Incidence, Outcomes, and Opportunity for Left Ventricular Assist Device Weaning for Myocardial Recovery

BACKGROUND

Myocardial recovery occurs in patients with advanced heart failure on left ventricular assist device (LVAD) support, but there is the premise that it is rare with uncertain results.

OBJECTIVES

The goal of this study was to investigate the incidence and consequence of LVAD explant after myocardial recovery.

METHODS

Using the United Network for Organ Sharing registry, LVAD implants in the United States between 2005 and 2020 were tracked until death, transplantation, or explant for myocardial recovery. The cohort undergoing explant was followed up for heart failure relapse (defined as relisting followed by delisting due to death, being too ill, or transplantation; or second durable LVAD implant).

RESULTS

Of 15,728 LVAD implants, 126 patients underwent explant for recovery, which only occurred in 55 (38%) of 145 implanting centers. The crude cumulative incidence was 0.7% at 2 years, whereas the incidence reached 4.7% among designated centers in the selected young nonischemic cohort. Of 126 explanted patients, 76 (60%) were subsequently delisted for sustained recovery. Heart failure relapsing had a relatively higher hazard in the early phase, with a 30-day incidence of 6% (7 of 126) but tapered following with the freedom rate of 72.5% at 4 years.

CONCLUSIONS

In the United States, LVAD explant for myocardial recovery was underutilized, leading to a very low incidence at the national level despite a realistic rate being achieved in designated centers for selected patients. With follow-up extending up to 4 years after explant, more than one-half were successfully removed and stayed off the waitlist, and approximately 70% were free from heart failure relapse events.

The Evaluation and Management of Coronary Artery Disease in the Lung Transplant Patient

Lung transplantation can greatly improve quality of life and extend survival in those with end-stage lung disease. In order to derive the maximal benefit from such a procedure, patients must be carefully selected and be otherwise healthy enough to survive a high-risk surgery and sometimes prolonged immunosuppressive therapy following surgery. Patients therefore must be critically assessed prior to being listed for transplantation with close attention paid towards assessment of cardiovascular health and operative risk. One of the biggest dictators of this is coronary artery disease. In this review article, we discuss the assessment and management of coronary artery disease in the potential lung transplant candidate.

Left Ventricular Unloading With Impella Versus IABP in Patients With VA-ECMO: A Systematic Review and Meta-Analysis

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) use for circulatory support in cardiogenic shock results in increased left ventricular (LV) afterload. The use of concomitant Impella or intra-aortic balloon pump (IABP) have been proposed as adjunct devices for LV unloading. The authors sought to compare head-to-head efficacy and safety outcomes between the 2 LV unloading strategies. We conducted a search of Medline, EMBASE, and Cochrane databases to identify studies comparing the use of Impella to IABP in patients on VA-ECMO. The primary outcome of interest was in-hospital mortality. The secondary outcomes included transition to durable LV assist devices/cardiac transplantation, stroke, limb ischemia, need for continuous renal replacement therapy, major bleeding, and hemolysis. Pooled risk ratios (RRs) with 95% confidence interval and heterogeneity statistic I2 were calculated using a random-effects model. A total of 7 observational studies with 698 patients were included. Patients on VA-ECMO unloaded with Impella vs IABP had similar risk of short-term all-cause mortality, defined as either 30-day or in-hospital mortality- 60.8% vs 64.9% (RR 0.93 [0.71 to 1.21], I2 = 71%). No significant difference was observed in transition to durable LV assist devices/cardiac transplantation, continuous renal replacement therapy initiation, stroke, or limb ischemia between the 2 strategies. However, the use of VA-ECMO with Impella was associated with increased risk of major bleeding (57.2% vs 39.7%) (RR 1.66 [1.12 to 2.44], I2 = 82%) and hemolysis (31% vs 7%) (RR 4.61 [1.24 to 17.17], I2 = 66%) compared with VA-ECMO, along with IABP. In conclusion, in patients requiring VA-ECMO for circulatory support, the concomitant use of Impella or IABP had comparable short-term mortality. However, Impella use was associated with increased risk of major bleeding and hemolysis.

Outcomes of Simultaneous Heart and Kidney Transplantation

BACKGROUND

Simultaneous heart-kidney transplantation has been increasingly performed in end-stage heart failure patients with concurrent kidney dysfunction despite limited evidence supporting its indications and utility.

OBJECTIVES

The purpose of this study was to investigate the effects and utility of simultaneously implanted kidney allografts with various degrees of kidney dysfunction during heart transplantation.

METHODS

Using the United Network for Organ Sharing registry, long-term mortality was compared in recipients with kidney dysfunction who underwent heart-kidney transplantation (n = 1,124) vs isolated heart transplantation (n = 12,415) in the United States between 2005 and 2018. In heart-kidney recipients, contralateral kidney recipients were compared for allograft loss. Multivariable Cox regression was used for risk adjustment.

RESULTS

Long-term mortality was lower among heart-kidney recipients than among heart-alone recipients when recipients were on dialysis (26.7% vs 38.6% at 5 years; HR: 0.72; 95% CI: 0.58-0.89) or had a glomerular filtration rate (GFR) of <30 mL/min/1.73 m² (19.3% vs 32.4%; HR: 0.62; 95% CI: 0.46-0.82) and GFR of 30 to 45 mL/min/1.73 m² (16.2% vs 24.3%; HR: 0.68; 95% CI: 0.48-0.97) but not in GFR of 45 to 60 mL/min/1.73 m². Interaction analysis showed that the mortality benefit of heart-kidney transplantation continued up to GFR 40 mL/min/1.73 m². The incidence of kidney allograft loss was higher among heart-kidney recipients than among contralateral kidney recipients (14.7% vs 4.5% at 1 year; HR: 1.7; 95% CI: 1.4-2.1).

CONCLUSIONS

Heart-kidney transplantation relative to heart transplantation alone provided superior survival for dialysis-dependent recipients and non-dialysis-dependent recipients up to a GFR of approximately 40 mL/min/1.73 m² but at the cost of almost twice the risk of kidney allograft loss than contralateral kidney allograft recipients.

