Biomechanical evaluation of two miniplate fixations applied in the anterior region after Le Fort I osteotomy: an experimental study.

The aim of this experimental study was to evaluate the reliability of two-plate fixations applied to the anterior region of the maxilla after Le Fort I osteotomy in terms of stability. Twenty polyurethane-based skull models were used to evaluate two fixation techniques. Two groups consisting of four and two L-shaped titanium miniplates were tested. Each group was tested with the application of vertical forces in the anteroposterior direction using a servohydraulic testing unit. The displacement values in each group at each stage (from 10 N - 120 N) were compared using the Mann-Whitney U test. The displacement values for the two groups were not statistically significant up to 20 N, but differed significantly between 20 N and 120 N (p < 0.05). The results showed that the biomechanical behaviour of fixation with four miniplates was better than that of two after a load of 20 N. It can be concluded that when the amount of maxillary advancement is increased to 10 mm or more, fixation with only two plates does not provide sufficient stability experimentally.

Evaluation of the Effectiveness of Liquid Platelet-Rich Fibrin and Deproteinized Bovine Bone Mineral Mixture on Newly Formed Bone in Maxillary Sinus Augmentation: A Split-Mouth, Histomorphometric Study.

OBJECTIVE: We aimed to investigate the effectiveness of the liquid PRF-DBBM mixture on new bone formation in maxillary sinus augmentation. MATERIAL AND METHODS: Seven patients requiring two-stage bilateral maxillary sinus augmentation were included in the study. The patients were selected according to the criteria of having an alveolar bone height of at least 2 mm in the atrophic region. The elevated sinus cavities were randomly grafted with DBBM + liquid PRF (test) or DBBM alone (control) in a split-mouth design. Bone samples were collected during implant surgery with a trephine bur for histomorphometric evaluation after 4 months. RESULTS: In the control group, the newly formed bone was 39.49%, the mature bone was 15.66%, the residual graft was 15.62%, and the fibrous tissue ratio 28.59%, while in the test group, the newly formed bone (NFB) was 45.95%, the mature bone was 14.40%, the residual graft was 10.32%, and the fibrous tissue was 29.31%. No statistically significant difference was found between the groups in terms of the parameters studied (p > 0.05). The mean osteocalcin score in the control group was 2.70 ± 0.39, while it was 2.81 ± 0.36 in the test group. There was no statistically significant difference between the averages of osteocalcin scores of the groups (p > 0.05). CONCLUSION: The results of our study showed that DBBM is a reliable graft material for maxillary sinus augmentation even in the early period. Combining of DBBM with liquid-PRF contributed to new bone formation over a four-month period, but this contribution was not statistically significant.

Comparison of serratus plane block alone and in combination with pectoral type 1 block for breast cancer surgery: a randomized controlled study.

BACKGROUND/AIM: Concurrent application of ultrasound-guided pectoral type 1 (PECS I) and serratus plane block (SPB) is one of the most appropriate multimodal analgesic strategies for reducing acute post-mastectomy pain. The purpose of the present study was to compare the analgesic efficacy of SPB alone, or in combination with PECS I block for post-mastectomy pain following breast cancer surgery. MATERIALS AND METHODS: Sixty participants undergoing breast cancer surgery were randomly assigned to two groups. After anesthesia induction, group S (n =30) received SPB alone, whereas the SPECS group (n =30) received a combination of PECS I and SPB. Pain scores at 0, 1, 2, 6, 12, 24 h postoperatively, intra-operative fentanyl consumption, postoperative time to first rescue analgesia, nausea, vomiting, patient satisfaction, and anesthesia-related complications were recorded. RESULTS: Pain scores in the SPECS group were significantly lower than group S throughout the follow-up period (p <0.001). A significant reduction in postoperative rescue morphine consumption (p =0.01, median difference 7 mg, 95 % confidence interval: 5.1-7.9 mg) and intraoperative fentanyl consumption (p =0.01) in the SPECS group compared with group S. Moreover, postoperative nausea and vomiting were lower, and patient satisfaction was higher in the SPECS group compared with that of the group S. CONCLUSIONS: These results suggest that SPB application and PECS I provide more effective and reliable perioperative analgesia and increase patient satisfaction in breast cancer surgery. HIPPOKRATIA 2021, 25 (1):8-14. TRIAL REGISTRATION NUMBER: NCT03899545.

