Orthognathic surgery and aligners. A comparative assessment of periodontal health and quality of life in postsurgical orthodontic treatment with aligners versus traditional fixed appliances: a randomized controlled trial.

BACKGROUND: Removable clear aligners have become very popular in the last few decades, but they are still little used in the field of orthognathic surgery (OS). The objective of this study was to compare periodontal health and quality of life (QoL) associated to postsurgical orthodontic treatment. MATERIAL AND METHODS: Patients with dentofacial deformities undergoing OS were randomly allocated to receive postsurgical orthodontic treatment with either fixed orthodontic appliances or Invisalign. The main outcomes were periodontal health and QoL. Plaque index, probing depth and bleeding on probing were assessed as periodontal health indicators. QoL was assessed through the Orthognathic Quality of Life Questionnaire (OQLQ-22) and the Oral Health Impact Profile (OHIP-14). Data were analyzed before surgery and end of treatment. Total duration of treatment was also recorded. RESULTS: Twenty-eight patients were randomized, (16 women, 12 men). Periodontal assessment showed better outcomes for the Invisalign group: bleeding on probing (p=0.013), plaque index (p=0.001) and probing depth (p<0.001). The QoL questionnaires showed significant differences in favor of the Invisalign group: OHIP-14 (p=0.004) and OQLQ-22 (p=0.002). Total duration of treatment was similar in both groups (p=0.575). CONCLUSIONS: Compared to traditional orthodontics with fixed appliances, patients managed with clear aligners after OS (surgery-first approach) had better periodontal health and QoL outcomes.

Impact of local urban design and traffic restrictions on air quality in a medium-sized town.

Traffic is the major air pollution source in most urban areas. Nowadays, most of the strategies carried out to improve urban air quality are focused on reducing traffic emissions. Nevertheless, acting locally on urban design can also reduce levels of air pollutants. In this paper, both strategies are studied in several scenarios for a medium-sized town of the Basque Country (Spain). Two main actions are analysed in order to reduce traffic emissions: (1) minor extension ofa pre-existing low emission zone (LEZ); (2) substitution of 10% of passenger cars that are older than 5 years by hybrid and electric vehicles. Regarding local urban design, three alternatives for the development of one side of a street canyon are considered: (1) a park with trees; (2) an open space without obstacles; (3) a building. Two different urban traffic dispersion models are used to calculate the air quality scenarios: PROKAS (Gaussian&box) to analyse the reduction of traffic emissions in the whole urban area and WinMISKAM (CFD) to evaluate specific urban designs. The results show the effectiveness of the analysed actions. On one hand, the definition of a small LEZ, as well as the introduction in 2015 of vehicles with new technology (hybrid and electric), results in minor impacts on PM10 and NO2 ambient concentrations. On the other hand, local urban design can cause significant variation in spatial distribution ofpollutant concentrations emitted inside street canyons. Consequently, urban planners should consider all these aspects when dealing with urban air pollution control.

The combined coronal-transconjunctival approach: an innovative surgical access for orbital exenteration in craniofacial resection.

Malignant tumours arising in the paranasal sinuses or maxilla usually spread to the surrounding regions. The skull base and the anterior cranial fossa are frequently affected as well. When the resection of a tumour involves an orbital exenteration, a transconjunctival-perilimbic incision can be added to a coronal approach in order to preserve the eyelids and the conjunctiva, avoiding cutaneous midfacial incisions. Patients with a diagnosis of malignant tumour affecting the orbit, upper jaw, paranasal sinuses, and/or anterior skull base were eligible for this technique. Tumoural invasion of the eyelids, conjunctiva, lacrimal system, or surrounding skin was considered a contraindication for this technique. A retrospective study of the clinical records was performed and age, type of tumour, location, and reconstructive technique were evaluated. Eight patients referred to the study department between 2015 and 2019 were selected. All patients underwent craniofacial surgery and orbital exenteration. The transconjunctival-perilimbic approach was combined with a coronal incision in all cases. In our experience, the transconjunctival-perilimbic approach to orbital exenteration proposed in this paper can be used successfully in skull base surgery. Combined with a coronal and transmandibular approach, it allows wide access to the facial skeleton/anterior skull base while avoiding skin incisions in the midface.

