Head Angulation Research Articles

Head-Shaft Angle Influences Isometric Shoulder Strength Levels after Intramedullary Nailing of Proximal Humerus Fractures: A Pilot Study.

Proximal humerus fractures are common fractures of the elderly population which can lead to long-term compromise of a patient's shoulder function. Closed reduction and internal fixation with intramedullary nailing is a well-established surgical technique yielding good outcomes, as perceived by patients, obtained via Patient-Reported Outcome Measures, and objectified by clinical shoulder testing. Apart from conventional range-of-motion testing and clinical shoulder tests, strength testing of the shoulder is a yet-neglected but meaningful and standardizable outcome parameter. In this study, isometric shoulder strength is evaluated in relation to fracture morphology/postoperative reduction quality as well as with patient-reported outcomes. 25 patients (mean age 73.2 ± 10.5 years) underwent isometrics strength-testing of the shoulder joint in the scapular plane (abduction) as well as in the sagittal plane (flexion) as well as hand-grip strength-testing at 4.5 ± 1.88 years follow-up. Pre- and postoperative radiographs were analysed. Patients completed ASES and CMS questionnaires. Patients exhibited a decrease in abduction and flexion force (-24.47% and -25.30%, respectively, p < 0.001) using the contralateral, uninjured arm as reference. Abduction force tended to be decreased in three- and four-part fractures. Patient satisfaction correlated negatively with the relatively reduced force of the affected arm. Varus-angulated humeral heads produced significantly lower abduction force output than valgus- or physiologic angulation (p = 0.014), whereas flexion force was unaffected (p = 0.468). The anatomical reduction had no influence on shoulder strength. Proximal humerus fractures may cause a significant reduction in shoulder function, both reported by patients and objectified by shoulder strength testing. Varus head angulation demonstrated the greatest loss of shoulder strength and should be avoided to ensure proper functioning. Further, strength testing seems a valuable outcome parameter for a thorough shoulder examination with easy obtainability.

Variations in head tilt during the acquisition of CBCT scans and their effects on effective radiation dose.

This study evaluated the impact of variations in anteroposterior and lateral tilts of patients' head on radiation-weighted doses to organs/tissues and effective doses using three different cone beam computed tomography machines. An anthropomorphic phantom was used to estimate radiation doses in three CBCT machines (OP300, Eagle X 3D, and Eagle Edge). Thermoluminescent dosimeters were placed in regions corresponding to pre-stablished organ/tissues. CBCT examinations from the posterior mandible and anterior maxilla regions were acquired, with three different anteroposterior angulations (0°, 30°, and 45°), and from the posterior mandible in three different lateral angulations (0°, 20° to the left, and 20° to the right side). Radiation-weighted doses for each organ/tissue and effective doses were calculated for each machine and angulation. For the posterior mandible acquisitions, anteroposterior angulations of the head at 30° and 45° yielded a reduction in effective doses in all three devices. A 20° tilt to the right side resulted in lower doses than to the left (same side as the FOV). For the anterior maxilla, increased anteroposterior angulation was associated with reduction in effective dose in two devices. Effective doses are lower when small FOV CBCT exams of the posterior mandible and anterior maxilla are acquired with increased anteroposterior head angulation at 30° and 45°. For FOV in the posterior mandible, a 20° lateral tilt towards the side opposite to the FOV also yields lower effective doses. The main contribution to these dose reductions is the decrease in dose to salivary glands.

