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Abstract Background: Open-vent jet nebulizers are frequently used to promote drug deposition in the lung, but their clinical efficacy and indications are not clear. Our study compared lung deposition of amikacin using two different configurations of a jet nebulizer (Sidestream®): one vented (N1) and one unvented with a corrugated piece of tubing (N2). Methods: In vitro nebulizer performance was assessed by laser diffraction and filtering. Lung delivery was evaluated by scintigraphy in baboons as a child model, and by amikacin urinary drug concentration in seven healthy spontaneously breathing volunteers. Subjects were randomly assigned to the two nebulizer systems (N1 and N2). Results and conclusions: In vitro results showed a higher efficiency of N2 than N1 in terms of lung deposition prediction (95±3 mg vs. 70±0 mg; p<0.0001). Radioactivity deposition in the baboons' lungs was lower with N1 than with N2 (1.8% vs. 4.7% of nebulizer charge; p<0.05). The total daily amount of amikacin urinary excretion was lower with N1 than with N2 (29.5 mg vs. 40.1 mg; p<0.01). Conversely, in vivo drug output rate was higher with N1 than with N2 (3.1 mg/min vs. 2.2 mg/min; p<0.05). Using a corrugated piece of tubing with standard jet nebulizers delivers higher doses to the lungs than open-vent jet nebulizers. The open-vent jet nebulizer might be recommended for rapid administration of a lower dose to the lungs and the standard jet nebulizer with corrugated piece of tubing for a higher dose in the lungs.

Objective To describe the normal cortical projections of periodontal mechanoreceptors. Material and methods A device using von Frey filaments delivered 1-Hz punctate tactile stimuli to the teeth during fMRI. In a block design paradigm, tooth (T) 11 and T13 were stimulated in ten volunteers and T21 and T23 in ten other subjects. Random-effect group analyses were performed for each tooth, and differences between teeth were examined using ANOVA. Results The parietal operculum (S2) was activated bilaterally for all teeth; the postcentral gyrus (S1) was activated bilaterally for T21 and T23 and contralaterally for T11 and T13. In the second-level analysis including the four teeth, we found five clusters: bilateral S1 and S2, and left inferior frontal gyrus, with no difference between teeth in somatosensory areas. However, the ANOVA performed on the S1 clusters found separately in each tooth showed that S1 activation was more contralateral for the canines. Conclusion One-hertz mechanical stimulation activates periodontal mechanoreceptors and elicits bilateral cortical activity in S1 and S2, with a double representation in S2, namely in OP1 and OP4. Clinical relevance The cortical somatotopy of periodontal mechanoreceptors is poorly described. These findings may serve as normal reference to further explore the cortical plasticity induced by periodontal or neurological diseases.

We present an original three-dimensional cephalometric analysis based on a transformation of a classical two dimensional topological cephalometry. To validate the three-dimensional cephalometric CT based concept we systematically compared the alignments of anatomic structures. We used digital lateral radiography to perform the classical two-dimensional cephalometry, and a three-dimensional CT surface model for the three-dimensional cephalometry. Diagnoses based on both two-dimensional and three-dimensional analyses were adequate, but the three-dimensional analysis gave more information such as the possibility of comparing the right and left side of the skull. Also the anatomic structures were not superimposed which improved the visibility of the reference landmarks. We demonstrated that three-dimensional analysis gives the same results as two-dimensional analysis using the same skull. We also present possible applications of the method.