Assessment of pulp volume changes after surgically assisted rapid palatal expansion.

Maxillary transverse deficiency is a common skeletal problem. When the patient is younger, it is treated by rapid palatal expansion by using orthodontic appliances. If this fails or the patient is older, which means skeletal growth is completed, surgically aided rapid palatal expansion (SARPE) becomes necessary. In this technique, after the osteotomies have been made, the two maxillary bones are distracted by tooth-borne device. Since a tooth-borne device will apply the distraction forces on the teeth, the pulp volumes may change. Our aim was to investigate the volume changes of the tooth pulps after SARPE in which a tooth-borne device was used. We scanned our database and included 20 patients (7 males and 13 females) aging between 16 and 30 (mean 19.5±3.97) to this retrospective study. All the patients had undergone SARPE surgeries and they had pre-surgery and postconsolidation cone beam computerized tomography (CBCT) images. All the surgeries had been done in similar ways; all the patients had used similar tooth-borne modified acrylic bonded expansion device. We divided the maxillary teeth into three groups: the incisors, the premolars and the molars. We imported the CBCT images of each patient into 3D Slicer software. We calculated volumes of pulps for all maxillary teeth. We compared volumes with paired t test. Statistical significance level was accepted as P< .05. The devices had been left in place between 83 and 179 days including distraction and consolidation periods (mean 121.35±27.83 days). Amount of the expansions varied between 6.03mm and 11.16mm (mean 7.19±1.18mm). We found a statistically significant decrease of the pulp volumes in incisor, premolar and molar teeth (P<.001) between pre-surgery and postconsolidation periods. When using tooth-borne devices in SARPE, their impacts on teeth pulps should also be considered.

The assesment of relationship between the angulation of impacted mandibular third molar teeth and the thickness of lingual bone: A prospective clinical study.

BACKGROUND: Our purpose was to investigate the relationship between the angulation of mandibular third molars and the thickness of the lingual bone, which can affect the risk of lingual nerve damage during lower third molars surgical extraction. MATERIAL AND METHODS: This study consisted of 104 patients (42 males and 62 females), aged between 18-42 years (24.67 ± 6.11 years). Cone Beam Computed Tomography (CBCT) images were taken for preoperative assessment. The teeth were divided into four groups according to their positions: mesioangular, distoangular, vertical and horizontal. Lingual bone thickness around impacted teeth were measured at three points: cementoenamel junction (CEJ) of the mandibular second molar, mid-root of the impacted third molar, and apex of the impacted third molar root. Two predisposing factors of lingual nerve damage were recorded: lingual bone perforated by the impacted tooth and lingual bone thinner than 1 mm. Additionally, buccolingual angulations of the teeth in each group were measured. Impacted mandibular third molars were removed in usual way. One week after surgery, the patients were evaluated regarding lingual nerve paresthesia. RESULTS: None of the 104 patients experienced paresthesia, including the ones who had teeth with close proximity with lingual nerve. The mean thickness of bone was 1.21±0.63 mm at CEJ of the second molar; 1.25±1.02 mm at the mid-root; and 1.06±1.31 mm at the apex. Horizontally impacted teeth had thinner lingual bone at mid-root level (p=0.016). Buccolingual angulated teeth were more often associated with perforated lingual bone (p=0.002). Buccolingual and mesial/distal angulation had negative correlation with lingual bone thickness (p<0.05). CONCLUSIONS: As the buccolingual and mesiodistal angulations increase, lingual bone thickness decreases. Horizontally impacted teeth seemed to compromise the integrity of the lingual bone more than impacted teeth in other positions. During the surgery, thin or perforated lingual bone may result in displacement of the impacted tooth lingually.

