Design and evaluation of a deep learning-based automatic segmentation of maxillary and mandibular substructures using a 3D U-Net.

Background: Current segmentation approaches for radiation treatment planning in head and neck cancer patients (HNCP) typically consider the entire mandible as an organ at risk, whereas segmentation of the maxilla remains uncommon. Accurate risk assessment for osteoradionecrosis (ORN) or implant-based dental rehabilitation after radiation therapy may require a nuanced analysis of dose distribution in specific mandibular and maxillary segments. Manual segmentation is time-consuming and inconsistent, and there is no definition of jaw subsections. Materials and methods: The mandible and maxilla were divided into 12 substructures. The model was developed from 82 computed tomography (CT) scans of HNCP and adopts an encoder-decoder three-dimensional (3D) U-Net structure. The efficiency and accuracy of the automated method were compared against manual segmentation on an additional set of 20 independent CT scans. The evaluation metrics used were the Dice similarity coefficient (DSC), 95% Hausdorff distance (HD95), and surface DSC (sDSC). Results: Automated segmentations were performed in a median of 86 s, compared to manual segmentations, which took a median of 53.5 min. The median DSC per substructure ranged from 0.81 to 0.91, and the median HD95 ranged from 1.61 to 4.22. The number of artifacts did not affect these scores. The maxillary substructures showed lower metrics than the mandibular substructures. Conclusions: The jaw substructure segmentation demonstrated high accuracy, time efficiency, and promising results in CT scans with and without metal artifacts. This novel model could provide further investigation into dose relationships with ORN or dental implant failure in normal tissue complication prediction models.

Imaging the Tight Orbit: Radiologic Manifestations of Orbital Compartment Syndrome.

BACKGROUND AND PURPOSE: Orbital compartment syndrome is a sight-threatening emergency caused by rising pressure inside the orbit. It is usually diagnosed clinically, but imaging might help when clinical findings are inconclusive. This study aimed to systematically evaluate imaging features of orbital compartment syndrome. MATERIALS AND METHODS: This retrospective study included patients from 2 trauma centers. Proptosis, optic nerve length, posterior globe angle, morphology of the extraocular muscles, fracture patterns, active bleeding, and superior ophthalmic vein caliber were assessed on pretreatment CT. Etiology, clinical findings, and visual outcome were obtained from patient records. RESULTS: Twenty-nine cases of orbital compartment syndrome were included; most were secondary to traumatic hematoma. Pathologies occurred in the extraconal space in all patients, whereas intraconal abnormalities occurred in 59% (17/29), and subperiosteal hematoma in 34% (10/29). We observed proptosis (affected orbit: mean, 24.4 [SD, 3.1] mm versus contralateral: 17.7 [SD, 3.1] mm; P < .01) as well as stretching of the optic nerve (mean, 32.0 [SD, 2.5] mm versus 25.8 [SD, 3.4] mm; P < .01). The posterior globe angle was decreased (mean, 128.7° [SD, 18.9°] versus 146.9° [SD, 6.4°]; P < .01). In 69% (20/29), the superior ophthalmic was vein smaller in the affected orbit. No significant differences were detected regarding the size and shape of extraocular muscles. CONCLUSIONS: Orbital compartment syndrome is characterized by proptosis and optic nerve stretching. In some cases, the posterior globe is deformed. Orbital compartment syndrome can be caused by an expanding pathology anywhere within the orbit with or without direct contact to the optic nerve, confirming the pathophysiologic concept of a compartment mechanism.

Real-world evidence from over one million COVID-19 vaccinations is consistent with reactivation of the varicella-zoster virus.

