such as panoramic radio graph (OPG) and lateral cephalograms at significant level P < 0.05. Results: In extraction group, there were more possibility of the eruption, more mesial movement and more angulation changes noted compare to non-extraction group. Conclusion: Panoramic radiographs were more accurate when compared to lateral cephalogram while checking minor changes.

Influence of first Premolar Extraction on Second and Third Molar Angulation - A Clinical Study

Background: In modern populations, the impaction rate is higher for third molars than for any other tooth. Due to the speculation of third molar role on late incisor crowding, many orthodontists prescribe removal of third molars before, during or just after orthodontic treatment. Objectives: The aim of this study was to compare whether orthodontic extraction of first premolar lead to any angular changes in second and third molars. Material and method: Orthopantograms of 20 patients undergoing orthodontic treatment were collected pre and post treatment. The patients were divided into two groups - nonextraction and extraction group. Each group consisted of 10 patients. The angles were measured between the long axis of 2 nd molar and 3 rd molar with horizontal plane. Changes in 2 nd and 3 rd molar angulation from pre-treatment to post treatment for two groups were compared by Mann- Whitney utest. Results: Statistical analysis revealed that maxillary and mandibular 2 nd and 3 rd molar showed an improvement in angulation but it was statistically non-significant. Conclusion: The findings of the present investigation suggest that premolar extraction therapy has a favourable effect on maxillary second&third molar angulation, while no changes in mandibular second&third molar angulation during treatment were found in patients treated with and without premolar extractions.

A study to evaluate the changes in 3rd molar angulation with extraction of four premolars in class II malocclusion therapy

Aim: The objectives of the study are to evaluate the changes in third molar angulation during orthodontic treatment with extraction of premolars in Class II malocclusions, and to evaluate the relationship between the angulation of third molars and positional changes of incisors and molars. Materials and Methods: This study was conducted on lateral cephalograms and dental panoramic tomograms of 30 patients (mean age 13.48 years) with skeletodental Class II malocclusion treated with four first premolar extractions. Twenty-four cases were treated with edgewise, and six were treated with Begg technique. The changes in the eruption pattern of the third molars were observed at the beginning of the treatment (T1) and at the end of the treatment (T2). The changes in the anteroposterior position of the incisors and molars, original molar space, and mesiodistal third molar angulation were tested by paired t-test. Results: The positional changes of the upper/lower incisors and first molars and original molar space were found similar in edgewise and Begg technique. Original molar space was increased in both jaws during orthodontic treatment. Long axis angle of the upper right third molar due to occlusal plane was increased nonsignificantly. Lower right third molars uprighted significantly. A positive correlation was found between the inclination of the lower right third molars and position of lower incisors and first molars. Conclusion: Treatment with extraction of premolars result in a greater space in the third molar region as a result of the mesial movement of the molars during space closure.

Second-Generation Ceramic First Metatarsophalangeal Joint Replacement for Hallux Rigidus

Ceramic first metatarsophalangeal (MP) joint replacement has been reported for treatment of hallux rigidus, but there are no published mid- or long-term studies available. We present our midterm results using a second-generation ceramic first MP joint implant. A retrospective review of clinical data and radiographs was performed for 31 feet (24 women; mean age at surgery, 55 ± 6 years) who had first MP joint replacement with a second-generation ceramic prosthesis (primary, 29 feet; revision, 2 feet). Mean follow-up was 81 ± 27 months after surgery Mean first MP passive range of motion was 32 ± 17 degrees (dorsi- and plantarflexion). Mean AOFAS score was 72 ± 19 points and Foot Function Index was 27 ± 26 points (all 31 feet). Clinical rating for 29 feet that had surgery as a primary procedure was excellent in 5 feet (17%), good in 8 feet (28%), fair in 3 feet (10%), and poor in 13 feet (45%). Patients were satisfied with the outcome in 24 feet (77%). Follow-up radiographs showed that radiolucency, change in angulation, sinkage, and malalignment of the metatarsal or proximal phalanx components were common. Complications included 1 superficial wound infection, and revision was performed in 5 feet (16%) because of loosening, sinkage, subluxation, pain, or fractured prosthesis. Implant survival was 92% at 5 years, 85% at 7 years, and 68% at 9 years. The results of second-generation ceramic first MP joint replacement in our series demonstrated poor clinical and radiological results with a high revision rate. Level IV, case series.

Effect of premolar extraction and presence of the lower third molar on lower second molar angulation in orthodontic treatment.

To evaluate the change in mandibular second-molar (M2) angulation in orthodontic treatment with premolar extraction and lower third molar (M3). Panoramic radiographs were evaluated in 3 groups of 129 participants: (1) control, no orthodontic treatment (n = 65); (2) extraction, orthodontic treatment with premolar extraction (n = 30); and (3) nonextraction, orthodontic treatment without premolar extraction (n = 34). The angular difference and ratio of M2 to the first molar (M1), the change in the angulation of M2 between pre- and postorthodontic treatment, and the distal bone level of M2 were assessed. The angular difference and ratio of M2 to M1, the angulation change of M2 between pre- and postorthodontic treatment, and the distal bone level of M2 were higher in the nonextraction group than in the control and extraction groups. The successful orthodontic alignment of the M2 may not be achieved in nonextraction cases when the M3s are present.

