The effect of surgical medicaments on peripheral nerve function

Preparation and assessment of agar/TEMPO-oxidized bacterial cellulose cryogels for hemostatic applications

In this work, we have demonstrated agar and oxidized bacterial cellulose cryogels as a potential hemostatic dressing material. TEMPO-oxidized bacterial cellulose (OBC) was incorporated into the agar matrix, improving its mechanical and hemostatic properties. The oxidation of bacterial cellulose (BC) was evidenced by chemical characterization studies, confirming the presence of carboxyl groups. The in vitro blood clotting test conducted on agar/OBC composite cryogels demonstrated complete blood clotting within 90 seconds, indicating their excellent hemostatic efficacy. The cryogels exhibited superabsorbent properties with a swelling degree of 4200%, enabling them to absorb large amounts of blood. Moreover, the compressive strength of the composite cryogels was appreciably improved compared to pure agar, resulting in a more stable physical structure. The platelet adhesion test proved the significant ability of the composite cryogels to adhere to and aggregate platelets. Hemocompatibility and cytocompatibility tests have verified the safety of these cryogels for hemostatic applications. Finally, the material exhibited remarkable in vivo hemostatic performance, achieving clotting times of 64 seconds and 35 seconds when tested in the rat tail amputation model and the liver puncture model, respectively. The experiment results were compared with those of commercial hemostat, Axiostat, and Surgispon, affirming the potential of agar/OBC composite cryogel as a hemostatic dressing material.

[Surgical treatment tactics in patients with third molars located close to mandibular canal]

The tight fit of the roots of the third molars to the mandibular canal is the main predisposing factor of injury to the inferior alveolar nerve during tooth extraction surgery. Surgical treatment of 92 patients diagnosed with pericoronitis, retention of the third molar of the mandible, close fit of the roots of the third molar to the mandibular canal was performed. Four types of close fit of the roots of the third molars to the mandibular canal were revealed, according to CBCT, OPTG and clinical data. Most cases of paresthesia after the removal of the third molars are associated with an anatomical variation in the structure of the mandibular canal, in which the canal walls are partially formed by the cement of the tooth root. Two variants of postoperative management of the surgical wound are proposed, when an open section of the neurovascular bundle is detected at the bottom of the hole.

Toxicity of Carnoy's solution toward human keratinocytes: an in vitro study

The present study aimed to characterize the chemical elements and cytotoxicity of Carnoy's solution (CS) by comparing two different trademarked products (one Brazilian [NCS] and another imported [ICS]) using inductively coupled plasma mass spectrometry (ICP-MS) and human keratinocyte (HaCaT) cultures. For performing ICP-MS, the solutions were diluted according to calibration curves, and the chemical elements were analyzed with a spectrometer. HaCaT cells were exposed to CS concentrations ranging from 0.10% to 20% for 3 or 5 min. Cell viability was evaluated immediately (T0), 24 h (T1), and 7 days (T2) after exposure to CS using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) reduction assay. Data were analyzed using a t-test for ICP-MS and analysis of variance followed by Tukey's post-hoc test for MTT assay, both considering statistical significance at p<0.05. ICP-MS results revealed that ICS presented significantly lower concentrations of 12 chemical elements than NCS. The results of MTT assay revealed that at T0, ICS was more cytotoxic than NCS regardless of the time of exposure (p < 0.05). At T1, the only difference between the groups was at a concentration of 0.10% after 5 min of exposure. At T2, at a concentration of 0.5%, ICS resulted in a significant reduction in cell viability compared to NCS (p < 0.05). Thus, the results showed that ICS was more cytotoxic than NCS. Collectively, our findings suggest that the individual compositions of different CS formulations should be investigated.

