Dosimetric evaluation of the effect of dental implants in head and neck radiotherapy.

OBJECTIVE: The aim of the study was to examine the dose enhancement from scattered radiation at bone-dental implant interfaces during simulated head and neck radiotherapy. STUDY DESIGN: Four cylindrical titanium dental implants with 3 different sizes and lengths were implanted into a human mandible in 4 different positions. Ionization measurements for 6 MV X, 25 MV X, and Co-60 gamma rays were done. Thermoluminescent dosimeter (TLD 100 ) chips were used to measure radiation dose enhancement due to the scattered electrons from titanium and electronic disequilibrium at the tissue-metal interface. RESULTS: The results showed that for Co-60, there is a 21% maximum increase in dose to alveolar mandibular bone at the close proximity to the titanium. For 6-MV x-rays the dose enhancement increase was almost the same or slightly lower than for Co-60, while for 25-MV high-energy x-rays, dose enhancement was lower than that of others. This increase in dose enhancement fell off rapidly and became insignificant at 2 mm from the interface. CONCLUSION: Total dose that may lead to osteoradionecrosis risk of the mandible is slightly but not significantly affected by the scattered dose of the dental implants of lower jaw in the radiation field exposed to 3 different radiation beams.     

Comparison of randomized preemptive dexketoprofen trometamol or placebo tablets to prevent withdrawal movement caused by rocuronium injection

Rocuronium is a non-depolarizing neuromuscular blocking agent which is associated with injection pain and induces withdrawal movement of the injected hand or arm or generalized movements of the body after intravenous injection. The aim of this randomized study was to compare the efficacy of pretreatment with oral dexketoprofen trometamol (Arvelles^®; Group A) with placebo (Group P) without tourniquet to prevent the withdrawal response caused by rocuronium injection. The study cohort comprised 150 American Society of Anaesthesiologists class I–III patients aged 18–75 years who were scheduled to undergo elective surgery with general anesthesia. The patients response to rocuronium was graded using a 4-point scale [0 = no response; 1 = movement/withdrawal at the wrist only, 2 = movement/withdrawal involving the arm only (elbow/shoulder); 3 = generalized response]. The overall incidence of withdrawal movement after rocuronium injection was significantly lower in Group A (30.1 %) than in Group P (64.6 %) (p < 0.001). The incidence of score 0 withdrawal movements was higher in Group A (69.9 %) than in Group P (35.4 %), that of score 1 withdrawal movements was similar between groups (Group A 21.9 %; Group B 26.1 %) (p = 0.560) and that of score 2 withdrawal movements was lower in Group A (8.2 %) than in Group P (38.5 %) (p < 0.001). There were no score 3 withdrawal movements in either group (p > 0.05). These results demonstrate that the preemptive administration of dexketoprofen trometamol can attenuate the degree of withdrawal movements caused by the pain of the rocuronium injection.     

Multiple Perforations along the Entire Colon as a Complication of Intestinal Behcet's Disease: A Rare Case

Colonic complications of Behcet''s disease due to intestinal involvement are rarely reported in the literature. Ulcers are the most frequently seen intestinal complications that cause bleeding and perforation predominantly in the ileocecal region. In this article, we report a patient with Behcet''s disease who presented with multiple perforations along the entire colon. Postoperative histopathological examination revealed multiple ulcers containing lymphocytic infiltrations in the small peripheral and submucosal venules. Intimal thickening and fresh intraluminal fibrin thrombosis were also seen in these venules.     

Multivessel Coronary Thrombosis in a Patient with Idiopathic Thrombocytopenic Purpura

A 49-year-old woman who had idiopathic thrombocytopenic purpura was admitted to our hospital with severe chest pain. Electrocardiography revealed inferolateral myocardial infarction. The patient underwent immediate coronary angiography, which revealed thrombi in the left coronary system. Percutaneous intervention was not indicated, because the thrombi had occluded the distal segments of multiple coronary arteries. Administration of tirofiban satisfactorily dissolved the thrombi.Key words: Coronary thrombosis, multivessel; myocardial infarction; platelet aggregation inhibitors/therapeutic use; purpura, thrombocytopenic, idiopathic/therapy; tirofibanIdiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder in which autoantibodies bind platelets, leading to their sequestration by the reticuloendothelial system.¹ Patients with ITP typically have mucocutaneous bleeding. Although such reports are rare, thrombotic complications such as acute myocardial infarction (MI) and stroke also occur in patients with ITP.^2–4 We present the case of a middle-aged woman with ITP who sustained an acute MI caused by multivessel coronary thrombosis.     