Intraoral anastomosis in maxillary microvascular reconstruction after oncological excision.

Microvascular anastomosis using an intraoral approach can avoid unnecessary external incisions thus improving patient satisfaction. Furthermore, in case of short pedicle flaps, the lack of proximity of the recipient vessels can be a problem in microvascular reconstruction of the midface. We present our experience in six patients treated for tumours affecting the midface and reconstructed with microvascular flaps through anastomosis to the intraoral aspect of the facial vessels, with the aim of reviewing the use of this technique. Our results showed that intraoral anastomosis is a feasible technique that can be used in the reconstruction after tumours resection, avoiding additional external incisions in patients with no previous cervicotomy incisions. In two cases, a vein graft was interposed to perform the intraoral arterial anastomosis in a tension-free situation without increasing morbidity. The technical features and advantages of intraoral anastomosis were reviewed.

Learners' acceptance of a webinar for continuing medical education.

The aim of this study was to evaluate learners' acceptance of a webinar for continuing medical education that was instigated by the International Association of Oral and Maxillofacial Surgeons (IAOMS). A live, interactive webinar on orthognathic surgery was broadcast via the Internet. The learners' acceptance of the webinar was evaluated using a standardized, validated questionnaire (Student Evaluation of Educational Quality, SEEQ). One hundred and fifty-three participants attended the webinar; 55 participants (46 male, nine female) completed the questionnaire. The mean age of the respondents was 41.6±10.0years. The age of male and female respondents did not differ significantly. The respondents were spread over five continents, with the highest number from Brazil. The SEEQ showed a high level of acceptance for almost all subscales. There was no statistically significant difference between male and female respondents concerning acceptance of the webinar (P=0.614). The wide distribution of participants shows the potential for webinars as facilitators of barrier-free distribution of knowledge. The webinar was well accepted by the attendees independent of sex, specialty, and work experience. However, the sex ratio reflects the underrepresentation of women in oral and maxillofacial surgery.

Cocaine-related syndrome and palatal reconstruction: report of a series of cases.

Intranasal cocaine abuse may cause significant local ischaemic necrosis and destruction of the nasal and midfacial bones and soft tissue, leading to development of a cocaine-induced midline destructive lesion. Review of the English-language literature reveals only a few case reports describing hard and/or soft palatal perforation related to cocaine inhalation. To date, among the reconstructive techniques of the palate, different surgical options have been reported such as local, regional and free flaps. Common prosthetic obturators have also been used. Presented here are six cases of cocaine abuse showing different types of cocaine-related palatal lesions treated with different surgical approaches including local and free flaps. Mean follow-up was 3 years. A surgical variation of Marshall's classic technique for insetting a free flap in such lesions is proposed.

Understanding medicinal taste and odour formation in drinking waters.

The formation of bromophenols during chlorination of phenol- and bromide-containing waters can be critical for taste and odour problems in drinking waters. The work performed has confirmed that flavour threshold concentrations of some bromophenols are in the ng/L range. In addition, under typical drinking water conditions, kinetic experiments and model simulations performed have shown that (1) bromination is the predominant reaction pathway, (2) bromophenol reaction kinetics are rapid leading to taste-and-odour episodes that last for short periods of 10-20 min, (3) increasing phenol concentration and pH tends to increase taste and odour intensity, (4) increasing chlorine or bromide concentrations tends to shorten the duration of the taste-and-odour episode.

The use of free flaps in skull base reconstruction.

Skull base tumours are rare, comprising less than 1% of all tumours of the head and neck. Surgical treatment of these tumours involves the approach, the resection, and the reconstruction of the defect, which present a challenge due to the technical difficulty and anatomical complexity. A retrospective study of 17 patients with tumours involving the skull base, treated by resection and immediate reconstruction using microsurgical free flaps, is presented; 11 were men and six were women. The following types of flap were used: osteocutaneous fibula flaps, fasciocutaneous anterolateral thigh flaps, and myocutaneous latissimus dorsi flaps. The most common histology of the tumours was squamous cell carcinoma. The most frequent point of origin was the paranasal sinuses (58.8%). All of the free flaps used for reconstruction were viable. A cerebrospinal fluid fistula occurred in two patients, and in one of these cases, meningoencephalitis led to death. In conclusion, the reconstruction of large defects of the skull base after ablation requires a viable tissue that in many cases can be obtained only through the use of microvascular free flaps. The type of flap to be selected depends on the anatomical structures and size of the defect to be restored.