Doxorubicin-Loaded In Situ Gel Combined with Biocompatible Hydroxyethyl Cellulose Hemostatic Gauze for Controlled Release of Drugs and Prevention of Breast Cancer Recurrence Postsurgery

Biodegradable hemostatic gauze used for surgical hemostasis has attracted great interest due to its excellent compliance and local anti-inflammatory and therapeutic effects when combined with drugs. Herein, we demonstrate the successful fabrication of water-soluble absorbed cellulose hemostatic material by introducing a biocompatible hydroxyethyl cellulose (HEC) hemostasis gauze into doxorubicin-loaded in situ gel (GEL(DOX)) for the prevention of breast cancer recurrence after surgical tumor resection. The present results show that HEC has a shorter metabolic period, no anaphylaxis and peripheral nerve toxicity, and possesses more advantages than oxidative regenerated cellulose hemostasis gauze, a commercially available product in market. HEC is of the physical hemostasis in mechanism, which does not induce physiological hemostasis and hemolysis. In addition, the combination of HEC with GEL(DOX) not only stops the bleeding efficiently, but also effectively reduces the proliferation of tumor with no cardiac toxic and bone marrow suppression. After treatment, the tumor inhibition rate is up to 90%, resulting in prolonged survival time to 58 days. In conclusion, HEC hemostatic gauze has a broad prospect in clinical application due to its perfect biocompatibility, and we envision that it is a new strategy for the prevention of breast cancer to implant HEC hemostatic gauze containing GEL(DOX) at the postoperative site after surgery.

Iatrogenic trigeminal post-traumatic neuropathy: a retrospective two-year cohort study

With the growing demand for dental work, trigeminal nerve injuries are increasingly common. This retrospective cohort study examined 53 cases of iatrogenic trigeminal nerve injury seen at the Department of Oral and Maxillofacial Surgery, University Hospitals of Leuven between 2013 and 2014 (0.6% among 8845 new patient visits). Patient records were screened for post-traumatic trigeminal nerve neuropathy caused by nerve injury incurred during implant surgery, endodontic treatment, local anaesthesia, tooth extraction, or specifically third molar removal. The patients ranged in age from 15 to 80years (mean age 42.1years) and 68% were female. The referral delay ranged from 1day to 6.5years (average 10months). The inferior alveolar nerve (IAN) was most frequently injured (28 cases), followed by the lingual nerve (LN) (21 cases). Most nerve injuries were caused during third molar removal (24 cases), followed by implant placement (nine cases) and local anaesthesia injuries (nine cases). Pain symptoms were experienced by 54% of patients suffering IAN injury, compared to 10% of patients with LN injury. Persistent neurosensory disturbances were identified in 60% of patients. While prevention remains the key issue, timely referral seems to be a critical factor for the successful treatment of post-traumatic neuropathy.

Neurotoxicity evaluation of three root canal sealers on cultured rat trigeminal ganglion neurons

Background

The aim of this study was to investigate the possible neurotoxic effects of 3 root canal sealers (RCSs) (AH Plus, GuttaFlow, iRoot SP) on cultured rat trigeminal ganglion (TG) neurons.

Material and Methods

Primary cultures of TG neurons were obtained from 1 to 2-day old rats. Freshly mixed RCSs were incubated in sterile phosphate buffered saline and cells were incubated with supernatants of the RCSs for different time intervals (1-, 3-, 6- and 24-h; 1 or 1/10 diluted) and viability/cytotoxicity was tested by counting the number of live cells. Pair of dishes with cells from the same culture incubated with only culture medium was considered as negative controls. Cell images were captured and acquired at x200 magnification using a microscope equipped with a camera using special image program. The viable cells were manually counted assigned from the images for each dose and incubation duration. Data was analysed by using 1-way analysis of variance with Tukey post hoc tests.

Results

There was no significant change in cell viability after short duration of incubation (1- and 3-h) with the supernatant of any of RCSs, except for undiluted-AH Plus at 3-h. When AH Plus was compared with other RCSs, for diluted supernatants, there was only significant difference between iRoot SP and AH Plus at 24-h (P<0.05). Whereas undiluted-AH Plus was significantly more cytotoxic for 3-, 6- and 24-h periods as compared to respective incubation periods of undiluted other groups (P<0.05). GuttaFlow groups had similar neurotoxic effect on cells for all test periods.