High-Risk Pulmonary Embolism During Labor: JACC Patient Care Pathways

While in labor, a 37-year-old woman developed acute dyspnea, hypoxemia, and tachycardia. Transthoracic echocardiography demonstrated severe right ventricular dilation and dysfunction, raising the suspicion of acute pulmonary embolism. The patient indeed had bilateral pulmonary embolism, necessitating percutaneous thrombectomy. Her course was complicated by another saddle pulmonary embolus, heparin-induced thrombocytopenia, and COVID-19 infection. This clinical case illustrates the importance of prompt diagnosis of acute pulmonary embolism in a peripartum female patient, the multidisciplinary approach of management, and how to approach clinical complications such as heparin-induced thrombocytopenia. Furthermore, long-term management in acute pulmonary embolism is presented.

High-Risk Pulmonary Embolism During Labor: JACC Patient Care Pathways

While in labor, a 37-year-old woman developed acute dyspnea, hypoxemia, and tachycardia. Transthoracic echocardiography demonstrated severe right ventricular dilation and dysfunction, raising the suspicion of acute pulmonary embolism. The patient indeed had bilateral pulmonary embolism, necessitating percutaneous thrombectomy. Her course was complicated by another saddle pulmonary embolus, heparin-induced thrombocytopenia, and COVID-19 infection. This clinical case illustrates the importance of prompt diagnosis of acute pulmonary embolism in a peripartum female patient, the multidisciplinary approach of management, and how to approach clinical complications such as heparin-induced thrombocytopenia. Furthermore, long-term management in acute pulmonary embolism is presented.

Coronary Dissection and Right Heart Failure Salvaged by PCI With Percutaneous Intraluminal Microaxial RV-Assist Support

Right heart failure is a dreaded sequelae of proximal right coronary artery occlusion that can complicate an angiogram or percutaneous coronary intervention. This case illustrates the use of a percutaneous intraluminal microaxial right ventricular assist device for high-risk percutaneous coronary intervention of an ostial right coronary artery dissection in refractory right heart failure. (Level of Difficulty: Advanced.)

Characterization of Myocardial Injury in Patients With COVID-19

BACKGROUND

Myocardial injury is frequent among patients hospitalized with coronavirus disease-2019 (COVID-19) and is associated with a poor prognosis. However, the mechanisms of myocardial injury remain unclear and prior studies have not reported cardiovascular imaging data.

OBJECTIVES

This study sought to characterize the echocardiographic abnormalities associated with myocardial injury and their prognostic impact in patients with COVID-19.

METHODS

We conducted an international, multicenter cohort study including 7 hospitals in New York City and Milan of hospitalized patients with laboratory-confirmed COVID-19 who had undergone transthoracic echocardiographic (TTE) and electrocardiographic evaluation during their index hospitalization. Myocardial injury was defined as any elevation in cardiac troponin at the time of clinical presentation or during the hospitalization.

RESULTS

A total of 305 patients were included. Mean age was 63 years and 205 patients (67.2%) were male. Overall, myocardial injury was observed in 190 patients (62.3%). Compared with patients without myocardial injury, those with myocardial injury had more electrocardiographic abnormalities, higher inflammatory biomarkers and an increased prevalence of major echocardiographic abnormalities that included left ventricular wall motion abnormalities, global left ventricular dysfunction, left ventricular diastolic dysfunction grade II or III, right ventricular dysfunction and pericardial effusions. Rates of in-hospital mortality were 5.2%, 18.6%, and 31.7% in patients without myocardial injury, with myocardial injury without TTE abnormalities, and with myocardial injury and TTE abnormalities. Following multivariable adjustment, myocardial injury with TTE abnormalities was associated with higher risk of death but not myocardial injury without TTE abnormalities.

CONCLUSIONS

Among patients with COVID-19 who underwent TTE, cardiac structural abnormalities were present in nearly two-thirds of patients with myocardial injury. Myocardial injury was associated with increased in-hospital mortality particularly if echocardiographic abnormalities were present.

COVID-19 critical illness pathophysiology driven by diffuse pulmonary thrombi and pulmonary endothelial dysfunction responsive to thrombolysis

Patients with severe COVID-19 disease have been characterized as having the acute respiratory distress syndrome (ARDS). Critically ill COVID-19 patients have relatively well-preserved lung mechanics despite severe gas exchange abnormalities, a feature not consistent with classical ARDS but more consistent with pulmonary vascular disease. Many patients with severe COVID-19 also demonstrate markedly abnormal coagulation, with elevated d-dimers and higher rates of venous thromboembolism. We present four cases of patients with severe COVID-19 pneumonia with severe respiratory failure and shock, with evidence of markedly elevated dead-space ventilation who received tPA. All showed post treatment immediate improvements in gas exchange and/or hemodynamics. We suspect that severe COVID-19 pneumonia causes respiratory failure via pulmonary microthrombi and endothelial dysfunction. Treatment for COVID-19 pneumonia may warrant anticoagulation for milder cases and thrombolysis for more severe disease.

COVID-19 Critical Illness Pathophysiology Driven by Diffuse Pulmonary Thrombi and Pulmonary Endothelial Dysfunction Responsive to Thrombolysis

Patients with severe COVID-19 disease have been characterized as having the acute respiratory distress syndrome (ARDS). Critically ill COVID-19 patients have relatively well-preserved lung mechanics despite severe gas exchange abnormalities, a feature not consistent with classical ARDS but more consistent with pulmonary vascular disease. Patients with severe COVID-19 also demonstrate markedly abnormal coagulation, with elevated D-dimers and higher rates of venous thromboembolism. We present five cases of patients with severe COVID-19 pneumonia with severe respiratory failure and shock, with evidence of markedly elevated dead-space ventilation who received tPA. All showed post treatment immediate improvements in gas exchange and/or hemodynamics. We suspect that severe COVID-19 pneumonia causes respiratory failure via pulmonary microthrombi and endothelial dysfunction. Treatment for COVID-19 pneumonia may warrant anticoagulation for milder cases and thrombolysis for more severe disease.