Relationship of Beam Angulation and Radiation Exposure in the Cardiac Catheterization Laboratory

The aim of this study was to analyze the relationship between beam angulation and air kerma in a modern cardiac catheterization laboratory. Recent reports have identified the merits of reducing radiation scatter, an important determinant of radiation dose in the catheterization laboratory. Radiation scatter is poorly characterized in the context of catheterization laboratories using modern digital equipment. Understanding the principles of dosimetry may reduce the radiation exposure to patients, providers, and medical staff. Prospectively captured radiation data were extracted from a database of 1,975 diagnostic catheterizations (DCs) and 755 percutaneous coronary interventions (PCIs), which included 138,342 fluoroscopic and 35,440 acquisition (cine) sequences. Fluoroscopy and acquisition modes were categorized into tertiles based on the total air kerma measured at a standard reference point. Radiation maps were modeled according to the relative proportion of exposure in each projection. Median air kerma during DCs and PCIs was 677 and 2,188 mGy, respectively. Fluoroscopy contributed to 66.3% of total dose during PCIs compared with 39.7% during DCs (p<0.001). Fluoroscopy was more sensitive to changes in angulation with a rapid increase in total air kerma on small increases in beam angulation. Complex spatial maps were created to study the impact of angulation and other covariates on total air kerma. Besides beam angulation, body surface area was the strongest predictor of the total air kerma. This study uniquely describes radiation dosimetry using contemporary equipment in areal-world setting. Extreme angulations were associated with high air kerma values. Fluoroscopy compared with acquisition was more sensitive to changes in angulation, with relatively larger increases in total air kerma with small increases in steepness of the angulation.

Swing phase kinematics of horses trotting over poles

Trotting over poles is used therapeutically to restore full ranges of limb joint motion. The mechanics of trotting over poles have not yet been described, hence quantitative evidence for the presumed therapeutic effects is lacking. To compare limb kinematics in horses trotting over level ground, over low poles and over high poles to determine changes in joint angulations and hoof flight arcs. Repeated measures experimental study in sound horses. Standard motion analysis procedures with skin-fixed reflective markers were used to measure swing phase kinematics from 8 horses trotting on level ground, over low (11 cm) and high (20 cm) poles spaced 1.05 ± 0.05 m apart. Spatiotemporal variables and peak swing phase joint flexion angles were compared using repeated measures ANOVA (P<0.05) with Bonferroni correction for pairwise post hoc testing. Peak heights of the fore and hind hooves increased significantly and progressively from no poles (fore: 13.8 ± 3.8 cm; hind: 10.8 ± 2.4 cm) to low poles (fore: 30.9 ± 4.9 cm; hind: 24.9 ± 3.7 cm) and to high poles (fore: 41.0 ± 3.9 cm; hind: 32.7 ± 4.0 cm). All joints of the fore- and hindlimbs contributed to the increase in hoof height through increased swing phase flexion. The hooves cleared the poles due to increases in joint flexion rather than by raising the body higher during the suspension phases of the stride. The increases in swing phase joint flexions indicate that trotting over poles is effective for activating and strengthening the flexor musculature. Unlike the use of proprioceptive stimulation devices in which the effects decrease over time due to habituation, the horse is required to elevate the hooves to ensure clearance whenever poles are present. The need to raise the limbs sufficiently to clear the poles and place the hooves accurately requires visuomotor coordination, which may be useful in the rehabilitation of neurological cases. The Summary is available in Chinese - see Supporting information.

Canine retraction and anchorage loss: Self-ligating versus conventional brackets in a randomized split-mouth study

To evaluate the velocity of canine retraction, anchorage loss and changes on canine and first molar inclinations using self-ligating and conventional brackets. Twenty-five adults with Class I malocclusion and a treatment plan involving extractions of four first premolars were selected for this randomized split-mouth control trial. Patients had either conventional or self-ligating brackets bonded to maxillary canines randomly. Retraction was accomplished using 100-g nickel-titanium closed coil springs, which were reactivated every 4 weeks. Oblique radiographs were taken before and after canine retraction was completed, and the cephalograms were superimposed on stable structures of the maxilla. Cephalometric points were digitized twice by a blinded operator for error control, and the following landmarks were collected: canine cusp and apex horizontal changes, molar cusp and apex horizontal changes, and angulation changes in canines and molars. The blinded data, which were normally distributed, were analyzed through paired t-tests for group differences. No differences were found between the two groups for all variables tested. Both brackets showed the same velocity of canine retraction and loss of anteroposterior anchorage of the molars. No changes were found between brackets regarding the inclination of canines and first molars.

An assessment of the maxilla after rapid maxillary expansion using cone beam computed tomography in growing children.

IntroductionWith the advent of cone beam computed tomography (CBCT), it is now possible to quantitatively evaluate the effects of rapid maxillary expansion (RME) on the entire maxillary complex in growing patients. ObjectiveThe purpose of this study is to use three-dimensional images to evaluate the displacement that occurs at the circummaxillary sutures (frontonasal, zygomaticomaxillary, intermaxillary, midpalatal, and transpalatal sutures) following rapid maxillary expansion in growing children. MethodsThe CBCT scans of 25 consecutively treated RME patients (10 male, 15 female) with mean age of 12.3 ± 2.6 years, were examined before expansion and immediately following the last activation of the expansion appliance. ResultsStatistically significant (P < 0.05) amounts of separation were found for the displacement of the bones of the frontonasal suture, the intermaxillary suture, the zygomaticomaxillary sutures, and the midpalatal suture. The change in angulation of the maxillary first molars due to RME was also statistically significant. There was no statistically significant displacement of the transpalatal suture. ConclusionsRapid maxillary expansion results in significant displacement of the bones of circummaxillary sutures in growing children.