The relationship between humeral head angulation and bone void within the humeral head in proximal humerus fractures

BackgroundThe variability of humeral head angulation in proximal humerus fractures (PHFs) is a noteworthy observation. The purpose of this study was to investigate the potential association between humeral head angulation and bone void within the humeral head in PHFs. MethodsWe used the reconstruction function in Mimics software to generate three-dimensional models of fractures. Bony landmarks were employed to accurately define the calcar and humeral head zone. Boolean subtraction was performed to calculate the volume of head bone void. ResultsThe cohort consisted of 60 (74.1 %) varus, 21 (25.9 %) valgus, and 23 (22.1 %) neutral angulated PHFs. The mean percentage of humeral head bone void was 38.5 ± 17.8 in varus, 36.3 ± 15.7 in valgus, and 30.1 ± 10.6 in neutral angulated PHFs. A significant difference was observed between the varus and neutral groups (P = 0.035). In addition, an analysis of humeral head bone void was conducted among patients aged over 65 years old, revealing a mean percentage of 42.7 ± 16.4 in varus (27 cases), 34.8 ± 14.5 in valgus (13 cases), and 28.1 ± 11.8 in neutral (8 cases) angulated PHFs. The difference between the varus and neutral groups was also significant (P = 0.023). ConclusionAll types of angulation patterns exhibited humeral head bone void to some extent, with the varus-displaced PHFs demonstrating more obvious defects in comparison to the neutral angulated type.

At-Risk Tackling Techniques and Effectiveness in English Premiership Rugby.

Head-down tackling has been associated with higher rates of head and neck injuries and less successful tackles compared with head-up tackling in American football. In rugby, head and neck injuries have been associated with tackling, with the tackler's head positioned in front of the ball carrier. To assess the success and risks of tackling techniques used in the English Rugby Premiership matches. Cross-sectional study; Level of evidence, 3. Three reviewers analyzed 1000 consecutive solo defensive tackling attempts during the 2022 to 2023 season in 6 English Rugby Premiership matches. Slow-motion replays were used to analyze the success of the tackling attempt in terms of head angulation (head up vs head down), head position relative to the offensive player's waist at point of contact, and tackling method (inside shoulder, arm, head across the bow, and head-to-head). The chi-square test or Fisher exact test was used to analyze categorical data, and the 2-tailed Student t test or the Mann-Whitney U test was used to analyze continuous data. The mean interrater reliabilities for analyzing the tackles were good across all groups (κ = 0.715). Head-up and head-down tackling occurred in 848 tackle attempts (84.8%) and 152 tackle attempts (15.2%), respectively. Head-up tackles were successful in 80.7% of the tackle attempts compared with 71.1% of the head-down tackle attempts (P = .0072). Tackles made at or above the waist were successful in 80.7% of the tackle attempts compared with 73.1% of tackles below the waist (P = .0193). The inside-shoulder technique had the highest successful tackle rate at 90.8%, compared with 44.2% with the arm technique (P < .0001) and 72.4% with the head-across-the-bow technique (P < .0001). The inside-shoulder technique resulted in head-up tackling in 84.8% of players compared with 59.8% with the head-across-the-bow technique (P < .0001) and 94.9% with arm tackling (P = .0001). There were 4 recorded injuries to the tackler: 2 neck injuries, 1 shoulder injury, and 1 wrist/hand injury. Head-up tackling, tackles made at or above the level of the offensive player's waist, and inside-shoulder tackling were found to be more efficient in producing successful tackles. The head-down, tackling below the waist, and head-across-the-bow techniques were associated with poor tackling and lower success rates.

Elastic-stable intramedullary nailing for radial neck fractures in children: clinical and radiological outcomes and risks for poor prognosis

