What is the relation between the presence of caries in the deciduous dentition and the chronology of the eruption of the permanent teeth?

Based on data obtained from a prospective epidemiological study in a random sample of 4468 Flemish children, accurate emergence ages for permanent teeth could be established. When data on permanent tooth emergence in different populations are compared, differences are most pronounced for premolars. Several authors hypothesised that this difference could be explained by a difference in caries experience in the primary molars. The purpose of this study was to quantify the effect of caries experience in a primary molar on the timing of emergence of its successor. The results indicate that the emergence of the premolars was accelerated by 2 to 8 months when its predecessor had been decayed and or filled but had not been extracted. Premature loss of maxillary primary molars resulted in a significant acceleration of the emergence of the premolars; this was not observed in the mandible. In conclusion, when considering permanent tooth emergence ages, caries experience in the primary dentition should be taken into account.     

Does the first file to bind correspond to the diameter of the canal in the apical region?

AIM: The aim of this study was to determine whether the first file that binds at the working length corresponds to the canal diameter. METHODOLOGY: Two similar groups (n = 10) of mandibular premolars with curved canals were selected on the basis of their morphology. Following access and pulp tissue removal, the first instrument that bound in each canal at the working length was determined. In one group the instrument used was a K-file, in the other group a Lightspeed instrument was used. After fixing the instruments in place, the apices were ground to the level of the working length and the diameters of both the instrument and the apical canal were recorded. RESULTS: In 75% of the canals, the instruments bound at one side of the wall only; in the other 25%, the instrument did not contact the wall. In 90% of the canals, the diameter of the instrument was smaller than the short diameter of the canal; this discrepancy was up to 0.19 mm. No significant difference in discrepancy was found between instruments (P > 0.05). CONCLUSIONS: Neither the first K-file nor the first Lightspeed instrument that bound at the working length accurately reflected the diameter of the apical canal in curved mandibular premolars. It is uncertain whether dentine can be removed from the entire circumference of the canal wall by filing the root canal to three sizes larger than the file that binds first.     

What does the patient expect from the dentist now and in the future?

In 1992 the Consumentenbond investigated which aspects patients consider to be important in the dental practice. The most important aspects were hygiene of the practice, technical skills of the dentist and the possibility to ask questions to the dentist. Internet will be more important in future communication with the consumer. At the moment, however, the quality of information from the internet is insufficient.     

On the parameters affecting the characteristics of the “wired” glucose oxidase anode

We recently described a redox polymer with an $\mathrm{Os}(N,N^{\prime }\text{-}\mathrm{dialkylated}\mathrm{biimidazole}{)}_3^{2+/3+}$ redox center with a redox potential of ?195 mV vs. Ag|AgCl, 800 mV reducing relative to its 2,2′-bipyridine analog. The tethering of the centers to a poly(4-vinylpyridine) backbone through a 13 atom long spacer arm, provided for an apparent electron diffusion coefficient as large as 5 × 8.10^?6 cm² s^?1. The glucose electro-oxidation catalyst formed by “wiring” glucose oxidase with this polymer allowed the electro-oxidation of glucose already at ?360 mV vs. Ag|AgCl at pH 7.2, near the reversible potential of glucose oxidase, at a current density of 1.3 mA cm^?2 in the presence of 32 mM glucose concentration. Here we consider the parameters affecting the characteristics of this anode, compare the characteristics with those of an anode made with a short-tethered “wire” and describe the optimization of the composition of the “wired” glucose oxidase.     

Does the thickness of the resin cement affect the bond strength of a fiber post to the root dentin?

This study aimed to evaluate the influence of cement thickness on the bond strength of a fiber-reinforced composite (FRC) post system to the root dentin. Eighteen single-rooted human teeth were decoronated (length: 16 mm), the canals were prepared, and the specimens were randomly allocated to 2 groups (n = 9): group 1 (low cement thickness), in which size 3 FRC posts were cemented using adhesive plus resin cement; and group 2 (high cement thickness), in which size 1 FRC posts were cemented as in group 1. Specimens were sectioned, producing 5 samples (thickness: 1.5 mm). For cement thickness evaluation, photographs of the samples were taken using an optical microscope, and the images were analyzed. Each sample was tested in push-out, and data were statistically analyzed. Bond strengths of groups 1 and 2 did not show significant differences (P = .558), but the cement thicknesses for these groups were significantly different (P < .0001). The increase in cement thickness did not significantly affect the bond strength (r2 = 0.1389, P= .936). Increased cement thickness surrounding the FRC post did not impair the bond strength.     