Conclusions

All tested RCSs exhibited a variable degree of neurotoxicity on these primary sensory neurons of orofacial tissues, depending on their chemical compositions. GuttaFlow and iRoot SP evoked a less toxic response to TG cells than AH Plus.

Key words:Neurotoxicity, trigeminal ganglia, cell culture, root canal sealer, AH Plus, GuttaFlow, iRoot SP.

Keratocystic Odontogenic Tumour with Extraosseal Spread: Evaluation of the Effect Carnoy's Solution

Keratocystic odontogenic tumour is relatively rare benign tumour. It is characterized by its fast aggressive growth and high risk of recurrence. Treatment is always surgical: conservative (enucleation, marsupialization) or aggressive (enucleation followed by application of Carnoy's solution, cryotherapy; peripheral ostectomy or en block resection of the jaw). Authors analysed retrospectively 22 patients who fulfilled inclusion criteria, i.e. had odontogenic keratocystic tumour of mandible, wherein antero-posterior dimension was at least 30 mm, and the tumour penetrated into the surrounding soft tissues. All patients underwent tumour enucleation, in 11 patients Carnoy's solution was given into the bone cavity after enucleation. The recurrence rate in the evaluation at least 36 months after surgery was both patient groups the same: 45.4%.

Keratocystic Odontogenic Tumours: Etiology, Pathogenesis and Treatment Revisited

INTRODUCTION

Among the pathological entities that affect the maxillofacial region, Keratocystic odontogenic tumour has been subject to a lot of debates, controversies and speculations because of its diverse nature and high recurrence rates.

MATERIALS AND METHODS

The authors conducted a search in English literature using the following keywords; "Odontogenic keratocyst" and "Keratocystic odontogenic tumour". The aim of the paper was to review all aspects of the entity, including etiology, pathogenesis, clinical and radiological manifestations, growth potential, recurrence and treatment modalities.

CONCLUSION

The controversial nature of the pathology not withstanding, there is in general a broad consensus on treating the entity conservatively with emphasis on a long term review.

Evaluating the effect of polytetrafluoroethylene and extractum cepae-heparin-allantoin gel in peripheral nerve injuries in a rat model

BACKGROUND

Peripheral nerves can be injured by congenital, mechanical, thermal or chemical causes. Peripheral nerve injuries are increasing in frequency, particularly in countries that are becoming more industrialized. Nerve and extremity injuries result in work loss and high treatment costs, and can lead to separation of patients from their social environment. Failure of nerve repair causes muscle functional losses, sensory losses and painful neuropathies.

OBJECTIVES

To compare the effects of condensed polytetrafluoroethylene (cPTFE) and cPTFE-extractum cepae-heparin-allantoin (cPTFE-EHA) gel compound on nerve and functional recovery, and the prevention of adhesion and scar tissue formation after total peripheral nerve injury repaired by primary suture in a rat model.

RESULTS

cPTFE alone and cPTFE-EHA gel was found to provide better functional recovery and nerve regeneration compared with primary repair only. In the macroscopic evaluation, the cPTFE-EHA gel was found to have no negative effect on wound healing and, despite increasing extra-neural scar tissue and adhesions, it had no negative effect on nerve function; in addition, it facilitated functional recovery.

CONCLUSIONS

Compared with the cPTFE application alone, the application of perineural cPTFE-EHA gel during peripheral nerve surgery appeared to provide better functional recovery without causing any significant changes in epineural and extraneural scar tissue formation.

Evaluating the effect of polytetrafluoroethylene and extractum cepae-heparin-allantoin gel in peripheral nerve injuries in a rat model

Background

Peripheral nerves can be injured by congenital, mechanical, thermal or chemical causes. Peripheral nerve injuries are increasing in frequency, particularly in countries that are becoming more industrialized. Nerve and extremity injuries result in work loss and high treatment costs, and can lead to separation of patients from their social environment. Failure of nerve repair causes muscle functional losses, sensory losses and painful neuropathies.