BACKGROUND: Reactivation of the varicella-zoster virus (VZV), which causes herpes zoster (HZ, synonym: shingles) in humans, can be a rare adverse reaction to vaccines. Recently, reports of cases after COVID-19 vaccination have arisen. OBJECTIVES: The aim of this study was to assess whether the frequency of HZ is found to increase after COVID-19 vaccination in a large cohort, based on real-world data. As a hypothesis, the incidence of HZ was assumed to be significantly higher in subjects who received a COVID-19 vaccine (Cohort I) vs. unvaccinated individuals (Cohort II). METHODS: The initial cohorts of 1 095 086 vaccinated and 16 966 018 unvaccinated patients were retrieved from the TriNetX database and were matched on age and gender in order to mitigate confounder bias. RESULTS: After matching, each cohort accounted for 1 095 086 patients. For the vaccinated group (Cohort I), 2204 subjects developed HZ within 60 days of COVID-19 vaccination, while among Cohort II, 1223 patients were diagnosed with HZ within 60 days after having visited the clinic for any other reason (i.e. not vaccination). The risk of developing shingles was calculated as 0.20% and 0.11% for cohort I and cohort II, respectively. The difference was statistically highly significant (P < 0.0001; log-rank test). The risk ratio and odds ratio were 1.802 (95% confidence interval [CI] = 1.680; 1.932) and 1.804 (95% CI = 1.682; 1.934). CONCLUSIONS: Consistent with the hypothesis, a higher incidence of HZ was statistically detectable post-COVID-19 vaccine. Accordingly, the eruption of HZ may be a rare adverse drug reaction to COVID-19 vaccines. Even though the molecular basis of VZV reactivation remains murky, temporary compromising of VZV-specific T-cell-mediated immunity may play a mechanistic role in post-vaccination pathogenesis of HZ. Note that VZV reactivation is a well-established phenomenon both with infections and with other vaccines (i.e. this adverse event is not COVID-19-specific).

Removal of patient-specific reconstruction plates after mandible reconstruction with a fibula free flap: is the plate the problem?

Computer-aided microvascular mandible reconstruction is an increasingly common procedure in oral and maxillofacial surgery. The aim of this retrospective single-centre study was to evaluate the rate and specifics of hardware removal after fibula free flap (FFF) fixation with a patient-specific reconstruction plate. The study included patients who underwent hardware removal between April 2017 and October 2019. Statistical analyses were performed regarding the different indications for plate removal (dental implantation versus complication) and the surgical approach (intraoral versus extraoral). Plate removal was performed in 29 of 98 patients (29.6%) after FFF fixation with a patient-specific reconstruction plate. Plate removal was done prior to dental implantation in 58.6% of cases and due to complications in 41.4%. Complications seen between reconstructive surgery and plate removal were less frequent in the dental rehabilitation group (8/17 vs 12/12; P=0.002). Within this group, 35.3% of plates were removed intraorally, and the majority of partial plate removals were performed in the patients with plate removal for dental rehabilitation (72.7% vs 27.3%). Hospitalization was shorter with an intraoral approach (1.7 days vs 4.0 days, P=0.052). The removal of patient-specific reconstruction plates prior to dental implantation is often partial and can be performed intraorally. The use of patient-specific miniplates for fixation of FFF might facilitate later dental rehabilitation.

Biomechanical comparison of polylactide-based versus titanium miniplates in mandible reconstruction in vitro.

OBJECTIVES: Evaluation of the mechanical integrity and reliability of polylactide-based miniplates for osseous free flap fixation at the mandible in an experimental study setup of a mandible reconstruction model. MATERIAL AND METHODS: 1.0mm titanium miniplates (group TI) (MatrixMandible, DePuy Synthes, Umkirch, Germany) and 1.5mm polylactide miniplates (group PL) (Inion CPS, Inion Oy, Tampere, Finland) were used to fix a polyurethane (PU) fibula segment to a PU mandible reconstruction model using monocortical non-locking screws. Mastication was simulated via unilateral cyclic dynamic loading at 1Hz with increasing loads (+ 0.15N/cycle, Bionix, MTS, USA). A 3D optical tracking system (Aramis, GOM, Braunschweig, Germany) was used to determine interosteotomy movements (IOM). RESULTS: IOM were higher in the polylactide group (distal: P=0.001, mesial: P=0.001). Differences in mean stiffness (titanium: 478±68N/mm; polylactide: 425±38N/mm, P=0.240) and mean force at a vertical displacement of 1.0mm (titanium: 201.6±87.1N; polylactide: 141.3±29.9N, P=0.159) were not significant. CONCLUSIONS: The results of this study suggest that polylactide-based miniplates provide reduced mechanical integrity and higher interosteotomy movements in comparison to titanium miniplates in vitro. Indications for clinical use of polylactide-based miniplates in mandible reconstruction have to be placed critically. Future studies will focus on clinical complications of polylactide-based plates in risk patients.