Does the great auricular nerve predict the size of the maintrunk of the facial nerve? A clinical and cadaveric study

There seems to be only individual clinical experience and some anecdotal evidence about a relation between the width of the great auricular nerve (GAN) and the size of the main trunk of the facial nerve during parotidectomy. To our knowledge no anatomical studies have been published. In this cadaveric and clinical study we measured the widest point of the GAN as it crosses the sternomastoid muscle before it divides, and the main trunk of the facial nerve before it bifurcates. Measurements were obtained from 16 patients who required formal superficial parotidectomies with identification of the facial nerve, and from 21 cadavers (16 formalin-fixed and 5 fresh frozen) where both sides were dissected. We recorded the results and the side of dissection. The mean (SD) width of the GAN and facial nerve from all the dissections was 2.75 (0.53) mm and 2.83 (0.54) mm, respectively. There was a strong correlation between the width of the nerves from both sides (left: r = 0.934, p < 0.001; right: r = 0.940, p < 0.001). The nerves did not differ significantly in size in patients or cadavers (GAN: right, p = 0.873; left, p = 0.486; facial nerve: right, p = 0.931; left, p = 0.691). We have found that the GAN accurately predicts the width of the main trunk of the facial nerve. This is particularly useful surgically as a narrow GAN can alert the surgeon to expect a small facial nerve.     

Are the B cells cast with the leading part in the Sjogren's syndrome scenario?

The autoimmune exocrinopathy Sjögren's syndrome (SS) is characterized by mononuclear cell (MNC) infiltrates of exocrine glands and overactivity of B lymphocytes. Although T cells have long been perceived as the prime effectors, increasing evidence indicates that the key role is rather served by B cells. Among related abnormalities are rheumatoid factor (RF), anti‐SSA/Ro, and anti‐SSB/La antibodies (Ab). Also, supporting this view is our finding of an increase in the number of circulating naïve mature B (Bm) cells, with a reciprocal decrease in that of memory B cells. Furthermore, a ratio of Bm2‐plus‐Bm2′ cells to early Bm5‐plus‐late Bm5 above 5 is diagnostic. This variation partly reflects the migration of active memory B cells into the exocrine glands of the patients, as well as into their skin. More recently, the B‐cell‐activating factor of the TNF family (BAFF) has been endorsed with a pivotal role in B‐cell survival and hence implicated in the pathogenesis of autoimmunity. In practice, B cells have turned quite attractive as a target for biotherapy. For example, treatment with anti‐CD20 Ab has afforded some benefits in this disease, while BAFF blockers are still on the way, but should expand our armamentarium for treating SS. With such B‐cell‐directed biotherapies in mind, we delineate herein the distinguishing traits of B lymphocytes in SS.     

What are the limitations of the non-patient-specific implant in titanium reconstruction of the orbit?

There is ongoing discussion about patient-specific implants (PSI) to reconstruct orbital defects. Although PSI offer excellent clinical outcome, they are expensive. Subsequently, their routine application is not indicated. The purpose of this study was to estimate the frequency of implant malposition and revision procedures after primary orbital repair with preformed plates and to identify cases where primary use of PSI would help to prevent revision surgery. All patients included in the study were operated on for orbital fractures at the Royal London Hospital between August 2017 and July 2018. Selection criteria included adult patients treated for orbital fractures with a titanium plate. Revision was planned in symptomatic patients presenting with clear implant malposition. Seventy-nine patients with 81 implants were included, 33 of whom had multiple orbital wall fractures (medial wall and floor or all four walls) and were summarised as group 2. Group 1 consisted of single orbital floor/medial wall fractures. The five patients for whom revision surgery was planned or undertaken because of radiological poorly positioned implants and substantial clinical symptoms all had multiple wall fractures. This finding was significant (p = 0.006). The major reason for revision was a defect that was too large for the prescribed plate. Patients with large orbital defects needing surgical treatment are at risk of implant malposition. The orbital reconstruction with preformed plate evidences good outcome in single wall fractures. However, the risk of malposition increases massively with fracture size. We therefore postulate that in large, two-wall fractures, primary treatment with a PSI has to be considered.     

Should we recruit trainees into the Oral and Maxillofacial Surgery pathway at the beginning of the second degree to ensure the long term viability of the specialty?

There has been a sustained decline in the number of trainees applying for entry into the Oral and Maxillofacial Surgery (OMFS) training program, which has sparked further debate on the issue of OMFS training and the future of the specialty in the United Kingdom. Here I discuss the option of recruiting the trainees into the program at the beginning of their second degree to streamline the training, and to improve the recruitment drive to ensure long term viability of the specialty