Introduction. Radial neck fractures in children are rare and account for 1-3% of all childhood trauma. Severe displacement of the fracture can lead to a higher incidence of complications, such as limited range of motion (ROM ), pain, instability, neurovascular trauma, premature physeal closure, cubitus valgus, radial head overgrowth, avascular necrosis and improper ossification. The treatment outcome depends on the injury type, treatment method and presence of complications. Aim. The purpose of the study was to assess the outcome of patients treated with elastic-stable intramedullary nailing (ESIN) regarding different radial head angulations and to search for risk factors of a poor outcome. Materials and methods. Twenty-six consecutive patients treated between October 2020, and March 2022, due to radial neck fracture were included in the study. Closed reduction and ESIN fixation were performed. If failed, A K-wire assisted reduction or open reduction was performed. A radiological evaluation was performed pre- and post surgery and at the last follow-up. At the last follow-up visit, the elbow range of motion (ROM ) was measured and the Mayo Elbow Performance Score (MEPS) was established. The followup was after 25 months. Results. The angulation before surgery was 42.4° and the next day after surgery was 6.9°, p = 0.0001. Further correction was observed and at the last follow-up it was 2.5°, p = 0.001. We found no complications besides one skin irritation by an implant and 2 reduced ROM . The MEPS was 97.7. The difference in MEPS between Judet IVB (angulation before surgery&gt; 80°) 92.5 and other patients 98.6 was significant, p = 0.04674. There was no significant difference in MEPS, ROM , between patients immobilized in a plater cast versus in a sling, Conclusions. Closed reduction with the use of ESIN can be considered a safe procedure with a low rate of complications. Patients with an angulation &gt;80° revealed worse functional effects. Cast immobilization did not reveal a negative or a positive impact on the treatment result.

Large Variability of Head Angulation During the Epley Maneuver: Use of a Head-Mounted Guidance System with Visual Feedback to Improve Outcomes.

The aim of this study was to show the variability in head angulation during the canalolith repositioning maneuvers to treat benign paroxysmal positional vertigo and to describe a head-mounted benign paroxysmal positional vertigo guidance system to measure the head orientation. A guidance system for benign paroxysmal positional vertigo was developed by NeuroEquilibrium Diagnostic Systems to measure head orientation and provide visual feedback and instructions to examiners during various maneuvers for benign paroxysmal positional vertigo. Twenty-five experienced examiners and 25 healthy volunteers (aged 21-35 years) were recruited. Each examiner applied the Epley maneuver twice in 1 volunteer: without and with the use visual feedback from a guidance system. Head orientation in both procedures was measured and compared. The trained examiners demonstrated a large variability in head orientation during the Epley maneuver, which was reduced by using the benign paroxysmal positional vertigo guidance system. There was a variability of 39-65° in head orientation measured without the guidance system. The use of the guidance system reduced the variation range to a sixfold decrease in variability. There is a large variability in head orientation when performing repositioning maneuvers, which could compromise the efficacy of benign paroxysmal positional vertigo treatment. Treatment for benign paroxysmal positional vertigo can be optimized by reducing this variability with a benign paroxysmal positional vertigo guidance system. It might also be a useful tool for teaching.

Comparing outcomes in the treatment of pediatric and adolescent intraarticular radial head fractures.

Intraarticular radial head (IARH) fractures are uncommon pediatric injuries with unpredictable yet poor outcomes. The aim of this study was to evaluate clinical outcomes of IARH fractures in pediatric and adolescent patients, by testing our hypothesis that surgically managed fractures would have less risk for an unplanned second surgery and better elbow range of motion at the final follow-up. A retrospective review of 53 IARH fractures was performed. Demographic and clinical data were recorded. Concomitant and associated injuries were documented. Initial management and any attempted reduction in the emergency room were documented. The primary outcome was the need for an unplanned second procedure. Motion at final follow-up, presence of pain and need for physical therapy were reviewed. Radiographs were carefully reviewed and analyzed for physeal status, displacement, angulation and percent of radial head involved. We rejected our hypothesis, however, because it was displaced fractures that tended to require an unplanned change in treatment at a higher rate than nondisplaced fractures, regardless of index management with or without surgery. Fracture displacement on the lateral radiograph was a significant risk factor compared to the anterior-posterior images, and younger patients, particularly those with open physis, were at higher risk of an unplanned second procedure. Moreover, 80% of displaced fractures had asymmetric elbow motion after healing was achieved. It is important to counsel patients and families regarding the potential for suboptimal outcomes and elbow stiffness regardless of treatment choice, in the setting of an initially displaced IARH fracture. Level of evidence: Level III.

