Effect of antibiotic pack on hard palate after fistula closure on nasal airflow and reoccurrence rate

This parallel blocked randomized controlled trial was done in two groups of 30 patients each to determine if placement of an antibiotic oral pack on the hard palate after hard palatal fistula repair reduces nasal air emission and fistula re-occurrence. Group A had an oral pack on the hard palate for 5 days post-operatively while group B did not. In group A, percentage of nasal air emission was tested using nasometry with and without pack. Paired t-tests were performed to compare nasal emissions for patients with and without pack. Recurrence of fistulas after 6 months between group A and B was tested using odds ratio. Effect of nasal air emission on fistula rates was tested using paired t-tests. There was a significant increase (p < 0.0001) in nasal emission after removal of the pack in group A. Fistula re-occurrence tended to be higher in group B (no pack) than group A but this was not significant (p = 0.242). There was no correlation between nasal air emission and fistula rates. In patients with recurrent fistulae, placement of an oral pack after fistula repair diminishes nasal air emission. Whether this has an impact on re-occurrence of fistulae needs to be investigated further

Prevalence of malocclusion and orthodontic treatment needs among 12–15-year-old schoolchildren of fishermen of Kutch coast, Gujarat, India

Background: Malocclusion is one of the most common dental problems in mankind. Planning orthodontic treatment as well as an interceptive approach within a public health system requires information on the prevalence of malocclusions.Aim: The aim of the study was to assess the prevalence of malocclusion and orthodontic treatment needs among 12–15-year-old school children of fishermen of Kutch coast, Gujarat, India.Materials and methods: A cross-sectional descriptive survey was conducted among 947 school children offishermen of Kutch coast, Gujarat, India aged 12–15 years. The prevalence of malocclusion and orthodontic treatment needs was assessed using Dental Aesthetic Index. General information on demographic data was also recorded. A c2 test, analysis of variance (ANOVA) and Sheffe’s test were employed for statistical analysis.Results: Malocclusion and orthodontic treatment need was reported among 33.4% of the participants. Younger age group and female gender had significantly greater treatment need. Males and older age groups had significantly lesser prevalence of anterior crowding and largest anterior maxillary irregularity.Conclusions: Orthodontic treatment need among 33.4% calls for developing school based oral health promotion programmes for children with an inculcation of orthodontic treatment and educational programmes for parents (fishermen) addressing prevention and early interceptive treatment of malocclusion

Fast pyrolysis of lignins with different molecular weight: Experiments and modelling

Lignins with number average molecular weights between 350 Da and 1900 Da were characterised and subsequently pyrolysed in a screen-heater at pressures of 500 Pa and 105 Pa between 425 °C and 793 °C. Upwards of 530 °C, the temperature turned out to have only a minor influence on the yields and composition of the oils produced. Clear trends were observed as a function of the molecular weight and pressure – (1) at increasing molecular weight of the lignin, the oil yield decreases while yields of char and gas increase, (2) the molecular weight of the oil is lower for oils produced at 105 Pa as compared to the ones obtained at 500 Pa, (3) above a certain molecular weight of the lignins, ∼400 Da for 105 Pa and ∼800 Da for 500 Pa, the molecular weight of the oil becomes independent of the molecular weight of the lignin. A mathematical model has been developed, which includes three concurrently occurring processes, viz. cracking and polymerisation reactions and removal, hence mass transport, of unconverted lignin and reaction products from the reaction zone. This model can describe all the trends observed experimentally and provides, after parametrisation, reasonable qualitative predictions of the yield and molecular weight of the oils. Knowledge of the role of the interplay between mass transport and chemistry in the pyrolysis process is further accumulating, and from this the development of lignin valorisation can avail. For instance, it has become clear that in the pyrolysis process the molecular weight of lignin oil, which is an important characteristic for the upgrading of the oil to chemicals and/or fuels, can be steered with the pressure

Photodynamic therapy with nanoparticles to combat microbial infection and resistance

Infections caused by drug-resistant pathogens are rapidly increasing in incidence and pose an urgent global health concern. New treatments are needed to address this critical situation while preventing further resistance acquired by the pathogens. One promising approach is antimicrobial photodynamic therapy (PDT), a technique that selectively damages pathogenic cells through reactive oxygen species (ROS) that have been deliberately produced by light-activated chemical reactions via a photosensitiser. There are currently some limitations to its wider deployment, including aggregation, hydrophobicity, and sub-optimal penetration capabilities of the photosensitiser, all of which decrease the production of ROS and lead to reduced therapeutic performance. In combination with nanoparticles, however, these challenges may be overcome. Their small size, functionalisable structure, and large contact surface allow a high degree of internalization by cellular membranes and tissue barriers. In this review, we first summarise the mechanism of PDT action and the interaction between nanoparticles and the cell membrane. We then introduce the categorisation of nanoparticles in PDT, acting as nanocarriers, photosensitising molecules, and transducers, in which we highlight their use against a range of bacterial and fungal pathogens. We also compare the antimicrobial efficiency of nanoparticles to unbound photosensitisers and examine the relevant safety considerations. Finally, we discuss the use of nanoparticulate drug delivery systems in clinical applications of antimicrobial PDT