DNA degradation by the mixture of copper and catechol is caused by DNA-copper-hydroperoxo complexes, probably DNA-Cu(I)OOH.

Free hydroxyl radicals (free (.)OH), singlet oxygen ((1)O(2)), or (. )OH produced by DNA-copper-hydroperoxo complexes are possible DNA-damaging reactive oxygen species (ROS) in the reaction system containing copper, catechol, and DNA. para-Chlorobenzoic acid (pCBA) degradation studies revealed that CuCl(2) mixed with catechol produced free (.)OH. In the presence of DNA, however, inhibition of the pCBA degradation suggested that another ROS is responsible for the DNA degradation. Of a series of ROS scavengers investigated, only KI, NaN(3), and Na-formate-all of the salts tested-strongly inhibited the DNA degradation, suggesting that the ionic strength rather than the reactivity of the individual scavengers could be responsible for the observed inhibition. The ionic strength effect was confirmed by increasing the concentration of phosphate buffer, which is a poor (.)OH scavenger, and was interpreted as the result of destabilization of DNA-copper-hydroperoxo complexes. Piperidine-labile site patterns in DNA degraded by copper and catechol showed that the mixture of Cu(II) and catechol degrades DNA via the intermediate formation of a DNA-copper-hydroperoxo complex. Replacement of guanine by 7-deazaguanine did not retard the DNA degradation, suggesting that the DNA-copper-hydroperoxo complexes do not bind to the guanine N-7 as proposed in the literature.

Mating type-correlated molecular markers and demonstration of heterokaryosis in the phytopathogenic fungus Thanatephorus cucumeris (Rhizoctonia solani) AG 1-IC by AFLP DNA fingerprinting analysis.

The destructive soil-borne plant pathogenic basidiomycetous fungus Thanatephorus cucumeris (Frank) Donk [anamorph: Rhizoctonia solani Kühn] is not a homogeneous species, but is composed of at least twelve anastomosis groups (AG), which seem to be genetically isolated. The genetics of several T. cucumeris anastomosis groups has been studied by analysis of heterokaryotic tuft formation in the area of contact between homokaryotic single-spore isolates, revealing that AG 1 is heterokaryotic and bipolar. To prove that tuft formation is due to heterokaryosis, AFLP DNA fingerprinting has been applied to a heterokaryotic T. cucumeris AG 1-IC isolate, its homokaryotic single spore-derived progeny, and newly formed heterokaryons. By means of AFLP markers, it is demonstrated that fluffy tufts formed upon pairing of homokaryons from different mating types are newly formed heterokaryons. Mating type-correlated markers have also been found, which will be useful for future studies of the genetics of this fungal species complex.

Mental illness and ischemic heart disease: analysis of psychiatric morbidity.

In this study we analyze from a cardiologic and psychiatric point of view a consecutive sample of 194 patients treated in a cardiology outpatient unit. A psychiatric morbidity of 44.8% is found, expressing itself fundamentally as depression and anxiety neurosis. It is observed how the presence of chest pain significantly conditions the appearance of psychiatric disturbance, there being, moreover, a tendency in the same direction with increasing degrees of impairment of cardiac function. Certain personal and sociocultural factors also play a significant role in the development of mental illness in these patients.

Factors related to the incidence and severity of cyclosporin-induced gingival overgrowth in transplant patients. A longitudinal study.

A longitudinal study was conducted during the first 6 months following transplant surgery in 100 heart, liver, or kidney transplant patients to assess the incidence and severity of cyclosporin-induced gingival overgrowth, as well as the most important associated factors. Gingival overgrowth, plaque, and gingivitis indices, in addition to cyclosporin blood concentration, were assessed monthly. Statistical analysis was applied to evaluate the relationship between gingival overgrowth and other study variables and to test the influence of age, sex, time, and transplant type. Forty-three percent (43%) of the patients developed gingival overgrowth. Gingival overgrowth increased significantly during the study, while plaque and gingivitis, subject to an oral hygiene training and motivation program, decreased significantly. The findings from this study would suggest that the basic factor influencing gingival overgrowth is cyclosporin blood concentration, followed by plaque/gingivitis level. The significant differences observed among transplant types, as well as among age groups, might be attributed to the differences in cyclosporin concentrations. An oral hygiene program prior to the transplant surgery is recommended.

