Clinical and computerized evaluation in study of temporo-mandibular joint intracapsular disease

AIM

In this work authors show a diagnostic criteria in study of TMID: neuro occlusal clinical evaluation (NOE), T-Scan 2 system and surface electromyography (sEMG).

METHODS

Nine patients 25-30 years old with TMID problem and 9 healthy group control have been selected and examined. On each patients it has been performed NOE, T-Scan and sEMG test. NOE has been calculated on each patient photos lateral mandibular excursion angle called: masticatory functional angle (AFM). T-Scan System is a computerized occlusal analyzer that provide in-depth understanding of the overall balance of the occlusion. At the same time of T-Scan record sEMG tests, in resting position and in maximum clench, have been performed.

RESULTS

In healthy control there were no AFM difference. In no healthy group there were difference between the two AFM greater than 6 degrees. T-Scan COF showed how in healthy group control there was never a difference of COF greater than 5%. In no healthy group the difference were greater than 5% P<0.05. T-scan showed difference of time force in maximum intercuspidation (MIFT) in healthy respect TMID patients. In healthy patients MIFT was higher than TMID patients P<0.05. sEMG test showed in non healthy group a great asymmetrical activation of masseter (MM). MM activation were greater on side affected by joint sound than the balance side P<0.001. sEMG show how in TMID patients maximum masseter activation is always lower than maximum masseter activation of healthy subjects P<0.001.

CONCLUSION

Neuro occlusal clinical evaluation (NOE) in TMID patients is supported by instrumental evaluation.

In vitro comparison of the cytotoxicity of two orthodontic composite resins

AIM

Several studies have reported that dental resin-based materials release substances with biological activity: for this reason in this study we evaluated the in vitro cytopathic effects of a self-curing and a light-curing orthodontic composite resins by a cytotoxicity test.

METHODS

The cytotoxic potential of specimens, prepared according to the manufacturer instructions, was evaluated using the thiazolyl blue tetrazolium bromide (MTT) assay on the mouse fibroblast cell line (3T3 Swiss) with 2 cells-material contact systems: the 24 h extracts method and the indirect toxicity method.

RESULTS

The results obtained in this study elicit a close agreement between the 2 procedures; from the data obtained in the reported experimental conditions, it was possible to establish that the examined chemical-cured material is more cytotoxic than the light-cured one.

CONCLUSIONS

From a clinical point of view, the photo-polymerizable resins are undoubtedly more useful in the daily practice, because of the larger precision of the bonding obtainable by the greater period available for setting the brackets before their lock. The results obtained in this study, even considering the limits of the in vitro tests, represent a further favourable feature of the light-curing composite resins. However, further investigations about the influence of polymerization methods of the materials on the biological effects are suggested to contribute to the determination of the best clinical operative conditions.

Intra-individual variability in the neuroprotective and promyelinating properties of conditioned culture medium obtained from human adipose mesenchymal stromal cells

BACKGROUND

Greater knowledge of mesenchymal stromal cell (MSC)-based therapies is driving the research into their secretome, identified as the main element responsible for their therapeutic effects. The aim of this study is to characterize the individual variability of the secretome of adipose tissue-derived MSCs (adMSCs) with regard to potential therapeutical applications in neurology.

METHODS

adMSCs were isolated from the intact adipose tissue of ten subjects undergoing abdominal plastic surgery or reduction mammoplasty. Two commercial lines were also included. We analyzed the expansion rate, production, and secretion of growth factors of interest for neurological applications (VEGF-A, BDNF, PDGF-AA and AA/BB, HGF, NGF, FGF-21, GDNF, IGF-I, IGF-II, EGF and FGF-2). To correlate these characteristics with the biological effects on the cellular targets, we used individual media conditioned with adMSCs from the various donors on primary cultures of neurons/astrocytes and oligodendrocyte precursor cells (OPCs) exposed to noxious stimuli (oxygen-glucose deprivation, OGD) to evaluate their protective and promyelinating properties, using MSC medium as a control group.