Objectives

To compare the effects of condensed polytetrafluoroethylene (cPTFE) and cPTFE-extractum cepae-heparin-allantoin (cPTFE-EHA) gel compound on nerve and functional recovery, and the prevention of adhesion and scar tissue formation after total peripheral nerve injury repaired by primary suture in a rat model.

Results

cPTFE alone and cPTFE-EHA gel was found to provide better functional recovery and nerve regeneration compared with primary repair only. In the macroscopic evaluation, the cPTFE-EHA gel was found to have no negative effect on wound healing and, despite increasing extraneural scar tissue and adhesions, it had no negative effect on nerve function; in addition, it facilitated functional recovery.

Conclusions

Compared with the cPTFE application alone, the application of perineural cPTFE-EHA gel during peripheral nerve surgery appeared to provide better functional recovery without causing any significant changes in epineural and extraneural scar tissue formation.

Comparison of the effects of new folkloric hemostatic agent on peripheral nerve function: an electrophysiologic study in rats

OBJECTIVE

The aim was to evaluate the effects of a new folkloric medicinal plant extract on peripheral nerve function compared with oxidized regenerated cellulose (OC) and bovine collagen (BC).

STUDY DESIGN

Under ketamine anesthesia a total of 40 male Sprague-Dawley rat right sciatic nerves were identified. Animals were randomly divided into 5 groups: OC, BC, ankaferd blood stopper (ABS), and negative and positive control groups. The recordings of nerve potentials were carried out using an electrophysiologic data acquisition system. After the application of substances, the nerve conduction velocity (NCV) was recorded for immediate (30 min), early (120 min), and delayed (3 wk) effects on nerve function.

RESULTS

Statistically, differences were not found among the hemostatic agents (OC, BC, and ABS) at baseline and all tested periods (early, immediate, and delayed; P > .05). The positive control group exhibited lower NCV values compared with the other solutions at the 30-minute period (P < .05) as well as the other tested time periods (P > .05). OC exhibited NCV values closer to the positive control group at 120 minutes (P > .05).

CONCLUSIONS

Folkloric medicinal hemostatic agent could be considered as an acceptable hemostatic material without resulting in any serious peripheral nerve function alterations. The possible desirable effects of bovine collagen and undesirable effects of oxidized cellulose on peripheral nerve function should not be overlooked.

Surgicel® (oxidized regenerated cellulose) granuloma mimicking local recurrent gastrointestinal stromal tumor: A case report

Unexpected clinical and/or imaging evidence of the recurrence of gastrointestinal stromal tumors soon after surgical resection may be complicated due to certain biological behavioral features of gastrointestinal stromal tumors. However, local hemostatic materials routinely used in abdominal surgery to achieve hemostasis intraoperatively may cause a foreign-body reaction, which appears to be indistinguishable from recurrent tumors in imaging studies. Thus, a second examination may be necessary to settle the true nature of the findings in such cases. If the resection and examination reveals a recurrent tumor, further proper oncological treatment is warranted, whereas if a foreign-body reaction is observed, radical or potentially harmful therapy may be withheld or cancelled. The present study retrospectively analyzes the case of an 83-year-old male patient who presented with a recurrent gastrointestinal stromal tumor four months after surgical resection, which was later identified as an intra-abdominal foreign-body granuloma caused by retained Surgicel^® residue. The present study aimed to demonstrate why foreign-body granuloma induced by local hemostatic materials should be incorporated into the differential diagnosis of recurrent gastrointestinal stromal tumors post-operatively, particularly soon after surgical resection has been performed.

Carnoy's solution in the mangement of odontogenic keratocyst

Carnoy's solution is a substance used as a complementary treatment after the conservative excision of odontogenic keratocyst. The application of Carnoy's solution promotes a superficial chemical necrosis and is intended to reduce recurrence rates. However, the inferior alveolar vascular–nervous plexus can occasionally be exposed after the removal of a lesion. The safety of the application of Carnoy's solution over this plexus has been reported, but to date, no clinical report has been made. The authors present a case that was given Carnoy's solution over the inferior alveolar vascular–nervous plexus as a complementary treatment for the keratocystic odontogenic tumor. Effective control of recurrence with low and transient neural morbidity was suggested with this technique.

