Characterization of patients with odontogenic necrotizing soft tissue infections in the head and neck area. A retrospective analysis.

OBJECTIVE: Necrotizing soft-tissue infection (NSTI) in the head and neck area may develop from odontogenic infections. The aim of this study was to characterize patients with NSTI in the head and neck with odontogenic origin in a well-defined prospectively collected cohort. MATERIAL AND METHODS: Patients with NSTI in the head and neck, hospitalized between 2013 and 2017 at Copenhagen University Hospital and registered in the Scandinavian INFECT database were included. Medical records of identified patients and from the INFECT database were screened for a defined set of data including the primary focus of infection, comorbidities, predisposing factors, clinical and radiographic diagnostics, course of treatment, and treatment outcome. RESULTS: Thirty-five patients with NSTI in the head and neck area were included in the study. A total of 54% had odontogenic origin, primarily from mandibular molars, and 94% had radiographic signs of infectious oral conditions. Overall, comorbidities were reported in 51% with cardiovascular disease being the most prevalent. In 20%, no comorbidities or predisposing conditions could be identified. The overall 30-day mortality rate was 9%. CONCLUSIONS: More than half of NSTI cases in the head and neck region had an odontogenic origin, and special attention should be paid to infections related to mandibular molars.

Usefulness of preoperative computed tomography findings for airway management in patients with acute odontogenic infection: a retrospective study.

Odontogenic infection is more likely to affect the airway and interfere with intubation than non-odontogenic causes. Although anesthesiologists predict the difficulty of intubation and determine the method, they may encounter unexpected cases of difficult intubation. An inappropriate intubation can cause airway obstruction due to bleeding and edema by damaging the pharynx and larynx. This study was performed to determine the most important imaging findings indicating preoperative selection of an appropriate intubation method. This retrospective study included 113 patients who underwent anti-inflammatory treatment for odontogenic infection. The patients were divided into two groups according to the intubation method: a Macintosh laryngoscope (45 patients) and others (video laryngoscope and fiberscope) (68 patients). The extent of inflammation in each causative tooth, the severity of inflammation (S1-4), and their influence on the airway were evaluated by computed tomography. The causative teeth were mandibular molars in more than 90%. As the severity of inflammation increased, anesthesiologists tended to choose intubation methods other than Macintosh laryngoscopy. In the most severe cases (S4), anesthesiologists significantly preferred other intubation methods (33 cases) over Macintosh laryngoscopy (9 cases). All patients with S4 showed inflammation in the parapharyngeal space, and the airway was affected in 41 patients. The mandibular molars were the causative teeth most likely to affect the airway and surrounding region. In addition to clinical findings, the presence or absence of inflammation that has spread to the parapharyngeal space on preoperative computed tomography was considered an important indicator of the difficulty of intubation.

Streptococcus anginosus: a stealthy villain in deep odontogenic abscesses.

Odontogenic infections (OIs) occasionally spread to deep facial and neck tissues. Our study aimed to explore the role of Streptococcus anginous group (SAG) in these severe OIs. A retrospective study of patients aged ≥ 18 years who required hospital care for acute OI was conducted. We analysed data of OI microbial samples and recorded findings of SAG and other pathogens. These findings were compared with data regarding patients' prehospital status and variables of infection severity. In total, 290 patients were included in the analyses. The most common (49%) bacterial finding was SAG. Other common findings were Streptococcus viridans and Prevotella species, Parvimonas micra, and Fusobacterium nucleatum. Infection severity variables were strongly associated with SAG occurrence. Treatment in an intensive care unit was significantly more common in patients with SAG than in patients without SAG (p < 0.001). In addition, SAG patients expressed higher levels of C-reactive protein (p = 0.001) and white blood cell counts (p < 0.001), and their hospital stays were longer than those of non-SAG patients (p = 0.001). SAG is a typical finding in severe OIs. Clinical features of SAG-related OIs are more challenging than in other OIs. Early detection of SAG, followed by comprehensive infection care with prompt and careful surgical treatment, is necessary due to the aggressive behaviour of this dangerous pathogen.

