Are antithrombotic agents necessary for head and neck microvascular surgery?

The aim of this prospective study was to determine the effect of antithrombotic agents in preventing thrombosis after head and neck reconstructive surgery. A randomized clinical trial of referred patients undergoing free flap surgery between February 2015 and July 2017 was conducted. Four hundred and fifty-four patients were randomly assigned to group A (n = 153), administered aspirin and low molecular weight dextran; group B (n = 150), administered low molecular weight heparin; and group C (n = 151), not administered any antithrombotic agent. Patient demographic characteristics, donor site, thrombosis, haematoma, and flap failure were recorded. Coagulation values including platelet count, prothrombin time, and activated partial thromboplastin time were measured during the perioperative period. Repeated-measures ANOVA and the χ² test were used for data comparisons. No significant inter-group differences were observed for postoperative microvascular thrombosis (P = 0.536) or flap failure (P = 0.615) among the three groups. There were more postoperative haematoma revisions in group B than in groups A and C (P = 0.032). It is concluded that postoperative antithrombotic agents neither provide a significant improvement in the free flap success rate nor decrease the risk of thrombosis and may increase the risk of haematoma.     

Are Hertwig’s epithelial root sheath cells necessary for periodontal formation by dental follicle cells?

ObjectiveThe role of Hertwig’s epithelial root sheath (HERS) cells in periodontal formation has been controversial. This study aimed to further clarify whether HERS cells participate in formation of the periodontium, and the necessity of HERS cells in differentiation of dental follicle cells (DFCs) for periodontal regeneration.DesignHERS cells and DFCs were isolated and identified from post-natal 7-day Sprauge-Dawley rats. In vitro, direct co-culture of HERS cells and DFCs as well as the individual culture of HERS and DFCs were performed and followed by alizarin red staining and the quantitative real-time polymerase chain reaction analysis. For in vivo evaluation, the inactivated dentin matrix (iTDM) was fabricated. HERS cells and DFCs were seeded in combination or alone on iTDM and then transplanted into the rat omentum. Scanning electron microscope and further histological analysis were carried out.ResultsIn vitro, mineral-like nodules were found in the culture of HERS cells alone or HERS + DFCs either by alizarin red staining or scanning electronic microscope. The mineralization and fiber-forming relevant mRNA expressions, such as bone sialoprotein, osteopontin, collagen I and collagen III in HERS + DFCs were significantly higher than that of the HERS or DFCs alone group. After transplantation in vivo, cementum and periodontal ligament-like tissues were formed in groups of HERS + DFCs and HERS alone, while no evident hard tissues and attached fibers were found in DFCs alone.ConclusionsHertwig’s epithelial root sheath cells directly participate in the formation of the periodontium, and they are essential for the differentiation of dental follicle cells to form periodontal structures. The combination use of Hertwig’s epithelial root sheath cells and dental follicle cells is a promising approach for periodontal regeneration.     

Are sectioning and soldering of short-span implant-supported prostheses necessary procedures?

The aim of this study was to evaluate the fit between dental abutments and the metal framework of a 3-unit fixed prosthesis screwed to two implants to determine whether sectioning and soldering of the framework are in fact necessary procedures. The study was based on a model of a metal framework of a 3-unit prosthesis screwed to two implants. A total of 18 metal frameworks were constructed and divided into 3 groups: (1) NS group - each framework was cast in one piece and not sectioned; (2) CS group - the components of each sectioned framework were joined by conventional soldering; and (3) LW group - the components of each sectioned framework were joined by laser welding. The control group consisted of six silver-palladium alloy copings that were not cast together. Two analyses were mperformed: in the first analysis, the framework was screwed only to the first abutment, and in the second analysis, the framework was screwed to both abutments. The prosthetic fit was assessed at a single point using a measuring microscope (Measurescope, Nikon, Japan) and the marginal gap was measured in micrometers. Statistical analysis was performed using analysis of variance (ANOVA), Scheffe's test, Student's t-test, and Mann-Whitney U test. The NS group had larger marginal gaps than the other groups (p<0.01), while the CS and LW groups had a similar degree of misfit with no significant difference between them. The results revealed that, in the case of short-span 3-unit fixed prostheses, the framework should be sectioned and soldered or welded to prevent or reduce marginal gaps between the metal framework and dental abutments.     

Are antibiotics effective for endodontic pain?

Although antibiotics are frequently prescribed to treat endodontic pain patients, there is little evidence from the clinical literature to support this indication. This review focuses on the clinical evidence regarding the efficacy of antibiotics for treating postendodontic pain.     

Is the tragal cartilage necessary for type 1 tympanoplasties?

The use of cartilage grafts in tympanoplasties is recommended in cases with a higher probability of failure. Many grafting techniques have been reported, including palisade, cartilage island, and cartilage shield grafts. Cartilage minimizes the inflammatory tissue reaction, ensures resistance against infection during the recovery process, and provides good support against the retraction by virtue of its rigidity.This study compared the anatomic and functional results of conchal cartilage, tragal cartilage, and temporal muscle fascia grafts in primary type 1 tympanoplasty. Between January 2007 and January 2011, 79 patients with subtotal dry tympanic membrane perforation and an intact ossicular chain underwent primary type 1 tympanoplasty in our clinic. The postoperative perforation closure ratios, air and bone pure tone averages, and mean air-bone gap (ABG) in the 3 groups were compared with the preoperative values. The improvement in the mean ABG was assessed.The perforation closure ratio was 80.6%, 100%, and 88.5% in the muscle fascia, conchal cartilage, and tragal cartilage groups, respectively, and the mean increase in the ABG was 5.7, 8.9, and 9.7 dB, respectively.The island graft with cartilage perichondrium, which has recently become popular, can be also used in type 1 tympanoplasty. Because it does not require a second incision, conchal cartilage can be used routinely in tympanoplasties performed via a postauricular approach.     

Are tie-over bolster dressings necessary for healing or success of full thickness skin graft reconstruction following facial skin cancer excision?

Skin grafts are commonly used for reconstruction of defects following excision of facial skin cancers. Tie-over bolster dressings are routinely placed to secure these grafts, but are they necessary for healing or graft success? A total of 96 patients was treated from 2013-2019 who underwent full thickness skin graft (FTSG) reconstruction following facial skin cancer excision were retrospectively analysed. All patients were treated by one consultant with non-fenestrated FTSG’s placed on defects varying from 10 to 55mm in maximum diameter. Grafts were sutured circumferentially with a continuous resorbable suture. Tie-over bolster dressings were not used, and the recipient site was dressed with Mepitel^TM and Steristrips^TM. Primary defect sites where we used this technique included the pinna, the nose and face, and less commonly, the scalp. Graft harvest sites included the neck, pre-auricular, and submental regions. Complete graft take was noted in 94/96 patients. Partial graft failure was observed in two patients, one who healed and had successful late scar revision surgery and one who was managed conservatively and healed well. Two further patients with complete graft healing later underwent minimal revisional contour surgery with satisfactory results. This retrospective study has shown FTSG success in cutaneous defects of the head and neck to be excellent without the use of tie-over bolsters. This has significant benefits of saving operative time, reducing cost, and sparing the patient both unnecessary intraoperative steps, and the inconvenience of a bolster with its often-painful removal. We recommend that the use of tie-over bolsters in the management of most FTSG reconstructed head and neck cutaneous defects be considered an unnecessary step. We believe there are no adverse effects of our described simple technique, and that there are significant benefits to the patient.