The Relationship Between Posture and Dynamic Balance In 10-12 Age Group Wrestlers

Purpose: Posture and balance control is based on a complex set of interrelated mechanisms. Coordination between the musculoskeletal system and the nervous system and receptors that provide this coordination, and the balance organ are needed to ensure postural regularity. This study aimed to determine the relationship between postural problems and dynamic balance. Methods: The study included 31 wrestling athletes aged 10-12 years. The participants were evaluated for posture analysis and dynamic balance in the study. Posture assessments of the participants were performed with the Posture Screen Mobile application and dynamic balance assessments were performed with the Y-Balance Balance test (YBT). Descriptive statistics, the Shapiro-Wilk test, and Pearson correlation analysis were used to analyze the data. The significance level was fixed as P ≤ .05. Results: In the study, a significant negative correlation was found between the forward head angulation of the participants and right and left YBT. Conclusions: In conclusion, forward head posture negatively affects dynamic balance in wrestling athletes aged 10-12 years. In addition to balance exercises for the development of dynamic balance, head posture should be evaluated, and the existing postural problem should be improved. Keywords: Children, dynamic balance, motor control; sports, posture.

Management of displaced humeral surgical neck fractures in daily clinical practice: hanging does not re-align the fracture

IntroductionIt is unclear if the collar and cuff treatment improve alignment in displaced surgical neck fractures of the proximal humerus. Therefore, this study evaluated if the neckshaft angle and extent of displacement would improve between trauma and onset of radiographically visible callus in non-operatively treated surgical neck fractures (Boileau type A, B, C).Materials and MethodsA consecutive series of patients (≥ 18 years old) were retrospectively evaluated from a level 1 trauma center in Australia (inclusion period: 2016–2020) and a level 2 trauma center in the Netherlands (inclusion period: 2004 to 2018). Patients were included if they sustained a Boileau-type fracture and underwent initial non-operative treatment. The first radiograph had to be obtained within 24 h after the initial injury and the follow-up radiograph(s) 1 week after trauma and before the start of radiographically visible callus. On each radiograph, the maximal medial gap (MMG), maximal lateral gap (MLG), and neck-shaft angle (NSA) were measured. Linear mixed modelling was performed to evaluate if these measurements would improve over time.ResultsSixty-seven patients were included: 25 type A, 11 type B, and 31 type C fractures.The mean age (range) was 68 years (24–93), and the mean number (range) of follow-up radiographs per patient was 1 (1–4). Linear mixed modelling on both MMG and MLG revealed no improvement during follow-up among the three groups. Mean NSA of type A fractures improved significantly from 161° at trauma to 152° at last follow-up (p-value = 0.004).ConclusionsApart from humeral head angulation improvement in type A, there is no increase nor reduction in displacement among the three fracture patterns. Therefore, it is advised that surgical decision-making should be performed immediately after trauma.Level of clinical evidenceLevel IV, retrospective case series.

Zygomatic Implants Placed in Immediate Function through Extra-Maxillary Surgical Technique and 45 to 60 Degrees Angulated Abutments for Full-Arch Rehabilitation of Extremely Atrophic Maxillae: Short-Term Outcome of a Retrospective Cohort.

The use of new devices for the rehabilitation of the severely atrophic maxillae needs validation. We aimed to report the short-term outcome of severely atrophic jaws rehabilitated with zygomatic implants with no implant head angulation placed extramaxillary in conjunction with standard implants. Forty-four patients were consecutively included with 77 zygomatic implants (31 abutments of 45 degrees and 46 abutments of 60 degrees) and 115 standard implants. Outcome measures were prosthetic survival, implant/abutment success, complications, modified plaque index (mPLI), modified bleeding index (mBI), mucosal seal efficacy evaluation (MSEE) >4 mm, and Zygomatic implants classification level (ZICL). Two patients (4.5%) were lost to follow-up. No prosthesis was lost; one patient lost one zygomatic implant; two angulated abutments of 60 degrees needed to be replaced in one patient due to an aesthetic complaint; rendering a cumulative success rate at 2-years of 95.3% and 95.9% using patient and implant/abutment as unit of analysis, respectively. Mechanical and biological complications occurred in 13 and six patients, respectively; all resolved. The median mPLI and mBI was 1; MSEE > 4 mm occurred in 17% and 21% of patients at 1- and 2-years, respectively; ZICL1 was registered in 80% of patients. The current protocol enabled good short-term outcomes.