Orbital apex syndrome secondary to apical periodontitis of a tooth: a case report.

BACKGROUND: Orbital apex syndrome (OAS) is a rare disease with a noticeable mortality rate. Although its etiology has been repeatedly assessed, few reports have concentrated on odontogenic infection. We presented a rare case of OAS secondary to apical periodontitis. CASE PRESENTATION: A 61-year-old male was admitted to our hospital for a 3-day history of left orbital and head pain, along with diplopia for 1-day. He also had toothache symptoms before his admission. Due to the atypical early symptoms of orbital apex and cranial nerve injury, no timely and effective diagnosis and treatment were initially provided. However, as the disease progressed and complications occurred, we timely adjusted the diagnosis and successfully controlled the infection. During the one-year follow-up, no recurrence of inflammation was observed; nevertheless, the ptosis and ophthalmoplegia persisted. CONCLUSIONS: OAS is a rare, while severe complication of odontogenic infection. This case had various symptoms and nerve injury in the orbital apical area. When disease is atypical in its early stages, treatment is easily overlooked. Early detection and suspicion of orbital apex-related complications should be heightened.

Prognostic factors for descending necrotizing mediastinitis development in deep space neck infections-a retrospective study.

OBJECTIVES: Descending necrotizing mediastinitis (DNM) is the most serious complication of deep neck infections (DNI). The objective of this retrospective study was to evaluate prognostic factors for DNM development in deep space neck infections. METHODS: The study enrolled patients admitted to the Emergency Center of Vojvodina with the diagnosis of multispace DNI with or without DNM either as the primary diagnosis or with discharged diagnosis after surgical treatment during 7-year period. The data were obtained from patient medical records. RESULTS: After final analysis total of 141 charts were randomized for statystical analysis, 124 charts in DNI and 17 in DNI + DNM groups. The most common cause of infection in both groups was odontogenic. On multivariate regression analysis of collected data infection of retropharyngeal, pretracheal and carotid space, C-reactive protein and procalcitonine values were statistically significant predictors for DNM development. CONCLUSIONS: Treatment and diagnosis of DNM requires multidisciplinary approach, with prompt clinical and radiological examinations, empirical broad spectrum antibiotic therapy and radical surgical debridement. Multispace neck infection and especially infection of retropharyngeal, carotid and pretracheal spaces are the most sensitive predictors for DNM development in deep space neck infections. CLINICAL RELEVANCE: If the infection from deep neck spaces reach retropharyngeal, carotid or pretracheal space, the DNM is probable to occur. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT04865003. Date of registration 27.4.2021.

Brain abscess mimicking acute stroke syndrome caused by dual Filifactor alocis and Porphyromonas gingivalis infections: A case report.

This case report is about a woman who had a brain abscess in the left parietal lobe that atypically presented as acute stroke-like syndrome. Pus samples from brain abscess aspiration revealed the periodontal pathogens Porphyromonas gingivalis and Filifactor alocis. After dental health care and 8 weeks of combined antimicrobial therapy, the patient recovered completely.

Deep Neck Infections: Demographic and Clinical Factors Associated with Poor Outcomes.