Craniofacial structures' development in prenatal period: An MRI study

INTRODUCTION

The development of skeletal structures (cranial base, upper and lower) and upper airways spaces (oropharyngeal and nasopharyngeal) of the skull has always been an issue of great interest in orthodontics. Foetal MRI images obtained as screening exam during pregnancy can help to understand the development of these structures using a sample cephalometric analysis.

MATERIAL AND METHODS

A total of 28 MRI images in sagittal section of foetuses from 20th to 32th weeks of gestation were obtained to dispel doubts about the presence of skeletal malformations. Cephalometric measurements were performed on MRI T2-dependent images acquired with a 1.5 T scanner. The Software Osirix 5 permits to study sagittal and vertical dimensions of the skull analysing linear measurements, angles and areas of the skeletal structures.

RESULTS

Vertical and sagittal dimension of cranial base, maxilla and mandible grow significantly (P < .01) between the second and third trimester of gestational period as well as nasopharyngeal and oropharyngeal spaces (P < .05). High correlation between the development of anterior cranial base and functional areas devoted to speech and swallow is demonstrated (r: .97).

CONCLUSIONS

The development of craniofacial structures during foetal period seems to show a close correlation between skeletal features and functional spaces with a peak between the second and third trimester of gestation. MRI images result helpful for the clinician to detect with a sample cephalometric analysis anomalies of skeletal and functional structures during prenatal period.

Assessing the effects of biomechanical overload on dairy parlor workers' wrist: Definition of a study approach and preliminary results

BACKGROUND

Dairy milking is a demanding work task that has been associated with hand and wrist musculoskeletal disorders. Clinical approaches to identify the early effects of musculoskeletal disorders among dairy parlor workers' wrist have not been well defined.

OBJECTIVES

The purpose of this pilot study was to develop a study protocol that would assist in the identification and quantification of hand and wrist disorders among dairy workers that perform tasks in the dairy parlor. Additionally, such a study protocol was needed to perform relatively rapid assessments of the wrist/hand on large samples of dairy workers.

METHODS

Fourteen dairy parlor workers were assessed for i) upper limb symptoms and work history through questionnaire, ii) a physical examination of the upper limb and in particular wrists and iii) wrist ultrasonography. An additional 21 unexposed paired participants (the control group) also participated in the data collection.

RESULTS

The study results identified two ultrasound acoustic windows characterized by the highest predictive value for alteration of the wrist's structure. Study results indicated an impairment of the distal median nerve in structure and mobility and impairment of the distal tendon of the muscle extensor carpi ulnaris that included dislocation and frank damage.

CONCLUSIONS

This study identified at least two acoustic windows that should be assessed with ultrasound studies on larger groups and in prospective periodical health surveillance of dairy workers. The study confirmed the wrist was at risk for biomechanical stress among workers conducting milking tasks in the dairy parlors.

Single tooth bite forces in healthy young adults

The assessment of bite forces on healthy single tooth appears essential for a correct quantification of the actual impact of single implant oral rehabilitations. In the present study, a new single tooth strain-gauge bite transducer was used in 52 healthy young adults (36 men, 16 women) with a complete permanent dentition. The influences of tooth position along the dental arch, of side, and of sex, on maximum bite force were assessed by an ANOVA. No significant left-right differences were found. On average, in both sexes the lowest bite force was recorded on the incisors (40-48% of maximum single tooth bite force), the largest force was recorded on the first molar. Bite forces were larger in men than in women (P < 0.002), and increased monotonically along the arch until the first or second permanent molar (P < 0.0001). The present data can be used as reference values for the comparison of dental forces in patients.

Comparison of unilateral chewing movements vs. dental guidance through the dental guidance ratio

STATEMENT OF PROBLEM

Limited knowledge exists about the interaction between dental morphology and mandibular excursive movements.

PURPOSE

This study evaluated dental guidance in lateral excursive movement and its relationship to jaw motion in unilateral chewing.

MATERIAL AND METHODS

Three-dimensional mandibular movement paths (in lateral guiding movements and in the final part of a monolateral chewing stroke) were collected with automated infrared motion analysis in 22 subjects with complete, permanent dentitions. On 2 traces selected from the recorded movements, the angular values projected in all planes of space obtained from 2 lines tangent to a point at a distance of 2.5 mm from maximum intercuspation were used to calculate a canine and a molar dental guidance ratio (DGR). Descriptive statistics were computed for the DGRs in the 3 spatial planes.

RESULTS

Assuming masticatory movements of any given subject are restricted or guided by dental anatomy, a value below 100% of the DGR was expected. This was true for the frontal plane only, with mean values of approximately 80% (working-side movements, canines, and molars) and approximately 60% (nonworking-side movements for both molars and canines). In the horizontal and sagittal planes, mean values between 102% and 137% were found.

CONCLUSION

Within the limitations of this study, masticatory movement was within the physical borders dictated by dental anatomy in the frontal plane only.

Morphometry of the orbital region: a soft-tissue study from adolescence to mid-adulthood

The objective of this study was to gain information about normal sex-related linear and angular dimensions of the orbital region; left-right symmetry; and growth changes between adolescence and mid-adulthood. The three-dimensional coordinates of several soft-tissue landmarks on the orbits and face were obtained by an electromagnetic digitizer in 40 male and 33 female adolescents aged 12 to 15 years, 73 female and 89 male young adults aged 19 to 30 years, and 41 male and 38 female adults aged 31 to 56 years. From the landmarks-binocular and intercanthal widths; paired height and inclination of the orbit relative to both the true horizontal (head in natural head position) and Frankfurt plane; length and inclination of the eye fissure; and the orbital height to eye fissure length ratio were calculated and averaged for age and sex. Comparisons were performed by factorial analysis of variance. Both the linear dimensions and the angular values were significantly larger in male subjects than in female subjects of corresponding age (p < 0.05). A significant effect of age was found (p < 0.05): while the linear distances and the orbital height-to-length ratio were greater in older people of the same sex, the inclination of the eye fissure decreased as a function of age. Both orbital inclinations were larger in the young adult group than in the adolescent and middle-aged groups. On average, the paired measurements were symmetrical, with similar values within each sex and age group. Data collected in this investigation could serve as a database for the quantitative description of human orbital morphology during normal adolescent and adult growth.

