Cyanoacrylate glue in socket repair: a comparative study.

This study aimed to compare socket repair with Nylon 5-0 suture and closure using cyanoacrylate biological glue after tooth extraction. Twenty male Wistar rats, each weighing approximately 200 g were submitted to the extraction of the right and left first molar teeth. On the right side, the alveolus was closed with 2 ethyl-cyanoacrylate glue, whereas on the left side closure was with a single interrupted Nylon 5-0 suture (Ethilon). The animals were sacrificed after 3, 7, 15, and 30 postoperative days, and images of histological sections of the alveolus were captured for analysis. Histomorphometry was performed using Image J software to quantify bone neoformation in the alveolus. The results showed that on the seventh postoperative day the side treated with 2-ethyl-cyanoacrylate presented a delay in relation to the sutured side. However, on days 15 and 30, the difference in bone neoformation between gradually decreased until the thirtieth postoperative day, with no significant difference in bone neoformation in the last period of analysis. There was no difference between neoformation in the two sides (p = 0.902) after statistical analysis of the histomorphometric results. In conclusion, socket repair after alveolus closure with 2-ethyl-cyanoacrylate allows complete bone neoformation after tooth extraction, and there is no significant difference when compared with closure with Nylon 5-0.

Pharyngeal airway space changes after maxillomandibular advancement: a five-year retrospective study.

The aim of this study was to compare the alterations in three regions of the airway-nasopharynx, oropharynx, and hypopharynx-in relation to the area of the midsagittal plane, volume, and minimal axial area after maxillomandibular advancement (MMA) surgery. Thirty patients who had undergone MMA surgery were evaluated at four time points: preoperative (T0), immediately postoperative (T1), 1year postoperative (T2), and ≥5 years postoperative (T3). All measurements were performed using computed tomography, analyzed in Dolphin Imaging 11.0 Premium 3D software. The area in the midsagittal plane presented a mean increase of 22.0% between T0 and T3 (P<0.001), with the highest increase in the oropharynx (24.1%, P<0.001). The total volumetric increase at T3 was 16.7% (P<0.001), with the highest increase in the nasopharynx (15.7%; P<0.001). The lowest minimal axial area was found for the oropharynx at all time points, and the highest increase in minimal axial area was found for the nasopharynx (114.9%; P<0.001). MMA surgery showed the highest increase in upper posterior airway between T0 and T1, and this was followed by a progressive reduction until T3, but with a statistically significant increase at T3 compared with T0 in all cases.

Hemodynamic mechanisms of the attenuated blood pressure response to mental stress after a single bout of maximal dynamic exercise in healthy subjects

To determine the hemodynamic mechanisms responsible for the attenuated blood pressure response to mental stress after exercise, 26 healthy sedentary individuals (age 29 ± 8 years) underwent the Stroop color-word test before and 60 min after a bout of maximal dynamic exercise on a treadmill. A subgroup (N = 11) underwent a time-control experiment without exercise. Blood pressure was continuously and noninvasively recorded by infrared finger photoplethysmography. Stroke volume was derived from pressure signals, and cardiac output and peripheral vascular resistance were calculated. Perceived mental stress scores were comparable between mental stress tests both in the exercise (P = 0.96) and control (P = 0.24) experiments. After exercise, the blood pressure response to mental stress was attenuated (pre: 10 ± 13 vs post: 6 ± 7 mmHg; P < 0.01) along with lower values of systolic blood pressure (pre: 129 ± 3 vs post: 125 ± 3 mmHg; P < 0.05), stroke volume (pre: 89.4 ± 3.5 vs post: 76.8 ± 3.8 mL; P < 0.05), and cardiac output (pre: 7.00 ± 0.30 vs post: 6.51 ± 0.36 L/min; P < 0.05). Except for heart rate, the hemodynamic responses and the mean values during the two mental stress tests in the control experiment were similar (P > 0.05). In conclusion, a single bout of maximal dynamic exercise attenuates the blood pressure response to mental stress in healthy subjects, along with lower stroke volume and cardiac output, denoting an acute modulatory action of exercise on the central hemodynamic response to mental stress.

Cephalometric and three-dimensional assessment of superior posterior airway space after maxillomandibular advancement.

