Correlation between Malocclusion and Mandibular Fractures: An Experimental Study Comparing Dynamic Finite Element Models and Clinical Case Studies

Mandibular fractures are very common in maxillofacial trauma surgery. While previous studies have focused on possible risk factors related to post-operative complications, none have tried to identify pre-existing conditions that may increase the risk of mandibular fractures. We hypothesized, through clinical observation, that anatomical conditions involving poor dental contacts, such as malocclusions, may increase the risk of mandibular fractures. This work was subdivided into two parts. In the first part, Digital Imaging and Communications in Medicine (DICOM) data of four healthy patients characterized by different dentoskeletal occlusions (class I, class II, class III, and anterior open bite) have been used to develop four finite element models (FEMs) that accurately reproduce human bone structure. A vertical and lateral impact have been simulated at increasing speed on each model, analyzing the force distribution within the mandibular bone. Both vertical and lateral impact showed higher level of stress at the impact point and in the condylar area in models characterized by malocclusion. Specifically, the class III and the open bite models, at the same speed of impact, had higher values for a longer period, reaching critical stress levels that are correlated with mandibular fracture, while normal occlusion seems to be a protective condition. In the second part of this study, the engineering results were validated through the comparison with a sample of patients previously treated for mandibular fracture. Data from 223 mandibular fractures, due to low-energy injuries, were retrospectively collected to evaluate a possible correlation between pre-existing malocclusion and fracture patterns, considering grade of displacement, numbers of foci, and associated CFI score. Patients were classified, according to their occlusion, into Class I, Class II, Class III, and anterior open bite or poor occlusal contact (POC). Class I patients showed lower frequencies of fracture than class II, III, and open bite or POC patients. Class I was associated with displaced fractures in 16.1% of cases, class II in 47.1%, class III in 48.8% and open bite/POC in 65.2% of cases (p-value < 0.0001). In class I patients we observed a single non-displaced fracture in 51.6% of cases, compared to 12.9% of Class II, 19.5% of Class III and 22.7% of the open bite/POC group. Our analysis shows that class I appears to better dissipate forces applied on the mandible in low-energy injuries. A higher number of dental contacts showed a lower rate of multifocal and displaced fractures, mitigating the effect of direct forces onto the bone. The correlation between clinical data and virtual simulation on FEM models seems to point out that virtual simulation successfully predicts fracture patterns and risk of association with different type of occlusion. Better knowledge of biomechanics and force dissipation on the human body may lead to the development of more effective safety devices, and help select patients to plan medical, orthodontic/dental, and/or surgical intervention to prevent injuries.

Long term follow-up of humoral and cellular response to mRNA-based vaccines for SARS-CoV-2 in patients with active multiple myeloma

Long-term kinetics of antibody (Ab) and cell-mediated immune (CMI) response to full anti-SARS-CoV-2 vaccine schedule and booster doses in Multiple Myeloma (MM) patients remain unclear. We prospectively evaluated Ab and CMI response to mRNA vaccines in 103 SARS-CoV-2-naïve MM patients (median age 66, 1 median prior line of therapy) and 63 health-workers. Anti-S-RBD IgG (Elecsys^®assay) were measured before vaccination and after 1 (T1), 3 (T3), 6 (T6), 9 (T9) and 12 (T12) months from second dose (D2) and 1 month after the introduction of the booster dose (T1D3). CMI response (IGRA test) was evaluated at T3 and T12. Fully vaccinated MM patients displayed high seropositivity rate (88.2%), but low CMI response (36.2%). At T6 the median serological titer was halved (p=0.0391) in MM patients and 35% reduced (p=0.0026) in controls. D3 (94 patients) increased the seroconversion rate to 99% in MM patients and the median IgG titer in both groups (up to 2500 U/mL), maintained at T12. 47% of MM patients displayed a positive CMI at T12 and double-negativity for humoral and CMI (9.6% at T3) decreased to 1%. Anti-S-RBD IgG level ≥346 U/mL showed 20-times higher probability of positive CMI response (OR 20.6, p<0.0001). Hematological response ≥CR and ongoing lenalidomide maintenance enhanced response to vaccination, hindered by proteasome inhibitors/anti-CD38 monoclonal antibodies. In conclusion, MM elicited excellent humoral, but insufficient cellular responses to anti-SARS-CoV-2 mRNA vaccines. Third dose improved immunogenicity renewal, even when undetectable after D2. Hematological response and ongoing treatment at vaccination were the main predictive factors of vaccine immunogenicity, emphasizing the role of vaccine response assessment to identify patients requiring salvage approaches.