Localization of gingival overgrowth in heart transplant patients undergoing cyclosporin therapy.

This research was aimed at determining and comparing the pattern of localization of both cyclosporin-induced gingival overgrowth and associated periodontal variables in heart transplant patients. Thirty-nine patients undergoing cyclosporin treatment were studied for 6 months following transplant surgery. Oral hygiene and gingivitis were evaluated using the Silness-Löe and Löe-Silness indices. Gingival overgrowth was measured using a periodontal probe to determine the height of the gingiva at six points per tooth. Statistical hypothesis testing was applied to calculate the significance of the results. Overgrowth average showed a steady and significant growth. The graphs depicting average overgrowth localization, "standard periodontograms," showed remarkable symmetry, and a significantly anterior mandibular papillary distribution. No overgrowth was observed in edentulous areas. The localization of plaque and gingivitis followed a similar pattern; a highly significant correlation was found with the overgrowth localization pattern. It was concluded that the elimination of plaque is an important preventive measure for cyclosporin-induced gingival overgrowth, and that tooth or periodontium related factors have a significant impact on its pathogenesis.

The role of hydroxyl radicals for the decomposition of p-hydroxy phenylacetic acid in aqueous solutions.

The chemical decomposition of p-hydroxyphenylacetic acid, a priority phenolic pollutant present in wastewaters from some agro-industrial plants, is studied by means of a single photochemical process produced by a polychromatic UV radiation and by hydroxyl radicals generated by the combination of UV radiation plus hydrogen peroxide and by the Fenton's reagent (hydrogen peroxide plus ferrous salts). Batch experiments were conducted to establish the degradation levels obtained and the quantum yields in the single photodecomposition process. An improvement in the decomposition of the phenolic acid in the combined UV/H2O2 oxidation is observed, due to the generation of OH radicals, and the contribution of the radical reaction to the global process is determined. In the Fenton's reagent oxidation, the effects of the operating variables (H2O2 and Fe2+ initial concentrations, pH, type of buffer used) are established and the rate constant for the reaction of p-hydroxyphenylacetic acid with OH radicals is evaluated from a kinetic model, its value being 7.02 x 10(8) M-1 s-1 at 20 degrees C.

Sliding osteotomies in mandibular reconstruction.

The aim of this article is to describe a few simple and atraumatic methods for mandibular reconstruction following the ablation of tumors or traumas. These reconstruction techniques are indicated for rebuilding short mandibular defects (less than 4 cm) or for patients in poor general condition with larger defects that cannot be remedied using longer and more complicated procedures. Five types of osteotomies were used: "C," single, double, bilateral sliding, and sagittal sliding. Osteotomies were performed on 14 patients, 13 with malignant tumors and one with a gunshot wound. Good results were obtained in 10 patients, total failure occurred in two, and complications without failure of the reconstruction arose in the other two.

Contribution of free radicals to chlorophenols decomposition by several advanced oxidation processes.

The chemical decomposition of aqueous solutions of various chlorophenols (4-chlorophenol (4-CP), 2,4-dichlorophenol (2-DCP), 2,4,6-trichlorophenol (2,4,6-TCP) and 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP)), which are environmental priority pollutants, is studied by means of single oxidants (hydrogen peroxide, UV radiation, Fenton's reagent and ozone at pH 2 and 9), and by the Advanced Oxidation Processes (AOPs) constituted by combinations of these oxidants (UV/H2O2 UV/Fenton's reagent and O3/UV). For all these reactions the degradation rates are evaluated by determining their first-order rate constants and the half-life times. Ozone is more reactive with higher substituted CPs while OH* radicals react faster with those chlorophenols having lower number of chlorine atoms. The improvement in the decomposition levels reached by the combined processes, due to the generation of the very reactive hydroxyl radicals. in relation to the single oxidants is clearly demonstrated and evaluated by kinetic modeling.