Abstract Background: Jet nebulizers coupled to spacers are frequently used to promote drug lung deposition, but their clinical efficacy has not been established. Few in vivo studies have been performed with mesh nebulizers, commonly used to nebulize antibiotics. Our study compared inhaled mass and urinary drug concentration of amikacin by using three different nebulizer delivery configuration systems: a standard unvented jet nebulizer (Sidestream®) used alone or coupled to a 110-mL corrugated piece of tubing and a vibrating mesh nebulizer (e-Flow rapid®). Method: The inhaled mass of amikacin was assessed using the residual gravimetric method. Delivery efficacy was evaluated by assessing amikacin urinary drug concentration in six healthy spontaneously breathing volunteers. Urinary amikacin was monitored by fluorescent polarization immunoassay then cumulative excreted amount and antibiotic elimination rate were calculated. Results and Conclusions: The total daily amount of amikacin urinary excretion (Cu) was almost twice as high with eFlow rapid® compared to Sidestream® used alone; intermediate values being observed when the device was coupled to a corrugated piece of tubing. The latter configuration was also associated with a higher total daily amount of amikacin urinary excretion. In vivo drug output rate was around threefold higher with the eFlow Rapid® than with the Sidestream® used in any configuration. These results were concordant to those obtained with in vitro analysis comparing inhaled mass of amikacin for the three nebulizers. The elimination constant (Ke) and the mass median aerodynamic diameter (MMAD) did not differ between the three devices. In conclusion, the vibrating mesh nebulizer is more efficient, promoting larger urinary drug concentration and drug output. Coupling a corrugated piece of tubing to the standard jet nebulizer favors delivery efficacy.

Objectives The purpose of this study is to compare the reproducibility of three-dimensional cephalometric landmarks on three-dimensional computed tomography (3D-CT) surface rendering using clinical protocols based on low-dose (35-mAs) spiral CT and cone-beam CT (I-CAT). The absorbed dose levels for radiosensitive organs in the maxillofacial region during exposure in both 3D-CT protocols were also assessed. Materials and methods The study population consisted of ten human dry skulls examined with low-dose CT and cone-beam CT. Two independent observers identified 24 cephalometric anatomic landmarks at 13 sites on the 3D-CT surface renderings using both protocols, with each observer repeating the identification 1 month later. A total of 1,920 imaging measurements were performed. Thermoluminescent dosimeters were placed at six sites around the thyroid gland, the submandibular glands, and the eyes in an Alderson phantom to measure the absorbed dose levels. Results When comparing low-dose CT and cone-beam CT protocols, the cone-beam CT protocol proved to be significantly more reproducible for four of the 13 anatomical sites. There was no significant difference between the protocols for the other nine anatomical sites. Both low-dose and cone-beam CT protocols were equivalent in dose absorption to the eyes and submandibular glands. However, thyroid glands were more irradiated with low-dose CT. Conclusions Cone-beam CT was more reproducible and procured less irradiation to the thyroid gland than low-dose CT. Clinical relevance Cone-beam CT should be preferred over low-dose CT for developing three-dimensional bony cephalometric analyses.

Abstract Background: Our study investigated the influence of the cannula's inner diameter (ID) and of its removal on the expected respiratory dose of amikacin, using three different jet nebulizer configurations (Sidestream®): vented (N1), unvented with a piece of corrugated tubing attached to the expiratory limb of the T attachment (N2), and unvented alone (N3). Methods: The jet nebulizer was filled with amikacin (500 mg/4 mL) and was attached to the tracheostomy tube. A lung model simulating spontaneous breathing was connected to the tracheostomy tube. A filter was connected between the nebulizer and the tracheostomy tube to measure the inhaled dose, and between the tracheostomy tube and the lung model to measure the respiratory dose. Different cannula IDs were tested (6.5, 8, 8.5, and 10 mm), and aerosol lost in the cannulas was determined. Results and conclusions: Respiratory dose varied between 96±1 mg and 44±3 mg, with higher values observed with N2. The aerosol lost in the cannula was significant and represented up to 63% of the inhaled dose. There was a negative correlation between the cannula's ID and the aerosol lost in the cannula. After removal of the internal cannula, an increase in the respiratory dose of up to 31.3% was observed. We recommend removing the inner tracheostomy cannula to nebulize a larger amount of drug through a tracheostomy tube. Among the three jet nebulizer configurations studied, we recommend the unvented one with a piece of corrugated tubing attached to the expiratory limb of the T attachment.