INTRODUCTION: Deep neck infections (DNIs) are abscesses located in the profound spaces of the neck and constitute one of the most common otolaryngological life-threatening emergencies. The aim of this study is to review the clinical and demographic data of patients with DNI and identify factors associated with prolonged hospitalization, reoperation, and mortality. METHODS: Retrospective review and analysis of 75 patients with DNI admitted from January 2015 to December 2019 in a tertiary referral hospital. RESULTS: Of 75 patients, 50 (66.6%) were males and 25 (33.3%) females. Age ranged from 18 to 91 years with a mean of 41.79 (±15.48). DNIs were odontogenic in 49 patients (65.3%). History of diabetes mellitus (DM) was positive in 26 patients (34.6%). The submandibular space was involved in 57 patients (76%). Streptococcus spp. were isolated in 35 patients (46%). Intubation for airway preservation was needed in 21 patients (28%) and tracheostomy in 6 (8%). Mediastinitis presented in 8 patients (10.67%), with a mortality rate of 62.5% (n = 5). Mean hospital stay was 9.13 days (±7.2). DM (p = 0.016), age (p = 0.001), BMI classification 3, 4, and 6 (p = 0.041), and intensive care unit (ICU) admission (p = 0.009) were associated with a longer stay. Surgical drainage was performed after 1.71 days (±1.65). Surgical reintervention was needed in 6 cases (8%) and was associated with temporal (p = 0.001) and masticator (p = 0.002) space involvement and DM (p = 0.009). Overall mortality was 8% and decreased to 1.5% when mediastinitis was excluded. Mediastinitis (p = 0.001), ICU admission (p < 0.0001), Streptococcus spp. (p = 0.019), and low hemoglobin levels (p = 0.004) were associated with mortality. DISCUSSION/CONCLUSION: DNIs are entities associated with high morbimortality. Mediastinitis and airway obstruction are life-threatening possible complications and should be promptly evaluated. Low HB could be used as a predicting factor for mortality.

Antibiotic utilization in emergency dental care in Stockholm 2016: a cross sectional study.

OBJECTIVES: To investigate systemic antibiotics utilization in emergency dental care and to determine the most common treatment measures performed during emergency visits in public versus private emergency care in Sweden. MATERIAL AND METHODS: Two questionnaires were answered by dentists at one large public and one large private emergency dental clinic in Stockholm, Sweden. The first questionnaire pertained to the emergency care provided to patients (n = 1023) and the second concerned the dentists' (n = 13) own knowledge and attitudes towards antibiotic treatment and oral infections. The results of the questionnaires were tested using a Chi-square test. RESULTS: Sixteen percent of all patients seeking emergency dental treatment received antibiotics. The most common overall reason for visiting an emergency clinic was pain (52%, n = 519). The most common diagnoses made by the participating dentists in the public clinic were tooth/filling fracture (17%, n = 91) and gingivitis (14%, n = 76), while in the private clinic they were tooth fracture (29%, n = 146) and symptomatic apical periodontitis (15%, n = 72). Although the number of patients with infection was higher in the public care clinic, there was no significant difference in total number of antibiotic prescriptions between the two clinics. The rate of patients receiving antibiotic prescription as sole treatment was 41% (n = 34) in private care and 31% (n = 18) in public care. Thirty-one percent (n = 4) of dentists prescribed antibiotics for patients with diagnoses normally not requiring antibiotics, citing reasons such as time limitation, patient request, patient travel, patient safety, and follow-up not possible. CONCLUSION: Although antibiotic prescription frequency among the Swedish emergency care dentists participating in this study was low, areas for improvement could include providing education to improve dentists' knowledge on both antibiotic prescription in emergency dental care and treatment of acute oral infections.

Cone beam computed tomography in the detection of reactional osteogenesis of the maxillary sinus: a case report.

This report describes a case of reactional osteogenesis associated with the residual roots of the maxillary left first molar (tooth 14) in a 42-year-old woman. During intraoral examination, an extensive carious lesion was observed in the residual roots of tooth 14. On the periapical radiograph, a radiolucent area with well-defined limits and regular shape was observed in association with these roots. The 3-dimensional cone beam computed tomographic evaluation revealed that the hyperdense mass was homogenous, not corticated, of defined limits, and irregular in shape and had the density of bone tissue. The mass was clearly associated with an inflammatory periapical lesion. In this clinical case, volumetric analysis established a diagnosis of reactional osteogenesis and facilitated removal of the focus of infection associated with its development. Three-dimensional examination of possible changes in the maxillary sinus is crucial when infectious processes are present in the posterior region of the maxilla.