A Century of Change towards Prevention and Minimal Intervention in Cariology.

Better understanding of dental caries and other oral conditions has guided new strategies to prevent disease and manage its consequences at individual and public health levels. This article discusses advances in prevention and minimal intervention dentistry over the last century by focusing on some milestones within scientific, clinical, and public health arenas, mainly in cariology but also beyond, highlighting current understanding and evidence with future prospects. Dentistry was initially established as a surgical specialty. Dental caries (similar to periodontitis) was considered to be an infectious disease 100 years ago. Its ubiquitous presence and rampant nature-coupled with limited diagnostic tools and therapeutic treatment options-meant that these dental diseases were managed mainly by excising affected tissue. The understanding of the diseases and a change in their prevalence, extent, and severity, with evolutions in operative techniques, technologies, and materials, have enabled a shift from surgical to preventive and minimal intervention dentistry approaches. Future challenges to embrace include continuing the dental profession's move toward a more patient-centered, evidence-based, less invasive management of these diseases, focused on promoting and maintaining oral health in partnership with patients. In parallel, public health needs to continue to, for example, tackle social inequalities in dental health, develop better preventive and management options for existing disease risk groups (e.g., the growing aging population), and the development of reimbursement and health outcome models that facilitate implementation of these evolving strategies. A century ago, almost every treatment involved injections, a drill or scalpel, or a pair of forceps. Today, dentists have more options than ever before available to them. These are supported by evidence, have a minimal intervention focus, and result in better outcomes for patients. The profession's greatest challenge is moving this evidence into practice.

Complication rates and clinical outcomes of osseous free flaps: a retrospective comparison of CAD/CAM versus conventional fixation in 128 patients.

Studies evaluating plate-related complications in patient-specific versus conventional fixation systems in free flap surgery are lacking. This was a retrospective study of 128 osseous free flaps with a minimum follow-up of 12 months. Wound healing disorders, plate exposure, fixation failure, and subtotal osseous union were recorded and evaluated statistically by univariate and regression analysis. Complication rates were as follows: wound healing disorders 33.6% (computer-aided design and computer-aided manufacturing (CAD/CAM) vs. conventional: 35.1% vs. 33.0%); plate exposure 21.9% (29.7% vs. 18.7%); fixation failure 7.0% (8.1% vs. 6.6%); subtotal osseous union 36.7% (45.9% vs. 33.0%). Radiotherapy (P<0.001) and more than two segments (P=0.026) were independent variables for the overall complication rate and were negatively correlated with the dental implantation rate. The time between diagnosis and ablative surgery was increased by 11.0days in the CAD/CAM group (34.2±16.2days vs. 23.2±12.0 days; P=0.002). Rates of dental rehabilitation were not significantly different (35.1% vs. 44.0%, P=0.358). On average, 3.2±1.7 dental implants were placed into flap segments. Plate-related complications were increased with radiotherapy and multisegment flaps. There was a non-significant trend towards increased complications with patient-specific plates in comparison to conventional reconstruction plates.

Clinical characteristics and immunohistochemical analysis of p53, Ki-67 and cyclin D1 in 80 odontogenic keratocysts.