Evaluation of stress by finite element analysis of the midface and skull base at the time of midpalatal osteotomy in models with or without pterygomaxillary dysjunction.

Surgically-assisted rapid maxillary expansion (SARME) is commonly used to treat skeletally mature patients with transverse discrepancies. Some osteotomies are made in areas that resist expansion, but there is no clear consensus about the sequence in which the osteotomies are made. Some clinicians do the pterygomaxillary osteotomy last, while others do it before the midpalatal osteotomy. We used the finite element method to measure the stresses on the midface, cranial base and pterygoid plates at the time of midpalatal osteotomy in two models, one with and one without pterygomaxillary dysjunction (PMD). In both, SARME consisted of maxillary bilateral osteotomy from the piriform rim to the pterygoid plate. Midpalatal osteotomy was also done in both. In the PMD model, minimum principal stresses increased on the midface, and maximum principal and von Mises stresses increased at the cranial base and on the pterygoid plates. Our results suggest that the stresses on the midface and cranial base can be reduced during midpalatal osteotomy in adults if the pterygomaxillary osteotomy is done last.

Effects of the dopamine D3 receptor agonist 7-hydroxy-2-(di-N-propylamino) tetralin in hyperthyroidism-induced premature ejaculation rat model.

Various factors are involved in the aetiology of premature ejaculation (PE). Hyperthyroidism is one of the causes of acquired PE, but the exact mechanism by which it causes the disorder is not yet understood. The aim of this study was to evaluate the role of the dopaminergic system in hyperthyroidism-induced PE by the intracerebroventricular microinjection of the preferentially active dopamine receptor agonist 7-hydroxy-2-(di-N-propylamino) tetralin (7-OH-DPAT) in a rat model of this disorder. Wistar rats were randomly divided into hyperthyroid and control groups, and ejaculation was induced by the ICV administration of 7-OH-DPAT. To evaluate the emission and expulsion phases of ejaculation, measurements of seminal vesicle pressure (SVP) and electromyographic recordings of the bulbospongiosus muscle were taken. The interval between the 7-OH-DPAT administration and the first ejaculation was significantly less in the hyperthyroid group (p < .01) than in the control group, and the maximum amplitude of the SVP values revealed a statistically significant difference between the groups (p < .01). The intervals between contractions of the seminal vesicle and bulbospongiosus muscles were also significantly less in the hyperthyroid group (p = .0187) than in the control group. No other results differed significantly between the groups. This study determined that hyperthyroidism altered only the emission phase of ejaculation.

Evaluation of strain values of critical anatomic regions for two different pterygomaxillary approaches in Le Fort I osteotomy: An experimental study.

BACKGROUND: The purpose of this experimental study was to measure stresses both on the pterygoid plates and the skull base following two different pterygomaxillary approaches in Le Fort I osteotomy. MATERIAL AND METHODS: The prepared skull models were randomly divided into 2 groups of 7. In the first group (A), the pterygomaxillary area was left intact. In the second group (B), pterygomaxillary separation was performed with a fine bur. The stresses were measured by using strain gauges. These strain gauges were attached to 6 different anatomical sites. The skull models were mounted on a servo-hydraulic testing unit. Each model was then subjected to a continuous linear tension until a plastic deformation was seen. RESULTS: The statistical analyses showed that there were no significant differences (p>.05) between the 2 groups regarding the strain values. Moreover, no statistical differences (p>.05) were found between the two groups in terms of maximum applied forces. CONCLUSIONS: Considering the clinical conditions, the present study shows that when Le Fort I osteotomy performed without pterygomaxillary separation, there is no significant stress on the skull base during the downfracture. Moreover, it is considered that there is no need for an excessive force applied to perform downfracture in Le Fort osteotomies without pterygomaxillary separation.

Effectiveness of binaural beats in reducing preoperative dental anxiety.