P110 ACCIDENTAL FINDING OF COR TRIATRIUM SINISTER IN AN ADULT: DIAGNOSIS MANAGMENT

A 45–year old woman presented at the emergency department for palpitations and fever. The EKG, thoracic x–ray and troponins were normal, only a neutrophil leucocytosis was found. The echocardiography showed a normal bi–ventricular and valvular function and a mobile, linear, mass in the left atrium. In order to exclude an infective vegetation the patient underwent to a 2D and 3D transesophageal echocardiography (Figure 1 and 2) which showed a left ventricle concentric remodelling (iLVmass 62 g/m2; RWT 0.45), preserved left and right ventricle function (LVEF according to Simpson 70%; FAC 50%) and valves function; inter–atrial septum defects were excluded, too. The mass was described as a mobile membrane in the left atrium at 2.11 cm from the mitral valve anular plane, which divided the atrium into two separate chambers with a large fenestration without trans–mitralic flow obstruction, supporting a cor triatrium sinister. We excluded endocarditis (the blood cultures were negative, too) and supra–valvular mitral ring (since the left appendage position in the antero–inferior side of the left atrium). The cardiac MRI showed (Figure 3) (SSFP–FIESTA, IR–GRE T1, STIR T2) confirmed the finding of a left atrium divided in two chamber by a iso–intense membraine from the coumadin ridge between the left upper pulmonary vein and the left appendage to the inter–atrial septum fossa ovalis, incomplete in the infero–lateral part. Venous drenaige and other congenital abnormalities were excluded. Miocarditis was excluded since no fibrosis in IR–GRE T1 and no edema in Triple T2 sequences. Since the non–obstructive cor triatrium sinister, grading IA according the Lucas classification, was confirmed, no surgical treatment was proposed and the patient was discharged without complications.

C46 A RARE CASE OF LANGERHANS CELLS HISTIOCYTOSIS CARDIO–VASCULAR INVOLVMENT

A 54–year–old woman presented at our department for clinical follow–up. She was affected by hypertension, hypercholesterolemia, diabetes insipidus and autoimmune hypotiroidism in substitutive therapy. She had chronic coronary syndrome treated by medical therapy after unsuccessfull left anterior descending artery percutaneous revascularization and underwent to left common iliac artery stenting. The echo–doppler study showed a thickening of both common and internal carotid. Moreover, the patients underwent a skin biopsy of nodular, purple lesions which showed a xanthomatous infiltration suggestive of Langherans cell histiocytosis (CD1A+ e S100+). A subsequent PET–TC total body demonstrated a FDG uptake tissue around the great vessels and a focal increased uptake in the proximal thirds of the left tibia and in the distal thirds of fibula. The patient underwent to a new skin biopsy which confirmed histiocytosis (S100+, langherin+, CD1a+, BRAFV600E negative) and to a negative bone biopsy. Since the diagnosis of histiocytosis was confirmed the association of mercaptopurine and steroid therapy was started. In our department we performed a follow–up echocardiography which showed normal left and right ventricle dimensions and a good bi–ventricular function (LVEF according to Simpson 55% and FAC 50%) and surprisingly a focal right atrial wall thinckening of 3 mm. Therefore, the cardiac MRI showed no oedema in triple T2, no late gadolinium enhancement inIR–GRE T1 and at the posteriori wall of the right ventricle a focal thickening of 2.3 x 2.4 cm of increased intensity and a disomogenous enhancement after contrast agent administration (Figure 1); the same non stenotic tissue was showed along the aortic arch and the discending aorta (Figure 2). The MRI characteristic of these cardio–vascular lesions are consistent with the diagnosis of Langeran’s cells histiocytosis.