OBJECTIVE: The aim of this study was to evaluate clinical parameters and expression patterns of Ki-67, cyclin D1 and p53 in odontogenic keratocysts. MATERIAL AND METHODS: In this study, fifty-three patients with 80 odontogenic keratocysts were included. The medical records of these patients were reviewed retrospectively. To elucidate the molecular pathogenesis of the disease, the expression of p53, Ki-67 and cyclin D1 was analyzed using immunohistochemistry. RESULTS: A total of 53 patients (mean age 38 years) with a median follow-up of 4.2 years (ranging from 4 days to 14.4 years) were evaluated. The rates of recurrence and post-operative complications varied depending on the surgical approach: cystectomy and peripheral ostectomy led to manageable low rates of complications and recurrence frequency. Immunohistochemical evaluation revealed that all lesions were positive for Ki-67 and cyclin D1 expression. The expression of Ki-67 was associated with the degree of inflammation. Cyclin D1 was expressed significantly higher in syndrome-associated keratocystic lesions. In contrast to non-syndromal lesions, all syndromal lesions expressed p53. CONCLUSION: This investigation demonstrates that the pathogenesis of syndromal keratocysts appears to differ from sporadic odontogenic keratocysts. Additionally, the primary and recurrent non-syndromal keratocysts have a similar etiology, as no differences in the expression patterns of Ki-67, p53 and cyclin D1 were observed.

Free flap surgery in Europe: an interdisciplinary survey.

Free flap surgery is essential for the aesthetic and functional reconstruction of various parts of the body. The aim of this study was to compare current concepts of perioperative flap management between ENT, craniomaxillofacial, and plastic surgeons. A European survey was conducted among 570 surgical departments, covering all aspects of free flap surgery. Focus was placed on antibiotic and antithrombotic drug use, aspects of osseous reconstruction, and flap monitoring strategies. One hundred and seventy-two medical units participated. A broad spectrum of anticoagulant regimens and a trend towards prolonged antibiotic prophylaxis were found. Fixation with (CAD/CAM) reconstruction plates was more popular than monocortical locking with miniplates in the mandible. Visual assessment and Doppler systems were reported to be the most common monitoring modalities. The flap loss rate was stated to be higher after osseous reconstruction. Only a few differences in perioperative flap management were identified between the different surgical fields, and osseous reconstruction appears to be the most challenging.

Functional Outcome of Completely Intracorporeal Robotic Ileal Ureteric Replacement.

OBJECTIVE: To assess perioperative, clinical, and functional outcomes following completely robotic ileal ureter. METHODS: We retrospectively reviewed 7 consecutive patients undergoing completely intracorporeal ileal ureteric replacement between November 2015 and May 2017. One patient had a solitary kidney. A 4-arm technique was used. In 5 patients, additional psoas hitch procedure was performed. Patients had retrograde filling and removal of the ileal stent and transurethral catheter at an average of 14 days postoperatively. Renal ultrasonography, serum analysis, and diuretic renography were performed at follow-up 3 months postoperatively. RESULTS: Mean operative time was 328 ± 66.3 minutes and median estimated blood loss was 100 mL (range 50-200); mean length of the ileal substitute was 20.4 cm (range 18-24). No case was converted to open surgery. In 1 patient, there was a prolonged insufficiency of the pyeloileal anastomosis, requiring prolonged stenting. Apart from that, there were no major complications and no open surgical or endoscopic reinterventions. On 3-month follow-up, all patients presented symptom-free, with no signs of obstruction on ultrasound and significantly improved glomerular filtration rate, creatinine levels, and differential renal function (P = .02, 0.03, and 0.046, respectively). Five patients had a diuretic halftime <10 minutes, 2 had a halftime between 10 and 20 minutes. CONCLUSION: Completely intracorporeal robotic ileal ureteric replacement results in full functional restoration of the upper tract in cases of long defects of the mid and upper ureter.

Performance of cone-beam computed tomography and multidetector computed tomography in diagnostic imaging of the midface: A comparative study on Phantom and cadaver head scans.