Evaluation of trigeminal nerve injuries in relation to third molar surgery in a prospective patient cohort. Recommendations for prevention

Trigeminal nerve injury is the most problematic consequence of dental surgical procedures with major medico-legal implications. This study reports the signs and symptoms that are the features of trigeminal nerve injuries caused by mandibular third molar (M3M) surgery. 120 patients with nerve injury following M3M surgery were assessed. All data were analysed using the SPSS statistical programme and Microsoft Excel. 53 (44.2%) inferior alveolar nerve (IAN) injury cases and 67 (55.8%) lingual nerve injury (LNI) cases were caused by third molar surgery (TMS). Neuropathy was demonstrable in all patients with varying degrees of paraesthesia, dysaesthesia (in the form of burning pain), allodynia and hyperalgesia. Pain was one of the presenting signs and symptoms in 70% of all cases. Significantly more females had IAN injuries and LNIs (p<0.05). The mean ages of the two groups of patients were similar. Speech and eating were significantly more problematic for patients with LNIs. In conclusion, chronic pain is often a symptom after TMS-related nerve injury, resulting in significant functional problems. Better dissemination of good practice in TMS will significantly minimize these complex nerve injuries and prevent unnecessary suffering.

Sialocele after parotid surgery: assessing the risk factors

OBJECTIVE

To assess possible factors contributing to the occurrence of a sialocele after parotid surgery.

STUDY DESIGN

Case series with chart review.

SETTING

Secondary otolaryngology service.

METHODS

One hundred two consecutive parotid operations by 1 surgeon were recorded. A high rate of sialocele formation was addressed by identifying possible contributing factors, sequentially introducing changes, and then analyzing the effect of such changes.

RESULTS

Twenty patients developed a sialocele (19.6%). Demographic variables of those who developed a sialocele were similar to those who did not. Factors examined included partial versus complete superficial parotidectomy, use of Surgicel, vacuum drain pressure, and postoperative duration for surgical drain. The only significant factor on regression analysis for increasing the risk of a sialocele development was the use of Surgicel (P = .023). Once the use of Surgicel stopped, the rate of sialocele formation diminished markedly (from 28.6% to 11.3%).

CONCLUSIONS

Sialocele can cause significant problems for the patient and surgeon in terms of delayed wound healing and increased clinic resources and frustration. This study suggests that the use of products such as Surgicel increases the risk of postoperative sialocele formation.

Secondary healing after removal of large keratocystic odontogenic tumor in the mandible: enucleation followed by open packing of iodoform gauze

PURPOSE

The aim of this retrospective study was to present the findings of an open packing method after enucleation of large keratocystic odontogenic tumors (KCOTs) in the mandible.

PATIENTS AND METHODS

We performed a retrospective case series study of 27 patients with KCOTs larger than 5 cm treated at our institution between September 2003 and September 2008. A conservative surgical treatment was applied, which involved enucleation of the primary lesion and open packing of the residual osseous defect with iodoform gauze for secondary healing. Bone regeneration, tumor recurrence, and surgical complications were observed and analyzed. We used the χ(2) test and Pearson correlation coefficient for statistical analysis.

RESULTS

The postoperative follow-up time was 52.3 months on average (range, 24 to 84 months). The packing gauze was changed every 2 weeks after enucleation, and the total duration for packing was 10.2 months on average (range, 7-15 months). Bone regeneration and satisfactory secondary healing were observed clinically and radiographically after treatment. Only 1 case had a recurrence 6 months after initial treatment, which was attributed to insufficient bony unroofing during enucleation. The recurrent lesion was re-treated by the same method, and no recurrence occurred in the following 6 years. No serious complications from this method of treatment were observed. No significant variables were found to be related to the recurrence.

CONCLUSIONS

Enucleation with subsequent open packing was shown to be a conservative and comfortable treatment for patients and appears to be an effective choice for the management of large KCOTs in the mandible.