Effects of precementation desensitizing laser treatment and conventional desensitizing agents on crown retention

This study aimed to compare the effect of precementation desensitizing laser treatment and conventional desensitizing agents on crown retention. Crowns were fabricated for 50 molar teeth, and specimens were assigned to 5 groups based on treatment method: untreated control group (CON), laser group (LAS), sodium fluoride group (FLU), Oxagel oxalate group (OXA), and Gluma primer group (GLU). All crowns were luted with glass-ionomer cement. Tensile force was applied for crown dislodgement. Recorded forces and calculated retentive strengths were as follows: CON (261 N) > LAS (223 N) = FLU (208 N) > GLU (161 N) = OXA (147 N) (P < .05). The differences in force magnitudes between all groups were significant (P < .05), except for LAS versus FLU and GLU versus OXA. The retention decrease was 15% for LAS, 20% for FLU, 38% for GLU, and 44% for OXA. Laser treatment had a less negative effect on retention for crowns luted with glass-ionomer cement than the other treatment modalities, and it may be a more suitable desensitization method if crown retention can be moderately sacrificed.     

The prosthodontic restoration of a self-inflicted gunshot maxillofacial defect: a short-term follow-up case report

A self-inflicted gunshot maxillofacial defect was restored with dental implants and various attachments. Following mandibular surgical reconstruction, a fixed full-arch implant-supported prosthesis was fabricated. The maxillary defect was restored with an obturator retained with bar-clip and ball attachments. Crowns with an unfavorable crown-to-root ratio were used to rectify a compromised unilateral interocclusal space. Functional rehabilitation was achieved without any pathologic sequelae and maintained over a 1-year observation period. Provision of a fixed implant-retained mandibular prosthesis opposing a specific design for a maxillary obturator provided short-term and optimistic prognosis in the management of a serious traumatic injury.     

Acute infectious purpura fulminans associated with asplenism or hyposplenism

Acute infectious purpura fulminans is a rapidly progressive syndrome of hemorrhagic skin necrosis associated with acute infection and disseminated intravascular coagulation. We report 5 cases of purpura fulminans and briefly review the literature. All cases were associated with encapsulated organisms (Streptococcus pneumoniae or Group A streptococcus), and 4 of the 5 patients had asplenism or functional hyposplenism.     

Isolation and culture of adult and fetal rabbit bladder smooth muscle cells and their interaction with biopolymers

Purpose: The aim of this study was to test the feasibility of isolation and culture of adult and fetal rabbit bladder smooth muscle cells (SMCs) and comparison of their interactions with different types of biodegradable biopolymers in cell culture. Methods: Bladder SMCs isolated from adult and fetus rabbits were identified by immunostaining for smooth muscle [alpha ]-actin and myosin. Growth kinetics of SMCs were estimated using population doubling time (PDT) and thymidine labeling index (TLI). Poly (D, L-lactide-co-glycolide; PLGA) copolymers were synthesized at 85:15 and 75:25 monomer ratios. The porous scaffolds prepared from these polymers were seeded with SMCs. The study compared the effectiveness of adsorbing fibronectin and fetal calf serum (FCS) on these biopolymers. The cells grown on these polymers were quantified using a neutral red uptake assay. Results: Over 90% of the 2 cell populations stained positive for SMC marker proteins. Fetal SMCs were seen to emerge from the tissue after 3 to 4 days, whereas adult SMCs were seen after 5 to 6 days. However, estimated PDT of fetal and adult SMCs was 85.2 and 54.5 hours, respectively, and TLI of adult SMCs was also higher than with fetal SMCs. Proliferation on 75:25 PLGA was better than for 85:15 and for both biopolymers; adsorption of FCS significantly affected cell attachment relative to fibronectin. Conclusions: Although fetal SMCs were shown to emerge from explants early after seeding onto dishes, doubling time and S-phase fraction of adult bladder SMCs were markedly higher than of fetal derived cells. Adsorption of serum proteins significantly enhances the attachment of both fetal and adult SMCs to biopolymers. J Pediatr Surg 38:21-24.