Surgical treatment of descending necrotising mediastinitis caused by odontogenic infection: a retrospective analysis of 20 patients.

OBJECTIVES: Analysing the results of patients with odontogenic descending necrotising mediastinitis (DNM) treated predominantly by transcervical approach. BACKGROUND: Odontogenic DNM is a rare but serious complication of dental disease and dental procedures. METHODS: Retrospective evaluation of 20 patients who underwent surgery for odontogenic DNM. RESULTS: The mean age was 33.95±12.24 years, and 18 patients (90 %) were men. Type I and diffuse form of DNM were identified in 8 (40 %) and 12 (60 %) patients, respectively. The mean time between the onset of symptoms and surgery was 7.16±4.23 days. The transcervical approach was used in 16 patients, combined cervicotomy and subxiphoid incision in three patients, and cervicotomy and posterolateral thoracotomy was used in one patient. Four patients were reoperated. The mean mediastinal drainage duration and postoperative length of stay (LOS) were 17.05±10.27 days and 20.70±10.87 days, respectively. Fourteen (70 %) patients received mechanical ventilation with a mean duration of 8.86±9.55 days. Comorbidities were present in five (26 %) patients; there were complications in 17 (85 %) patients. In-hospital mortality reached 5 % (1 patient). Thirty-five teeth were extracted. Lower mandibular molars represented 21 (62 %) of extracted teeth. Submandibular and submental spaces were the most affected by the presence of deep neck infection (five and four cases, respectively). CONCLUSION: This study supports the role of transcervical mediastinal drainage as an alternative approach in the surgical treatment of odontogenic DNM (Tab. 4, Fig. 2, Ref. 30).

[Results of modified submandibular surgical approach usage for the mouth floor phlegmons treatment with respect to dynamic of local non-specific resistance]. / Rezul'taty primeneniya modifitsirovannogo podnizhnechelyustnogo operativnogo dostupa dlya lecheniya odontogennykh flegmon dna polosti rta s uchetom dinamiki lokal'noi nespetsificheskoi rezistentnosti.

THE AIM OF THE STUDY: Was increasing of treatment effectiveness of patients with mouth floor odontogenic phlegmon (MFOP) by modified of surgical approach usage. MATERIALS AND METHODS: The prospective controlled, randomized, simple blinded clinical trial, II b level of evidence, comprised 86 patients with MFOP which formed main and control groups. The main group consisted of 40 patients treated with designed «Method for surgical treatment of odontogenic oral phlegmon of mouth floor with partial dissection of sublingual-submandibular sac¼. The control group involved 46 patients treated with traditional surgical procedure. The differences significance between the values has been evaluated with nonparametric Fisher's exact P-test and parametric Student's t-test for independent samples. RESULTS: The modified surgical approach statistically significantly (p<0.05) decreased the number of inflammatory complications (from 26±7% to 9±4%), terms of secondary sutures application (from 7.9±1.4 to 5.7±1.6 days) and time of hospital stay (from 9.4±1.8 to 8.3±1.7 days). On the 5th day of treatment white blood cells count in the main group was significantly (p<0.05) lower (7.2±1.1·109/l) than in controls (9.4±1.3·109/l) showing improved intoxication syndrome resolution in the main group. Index of reaction of bacteria adsorption to the oral epithelium in the main group on the 5th day of treatment was significantly (p<0.05) higher (77.1±6.9%) than in controls (62.4±7.1%). More successful correction of local non-specific resistance was registered in the main group. CONCLUSION: The proposed modified submandibular surgical approach is more effective for the treatment of patients with MFOP.

Deep odontogenic infections-identifying risk factors for nosocomial pneumonia.