Influence of the Bed Head Positioning on the Current Expiratory Volume of Pediatric Patients in Mechanical Ventilation: A Pilot Clinical Controlled Trial

he elevated bed head position is an important therapeutic intervention that can reduce respiratory complications associated with mechanical ventilation. The objective of this study was to evaluate the effects of elevation at the head of the bed on the tidal volume, pressure variables, hemodynamic data and peripheral oxygen saturation in pediatric patients on mechanical ventilation. Methods: In a before-and-after clinical trial, 52 patients of both sexes, with a chronological age of 28 days to 14 years old, were admitted to the pediatric intensive care unit for more than 24 hours. These were positioned at 0º, 30º, 45º and 60º of elevation of the head of the bed. For each position, the expiratory tidal volume, pressure variables, hemodynamic data and peripheral oxygen saturation were evaluated. Results: The patients presented an increase in the expired tidal volume, with the bed head angulation at 30º and 45º. Heart rate increased when the head was positioned at 60º. The peripheral oxygen saturation variable increased in the 30º and 45º positions. The systolic blood pressure variables and diastolic blood pressure showed a progressive increase in the 30º, 45º and 60º positions respectively. Significant effects on increasing the SatO2/FiO2 ratio were observed in the 30º and 45º positions. Conclusion: This study demonstrated a significant increase in expired tidal volume and an increase in the SatO2/FiO2 ratio with the patient positioned at 30º and 45º of elevation of the head of the bed. The peripheral oxygen saturation variable increased in the 30º and 45º positions. The elevated bed head position should be considered when monitoring children during mechanical ventilation.

Tissue sampling for biliary strictures using novel elbow biopsy forceps

We aim to evaluate the safety and feasibility of novel elbow biopsy forceps with a prebent head for sampling biliary strictures in our institution. A total of 24 patients (15 males and 9 females) with biliary stricture who underwent biliary biopsy during endoscopic retrograde cholangiopancreatography (ERCP) using novel elbow biopsy forceps from June 2019 to August 2020 were retrospectively included. The novel biopsy forceps had a head angulation of 30 degrees and were able to cannulate the bile duct and approach the biliary strictures easily to obtain adequate samples. The technical success rate, incidence of adverse events, and consistency of pathological and surgical specimens were assessed. This device was used successfully in all patients. A total of 52 biopsy specimens were obtained from 24 patients, and all specimens could be used for histopathological examination. Seventeen patients were diagnosed with malignancy based on biopsies, and all of them underwent surgical treatment. The histopathological findings of the biopsy specimens were in accordance with the postoperative pathology diagnoses. One of the seven patients was diagnosed with a benign lesion that was proven to be malignant during surgical treatment in the follow-up period. Two patients experienced a single episode of acute pancreatitis and recovered shortly after appropriate treatment. No patients experienced biliary perforation or biliary bleeding. Biopsy using novel elbow forceps in patients with biliary stenosis is feasible and safe. The novel device and related biopsy technique may be widely applied for biliary disease differentiation.

Does Head Orientation Influence 3D Facial Imaging? A Study on Accuracy and Precision of Stereophotogrammetric Acquisition.