The influence of different jaw positions on the endurance and electromyographic pattern of the biceps brachii muscle in young adults with different occlusal characteristics

To investigate the hypothesis of a functional coupling between the stomatognathic motor apparatus and the muscles of other body districts, as well as between occlusal conditions and neuromuscular performance, two groups of men (age range 20-26 years), with either normal occlusion (14 men) or malocclusion (15 men), sustained with their dominant arm a dumbbell weighing 80% of their maximum while maintaining different jaw positions: mouth open, without dental contact; mouth close, with light dental contact; maximum voluntary clench; maximum voluntary clench on two cotton rolls positioned on the posterior mandibular teeth; maximum voluntary clench on one cotton roll positioned on the right/left-side posterior mandibular teeth. Surface electromyography (EMG) of the biceps brachii muscle was performed, and the endurance time, mean root mean square (rms) potential, and mean median power frequency were computed. The mean potential and median power frequency were also computed for 2-s windows, and values as a function of time were interpolated by a linear regression analysis. Data were compared between groups and trials by using a factorial analysis of variance. The malocclusion group subjects could perform the exercise for a longer time span than the normal occlusion individuals (P < 0.005). During this endurance time their biceps brachii muscles contracted with different patterns: on average, in the malocclusion group they had a larger EMG amplitude (P < 0.005), and a shift of the power spectrum toward lower frequencies (P < 0.005). The factor 'jaw position' was significant only for the endurance time (P < 0.005). In both groups, the longest endurance time was found in the 'clench' trial, while the shortest in the 'right-side bite' trial. In conclusion, a morphologically altered occlusion does not always worsen the muscular performance of other body districts, and the use of occlusal supports (cotton rolls) is not always beneficial.

Three-dimensional inclination of the dental axes in healthy permanent dentitions--A cross-sectional study in a normal population

The 3-dimensional (3-D) inclination of the facial axis of the clinical crown (FACC) and the size of the clinical crowns were measured in 100 white northern Italians. The subjects consisted of 22 girls and 21 boys, ages 13-15 years (adolescents), and 31 women and 26 men, ages 16-26 years (adults), all with a complete permanent dentition and Class I dental relationships. The 3-D coordinates of dental landmarks were obtained with a computerized electromagnetic digitizer. Clinical crowns heights and FACC inclinations in the anatomical frontal and sagittal planes relative to 2 reference planes, maxillary and mandibular (between the incisive papilla and the intersection of the palatal/lingual sulci of the first permanent molars with the gingival margin), were calculated. Ages and sexes were compared by ANOVA. On average, the frontal plane FACCs of most teeth converged toward the midline plane of symmetry. In contrast, the incisors diverged from the midline plane or were nearly vertical. Within each quadrant, the inclinations of the postincisor teeth progressively increased. In the sagittal plane, most teeth had a nearly vertical FACC. FACC inclinations showed sex- and age-related differences (P < .05). In the frontal plane, the canines, premolars, and molars were more inclined in adolescents than in adults. In the sagittal plane, a large within-group variability was observed. Clinical crown height was significantly larger in males than in females in all maxillary and mandibular canines, premolars, second molars, maxillary central incisors, and first molars. With age, some degree of dental eruption was found in maxillary and mandibular canines, maxillary second premolars, and molars. The age-related decrease in FACC inclination may be the effect of a progressive buccal and mesial drift.

Repeatability of choku-tsuki and oi-tsuki in shotokan karate: a 3-dimensional analysis with thirteen black-belt karateka

13 black-belt karateka performed two different standardized counter-offensive techniques. The trajectories of selected body landmarks were studied by using a computerized image analyzer that allows a 3-dimensional reconstruction of standardized movements. The repeatability of both karate techniques was quantified for each participant. Analysis confirmed that more experienced karateka obtained the best repeatability, as already demonstrated in a preliminary study conducted with a smaller sample of less experienced participants.

Harmonic analysis of footprint symmetry in healthy adolescents

In the present study, the within-subject normal symmetry of footprint shape and size was analyzed from a mathematical standpoint. On the standardized left and right footprints of 83 adolescents (46 boys, 37 girls) aged 12-15 years (mean 13 years), the outline of each foot excluding the toes was identified and automatically digitized by a computerized video analyzer. Only those subjects with both left and right continuous footprints were further analyzed (36 boys, 26 girls). The footprint area was computed. The footprint shape, independent of its size, was quantified using the elliptic Fourier analysis with a 20-harmonic truncation. The symmetry in shape was quantified on an intra-subject basis by calculating a morphological distance D between the mathematical reconstructions of the left and right footprints of each subject. Symmetry in size was assessed by right-to-left area ratio. Subjects were grouped for sex, and the mean values computed. Mean footprint area was significantly larger in boys than in girls (p < 0.05). Asymmetry in size (area ratio) was 1.01 in girls, 1 in boys. Within-subject symmetry in footprint shape appeared high, with mean morphological distances of 5.95 in girls, and 6.06 in boys. No consistent associations between footprint symmetry and age, height and body weight, or shoe size were found. The mean size-independent shapes of the male and female left and right footprints were also calculated. Together with the analysis of individual asymmetry, they could be used as quantitative parameter in clinical diagnosis.

Harmonic analysis of mandibular form and symmetry with computerized tomographic views

OBJECTIVE

To quantitatively describe the isotropic (ie, orientation independent) morphologic characteristics of a standardized computed tomographic image of the mandible with the use of the elliptic Fourier series.

STUDY DESIGN

Spiral CT scans parallel to the mandibular plane and enclosing both mental foramina were obtained in 17 adults (9 edentulous women, mean age, 75 years; 4 edentulous men, mean age, 68 years; and 4 dentate men, mean age, 30 years). The mandibular outline was traced, digitized, and mathematically reconstructed with the elliptic Fourier series. Mandibular area, shape, and individual symmetry were quantified.