OBJECTIVES: To evaluate occurrence and risk factors for pneumonia in patients with deep odontogenic infection (OI). MATERIALS AND METHODS: All patients treated for deep OIs and requiring intensive care and mechanical ventilation were included. The outcome variable was diagnosis of nosocomial pneumonia. Primary predictor variables were re-intubation and duration of mechanical ventilation. The secondary predictor variable was length of hospital stay (LOHS). The explanatory variables were gender, age, current smoking, current heavy alcohol and/or drug use, diabetes, and chronic pulmonary disease. RESULTS: Ninety-two patients were included in the analyses. Pneumonia was detected in 14 patients (15%). It was diagnosed on postoperative day 2 to 6 (median 3 days, mean 3 days) after primary infection care. Duration of mechanical ventilation (p = 0.028) and LOHS (p = 0.002) correlated significantly with occurrence of pneumonia. In addition, re-intubation (p = 0.004) was found to be significantly associated with pneumonia; however, pneumonia was detected in 75% of these patients prior to re-intubation. Two patients (2%) died during intensive care unit stay, and both had diagnosed nosocomial pneumonia. Smoking correlated significantly with pneumonia (p = 0.011). CONCLUSION: Secondary pneumonia due to deep OI is associated with prolonged hospital care and can predict the risk of death. Duration of mechanical ventilation should be reduced with prompt and adequate OI treatment, whenever possible. Smokers with deep OI have a significantly higher risk than non-smokers of developing pneumonia. CLINICAL RELEVANCE: Nosocomial pneumonia is a considerable problem in OI patients with lengthy mechanical ventilation. Prompt and comprehensive OI care is required to reduce these risk factors.

Cefazolin versus ampicillin/sulbactam as an empiric antibiosis in severe odontogenic neck infection descending from the lower jaw-retrospective analysis of 350 cases.

OBJECTIVES: Odontogenic infections descending from the lower jaw may lead to severe health conditions. Commonly, a biphasic treatment of surgical drainage and antibiotic therapy is conducted. The choice of the administered empiric antibiotic agent remains debatable. MATERIAL AND METHODS: Retrospectively, we analyzed 350 medical records of patients who were consecutively treated with odontogenic infections descending from the lower jaw. All patients received surgical drainage and either cefazolin or ampicillin/sulbactam as empiric antibiosis. In particular, the number of secondary operations, infectious parameters, and length of in-hospital stay were investigated. RESULTS: The most frequently infected space was the perimandibular/buccal space for both groups followed by the submandibular space. Number of revision procedures, early recurrence, and length of stay presented no significant difference between both groups (p > 0.05). Inflammatory parameters (c-reactive protein, leukocytes) similarly decreased in both groups. CONCLUSION: Cefazolin targets the majority of the pathogens detected in severe odontogenic neck infections descending from the lower jaw and reveals comparable results to AMP/S in regard to the inflammatory parameters and in-hospital stay. CLINICAL RELEVANCE: Cefazolin is a feasible empiric antibiosis for odontogenic neck infections descending from the lower jaw if surgical drainage is performed.

Facial swelling for the emergency radiologist-typical and atypical causes.

There are a wide variety of inflammatory, infectious, and cystic lesions which may lead patients to seek acute care for facial swelling. Computed tomography (CT) has become the mainstay for imaging in the urgent/emergent setting. However, magnetic resonance imaging (MRI) can also serve as a powerful problem solving tool in the modern era. As volume continues to increase, a wide variety of facial pathology will be encountered by the emergency radiologist. Recognition of both common and uncommon pathology will assist in diagnosis and value-based care. This article serves as an image-rich review of the many causes of facial swelling with an emphasis on key imaging findings and possible complications.

Health status in patients hospitalised for severe odontogenic infections.