Hemostasis in oral surgery

The control of hemorrhage is a key component for the clinician to understand before performing oral surgical procedures. Hemostasis may be obtained primarily by local hemostatic measures. If hemostasis is not achieved with this modality, various hemostatic agents exist, which may be used as adjuncts to obtain hemostasis. Preoperative, perioperative, and postoperative methodologies toward hemostasis in oral surgery have been presented.

Minimising and managing nerve injuries in dental surgical procedures

The most significant complications from dental surgical interventions are iatrogenic trigeminal nerve injuries, which can result in permanent altered sensation and pain, causing considerable functional and psychological disability. This paper provides some useful tips on minimising the risks of these injuries. By understanding the risk factors and modifying the resulting intervention, more of these injuries may be prevented.

Bismuth iodoform paraffin paste: a review

Introduction:

This article reviews the literature pertaining to bismuth iodoform paraffin paste.

Overview:

Bismuth iodoform paraffin paste is used in most otolaryngology departments on a daily basis. Questions about its properties are common in postgraduate otolaryngology examinations. This article reviews bismuth iodoform paraffin paste's current and historical usage, constituents, properties, side effects, and radiographic properties, and its alternatives in otological and rhinological practice.

Unexpected temporary mental nerve deficit after extraction of mandibular first molar: case report

Temporary neurologic deficit affecting the distribution of the left mental nerve was reported in a warfarinized, diabetic patient who had a history of previous CVA with right-sided body weakness. The neurologic deficit was reported following routine extraction of a left mandibular first molar. Recovery of sensation began six weeks after the procedure. Possible mechanisms and preventive measures are discussed.

CLINICAL RELEVANCE

The reader should understand that mental paraesthesia can be an unexpected outcome in the most routine of mandibular extractions.

Injury of the Inferior Alveolar Nerve during Implant Placement: a Literature Review

Objectives

The purpose of present article was to review aetiological factors, mechanism, clinical symptoms, and diagnostic methods as well as to create treatment guidelines for the management of inferior alveolar nerve injury during dental implant placement.

Material and Methods

Literature was selected through a search of PubMed, Embase and Cochrane electronic databases. The keywords used for search were inferior alveolar nerve injury, inferior alveolar nerve injuries, inferior alveolar nerve injury implant, inferior alveolar nerve damage, inferior alveolar nerve paresthesia and inferior alveolar nerve repair. The search was restricted to English language articles, published from 1972 to November 2010. Additionally, a manual search in the major anatomy, dental implant, periodontal and oral surgery journals and books were performed. The publications there selected by including clinical, human anatomy and physiology studies.

Results

In total 136 literature sources were obtained and reviewed. Aetiological factors of inferior alveolar nerve injury, risk factors, mechanism, clinical sensory nerve examination methods, clinical symptoms and treatment were discussed. Guidelines were created to illustrate the methods used to prevent and manage inferior alveolar nerve injury before or after dental implant placement.

Conclusions

The damage of inferior alveolar nerve during the dental implant placement can be a serious complication. Clinician should recognise and exclude aetiological factors leading to nerve injury. Proper presurgery planning, timely diagnosis and treatment are the key to avoid nerve sensory disturbances management.

Trigeminal neuropathy

Trigeminal neuropathies (TNs) are well recognized disorders characterized and manifesting as skin and mucosal numbness in the region innervated by the trigeminal nerve. Facial numbness indicates trigeminal sensory alteration affecting the trigeminal system. TNs always pose differential location difficulties as multiple diseases are capable of producing them: they can be the result of traumatism, tumors, or diseases of the connective tissue, infectious or demyelinating diseases, or may be of idiopathic origin. Their importance is explained by the fact that TN may represent the first manifestation of tumor disease, or of relapse in patients with prior neoplastic processes. As such, these manifestations are ominous, and patient life expectancy is often short. The clinical exploration reveals a loss of sensitivity in the cutaneous territory corresponding to the affected nerve, which can be partial (hypoesthesia) or complete (anesthesia). The sensory defect is occasionally associated with hyperesthesia (i.e., the patient suffers a decrease in sensory perception, but when sensation is perceived, it may cause considerable discomfort). Complementary studies are needed to establish the etiologic diagnosis, with laboratory tests to discard the possible causative diseases underlying the trigeminal neuropathy, and the opportune radiographic examinations in the form of plain X-rays or a routine cranial computed tomography scan.