RESULTS

Mandibular area and symmetry were larger in men than in women (P <.05). In men, no effect of edentulousness was observed in either area or symmetry. Mandibular shape seemed to be influenced neither by sex nor by the presence of teeth.

CONCLUSION

Mandibular size and symmetry in the analyzed computed tomographic scan (which included only the mandibular basal bone) seemed to be sex related but independent of the dental status. Mandibular shape did not seem to be modified by sex or edentulousness. Different findings may be obtained in the analysis of a section of the alveolar bone.

A three-dimensional quantitative analysis of lips in normal young adults

OBJECTIVE

To supply information about (1) sex-related dimensions (linear distances and ratios, vermilion area, volume) of normal adult lips, (2) presence of sexual dimorphism, and (3) correlations between anthropometric characteristics of the lip and nose.

METHODS

The three-dimensional coordinates of soft tissue landmarks on the lips and nose were obtained using an optoelectronic instrument in 90 healthy young adult women and 90 healthy young adult men. From the landmarks, several linear distances (mouth width, total vermilion height, nose height, anatomic nose width, total lip height, upper lip height), the ratio of vermilion height to mouth width, and some areas (vermilion of the upper lip, vermilion of the lower lip, total vermilion) and volumes (upper lip volume, lower lip volume, total lip volume) were calculated. Linear correlation analyses between pairs of variables were also conducted within each sex.

RESULTS

All lip dimensions (distances, areas, and volumes) were significantly larger in men than in women (p<.005), but no sex differences were found in the vermilion height to mouth width ratio. Overall, mouth and nose dimensions were not significantly correlated, with the exceptions of the upper and lower lip volumes in both sexes and of the mouth and nose widths in the female sample, in which a modest part of the variance in one measurement could be explained by the other.

CONCLUSION

The dimensions of the mouth and the nose did not seem to be strictly related. Data collected in the present investigation could represent a database for the quantitative description of human lip morphology in adult subjects.

Morphometry of the normal human ear: a cross-sectional study from adolescence to mid-adulthood

The objective of this study was to supply information about: (1) normal gender-based dimensions of ears (linear distances and ratios, area); (2) left right symmetry; and (3) growth changes between adolescence and mid-adulthood. The three-dimensional co-ordinates of several soft-tissue landmarks on the ears and face were obtained by an electromagnetic digitizer in 40 male and 33 female adolescents aged 12-15 years. 73 young female and 89 young male adults aged 19-30 years, and 41 male and 38 female adults aged 31-56 years. From the landmarks, paired car width and length were calculated and averaged for age and gender, as well as the relevant ratios, ear areas and angles relative to the facial midline, and indices of left right symmetry. Comparisons were performed by factorial analysis of variance. All ear dimensions were significantly larger in men than in women (P < 0.005). A significant effect of age was found (P < 0.005), with larger values in older individuals. On average, the three-dimensional position of ears was symmetric, with symmetry coefficients ranging between 94 and 96%. Data collected in the present investigation could serve as a database for the quantitative description of human ear morphology during normal adolescent and adult growth.

Soft tissue facial growth and development as assessed by the three-dimensional computerized mesh diagram analysis

The normal growth and development of facial soft tissues from 6 years to adulthood has been studied by the 3D computerized mesh diagram analysis. The analysis allows independent quantifications of size and shape modifications both between different age groups, and between males and females. Normal age-related and sex-related references are provided. The three-dimensional facial morphometry method has been used for the collection of the x, y, z coordinates of 22 soft tissue landmarks in 2023 examinations performed on 1157 healthy white children and adolescents between 6 and 17 years of age and 191 young adults. The method detects the three-dimensional coordinates of retroreflective, wireless markers positioned on selected facial landmarks using two charge-coupled device cameras working in the infrared field. For each sex and age class, mean values were computed, and a standardized mesh of equidistant horizontal, vertical, and anteroposterior lines was consequently constructed. Within each age group, male meshes were superimposed on female meshes. Moreover, within each sex, the adult reference mesh was superimposed on the reference mesh of each age group. The global (size plus shape) difference was then evaluated by the calculation of the relevant displacement vectors for each soft tissue landmark. A global difference factor was calculated as the sum of the modules of all the displacement vectors. Consequently, a size normalization was performed, and the shape difference (size standardized) was then evaluated by the calculation of new relevant displacement vectors for each landmark, as well as a shape-global difference factor. When compared to the young adult situation, the largest child discrepancies were found in the soft tissue profile. After size standardization, shape differences were found in the forehead, nose, and chin. The soft tissue facial dimensions of boys and girls grow with similar characteristics and at the same rate between 6 and 11 years of age, but showed different patterns after this age. Within each age class, most of the sex-related differences were dimensional discrepancies that were corrected after size standardization. Nevertheless, before adolescence even these size differences were limited. On average, male faces had a larger forehead, longer and more vertical nose, more inferior and posterior gonia, more inferior and prominent lips, and a larger mouth than female faces of corresponding age.

The effects of a single intercuspal interference on electromyographic characteristics of human masticatory muscles during maximal voluntary teeth clenching

In 13 healthy subjects (eight men and five women, mean age, 22 years), an aluminum intercuspal interference (height, 0.25 mm) was placed on the maxillary right first premolar to study its effect on the contractile symmetry of the right and left masseter and anterior temporalis muscles when measured through a Percentage Overlapping Coefficient (POC), derived from surface electromyographic recordings of maximum voluntary teeth clenching. Additionally, and to estimate the potential of the experimental intercuspal interference to induce lateral displacement of the mandible, a Torque Coefficient (TC) was derived from surface electromyographic recordings. The conclusion was that the experimental occlusal interference gave rise to asymmetric contractile activity in the studied mandibular elevator muscles as well as a potential to displace the mandible in a lateral direction.

