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In this study we investigated periodontal healing of mandibular second molars following 'orthodontic extraction' of adjacent impacted third molars, under the null hypothesis that there would be no difference in probing pocket depths (PPD) and clinical attachment levels (CAL) at the distal aspect of second molars before and after treatment. A retrospective survey was conducted of 64 patients who consecutively underwent 'orthodontic extraction' of mandibular third molars in close anatomical relationship with the mandibular canal from January 1997 to January 2011. Age, smoking habit, and PPD and CAL at the distal aspect of second molars before and after treatment were recorded. A statistically significant difference was found in PPD and CAL before and after treatment for the overall sample and for the sample classified by age (>25 or ≤25 years), smoking habit (smoker or non-smoker), and type of third molar impaction (horizontal, mesioangular, or vertical). Median PPD and CAL reductions amounted to 6mm and 5mm, respectively. The null hypothesis was rejected and orthodontic extraction proved to be indicated for those impacted mandibular third molars at high risk of a postoperative periodontal defect at the distal aspect of the adjacent second molar.

Summary The phenotyping of the pathophysiology of obstructive sleep apnoea (OSA) lies at the core of tailored treatments and it is one of the most debated topics in sleep medicine research. Recent sophisticated techniques have broadened the horizon for gaining insight into the variability of the endotypic traits in patients with OSA which account for the heterogeneity in the clinical presentation of the disease and consequently, in the outcome of treatment. However, the implementation of these concepts into clinical practice is still a major challenge for both researchers and clinicians in order to develop tailored therapies targeted to specific endotypic traits that contribute to OSA in each individual patient. This review summarizes available scientific evidence in order to point out the links between endotypic traits (pharyngeal airway collapsibility, upper airway neuromuscular compensation, loop gain and arousal threshold) and the most common non-continuous positive airway pressure (CPAP) treatment options for OSA (mandibular advancement device, upper airway surgery, medication therapy, positional therapy) and to clarify to what extent endotypic traits could help to better predict the success of these therapies. A narrative guide is provided; current design limitations and future avenues of research are discussed, with clinical and research perspectives.

Study objectives: The use of mouse models in sleep apnea study is limited by the belief that central (CSA) but not obstructive sleep apneas (OSA) occur in rodents. We aimed to develop a protocol to investigate the presence of OSAs in wild-type mice and, then, to apply it to a validated model of Down syndrome (Ts65Dn), a human pathology characterized by a high incidence of OSAs. Methods: In a pilot study, nine C57BL/6J wild-type mice were implanted with electrodes for electroencephalography (EEG), neck electromyography (nEMG), and diaphragmatic activity (DIA), and then placed in a whole-body-plethysmographic (WBP) chamber for 8 h during the rest (light) phase to simultaneously record sleep and breathing activity. CSA and OSA were discriminated on the basis of WBP and DIA signals recorded simultaneously. The same protocol was then applied to 12 Ts65Dn mice and 14 euploid controls. Results: OSAs represented about half of the apneic events recorded during rapid-eye-movement-sleep (REMS) in each experimental group, while the majority of CSAs were found during non-rapid eye movement sleep. Compared with euploid controls, Ts65Dn mice had a similar total occurrence rate of apneic events during sleep, but a significantly higher occurrence rate of OSAs during REMS, and a significantly lower occurrence rate of CSAs during NREMS. Conclusions: Mice physiologically exhibit both CSAs and OSAs. The latter appear almost exclusively during REMS, and are highly prevalent in Ts65Dn. Mice may, thus, represent a useful model to accelerate the understanding of the pathophysiology and genetics of sleep-disordered breathing and to help the development of new therapies.

This study summarizes the available evidence from systematic reviews on the in vitro effects of photobiomodulation on the proliferation and differentiation of human bone and stromal cells by appraising their methodological quality. Improvements for future studies are also highlighted, with particular emphasis on in vitro protocols and cell-related characteristics. Six reviews using explicit eligibility criteria and methods selected in order to minimize bias were included. There was no compelling evidence on the cellular mechanisms of action or treatment parameters of photobiomodulation; compliance with quality assessment was poor. A rigorous description of laser parameters (wavelength, power, beam spot size, power density, energy density, repetition rate, pulse duration or duty cycle, exposure duration, frequency of treatments, and total radiant energy), exposure conditions (methods to ensure a uniform irradiation and to avoid cross-irradiation, laser-cell culture surface distance, lid presence during irradiation) and cell-related characteristics (cell type or line, isolation and culture conditions, donor-related factors where applicable, tissue source, cell phenotype, cell density, number of cell passages in culture) should be included among eligibility criteria for study inclusion. These methodological improvements will maximize the contribution of in vitro studies on the effects of photobiomodulation on human bone and stromal cells to evidence-based translational research.

Introduction: The purposes of this in-vivo study were to compare the modes of failure of uncoated and adhesive precoated metal brackets by using the adhesive remnant index, and to assess the quality of the enamel surface after cleanup by using the enamel damage index. Methods: Twelve Victory brackets (group A) and 12 Victory adhesive precoated brackets (group B) (both, 3M Unitek, Monrovia, Calif) were bonded onto the maxillary second premolars of 12 volunteers. The uncoated brackets were bonded with Transbond XT adhesive resin (3M Unitek). Replicas of the teeth were made before bonding (T0), after bracket removal (T1), and after cleanup (T2). Scanning electron microscope images of all labial enamel surfaces were taken at T0, T1, and T2, and these were evaluated according to the adhesive remnant index and the enamel damage index. Results: Evaluation of the adhesive remnant index scores with the chi-square test showed no statistically significant difference between the groups. Evaluation of the enamel damage index grades with the sign test for paired samples showed a statistically significant difference (P .01) between T0 and T2. Conclusions: Uncoated and precoated brackets exhibited similar debonding patterns. Additionally, the debonding method tested in this study did not restore the original enamel surface, although there was no clinically relevant enamel damage.

Riassunto Obiettivi Discutere il rischio di riassorbimento radicolare degli incisivi permanenti in presenza di ectopia del canino mascellare. Discussione Una posizione intraossea anomala del canino mascellare deve essere riconosciuta il piu precocemente possibile tramite un’attenta valutazione clinica e radiografica, quest’ultima a partire dagli 8 anni di eta. Risultati e conclusioni Si puo favorire la spontanea eruzione dei canini permanenti ectopici con l’estrazione precoce del canino deciduo, eventualmente associata a quella del primo molare deciduo, prevenendo cosi la comparsa di inclusioni (risolvibili solo a prezzo di terapie piu complesse, prolungate e biologicamente costose) e, soprattutto, evitando o limitando l’insorgenza di riassorbimenti radicolari (danno irreversibile e possibile fonte di contenzioso medico-legale).