The Effects of Hemostatic Agents on Peripheral Nerve Function: An Experimental Study

PURPOSE

In the practice of oral and maxillofacial surgery, hemostatic agents are sometimes placed in close proximity to peripheral nerves. In the present study, we evaluated immediate and delayed effects of 4 hemostatic agents (oxidized regenerated cellulose, 5% colloid silver-added gelatine sponge, bovine collagen, bone wax) on peripheral nerve function.

MATERIALS AND METHODS

A total of 25 rat sciatic nerves were prepared, and the amplitudes were recorded with a physiological data acquisition system. Animals were randomly assigned to 5 groups: control, oxidized regenerated cellulose, gelatine sponge, bone wax, and bovine collagen. The first hour records are defined as immediate effects of these hemostatic agents on nerve function. The animals were then allowed to recover for 4 weeks. At the end of this period, the same surgical and recording procedures were performed. These final records are defined as delayed effects of hemostatic agents on nerve function. According to nerve conduction velocity (NCV) and compound action potential (CAP) values of the experimental groups, early and delayed effects of each hemostatic agent were statistically compared with Bonferroni corrected test (P < .05).

RESULTS

Statistically, NCV was significantly reduced, and the CAP was significantly increased 1 hour after surgery (P < .05) in the group of oxidized regenerated cellulose. However, there were no significant differences after 4 weeks compared with the first records. In the gelatine sponge group, CAP was significantly increased 4 weeks after the application. In the bovine collagen and bone wax groups, NCV and CAP values (1 hour and 4 weeks after the application) were not statistically significant compared with initial control records.

CONCLUSION

The present study shows that bovine collagen is the most suitable hemostatic agent applicable for peripheral nerves.

Dissection and hemostasis with hydroxilated polyvinyl acetal tampons in open thyroid surgery

Background

The essential objectives for thyroidectomy are: avoidance of injury to the recurrent laryngeal nerves, conservation of the parathyroid glands, an accurate haemostasis and an excellent cosmesis. In the last 10 years major improvements and new technologies have been proposed and applied in thyroid surgery; among these mini-invasive thyroidectomy, regional anaesthesia and intraoperative neuromonitoring, and new devices for achieving dissection and haemostasis. Minor bleeding from small vessels could be a major complication in thyroid surgery. The purpose of ligating vessels is to maintain the surgical site free from an excess of blood and reduce blood loss in the patient.

Materials and methods

Hydroxylated polyvinyl acetal tampons (HPA) are made by a synthetic, open cell foam structure able to absorb fluids up to 25 times the initial weight. We tested their efficacy for small bleeding control and tissue dissection during several thyroid procedures.

Results

HPA tampons have been found extremely useful to absorb blood coming from minor and diffuse loss, helping to control bleeding by a combined action of fluid absorption and local compression. The porous design of the tampon allows the use of the suction device right through the tampon itself. Thanks to the initial mildly hard consistency, we also used HPA tampons as dissecting instruments.

Conclusion

In our experience the use of HPA tampons resulted extremely efficient for minor bleeding control, fluids removal and tissue dissection during thyroid surgery.

Etiology of Lingual Nerve Injuries in the Third Molar Region: A Cadaver and Histologic Study

PURPOSE

It has been suggested that different etiologies of lingual nerve damage in the third molar area will produce a different clinical and histologic appearance in the nerve. If the clinical and histologic pictures were different, it could result in different treatments being recommended.

MATERIALS AND METHODS

Eight preserved cadavers (16 lingual nerves) were used for this study. As far as possible, the nerves were left in situ and damaged in a way that could be envisaged during third molar surgery. In each case, the damaged sections of nerve were photographed, resected, embedded in paraffin wax, sectioned in 5 mum sections, stained with hematoxylin-eosin, and examined histologically.