The influence of crossbite on the coordinated electromyographic activity of human masticatory muscles during mastication

The analysis of the masticatory muscle activity in subjects with altered occlusal relationships could provide useful data of the functional impact of morphological discrepancies. Thirty subjects aged 16-18 years, with a sound, full permanent dentition, bilateral angle class I, and an overjet and overbite between 2 and 5 mm, were examined. The control group (10 male, 10 female) had no crossbite, while the crossbite group (four male, six female) had a posterior unilateral crossbite (five on the left side, five on the right side). The electromyographic activity of the left and right masseter and temporalis anterior muscles was recorded during 15 s of unilateral (left and right) chewing of gum, and expressed as a percentage of the maximum voluntary clench on cotton rolls. For each subject, the masticatory frequency, the confidence ellipse of the simultaneous differential left-right masseter and temporal activity (Lissajous figure), and an index of muscular symmetry, were computed to assess muscular coordination. In the crossbite subjects, the four analysed muscles appeared to contract with altered and asymmetric patterns. A large variability was found, and the confidence ellipses calculated for the chewing tests performed on the crossed sides were not significant, while the confidence ellipses of the uncrossed side chewing were different from the ellipses computed in the normal occlusion group. The altered occlusal relationship influenced the coordination of the masticatory muscles during chewing on both sides. The functional alteration was more apparent when the side with the altered morphology was directly involved, i.e. when chewing was performed on the crossbite side.

Three-dimensional dental arch curvature in human adolescents and adults

The three-dimensional arrangement of dental cusps and incisal edges in human dentitions has been reported to fit the surface of a sphere (the curve of Monson), with a radius of about 4 inches in adults. The objective of the current study was to compare the three-dimensional curvature of the mandibular dental arch in healthy permanent dentitions of young adults and adolescents. The mandibular casts of 50 adults (aged 19 to 22 years) and 20 adolescents (aged 12 to 14 years) with highly selected sound dentitions that were free from temporomandibular joint problems were obtained. The three coordinates of cusp tips excluding the third molars were digitized with a three-dimensional digitizer, and used to derive a spherical model of the curvature of the occlusal surfaces. From the best interpolating sphere, the radii of the left and right curves of Spee (quasi-sagittal plane) and of molar curve of Wilson (frontal plane) were computed. Mandibular arch size (interdental distances) was also calculated. The occlusal curvature of the mandibular arch was not significantly influenced by sex, although a significant effect of age was found (Student t, P <.005). The radii of the overall sphere, right and left curves of Spee, and curve of Wilson in the molar area were about 101 mm in adults, and about 80 mm in adolescents. Arch size was not influenced by either sex or age. The different curvatures of the occlusal plane in adolescents and adults may be explained by a progressive rotation of the major axis of the teeth moving the occlusal plane toward a more buccal position. These dental movements should be performed in a frontal plane on an anteroposterior axis located next to the dental crown.

Size and shape of the human first permanent molar: a Fourier analysis of the occlusal and equatorial outlines

Form can be viewed as a combination of size and shape. Shape refers to the boundary outline independently from its orientation, relation to reference planes, and dimension (or size). Shape and its changes could be quantified by mathematical methods such as the Fourier series. In this investigation, Fourier analysis has been used to quantify the morphologic characteristics (size and shape) of the outline of the occlusal surface and maximum circumference (equator) in 259 normal, healthy human first permanent maxillary and mandibular molars and to assess the effect of sex. Large within-group variability was found in the Fourier coefficients. Both equatorial and occlusal molar areas were on average larger in male than in female homologous teeth, but the difference was statistically significant only for the equatorial areas. The mean ratios between equatorial and occlusal dental areas were independent from arch (maxillary and mandibular), side, or sex. Both equatorial and occlusal outlines of left and right homologous molars within sex and arch were similar, without size and shape differences. Similarly, no sex differences in shape were found in the comparison of homologous teeth. The method used in the present study could supply information about dental shape in both its entirety and local variations. In particular, the method is extremely sensitive to local variations in dental shape, and it could be usefully employed to compare single teeth to a standard.

Reliability of soft tissue references for anteroposterior measurement of dental bases

The aims of the present investigation were to devise a new anteroposterior measurement of maxillomandibular discrepancies that would consider both hard and soft tissue contributions, and to verify the correlation of this measurement to a well-established linear assessment of anteroposterior discrepancy. On the pretreatment lateral cephalographs of 300 orthodontic patients (162 males, 138 females) aged between 6 and 50 years, the Wits appraisal and a new "soft tissue" Wits appraisal (linear distance between the projections of soft tissue A and B points on the bisecting occlusal plane) were measured. In the analyzed sample, the former was more variable than the latter. The two measurements were significantly correlated to each other without sex- or age-characteristic patterns. From the correlation, reference values for the new measurement were estimated and found to be between -1.9 mm and 5.4 mm for individuals with a normal occlusion. The new measurement could allow a more careful evaluation of the soft tissue drape together with the underlying hard tissue structure.

A three-dimensional computerized mesh diagram analysis and its application in soft tissue facial morphometry

A modified computerized mesh diagram analysis that allows rapid and independent quantifications of soft tissue facial size and shape in the three-dimensional space is presented. Normal references are provided, and the application of the method is also exemplified by the analysis of two maxillofacial surgical patients. The Three-Dimensional Facial Morphometry method has been used for the collection of the x, y, z coordinates of 22 soft tissue landmarks in 50 men and 50 women (all healthy young white adults). The method detects the three-dimensional coordinates of retroreflective, wireless markers positioned on selected facial landmarks with two charge-coupled device cameras, working in the infrared field. The midpoint between the right and left tragus landmarks served as the origin of the coordinate axes, and the landmark coordinates were rotated, setting the intercantheal line horizontal on both the frontal and the horizontal planes, and the Camper's plane inclined at -7.5 degrees on the sagittal plane. A standardized mesh of equidistant horizontal (dimension: half the upper face width), vertical (half the vertical projection of upper face height), and anteroposterior (half the horizontal projection of upper face depth) lines was consequently constructed. The lattice was replicated on the entire face and comprised 84 parallelepipeds. Both male and female reference meshes had a harmonious and symmetric appearance, with gender differences in facial size but not in facial shape. The standard normal reference was superimposed on the patient's tracing, and the global (size plus shape) difference was then evaluated by the calculation of the relevant displacement vectors for each soft tissue landmark. A global difference factor was calculated as the sum of the modules of all the displacement vectors. Consequently, a size normalization was performed, and the shape difference (size-standardized) was then evaluated by the calculation of new relevant displacement vectors for each landmark, as well as a shape--global difference vectors.