Objectives One of the key aspects of three-dimensional (3D) craniofacial cephalometry is the measurement of posterior cranial base angle as this area is deeply involved in craniofacial development. The purpose of our retrospective study was to define the best reproducible 3D posterior cranial base angles among five 3D angles transposed from 2D cephalometry (Cousin, BL1 of Ross and Ravosa, Bjork, Delaire, CBA4 of Liberman) and seven 3D angles based on physical anthropology studies and on new concepts (R1 to R7). The null hypothesis was that all 3D posterior cranial base angles were equally reproducible. Material and methods We used a preoperative low-dose computed tomography (CT) data from 20 adult patients undergoing orthognathic surgery after approval by local ethical committee. Two independent observers performed two series of 23 3D landmark identifications on 3D CT surface rendering of each patient using Maxilim software. Then, the same observers performed twice 3D cephalometric analyses (23 landmarks, 4 midpoints, 19 planes) that provided the automatic measurement of 12 posterior cranial base angles. Results Inter-observer correlation coefficient varied from 0.545 (Cousin) to 0.695 (CBA4 of Liberman) and from −0.177 (R2) to 0.827 (R4). Conclusions The null hypothesis was rejected. The most reproducible angle was 3D angle R4 based on “basion,” “superior optic” (right, left), and “crista galli inferior” landmarks. Clinical relevance R4 angle might be used as reference 3D posterior cranial base angle in further clinical studies involving 3D cephalometry as a diagnostic tool for orthodontics and for orthognathic surgery.

The aim of the present study was to assess the somatosensory function in the peri-implant soft tissues in the anterior jaw bone by means of two psychophysical tests. Light-touch sensation (LTS) and two-point discrimination (2PD) were performed before, and at planned intervals until 18 months after the placement of one or two implants in the anterior maxilla. The same tests were used on the contralateral control sites. The psychophysical threshold was determined by performing the staircase method. The mean values and standard deviation of LTS and 2PD, pooled over the four sessions at each test area, were calculated. Despite a large intersubject variation in both the LTS and 2PD, significantly high intra-individual correlations were found ( P  < 0.005). For LTS, the thresholds were not significantly affected over time ( P  > 0.05) on both implant and control sites. The 2PD increased significantly after surgery and maintained the higher discriminatory sense for 1 year ( P -value 0.005). The control sites remained stable over time. However, no correlation was revealed between LTS and 2PD perception (Pearson correlation test). In this prospective study, no major differences between the different sites and testing sessions were reported; except for the 2PD thresholds which were lowered after implant surgery. These findings suggest that the regenerated nerves may be responsible for the increased 2PD sensitivity in the peri-implant soft tissue. The unchanged LTS thresholds did not allow confirming this hypothesis.

IntroductionOur knowledge of facial muscles is based primarily on atlases and cadaveric studies. This study describes a non-invasive in vivo method (3D MRI) for segmenting and reconstructing facial muscles in a three-dimensional fashion.MethodsThree-dimensional (3D), T1-weighted, 3 Tesla, isotropic MRI was applied to a subject. One observer performed semi-automatic segmentation using the Editor module from the 3D Slicer software (Harvard Medical School, Boston, MA, USA), version 3.2.ResultsWe were able to successfully outline and three-dimensionally reconstruct the following facial muscles: pars labialis orbicularis oris, m. levatro labii superioris alaeque nasi, m. levator labii superioris, m. zygomaticus major and minor, m. depressor anguli oris, m. depressor labii inferioris, m. mentalis, m. buccinator, and m. orbicularis oculi.Conclusions3D reconstruction of the lip muscles should be taken into consideration in order to improve the accuracy and individualization of existing 3D facial soft tissue models. More studies are needed to further develop efficient methods for segmentation in this field.

Sialolithiasis is an uncommon disorder in childhood. Initially asymptomatic, symptoms may appear gradually. These can vary from moderate discomfort to severe pain with large glandular swelling accompanied by trismus. The correct interpretation of symptoms and a proper investigation for localization of salivary stones are important for effective treatment. A case of submandibular sialolithiasis in a 9-year-old girl is used to exemplify the problems had in clinical diagnosis.