RESULTS

The scalpel clinically produced a clean wound with sharply defined edges; this was confirmed histologically with minimal disruption to the fascicles. The 702 fissure bur produced a ragged stretch-type injury clinically, and histologically this was confirmed with an irregular-edged border to the lesion and stretching and internal damage to the fascicles immediately adjacent to the wound. The crush injury clinically caused considerable apparent damage to the nerve, which was confirmed histologically with crushing and disruption of the fascicles and reduction to approximately 25% of their preinjury thickness. The stretch injury clinically showed no damage, but histologically showed irregular internal disruption of the fascicles over the whole area subject to stretching movements.

CONCLUSION

It does appear that different modalities in nerve injury produce a different type of injury both clinically and histologically. This information has implications for both natural clinical recovery and the indications for surgical intervention. Clinical recovery may occur best with close approximation of a sharp scalpel-type wound or excision of a crushed area of nerve with reapproximation of the nerve endings, but a ragged wound caused by a fissure bur may require excision back to healthy nerve with subsequent reapproximation, whereas with the stretching injury it may be difficult to ascertain the edges and limits of the wound, and difficult to repair, and it may be most appropriate to rely on a natural healing process for the best results.

Influence of new technologies on thyroid surgery: state of the art

The history of thyroid surgery starts with Billroth, Kocher and Halsted, who developed the technique for thyroidectomy between 1873 and 1910. In general, the essential objectives for thyroidectomy are conservation of the parathyroid glands, avoidance of injury to the recurrent laryngeal nerve, an accurate hemostasis and an excellent cosmesis. In the last 20 years, major improvements and new technologies have been proposed and applied in thyroid surgery; among these are mini-invasive thyroidectomy, new devices for achieving hemostasis and dissection, regional anesthesia and intraoperative neuro-monitoring.

Neurosensory changes after liquid nitrogen cryotherapy

PURPOSE

The study goal was to evaluate neurosensory changes after liquid nitrogen cryotherapy in the management of mandibular lesions in close proximity to the inferior alveolar nerve.

PATIENTS AND METHODS

The design of the study was a retrospective review. Sixteen patients with posterior mandibular lesions (15 odontogenic keratocysts and 1 fibromyxoma) in close proximity to the inferior alveolar nerve were treated with a standardized enucleation and cryotherapy technique. Postoperative evaluation included patients report of symptoms and formal neurosensory testing.

RESULTS

All patients had altered sensation in the distribution of the inferior alveolar nerve immediately after cryotherapy. Two patients experienced anesthesia, and the remaining 14 patients showed paresthesia. The average time for return or improvement in sensation was 91 days (range, 6 to 235 days). The average time of follow-up was 2.6 years (range, 0.5 to 7.3 years). At the time of last follow-up, no patients had anesthesia or dysesthesia. Four patients had full return of sensation and 12 patients had paresthesia. No patients reported significant difficulty from abnormal nerve function. All 16 patients experienced some return of sensation; 9 patients had full or near full return of sensation.

CONCLUSIONS

Based on these results, the combination of enucleation and liquid nitrogen cryotherapy produces minimal alteration of inferior alveolar nerve function.

Unicystic ameloblastoma--use of Carnoy's solution after enucleation

A retrospective analysis of 29 patients with a histologically confirmed diagnosis of unicystic ameloblastoma is reported with special emphasis on a treatment regime employing enucleation and application of Carnoy's solution. Despite the finding that 93% of lesions exhibited mural invasion, a recurrence rate of 10% after treatment is reported, suggesting a possible benefit of Carnoy's solution against recurrence.

Current management of damage to the inferior alveolar and lingual nerves as a result of removal of third molars

In this review we present algorithms to guide the clinical management of patients who sustain damage to the inferior alveolar or lingual nerves during the removal of lower third molars. Monitoring recovery using simple sensory testing allows those patients who may benefit from some form of intervention to be identified. There is good evidence that some surgical procedures produce worthwhile improvements in sensation but management of nerve injury-induced dysaesthesia remains problematic.