Elliptic Fourier analysis of mandibular shape

Craniofacial growth and development involve both size and shape variations. Shape variations can be assessed independently from size using mathematical methods such as the elliptic Fourier analysis, which allows a global evaluation of the shape of organs identified by their outlines independently from size, spatial orientation, and relation to reference planes. The mandibular outlines were digitized from the tracings of the Bolton standards (lateral view) from 1 to 18 years of age, and the age differences in shape independently from size were quantified using the elliptic Fourier series. A "morphologic distance" MD (i.e., a measurement of differences in shape) between each younger mandible and the oldest one was computed using the relevant Fourier coefficients like the cartesian coordinates in standard metric measurements. MD equals 0 when the profiles are identical. MD (Y) between the Bolton standard at 18 years of age and all the other Bolton tracings were significantly correlated (correlation coefficient r = 0.987, P < or = 0.001) with age (X) (semi-logarithmic interpolation Y = -3.87.log(e) X + 13.593). Differences between the size-independent shape of the Bolton standard at 18 years and the relevant plot at 1 year were located at the chin, gonion, coronoid process, anterior border of the ramus. Size differences were measured from the areas enclosed by the mandibular outlines. Mandibular area (Y) increased about 2.58 times from 1 to 18 years of age (X) (Y = -0.071.X2 + 4.917.X + 35.904, r = 0.997, P < or = 0.001). The shape effect was largely overwhelmed by the very evident size increments, and it could be measured only using the proper mathematical methods. The method developed could also be applied to the comparison between healthy and diseased individuals.

Open-close movements in the human temporomandibular joint: does a pure rotation around the intercondylar hinge axis exist?

Mandibular movements near the maximum intercuspal position were analysed for the location of the mean instantaneous centre of curvature of the interincisal point path. Measurements were performed using a kinesiograph in 28 healthy young adults with sound dentitions and free from temporomandibular joint disorders. The subjects performed habitual open-close cycles at different speeds; opening movements starting from the centric relation occlusion were also analysed. In none of the 28 subjects was the interincisal point path derived from pure rotation movements performed around the intercondylar axis, not even in the first millimetres of motion. Translation and rotation were always combined, and the position of the centre of curvature changed during the motion, showing different characteristics in the open and close movements; these patterns were also dependent upon motion speed. The results show that the hinge axis theory cannot explain the mandibular movements because a pure rotation did not occur around the intercondylar axis.

Shape of the human corpus callosum in childhood. Elliptic Fourier analysis on midsagittal magnetic resonance scans

RATIONALE AND OBJECTIVES

The authors previously investigated the midsagittal magnetic resonance images of neurologically intact adults, and analyzed the shape of corpus callosum from a mathematic standpoint. Significant effects of age were demonstrated, without significant sex differences. In the current study, the same mathematic method was applied to analyze the sex and age shape differences of the human corpus callosum in childhood.

METHODS

On the midsagittal magnetic resonance images of 84 neurologically intact children (39 boys, 45 girls, aged 4 months to 15 years) the outline of the corpus callosum was identified. Its shape was quantified using elliptic Fourier analysis, which allows for global evaluation of the shape of organs identified by their outlines independently from size, spatial orientation, and relationship to reference planes. Subjects were grouped by sex and age.

RESULTS

The shape of the corpus callosum within age and sex classes in childhood was more homogeneous than in adulthood. A significant effect of age was demonstrated by the analysis of variance; however, no significant sex differences were found.

CONCLUSIONS

Corpus callosum shape in midsagittal magnetic resonance images was strongly influenced by central nervous system development and aging, but the influence of sex was not sufficient to be detected by current standard magnetic resonance imaging technology, and by the available sample sizes. The current investigation supplies data on the normal callosal shape in the first two decades of life, thus completing previous analysis.

Facial three-dimensional morphometry

Three-dimensional facial morphometry was investigated in a sample of 40 men and 40 women, with a new noninvasive computerized method. Subjects ranged in age between 19 and 32 years, had sound dentitions, and no craniocervical disorders. For each subject, 16 cutaneous facial landmarks were automatically collected by a system consisting of two infrared camera coupled device (CCD) cameras, real time hardware for the recognition of markers, and software for the three-dimensional reconstruction of landmarks' x, y, z coordinates. From these landmarks, 15 linear and 10 angular measurements, and four linear distance ratios were computed and averaged for sex. For all angular values, both samples showed a narrow variability and no significant gender differences were demonstrated. Conversely, all the linear measurements were significantly higher in men than in women. The highest intersample variability was observed for the measurements of facial height (prevalent vertical dimension), and the lowest for the measurements of facial depth (prevalent horizontal dimension). The proportions of upper and lower face height relative to the anterior face height showed a significant sex difference. Mean values were in good agreement with literature data collected with traditional methods. The described method allowed the direct and noninvasive calculation of three-dimensional linear and angular measurements that would be usefully applied in clinics as a supplement to the classic x-ray cephalometric analyses.

A computerized non-invasive method for the assessment of human facial volume

The three-dimensional coordinates of 22 standardized soft-tissue facial landmarks were used in the definition of a three-dimensional model of the adult human face. The model allows the estimation of the volume of the face in toto and of its parts (upper, middle and lower thirds, nose). Landmark coordinates were collected in 80 healthy young adults (40 men and 40 women selected according to criteria of dentofacial normality) by infrared photogrammetry by an automated instrument, and facial volumes calculated. Sample variability was larger in women than in men; the nose and the upper third of face had the largest variability regardless of gender. On average, all volumes computed in men were significantly larger than the corresponding values computed in women. Also the lower-to-middle third face ratio was significantly higher in men than in women. The sexual dimorphism in human facial volume did not involve the different parts of the face to the same extent: a large part of male facial volume preponderance was explained by the lower third of face. The proposed facial model could adequately represent the human face in all those research and clinical fields where noninvasive surface measurements could be employed alone or in support of conventional radiographic data.