Binaural beats are an auditory illusion perceived when two different pure-tone sine waves are presented one to each ear at a steady intensity and frequency. We evaluated their effectiveness in reducing preoperative anxiety in dentistry. Sixty patients (30 in each group) who were to have impacted third molars removed were studied (experimental group: 20 women and 10 men, mean (range) age 24 (18-35) years, and control group: 22 women and 8 men, mean (range) age 28 (15-47) years). All patients were fully informed about the operation preoperatively, and their anxiety recorded on a visual analogue scale (VAS). The local anaesthetic was given and the patients waited for 10minutes, during which those in the experimental group were asked to listen to binaural beats through stereo earphones (200Hz for the left ear and 209.3Hz for the right ear). No special treatment was given to the control group. In both groups anxiety was then recorded again, and the tooth removed in the usual way. The paired t test and t test were used to assess the significance of differences between groups. The degree of anxiety in the control group was unchanged after the second measurement (p=0.625), while that in the experimental group showed a significant reduction in anxiety (p=0.001). We conclude that binaural beats may be useful in reducing preoperative anxiety in dentistry.

Time-course changes of nLDL-induced erectile dysfunction.

Hyperlipidemia is an important risk factor for atherosclerosis and is frequently seen in patients with erectile dysfunction (ED). This study was designed to evaluate whether the acute effect of native low-density lipoprotein (nLDL) on intracavernosal pressure (ICP) is reversible and related to plasma asymmetrical dimethylarginine (ADMA), endogenous inhibition of endothelial nitric oxide synthase (eNOS) levels and eNOS expression in cavernous tissues. Hyperlipidemia was induced by a single dose of intravenous 4 mg kg-1 nLDL. Experiments were performed 72 h (72H), 2 weeks (2W) and 8 weeks (8W) after nLDL injection. Endothelium-dependent relaxations, the ratio of ICP to mean arterial pressure (MAP; ICP/MAP), plasma ADMA levels and eNOS mRNA and protein levels were evaluated. The ICP/MAP ratio decreased in both the 2W and 8W groups. Endothelium-dependent relaxation responses to acetylcholine in the rat thoracic aorta were damaged in the 8W group. Plasma ADMA levels increased in the 8W group. mRNA expression of eNOS decreased in a time-dependent manner, whereas the protein expression increased. These results suggest that acute nLDL injection-induced impairments in erectile functions during an 8-week period are irreversible and might be related to an increase in ADMA levels and changes in the regulation of the eNOS/NO pathway.

Histopathological evaluation of dental follicles of clinically symptomatic and asymptomatic impacted third molars.

BACKGROUND AND AIMS: Surgical removal of impacted teeth is a common operation in oral surgery. Thus, pathological potential of impacted third molars is extensively studied. However, many of those studies based on data collected from analysis of radiographs only. The purpose of this retrospective study was to compare the follicles of symptomatic and asymptomatic impacted third molars histopathologically for a number of characteristics. MATERIALS AND METHODS: Records of the patients who had been previously operated for impacted third molars were reviewed. Eighty-three patients were selected and divided into two groups, clinically symptomatic and clinically asymptomatic. None of the patients had a radiographic pericoronal radiolucency of wider than 2.5 mm. Histopathological samples of the patients were obtained and re-examined by two pathologists. Two groups were statistically compared for 12 histological parameters. RESULTS: Eleven of the 12 parameters had statistically significant differences (P < 0.05), whereas one parameter (odontogenic remnants) was found not to be significantly different between the groups. CONCLUSION: A delay in impacted third molar surgery can lead to further pathological changes in dental follicles and can increase severity of the inflammation. Moreover, dimensions of the pericoronal radiolucency may not provide a correct interpretation of the pathological changes in the region.

Clinical, angiographic and procedural characteristics of longitudinal stent deformation.