Safety of Rapid Daratumumab Infusion: A Retrospective, Multicenter, Real-Life Analysis on 134 Patients With Multiple Myeloma

Background

The anti-CD38 monoclonal antibody daratumumab is the backbone of most anti-multiple myeloma (MM) regimens. To mitigate the risk of infusion-related reactions (IRRs), intravenous daratumumab administration requires 7 hours for the first infusion and 3.5-4 hours thereafter, thus making daratumumab-containing regimens burdensome for patients and health care resources. Preliminary data suggest that a rapid (90-minute) infusion of daratumumab is safe and does not increase IRRs. The rapid schedule was adopted by our centers since 2019.

Methods

We conducted an observational multi-center, real-life study to assess the safety of rapid daratumumab infusion protocol from the third administration in relapsed MM patients receiving daratumumab alone or in combination with lenalidomide-dexamethasone or bortezomib-dexamethasone. The primary endpoint was the safety of the rapid infusion protocol, particularly in terms of IRRs.

Results

A total of 134 MM patients were enrolled. IRRs occurred in 7 (5%) patients and were mostly mild (6/7 of grade 1-2), with only 1 patient experiencing a grade 3 IRR. Due to the IRRs, 5 (3.7%) patients discontinued the rapid infusions and resumed daratumumab at the standard infusion rate, while 1 patient permanently discontinued daratumumab. In 4/7 patients (57%), IRRs occurred while resuming rapid daratumumab infusions after a temporary interruption (2-4 months). No other adverse event was considered related to the rapid infusion protocol.

Conclusions

Our findings confirmed the safety of rapid daratumumab infusions starting from the third administration. In case of prolonged daratumumab interruption, it is advisable to resume infusions at the standard rate (3.5 hours) before switching to the rapid infusion.

Factors affecting progression to permanent atrial fibrillation in an unselected population of patients with non-permanent form of atrial fibrillation

Background

Natural history of atrial fibrillation (AF) shows a progression of arrhythmia from non-permanent to permanent AF. Permanent AF was found associated with a worse prognosis than non-permanent one.

Aim

To assess the factors associated with progression to permanent AF in an unselected population of AF patients with non-permanent AF.

Methods

In this prospective study we enrolled in- as well as out-patients with non-permanent AF and age ≥18 years, with at least one episode of ECG-documented AF within 1 year. The patients were followed-up at 1 month and every 6 months thereafter.

Results

Out of 523 patients, 314 (60%) were in non-permanent AF (80 [25.5%] paroxysmal AF, 165 [52.5%] persistent AF, 69 [2%] first diagnosed AF), mostly male (188, 59.9%), median age 71 years (IQ range 62–77), median CHA2DS2VASc 3 (1–4), median HATCH score 1 (1–2). After a median follow-up of 701 (IQ range 437–902) days, 66 patients (21%) showed permanent AF.

CHA2DS2VASc and HATCH scores were incrementally associated to progression to permanent AF (CHA2DS2VASc χ2 p=0.001; HATCH χ2 p=0.017; p for trend CHA2DS2VASc &lt;0.001, HATCH p=0.001).

At multivariable Cox proportional hazard regression the following variables were significantly associated with AF progression: age (hazard ratio [HR] 1.041; 95% CI: 1.004–1.079; p=0.028), at least moderate left atrial (LA) enlargement (&gt;42 ml/m2) (HR 2.092; 95% CI: 1.132–3.866; p=0.018), antiarrhythmics drugs after the enrollment (HR 0.087; 95% CI: 0.011–0.662; p=0.018), EHRA score &gt;2 (HR 0.351; 95% CI: 0.158–0.779; p=0.010) and Valvular HD (HR 2.161; 95% CI: 1.057–4.420; p=0.035). Adding LA dilation to HATCH score (HATCH-LA) and assigning 2 points based on multivariable Cox regression, HATCH-LA was statistically better in ROC curves in prediction of AF progression vs HATCH score (area under the curve 0.695 vs 0.636; DeLong p=0.0225). Survival-free curves on freedom from permanent AF using as discriminator HATCH-LA score ≤2 vs &gt;2 led to a statistically significant difference (χ2=16.080 p&lt;0.001), but the same was not found for HATCH score (χ2 =3.099; p=0.078).