A three-dimensional evaluation of human facial asymmetry

Soft-tissue facial asymmetry was studied in a group of 80 young healthy white Caucasian adults (40 men, 40 women) with no craniofacial, dental or mandibular disorders. For each subject, the 3-dimensional coordinates of 16 standardised soft-tissue facial landmarks (trichion, nasion, pronasale, subnasale, B point, pogonion, eye lateral canthi, nasal alae, labial commissures, tragi, gonia) were measured by infrared photogrammetry by an automated instrument. The form of the right and left hemifaces was assessed by calculating all the possible linear distances between pairs of landmarks within side. Side differences were tested by using euclidean distance matrix analysis. The mean faces of both groups were significantly asymmetric, i.e. the 2 sides of face showed significant differences in shape, but no differences in size.

Shape of the human corpus callosum. Elliptic Fourier analysis on midsagittal magnetic resonance scans

RATIONALE AND OBJECTIVES

Sex, age, or functional-asymmetry-related variations in the size and shape characteristics of the midsagittal magnetic resonance (MR) image of the human corpus callosum (CC) have been widely investigated in the last 10 years, with conflicting results. In the current study, the authors attempted to analyze the sex- and age-related shape differences of the human CC in a large sample of adult subjects from a mathematical standpoint.

METHODS

On the midsagittal MR images of 143 neurologically intact adults (75 women, 68 men, 21 to 81 years of age) the outline of the CC was identified. The shape of the CC was quantified using elliptic Fourier analysis, which allows for a global evaluation of the shape of organs identified by their outlines independent of their size, spatial orientation, and relation to reference planes. Subjects were grouped by sex and age.

RESULTS

The shape of the human CC within age and sex class was highly variable. The analysis of variance showed a significant effect of age; however no significant sex differences could be demonstrated.

CONCLUSIONS

Larger sample sizes are required to definitively assess the normal shape variations in human CC. The method developed also could be applied to the comparison of healthy and diseased individuals.

A three-dimensional study of sexual dimorphism in the human face

The sexual dimorphism in three-dimensional facial form (size plus shape) was investigated in a sample of 40 men and 36 women by using Euclidean-distance matrix analysis. Subjects ranged in age from 19 to 32 years, had excellent dentitions, and had no craniocervical disorders. For each subject, 16 facial landmarks were automatically collected using a computerized system consisting of two infrared CCD cameras, real-time hardware for the recognition of markers, and software for the three-dimensional reconstruction of landmarks' x, y, z coordinates. Euclidean-distance matrix analysis confirmed the well-known size difference between adult male and female faces (men's faces being 6% to 7% larger than women's faces), while it demonstrated no significant gender differences in three-dimensional facial shape. This result contrasted with the shape differences previously found when separate two-dimensional frontal and sagittal plane projections were analyzed. It could be explained by a relative three-dimensional compensation between the different facial dimensions.

Comparison of soft tissue facial morphometry in children with Class I and Class II occlusions

Three-dimensional soft tissue facial morphometry was investigated in a sample of 167 children aged 6 to 9 years by using a new noninvasive computerized method. For each child, 16 cutaneous facial landmarks were automatically collected by a system consisting of two infrared CCD cameras, real-time hardware for the recognition of markers, and software for the three-dimensional reconstruction of the x, y, and z coordinates of landmarks. From these landmarks, 15 linear and 10 angular measurements and five linear distance ratios were computed. For each age class, mean values were computed for all children with a bilateral Angle Class I occlusion (modified according to Katz) and compared with values obtained in children with a bilateral Class II occlusion. Most of the differences involved three-dimensional angular measurements: Class II children had more convex faces in the sagittal plane and a less prominent mandible than did Class I children. No differences were found in the linear measurements. Only the lower facial height ratio was different between the two occlusion groups, but the difference was not consistent among all the age groups.

Dental arch asymmetry in young healthy human subjects evaluated by Euclidean distance matrix analysis

Form differences between biological structures can be evaluated using several approaches. A recently proposed method (Euclidean distance matrix analysis; EDMA) seems to be able to differentiate between size and shape differences. Here it has been applied to study the asymmetry of mandibular and maxillary arches in 50 men and 45 women with sound dentitions. The centres of gravity (centroids) of the occlusal surfaces of all permanent teeth (right second molar to left second molar) were individualized on the dental casts of subjects. The form of the right and left maxillary and mandibular hemi-arches was separately assessed by calculating all the possible linear distances between pairs of teeth within arch and side. Side differences were tested by EDMA. In men, the maxillary and the mandibular arches were both symmetrical (i.e. there were no significant differences in size or shape between the left and right hemi-arches). In women, the mandibular arch was symmetrical, but in the maxillary arch the two antimeres had a significantly different shape. No size differences were found between the left and right female hemi-arches.

Kinesiographic three-dimensional evaluation of mandibular border movements: a statistical study in a normal young nonpatient group

Mandibular border movements were studied in a group of 74 healthy young men and women with sound dentitions and class I molar relationships. Movements were directly performed by the subjects and recorded with a mandibular kinesiograph, and slopes of the first millimeters of motion in the anterior and lateral guidances were calculated. In anterior guidance, the sagittal plane slope was steeper in men than in women, whereas the horizontal plane slope showed no gender differences. In the lateral guidances, frontal plane slopes were steeper in men than in women, with no side differences. The horizontal plane slope presented no side or sex differences. Most of the subjects demonstrated asymmetric guidances for both protrusive and the laterotrusive movements. These findings suggest that criteria for defining the norm should include asymptomatic asymmetry instead of strict morphologic symmetric appearance.