Recently, longitudinal stent deformation (LSD) has been reported increasingly. Even though the reported cases included almost all stent designs, most cases were seen in the Element™ stent design (Boston Scientific, Natick, MA, USA). It is considered that stent design, lesion and procedural characteristics play a role in the etiology of LSD. Yet, the effect of LSD on long-term clinical outcomes has not been studied well. Element stents implanted between January 2013 and April 2015 in our hospital were examined retrospectively. Patients were grouped into two according to the presence of LSD, and their clinical, lesion and procedural characteristics were studied. Twenty-four LSD's were detected in 1812 Element stents deployed in 1314 patients (1.83 % of PCI cases and 1.32 % of all Element stents). LMCA lesions (16.7 % vs 1.6 %, p < 0.001), complex lesions (75 % vs 35.1 %, p < 0.001), bifurcation lesions (37.5 % vs 18.3 %, p = 0.017), ostial lesions (33.3 % vs 12.8 %, p = 0.003), using of extra-support guiding catheter (54.2 % vs 22.3 %, p < 0.001) and extra-support guidewire (37.5 % vs 16.2 %, p = 0.005) were found to be more frequent in cases with LSD than in cases without it. In addition, the number of stents, stent inflation pressure and the use of post-dilatation were significantly different between the two groups. Two patients had an adverse event during the follow-up period. LSD is a rarely encountered complication, and is more common in complex lesions such as ostial, bifurcation and LMCA lesions. The use of extra-support guiding catheter, extra-support guidewires and low stent inflation pressure increases the occurrence of LSD. Nevertheless, with increased awareness of LSD and proper treatment, unwanted long-term outcomes can be successfully prevented.

Acute effect of rosiglitazone on relaxation responses in hypercholesterolemic corpus cavernosum.

Thiazolidinediones (TZDs) improve vascular endothelial dysfunction through non-genomic effects of peroxisomal proliferator-activated receptor γ. This study investigated the acute effect of one of the TZD, rosiglitazone, on endothelium-dependent relaxation response of corpus cavernosum (CC) in hypercholesterolemic rabbits. New Zealand rabbits were divided into two groups randomly as control and cholesterol groups. Hypercholesterolemia was induced by feeding rabbits with 2% cholesterol diet (w/w) for 6 weeks. Endothelium-dependent and -independent relaxation response of CC were evaluated in the presence of rosiglitazone by organ bath studies with cumulative doses of acetylcholine (Ach) and sodium nitroprusside (SNP). Maximal relaxation (Emax) response to Ach significantly decreased owing to hypercholesterolemia in CC tissues. However, in vitro incubation of rosiglitazone with different concentrations (0.1, 1 and 10 µm) did not improve the Ach-dependent Emax responses in hypercholesterolemic rabbit CC. Surprisingly, rosiglitazone caused a significant decrease in Ach-dependent relaxation in healthy CC. Emax responses to SNP did not differ in the presence of rosiglitazone in both the control and hypercholesterolemic groups. Rosiglitazone does not improve hypercholesterolemia-induced endothelial dysfunction in CC tissues while it dose-dependently impairs endothelium-dependent relaxation in healthy CC tissue.

The evaluation of brain natriuretic peptide changes and difficult airway predictors during perioperative period of pregnancy.

AIM: Airway changes, difficult ventilation, and intubation are the leading causes of morbidity and mortality in pregnancy, but no prospective study has evaluated the relationship between airway changes and brain natriuretic peptide (BNP) before and after cesarean section operations. The purpose of this study was to evaluate the relationship between BNP and airway changes in women undergoing delivery and during the postoperative period. MATERIALS AND METHODS: Included in this prospective study were a total of 35 pregnant females with ASA I physical status who were scheduled for cesarean section under general anesthesia. BNP levels, Mallampati classification, mouth opening, thyromental distance, sternomental distance, and the degree of neck extension were recorded before cesarean section and 24 h after the operation. Laryngeal views were also documented after intubation. RESULTS: Significant differences in BNP levels, Mallampati classification, mouth opening, thyromental distance, sternomental distance, and the degree of neck extension measurements arose between initial measurements and those measurements made 24 h postoperatively. Pre-delivery Mallampati I, II, III, IV scores of 6, 18, 7, 4 had by 24 h after cesarean section changed to 13, 13, 6, 3, respectively (p < 0.05). Initial BNP levels were 7.59 ± 6.30; postoperative levels were 52.39 ± 48.17. In this study we found a correlation between perioperative BNP levels and difficult intubation parameters. CONCLUSIONS: Within 24 h postpartum, Mallampati scores changed in 13 patients (30.95 %). Besides the correlation between BNP levels and difficult intubation parameters, we also found significant differences in initial and postoperative BNP values.