This study investigates the reliability and precision of anthropometric measurements collected from 3D images and acquired under different conditions of head rotation. Various sources of error were examined, and the equivalence between craniofacial data generated from alternative head positions was assessed. 3D captures of a mannequin head were obtained with a stereophotogrammetric system (Face Shape 3D MaxiLine). Image acquisition was performed with no rotations and with various pitch, roll, and yaw angulations. On 3D images, 14 linear distances were measured. Various indices were used to quantify error magnitude, among them the acquisition error, the mean and the maximum intra- and inter-operator measurement error, repeatability and reproducibility error, the standard deviation, and the standard error of errors. Two one-sided tests (TOST) were performed to assess the equivalence between measurements recorded in different head angulations. The maximum intra-operator error was very low (0.336 mm), closely followed by the acquisition error (0.496 mm). The maximum inter-operator error was 0.532 mm, and the highest degree of error was found in reproducibility (0.890 mm). Anthropometric measurements from alternative acquisition conditions resulted in significantly equivalent TOST, with the exception of Zygion (l)–Tragion (l) and Cheek (l)–Tragion (l) distances measured with pitch angulation compared to no rotation position. Face Shape 3D Maxiline has sufficient accuracy for orthodontic and surgical use. Precision was not altered by head orientation, making the acquisition simpler and not constrained to a critical precision as in 2D photographs.

Latest Trends in the Current Treatment of Proximal Humeral Fractures - an Analysis of 1162 Cases at a Level-1 Trauma Centre with a Special Focus on Shoulder Surgery.

The management of proximal humeral fracture (PHF) is not only complex but ever changing. Published epidemiological data are often dated and do not factor in demographic changes or the latest developments in implant material and surgical techniques. The primary aim of this study was to evaluate changes in the epidemiology and actual treatment of PHF at a level-1 trauma centre, with a special focus on shoulder surgery. 1. Between 2009 to 2012 and 2014 to 2017, an increase in complex PHF entities can be observed. 2. In correlation with fracture complexity, an increasing number of comorbidities, especially osteoporosis, can be observed. Between 2014 and 2017, a total of 589 patients (73% female; mean age: 68.96 ± 14.9 years) with 593 PHFs were treated. Patient records and imaging (XRs and CTs) of all patients were analysed. Fractures with ad latus displacement of a maximum of 0,5 cm and/or humeral head angulation of less than 20° were classified as non-displaced. Patients with displaced fractures were included in the analysis of the therapeutic algorithm. These results were compared to those of a cohort 2009 to 2012 (566 patients, 569 PHFs), which used the same inclusion criteria. The two cohorts showed comparable patient numbers, as well as gender and age distributions. Between 2009 to 2012 and 2014 to 2017, a decrease in 2-part fractures (13.9 to 8.6%) and a simultaneous increase in 4-part fractures (20.4 to 30%), and thus fracture complexity was observed. Further decreases were observed in conservative therapy (27.8 to 20.6%), nail osteosynthesis (10.7 to 2.7%) and anatomic shoulder arthroplasty (5,4 to 1%). Furthermore, there was an increase in the use of locking plate osteosynthesis (43.2 to 56.7%) and reverse shoulder arthroplasty (9 to 18.4%). The general trend shows an increase in surgical therapy between the years (72.2 to 79.4%), as well as an increase in osteoporosis incidence (13 to 20.6%). The greatest numbers of comorbidities were found in 3- and 4-part fractures. There is an increase in both the complexity of fractures and the number of surgically treated fractures between 2009 and 2012. Furthermore, an increase in osteoporosis numbers can be observed. New implants (PEEK, fenestrated screws for cement augmentation) and new surgical techniques (double plating osteosynthesis) were used as a result of increasing fracture complexity. Moreover, reverse total shoulder arthroplasty was used more commonly.

Functional and radiological results of percutaneous K-wire aided Métaizeau technique in the treatment of displaced radial neck fractures in children