RESULTS

The MSC secretome showed significant individual variability within the considered population with regard to PDGF-AA, PDGF-AB/BB, VEGF-A and BDNF. None of the MSC-derived supernatants affected neuron viability in normoxia, while substantial protection by high BDNF-containing conditioned MSC medium was observed in neuronal cultures exposed to OGD conditions. In OPC cultures, the MSC-derived supernatants protected cells from OGD-induced cell death, also increasing the differentiation in mature oligodendrocytes. Neuroprotection showed a positive correlation with VEGF-A, BDNF and PDGF-AA concentrations in the culture supernatants, and an inverse correlation with HGF, while OPC differentiation following OGD was positively correlated to PDGF-AA concentration.

CONCLUSIONS

Despite the limited number of adMSC donors, this study showed significant individual variability in the biological properties of interest for neurological applications for adMSC secretome, an under-researched aspect which may represent an important step in the translation of MSC-derived acellular products to clinical practice. We also showed the potential protection capability of MSC conditioned medium on neuronal and oligodendroglial lineages exposed to oxygen-glucose deprivation. These effects are directly correlated to the concentration of specific growth factors, and indicate that the remyelination should be included as a primary target in MSC-based therapies.

Effect of the Enveloppe Linguale Nocturne on atypical swallowing: surface electromyography and computerised postural test evaluation

AIM

Swallowing is a neuromuscular mechanism regulated by many nervous reflex arcs. Persistence of child swallowing at the end of dental eruption is called atypical swallowing (AS). This condition is related to a dysfunction of vertical maxillary growth called open bite. The authors treated this malocclusion with the Enveloppe Linguale Nocturne (ELN), or tongue positioner, created by Dr. Bonnet. The aim of this work is to evaluate the effect of ELN on swallowing and the postural variation obtained by its use.

MATERIALS AND METHODS

Seven patients affected by AS were evaluated. Surface Electromyography (sEMG) testing was performed on each patient with different tongue positions, and swallowing was evaluated with and without the ELN. A surface Electromyograph (Biopack) with 8 channels was used (4 channels for the right muscles and 4 for the left) on 4 groups of muscles: temporals, masseters (MM), submental (SUB) and sternocleidmastoids. On each patient a postural test using a computerised Postural test (Lizard) was also performed. Statistical analysis was done using the Graph pad Instat 3 both for sEMG activity and for computerised postural analysis.

RESULTS

All seven subjects had different results in the sEMG and footrest tests. The sEMG test results indicated that muscle activation and swallowing duration varied greatly with the use of ELN, with a reduction of time of swallow act (p = 0.002) and variation in contraction of muscles. Mean MM activation was higher without ELN than in tests performed with the appliance (p = 0.002). Mean SUB activation was higher with than without ELN (p = 0.0033). ELN has a therapeutic effect on posture too. Computerised postural test without device showed in all patients an alteration of barycentre as well as an elevated oscillatory record (A mmq; V mms). With ELN footrest kilogram difference (p = 0.0110), Oscillatory Area (P = 0.0102) and velocity of oscillation (P = 0.0102) presented a great reduction in respect to patients record without ELN.

CONCLUSION

With ELN the tongue reaches the physiologic position during the swallowing and it is possible to have a low dental contact without tongue interference. ELN has no dental retention or contact. For this reason sEMG swallowing test shows that ELN induces a Mm activation reduction compared to swallowing test without ELN (P = 0.002) and an increase of SUB activation (P = 0.0033). In the same way with ELN there is a significant reduction of time of swallowing (c.f. oral phase) (P = 0.002). Patients with ELN changed their posture with a complete modification of barycentre (Footrest unbalancing kg P = 0.0110), oscillatory movement area (Footrest Area difference P = 0.0102), and oscillatory Velocity (Footrest Velocity oscillation difference P = 0.0102). These data suggest that this appliance has a function in the rehabilitation of atypical swallowing. ELN produces a physiologic neuromuscular mechanism that induces the correction of tongue position.