Conclusions

In patients without permanent AF, progression of AF was independentely related to age, LA dilation, AF symptoms severity, antiarrhythmic drugs and Valvular HD. HATCH score predicted AF progression and adding to it LA dilation (at least moderate) improved patients stratification for the risk of evolution to permanent AF.

Funding Acknowledgement

Type of funding source: None

[Exercise training in chronic obstructive pulmonary disease. Comparative study of aerobic training of lower limbs vs. combination with upper limbs]

A prospective, randomized and controlled study has been performed in 28 patients with severe COPD. A group of 14 has been trained with their lower limbs (LL), while another similar group of 14 patients was also trained with their upper limbs (UL). Results showed improvement in both groups in the endurance test for LL, dyspnea scale, efficiency and muscular working capacity. A considerable improvement was observed in the oxygen uptake at the anerobic threshold (VO2AT) which suggests a training effect, expressed through an improvement in exercise tolerance. Only the group who trained UL showed a remarkable improvement in the dyspnea scale, endurance test and maximal static mouth pressure, showing a better intrinsic working capacity and participation of the UL muscles producing those manoeuvres. At the end of training, quality of life was significantly increased and the hospitalization rate was lower in both groups. According to these findings, it is suggested that patients with severe COPD included in training programmes add UL exercises to the LL usually carried out.

Effect of moderate physical training on left ventricular mass in mild hypertensive persons

Exercise might reduce blood pressure in mild essential hypertensive individuals, but it could raise left ventricular mass, counteracting the beneficial effects induced by a decrease in blood pressure. Seventeen (group 1) of 25 mild hypertensive patients, nonresponders to a 3-month low sodium diet (2 g/day), were admitted into a physical training program consisting of three weekly sessions of aerobics (20 minutes), bicycling at prefixed loads (20 minutes), and induced muscular relaxation (10 minutes). They were compared with 15 mild hypertensive patients (group 2), nonresponders to the low sodium diet who remained untrained. The follow-up lasted 15.7 +/- 5.8 months. There were significant blood pressure decreases in group 1 at rest (155 +/- 9.8/101 +/- 3.3 vs. 136 +/- 8.1/86 +/- 6.6 mm Hg, p less than 0.001) and at maximal effort (219 +/- 27.4/119 +/- 14.4 vs. 196 +/- 21.8/101 +/- 10.5 mm Hg, p less than 0.001). Maximal work capacity increased from 758.8 +/- 256.7 to 944.1 +/- 203.8 kpm (p less than 0.001). Echocardiographic left ventricular mass index tended to decrease (137.8 +/- 36.3 vs. 125.4 +/- 29.9 g/m2, p = NS), without any significant modification of either left ventricular volume index or left ventricular shortening fraction. No significant changes occurred in group 2. There was no correlation between blood pressure and left ventricular mass changes and left ventricular shortening fraction and left ventricular mass index changes. According to these results, it seems prudent to prescribe physical training to mild hypertensive patients because it does not induce left ventricular mass increases.(ABSTRACT TRUNCATED AT 250 WORDS)

Recovery of low thymic hormone levels in cancer patients by lysine-arginine combination

Thymic hormones are required for maturation and maintenance of the immune efficiency. It has been previously demonstrated that with advancing age there occurs a progressive reduction of the plasma level of one of the best known thymic peptides, i.e. thymulin, and that the administration of an amino acid combination (lysine-arginine, as present in the commercial preparation Lysargin, Baldacci, Italy) to elderly individuals is able to increase the synthesis and/or release of thymulin to values comparable to those recorded in young subjects. In the present paper we report evidence that cancer patients show much lower thymulin values than those recorded in healthy age-matched individuals and that the oral administration of the amino acid preparation is able to significantly increase thymulin levels even over the values of age-matched controls and to increase the number of peripheral T-cell subsets. It is suggested that such an effect is mediated through the known secretagogue activity of the amino acids on the pituitary release of growth hormone, which has a modulating effect on the thymic endocrine activity.