ObjectivesThe aim of the present study was to determine the radiological and functional results and the efficiency of paediatric radial neck fracture fixation following reduction with the Métaizeau technique together with percutaneous K-wire applied under fluoroscopy to ensure minimum soft tissue damage. MethodsThe study included 20 patients with Judet Type 3, Type 4a and Type 4b fractures operated on with the Métaizeau technique aided by percutaneous K-wire between 2007 and 2014. The mean age of the patients was 9.75 years (range, 4–13 years). Mean preoperative angulation was measured as 52.4° (range, 35°–85°). The average postoperative follow-up time was 34.65 months (range, 13–84) months. Postoperative radiological evaluations were made according to the Ursei classification and functional assessment with the Tibone – Stoltz classification system. ResultsRadiologically, the difference between preoperative and postoperative radius head angulation was found statistically significant (p0.001). In the clinical assessment of injured and uninjured arms, there was no statistically significant difference between flexion-extension (p = 0.330) and supination-pronation range of motion (p = 0.330) and carrying angles (p = 0.094). According to the radiological Ursei evaluation, 17 (85%) patients were in perfect condition and 3 (15%) were good. In the classification of Tibone – Stoltz, 16 (80%) patients were evaluated as perfect, 3 (15%) as good and 1 (5%) as fair. ConclusionFrom the results of this study and related literature, the use of the Métaizeau technique in displaced radial neck fractures requiring surgical treatment in children can be recommended since it creates minimum damage to the soft tissue, is easy to apply and the results are satisfactory. Level of evidenceLevel IV, therapeutic study.

Incisor inclination and perceived tooth colour changes.

Social attractiveness is influenced by a variety of different smile-related factors. We evaluated whether the degree of upper central incisor proclination can result in tooth colour change. Forty young adult subjects (20-25 years) in good health with a complete sound dentition were selected. The subjects were seated in standardized light conditions with an above-directed light source. Their natural head position was stated as 0 degrees. To mimic the range of possible anterior torque movements they were asked to tilt their heads upward +15 degrees (upward tilting) and downward -15 degrees (downward tilting). Frontal macro photographs, parallel to the Frankfort plane of the patient's natural head position were taken at the three head angulations (+15, 0, and -15 degrees ). Photographs were analysed for colour differences at the centre of the incisor clinical crowns with a CIE L*a*b* colour model based software. A paired t-test was used to test for significance between each value for each inclination. Differences were found between the CIE L*a*b* colour values for: upward tilting, downward tilting, and -15 to +15 degrees (total tilting) except for b* values for downward tilting. As the inclination of the subject's head changed downward, the upper incisors were retroclined and the CIE L*a*b* values indicated a darker and less green but redder colour component. As the inclination of the subject's head changed upwards the upper incisors were proclined and the L*a*b* values indicated a lighter and less green and yellow but redder and bluer colour component. Proclination of upper incisors caused lighter tooth colour parameters compared to retroclined incisors and colour changes. Orthodontic change of upper incisor inclination may induce alterations on how tooth colour is perceived.

Epidemiology and treatment reality of proximal humeral fractures at a level-1 trauma center

The treatment of proximal humeral fractures (PHF) is challenging. Recently, more restrictive displacement criteria have been introduced and the lack of treatment algorithms in the literature has been emphasized. The primary purpose of this study was to evaluate the epidemiology and treatment reality of PHF at a specialized level-1 trauma center according to current displacement criteria. The secondary aim was to assess whether a standardized treatment algorithm can be adhered to during daily clinical routine. In all, 566 patients (71.4 % female; average age, 68.1 ± 15 years) with 569 PHF were included in this retrospective cohort study. All medical records and existing x‑rays as well as computed tomography scans were analyzed. Only fractures with ad latus displacement of max 0.5 cm and/or a humeral head angulation of less than 20o were classified as nondisplaced. Patients with displaced fractures were included for evaluation of a standardized treatment algorithm. The most common fracture type was a three-part fracture (39.9 %, n = 227); 70.9 % of fractures (389/569) were displaced and therefore treated operatively. The accordance between the final operative treatment that patients received and the recommended surgical treatment on the basis of the algorithm was 90.2 % (351/389). In contrast to the rate of 15 % dislocated fractures reported by Charles Neer in 1970, more than 70 % of fractures were found to be displaced when more restrictive displacement criteria were applied. More than 90 % of displaced fractures were treated as recommended by the treatment algorithm. Fractures that fitted the least into the treatment scheme were more complex fractures of patients aged 60 years and older.