The behaviour of titanium as a biomaterial: microscopy study of plates and surrounding tissues in facial osteosynthesis.

Titanium has become the biomaterial of choice for facial osteosynthesis. Titanium is considered a highly biocompatible and corrosion resistant material, although the ultrastructural behaviour of titanium in human tissues after bone fixation is not well documented. A prospective scanning electron microscopy study was carried out on 37 commercially pure titanium miniplates which were removed from 23 patients who had undergone surgery for maxillofacial trauma or deformity. Twenty two cases were used as a control group. Implant-bone specimens were excised using tungsten burs and studied with a scanning electron microscope (Jeol JSM-T-300). Findings at the bone-titanium interface were analyzed, as well as the presence of contaminating bodies on the specimen surface. Biopsies were also obtained from the soft tissues adjacent to 20 miniplates, then sectioned and stained with Haematoxilin-Eosin for histological evaluation by light microscopy. The results showed good ultrastructural osseointegration of the osteosynthesis material in most cases (81.8%). Mobility was found upon removal in 80% of plates which showed clinical complications. A significant correlation was found between the degree of microscopical osseointegration and macroscopic fixation of the plate. Microscopical contamination was found in 100% of the nine plates with intraoral exposure, while only 36% of the 22 miniplates of the control group had contaminating elements (P < 0.001). Thirty-five point one percent of the plates showed hole-like substance loss images, whose size ranged from 10-25 mu. Light microscopy showed granular deposits in soft tissues surrounding the plates in 80% of the 20 specimens investigated. Our findings suggest a higher development of corrosion in titanium than previously reported. These findings are not correlated, however with the clinical complications.

Extraskeletal myxoid chondrosarcoma of the infratemporal fossa: a case report.

Extraskeletal myxoid chondrosarcoma is a rare tumour affecting the head and neck. We present a new case located in the midfacial region. Clinical, pathological and therapeutical features are reviewed.

Rate constants for the reactions of ozone with chlorophenols in aqueous solutions.

The oxidation by ozone of several chlorophenols (CPs): 4-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, 2,3,4, 6-tetrachlorophenol, tetracholorocatechol (3,4,5, 6-tetrachloro-2-hydroxy phenol) and 4-chloroguaiacol (4-chloro-2-methoxy phenol), is studied in order to provide values of the overall rate constant for the reaction between ozone and these chlorophenols. Single ozonation experiments of 4-chlorophenol were conducted in an homogeneous system, and ozonation reactions of CP mixtures were performed in a heterogeneous system, leading to the evaluation of the overall ozonation rate constants in acidic aqueous solutions. These second order rate constants increase several order of magnitude with the pH as does the degree of deprotonation of the dissolved compounds (i.e. from 10(3) to 10(9)l/(mols) for different CPs). The specific rate constants for the ozonation of the non-dissociated and dissociated forms of the studied CPs are also determined and reported. The values obtained allow calculation of the overall rate constants and prediction of the reactivities of the several CPs at different operating conditions in the whole range of pH.

Reversion of gingival hyperplasia in a heart transplant patient upon interruption of cyclosporine therapy.

A heart transplant patient undergoing a combined cyclosporine and prednisone treatment was monitored during the 18 months following transplantation. A complete oral and dental examination was performed in each of the first six months after transplantation, and then in the 9th, 12th, 15th, and 18th months. The data collected included gingival hyperplasia secondary to cyclosporine use, and clinical and periodontal variables. Histological studies were also conducted on gingival tissue samples in months 1, 3, 9, 15, and 18. Cyclosporine treatment was replaced by azathioprine treatment in month 10 because the patient was experiencing nephrotoxicity. Between months 9 and 18, gingival hyperplasia regressed by 26.5% due to a reduction in the fibrous connective tissue mass, fibroblasts, and inflammatory infiltration. The control group included 13 heart transplant patients subject to equivalent conditions except discontinuance of cyclosporine treatment; seven of the patients had developed hyperplasia by month 9. Average hyperplasia in the control group increased by 2% between months 9 and 18; only one patient showed a 6.2% decrease in hyperplasia. This provides further evidence for the causal relationship between cyclosporine therapy and gingival hyperplasia, and suggests that this side-effect is reversible.