OBJECTIVE: Previous findings refer to certain predisposing medical conditions that compound the risk of developing severe and potentially lethal acute odontogenic infections (OI). The objective of this study was to clarify this rationale and infection severity in general. MATERIAL AND METHODS: Records of patients aged ≥18 years requiring hospital care for deep OI were retrospectively investigated. The main outcome variable was need for intensive care unit (ICU) treatment. Additional outcome variable was occurrence of infection complications and/or distant infections. Several parameters describing patients' prior health and recent dental treatment were set as independent variables. RESULTS: Of the 303 acute OI patients included, 71 patients (23%) required treatment in the ICU, with no significant difference between previously healthy and patients with disease history. OIs originating from teeth in the mandible compared with maxilla had 7.8-fold risk (p = .007) for ICU treatment in binary logistic regression analyses. Elevated levels of infection parameters at hospital admission predicted further ICU stay. Infection complications and/or distant infections occurred in 7.6% of patients, of which septicaemia and pneumonia were the most common. The mortality rate was 0.3%. Infection complications and/or distant infections occurred significantly more often in smokers (p = .001) and in patients with excessive consumption of alcohol or drugs (p = .025), however smoking showed 3.5-folded independent risk for infection complications and/or distant infections (p = .008) in logistic regression. CONCLUSIONS: Severe OIs often occur in previously healthy patients. Smokers in particular are prone to the most serious OIs.

Antimicrobial susceptibility surveillance of bacterial isolates recovered in Japan from odontogenic infections in 2013.

We report on the findings of the first antimicrobial susceptibility surveillance study in Japan of isolates recovered from odontogenic infections. Of the 38 facilities where patients representing the 4 groups of odontogenic infections were seen, 102 samples were collected from cases of periodontitis (group 1), 6 samples from pericoronitis (group 2), 84 samples from jaw inflammation (group 3) and 54 samples from phlegmon of the jaw bone area (group 4) for a total of 246 samples. The positivity rates of bacterial growth on culture were 85.3%, 100%, 84% and 88.9%, respectively, for groups 1, 2, 3 and 4. Streptococcus spp. isolation rates according to odontogenic infection group were 22% (group 1), 17.7% (group 3) and 20.7% (group 4). Anaerobic isolation rates were 66.9% (group 1), 71.8% (group 3) and 68.2% (group 4). Drug susceptibility tests were performed on 726 strains excluding 121 strains that were undergrown. The breakdown of the strains subjected to testing was 186 Streptococcus spp., 179 anaerobic gram-positive cocci, 246 Prevotella spp., 27 Porphyromonas spp., and 88 Fusobacterium spp. The isolates were tested against 30 antimicrobial agents. Sensitivities to penicillins and cephems were good except for Prevotella spp. The low sensitivities of Prevotella spp is due to ß-lactamase production. Prevotella strains resistant to macrolides, quinolones, and clindamycin were found. No strains resistant to carbapenems or penems were found among all strains tested. No anaerobic bacterial strain was resistant to metronidazole. Antimicrobial susceptibility testing performed on the S. anginosus group and anaerobic bacteria, which are the major pathogens associated with odontogenic infections, showed low MIC90 values to the penicillins which are the first-line antimicrobial agents for odontogenic infections; however, for Prevotella spp., penicillins combined with ß-lactamase inhibitor showed low MIC90 values.

Odontogenic infection as a predisposing factor for pathologic disorder development in maxillary sinus.

OBJECTIVE: To investigate an association between odontogenic infections (OI) and maxillary sinuses pathologic disorder (MSPD). The distance between the sinus floor and the root apex of upper posterior teeth was also assessed. METHODS: Out of 4,402 cone beam computed tomography scans, 230 were selected, and 431 teeth were evaluated regarding the presence of OI: bone loss with furcation involvement, periapical and endodontic-periodontal lesions. The maxillary sinuses were assessed regarding the presence of MSPD, which was considered as mucosal thickening, opacification of the sinus and mucous retention cyst. RESULTS: There was a significant association between OI and MSPD (p < .001). Periodontal bone loss with furcation involvement, periapical lesions and endodontic-periodontal lesions increased the risk of opacification of the sinuses by 11.6, 34.1 and 228.8 times, respectively. The frequency of the different types of MSP showed not to be associated with a group of teeth or dental root. Conversely, the presence of MSP was associated with a significant shorter distance between the palatine root apex and the sinus floor (p < .001). CONCLUSION: There is a relationship between infectious process of teeth and MSPD. The proximity between the apex of palatine roots and the maxillary sinus floor showed to be a predisposing factor for MSPD.