Evaluation of linear measurements of implant sites based on head orientation during acquisition: An ex vivo study using cone-beam computed tomography.

PurposeThis study evaluated the effect of various head orientations during cone-beam computed tomography (CBCT) image acquisition on linear measurements of potential implant sites.Materials and MethodsSix dry human skulls with a total of 28 implant sites were evaluated for seven different head orientations. The scans were acquired using a Hitachi CB-MercuRay CBCT machine. The scanned volumes were reconstructed. Horizontal and vertical measurements were made and were compared to measurements made after simulating the head position to corrected head angulations. Data was analyzed using a two-way ANOVA test.ResultsStatistical analysis revealed a significant interaction between the mean errors in vertical measurements with a marked difference observed at the extension head position (P<0.05). Statistical analysis failed to yield any significant interaction between the mean errors in horizontal measurements at various head positions.ConclusionHead orientation could significantly affect the vertical measurements in CBCT scans. The main head position influencing the measurements is extension.

Comparison of the head and neck position of elite dressage horses during top-level competitions in 1992 versus 2008

Among veterinary surgeons, interest has recently increased in the role of the horse's neck as a causative factor in complex locomotor disturbances. Specifically, controversy surrounds the trend for the head to be carried behind the vertical (BHV) in contravention of Fédération Equestre Internationale (FEI) rules. The aim of this study was to determine whether the head angulation of elite dressage horses has changed over the last 25 years, and whether head angulation correlates with the competition score awarded. Head angle was measured from videos recorded during the Grand Prix test at the 1992 Olympic Games and the 2008 World Cup Final, during collected canter (CC), collected trot (CT), passage (Pa), and piaffe (Pi).Head angulations were BHV in CC and CT in both 1992 and 2008. The likelihood of being BHV during Pa or Pi was significantly greater in 2008 than in 1992 (P < 0.05). Higher scores correlated significantly with head positions that were further BHV during Pi in 2008 (P < 0.05). Head angulations were orientated BHV in all paces in 2008, whereas in 1992 this was only the case for CT and CC. These findings support the hypothesis that, in recent years, FEI dressage judges have not penalised horses for a head position BHV. The findings also support the need for further studies of the effects of head and neck position on the health of horses.

Optimized separation of left and right liver lobe in dynamic 99mTc-mebrofenin hepatobiliary scintigraphy using a hybrid SPECT-CT scanner

To correctly display the left and right liver lobe separately on dynamic projection scintigraphy, it is essential to adjust the collimator to the angle of the plane between the two liver lobes. We propose an optimized protocol for separating left and right liver lobe in (99m)Tc-mebrofenin hepatobiliary scintigraphy in a hybrid SPECT-CT device. The protocol uses the inherent attenuation correction low-dose CT (AC-CT) for individually adjusting gamma camera head angulation. The results of this protocol are compared with hypothetical results based on previous MRI, fixed angle, and traditional frontal projection. The absolute and relative degrees of overlapping volume between left and right liver lobe parenchyma for frontal projection, 45° right anterior oblique (RAO) projection, RAO angulation based on previously acquired MRI, and RAO based on the AC-CT were measured in 14 patients who underwent (99m)Tc-mebrofenin hepatobiliary scintigraphy. Relative degree of overlap was 31.3±15.2% for frontal projection, 8.2±6.5% for 45° RAO, 5.5±3.5% for RAO based on previous MRI, and 3.6±2.5% for RAO based on AC-CT. The relative overlap of RAO projections based on previous MRI was significantly lower than for frontal projection (p<0.05). Use of the angle from the prior AC-CT, however, resulted in an even lower degree of overlap (p<0.05). Performing (99m)Tc-mebrofenin hepatobiliary scintigraphy using RAO detector alignment with an angle derived from a prior CT obtained in the SPECT-CT scanner can significantly reduce the degree of overlap between right and left liver lobe. If SPECT-CT is not available, previous CT or MRI or a fixed angle of 45° may be used.