Evaluation of adiponectin and lipoprotein(a) levels in cardiac syndrome X.

AIMS: Low adiponectin and high lipoprotein(a) [Lp(a)] levels are associated with endothelial dysfunction, atherosclerosis, and coronary artery disease. Cardiac syndrome X (CSX) is characterized by anginal symptoms, positive stress test, and documentation of normal epicardial coronary arteries with angiography. In this study we aimed to investigate the relationship between CSX and circulating levels of adiponectin and Lp(a). PATIENTS AND METHODS: We enrolled 53 female patients with CSX and 33 patients as the control group. The diagnosis of CSX was made according to presence of angina, findings suggestive of ischemia during stress electrocardiography or myocardial perfusion scintigraphy, and documentation of normal coronary arteries in coronary angiography. The control group consisted of patients with atypical angina and normal stress electrocardiography test results. Both groups were matched in terms of hypertension, diabetes mellitus, and metabolic syndrome. RESULTS: Adiponectin levels were significantly decreased in patients with CSX (4.57 µg/ml vs. 13.18 µg/ml; p=0.001); however, Lp(a) levels were significantly increased (36.30 mg/dl vs. 7.24 mg/dl; p < 0.001). Low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) concentrations did not differ between the case group and the control group (p=0.14, p=0.62, p=0.64, respectively). There was no significant difference between groups in terms of age, body mass index, waist circumference hypertension, hyperlipidemia, diabetes mellitus, or metabolic syndrome. In multivariate analysis, Lp(a) and adiponectin were found to be independent predictors of CSX. An Lp(a) level of > 21 mg/dl had 84 % sensitivity and 96 % specificity {area under the curve (AUC)= 0.922, p < 0.0001, 95 % CI [0.842-0.970]} and an adiponectin level of ≤ 5.18 µg/ml also had 58.7 % sensitivity and 82.1 % specificity (AUC=0.726, p=0.0003, 95 % CI [0.609-0.823]) for detecting CSX. CONCLUSION: We detected low adiponectin and high Lp(a) levels in patients with CSX and these findings may be related to the microvascular injury in CSX.

Impact of valve surgery on serum osteopontin levels in patients with mitral regurgitation.

OBJECTIVE: Osteopontin (OPN), a sialoprotein present within atherosclerotic lesions, especially in calcified plaques, is linked to the progression of coronary artery disease and heart failure. We assessed the impact of valve surgery on serum OPN and left ventricular (LV) function in patients with mitral regurgitation (MR). METHODS: Thirty-two patients with severe MR scheduled for surgery were included in the study. Echocardiography markers were assessed preoperatively and at 3 months following the surgery and matched with the serum OPN levels. RESULTS: Valve surgery was associated with a reduction of the ejection fraction (EF) from 55.2 ± 6.3 to 48.8 ± 7.1% after surgery, p < 0.001. Following surgery, the OPN level was significantly higher than preoperatively (mean 245, range 36-2,284 ng/ml vs. 76, 6-486 ng/ml, p = 0.007). Preoperative OPN exhibited a slight negative correlation with the EF (r = -0.35, p = 0.04), and a moderate correlation with vena contracta (r = -0.38, p = 0.02). There were no other meaningful correlations between conventional echocardiographic parameters and OPN. CONCLUSION: Following valve surgery due to severe MR, patients exhibited a decrease in EF and an increase in OPN levels. The assessment of preoperative OPN failed to strongly predict probable LV dysfunction.