The purpose of this study was to quantify cephalometric and three-dimensional alterations of the posterior airway space of patients who underwent maxillomandibular advancement surgery. 20 patients treated by maxillomandibular advancement were selected. The minimal postoperative period was 6 months. The treated patients underwent cone-beam computed tomography at 3 distinct time intervals, preoperative (T1), immediate postoperative period up to 15 days after surgery (T2), and late postoperative period at least 6 months after surgery. The results showed that the maxillomandibular advancement promoted an increase in the posterior airway space in each patient in all the analyses performed, with a statistically significant difference between T2 and T1, and between T3 and T1, p<0.05. There was a statistical difference between T2 and T3 in the analysis of area and volume, which means that the airway space became narrower after 6 months compared with the immediate postoperative period. The maxillomandibular advancement procedure allowed great linear area and volume increase in posterior airway space in the immediate and late postoperative periods, but there was partial loss of the increased space after 6 months. The linear analysis of airway space has limited results when compared with analysis of area and volume.

Hemodynamic mechanisms of the attenuated blood pressure response to mental stress after a single bout of maximal dynamic exercise in healthy subjects.

To determine the hemodynamic mechanisms responsible for the attenuated blood pressure response to mental stress after exercise, 26 healthy sedentary individuals (age 29 ± 8 years) underwent the Stroop color-word test before and 60 min after a bout of maximal dynamic exercise on a treadmill. A subgroup (N = 11) underwent a time-control experiment without exercise. Blood pressure was continuously and noninvasively recorded by infrared finger photoplethysmography. Stroke volume was derived from pressure signals, and cardiac output and peripheral vascular resistance were calculated. Perceived mental stress scores were comparable between mental stress tests both in the exercise (P = 0.96) and control (P = 0.24) experiments. After exercise, the blood pressure response to mental stress was attenuated (pre: 10 ± 13 vs post: 6 ± 7 mmHg; P < 0.01) along with lower values of systolic blood pressure (pre: 129 ± 3 vs post: 125 ± 3 mmHg; P < 0.05), stroke volume (pre: 89.4 ± 3.5 vs post: 76.8 ± 3.8 mL; P < 0.05), and cardiac output (pre: 7.00 ± 0.30 vs post: 6.51 ± 0.36 L/min; P < 0.05). Except for heart rate, the hemodynamic responses and the mean values during the two mental stress tests in the control experiment were similar (P > 0.05). In conclusion, a single bout of maximal dynamic exercise attenuates the blood pressure response to mental stress in healthy subjects, along with lower stroke volume and cardiac output, denoting an acute modulatory action of exercise on the central hemodynamic response to mental stress.

Resting and reflex heart rate responses during cholinergic stimulation with pyridostigmine in humans

Dysfunction of the autonomic nervous system is of prognostic value for sudden death after acute myocardial infarction. Although the use of beta-blockers to counteract the adrenergic hyperactivity has been shown to decrease mortality in these patients, there have been no reports on the role of cholinomimetic drugs in the prognosis of patients after myocardial infarction. The present study was designed to investigate the effect of the administration of pyridostigmine bromide, a reversible anti-cholinesterase agent, on cardiac cholinergic activity assessed by the resting and reflex heart rate responses. Eight healthy volunteers were submitted to a conventional 12-lead electrocardiogram to obtain resting heart rate, and to three non-invasive cardiovascular tests: respiratory sinus arrhythmia, Valsalva maneuver and 4-sec exercise test. On two different days and following a randomized crossover double-blind protocol, the experiments were performed before and 120 min after oral administration of either pyridostigmine bromide (30 mg) or placebo. Pyridostigmine increased (P<0.05) the duration of the R-R intervals at rest (pre: 898 ñ 30 msec; post: 1019 ñ 45 msec; pre-placebo: 916 ñ 26 msec; post: 956 ñ 28 msec; P>0.05). Although the duration of the R-R intervals during the autonomic tests was also increased (P<0.05), the derived indexes of maximal fluctuation during the maneuvers did not change. These results indicate that oral pyridostigmine produces tonic cardiac cholinergic stimulation while exerting no effect on its reflex changes. Further studies are needed to address the potential role of the administration of pyridostigmine in the prognosis of patients with acute myocardial infarction.