Ludwig's angina and steroid use: A narrative review.

BACKGROUND: Ludwig's angina, a rapidly progressive cellulitis causing airway obstruction, has traditionally been managed with antibiotics and surgical intervention. More controversial is the use of steroids in the management of patients with this condition. This article summarizes the literature of steroid use in the management of Ludwig's angina. METHODS: The study used a narrative review method alongside the PRISMA guidelines for systematic reviews. PubMed, Ovid Medline, Cochrane, and Web of Science were searched for cases of Ludwig's angina with documented steroid use in patient management. Inclusion criteria were articles in the English language with direct patient outcomes. There were 17 articles selected with 31 patient cases. RESULTS: Most reports of steroid use in Ludwig's angina in the literature are case reports, with one retrospective review, and one letter to the editor. Dexamethasone was the steroid of choice in most cases reviewed. All patient cases reported used antibiotics alongside their steroid use, and 27 out of 31 patient cases required surgery. Most patients recovered with no further sequelae or complications. Three (9.68%) patients suffered mortality due to unrelated causes. CONCLUSIONS: Primary literature reporting the use of steroids in the management of Ludwig's angina includes few cases. While the role steroids have in these cases remains uncertain, the articles summarized do not suggest an adverse influence, and may suggest a benefit.

Air dissection of the spaces of the head and neck: A new teaching and dissection method.

Our goal was to evaluate a new air dissection technique for the spaces of the head and neck using fresh-frozen cadavers. Eight sides from four fresh-frozen Caucasian cadavers were used in this study. Compressed air was initially placed into the pterygomandibular space while simultaneously observing the spaces of the head and neck. Subsequently, the pterygomandibular space on the contralateral side of the specimen was insufflated and observations made. For these methods, simultaneous observation of mediastina and lungs was made using intrathoracic endoscopy. On all sides, the buccal, submental, sublingual, parotid, parapharyngeal, and retropharyngeal spaces were insufflated on both ipsilateral and contralateral sides. Deviation of the larynx and trachea was observed externally and deviation of the mediastinum and lungs via intrathoracic endoscopy. We introduced air dissection into spaces of the head and neck. This new technique might help students, teachers, dentists, medical doctors, and other healthcare providers to better understand the three-dimensional anatomy of the spaces of the head and neck and their communicating pathways. Clin. Anat. 33:207-213, 2020. © 2019 Wiley Periodicals, Inc.

Schneiderian membrane thickness variation following endodontic procedures: a retrospective cone beam computed tomography study.

BACKGROUND: To assess the change of the Schneider membrane thickness measured by CBCT before and after root canal treatment, retreatment and pulp capping procedures. METHODS: This retrospective study was conducted on CBCT scans of a patient population of Guy's Hospital NHS Foundation Trust, London. Three groups of patients were studied: Group 1 consisted of patients referred for primary endodontic treatment; Group 2 for endodontic retreatment; Group 3 for indirect pulp capping procedures (serving as a control group). Follow up scans were carried out 1 year after treatment. Measurements were carried out on CBCT scans and data were analysed statistically by Wilcoxon Signed Rank Test. Linear regression was used to assess predictive parameters for membrane thickness. RESULTS: A statistically significant reduction of the Schneider membrane thickness was observed one year after endodontic treatment and retreatment (P < 0.05) but no significant reduction was observed after pulp capping procedures. Linear regression showed that age and gender were significant predictors influencing the Schneider membrane thickness. CONCLUSIONS: Within the limitations of this retrospective study, following root canal treatment and re-treatment a Schneiderian membrane thickness reduction occurred at 1-year follow-up. The removal of odontogenic infection following endodontic treatment may help reducing the thickness of the Schneider membrane.