PURPOSE: To compare multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) regarding radiation, resolution, image noise, and image quality. METHODS: CBCT and 256-MDCT were compared based on three scan protocols: Standard-dose (≈24 mGy), reduced-dose (≈9 mGy), and low-dose (≈4 mGy). MDCT images were acquired in standard- and high-resolution mode (HR-MDCT) and reconstructed using filtered back projection (FBP) and iterative reconstruction (IR). Spatial resolution in linepairs (lp) and objective image noise (OIN) were assessed using dedicated phantoms. Image quality was assessed in scans of 25 cadaver heads using a Likert scale. RESULTS: OIN was markedly higher in FBP-MDCT when compared to CBCT. IR lowered the OIN to comparable values in standard-mode MDCT only. CBCT provided a resolution of 13 lp/cm at standard-dose and 11 lp/cm at reduced-dose vs. 11 lp/cm and 10 lp/cm in HR-MDCT. Resolution of 10 lp/cm was observed for both devices using low-dose settings. Quality scores of MDCT and CBCT did not differ at standard-dose (CBCT, 3.4; MDCT, 3.3-3.5; p > 0.05). Using reduced- and low-dose protocols, CBCT was superior (reduced-dose, 3.2 vs. 2.8; low dose, 3.0 vs. 2.3; p < 0.001). CONCLUSION: Using the low-dose protocol, the assessed CBCT provided better objective and subjective image quality and equality in resolution. Similar image quality, but better resolution using CBCT was observed at higher exposure settings. KEY POINTS: • The assessed CBCT device provided better image quality at lower doses. • Objective and subjective image quality were comparable using higher exposure settings. • CBCT showed superior spatial resolution in standard-dose and reduced-dose settings. • Modern noise-reducing tools are used in CBCT devices currently. • MDCT should be preferred for assessment of soft-tissue injuries and oncologic imaging.

Technical and surgical aspects of the sphenopalatine ganglion (SPG) microstimulator insertion procedure.

Cluster headache (CH) is a debilitating, severe form of headache. A novel non-systemic therapy has been developed that produces therapeutic electrical stimulation to the sphenopalatine ganglion (SPG). A transoral surgical technique for inserting the Pulsante SPG Microstimulator into the pterygopalatine fossa (PPF) is presented herein. Technical aspects include detailed descriptions of the preoperative planning using computed tomography or cone beam computed tomography scans for presurgical digital microstimulator insertion into the patient-specific anatomy and intraoperative verification of microstimulator placement. Surgical aspects include techniques to insert the microstimulator into the proper midface location atraumatically. During the Pathway CH-1 and Pathway R-1 studies, 99 CH patients received an SPG microstimulator. Ninety-six had a microstimulator placed within the PPF during their initial procedure. Perioperative surgical sequelae included sensory disturbances, pain, and swelling. Follow-up procedures included placement of a second microstimulator on the opposite side (n=2), adjustment of the microstimulator lead location (n=13), re-placement after initial unsuccessful placement (n=1), and removal (n=5). This SPG microstimulator insertion procedure has sequelae comparable to other oral cavity procedures including tooth extractions, sinus surgery, and dental implant placement. Twenty-five of 29 subjects (86%) completing a self-assessment questionnaire indicated that the surgical effects were tolerable and 90% would make the same decision again.

Local full-thickness skin graft of the donor arm--a novel technique for the reduction of donor site morbidity in radial forearm free flap.

A novel technique to reduce donor site morbidity after radial forearm free flap (RFFF) harvest, using a local full-thickness skin graft (FTSG), is described. Thirty consecutive patients undergoing RFFF for head and neck reconstruction were enrolled in a prospective study. Donor site defect closure was performed with spindle-shaped FTSGs excised from the wavelike skin incision made for the vascular pedicle. Both the removal site of the FTSG on the volar forearm and the covered RFFF donor site healed uneventfully in 29 cases, with no impairment of function related to the skin graft. No skin graft failure and no exposure, tenting, or adherence of the flexor tendons occurred. All patients expressed satisfaction with postoperative pain, the functional outcome, and cosmetic appearance. Primary donor site defect closure could be achieved in all cases with the use of a local FTSG. This graft can be gained at the access incision for the vascular pedicle, avoids expansion of the incision for a local flap technique, and does not prolong wound healing, and thus reduces both donor site and graft site morbidity of the RFFF. This technique leads to an inconspicuous aesthetic result with no apparent relevant functional deficits and avoids the need for a second donor site.

Practitioner experience with sonic osteotomy compared to bur and ultrasonic saw: a pilot in vitro study.

The aim of the present study was to compare subjective experiences using bur, ultrasonic, and sonic osteotomy systems. Ten novice (N) and 10 expert (E) practitioners performed osteotomies on bovine ribs with each system. They scored ease of handling and sense of accuracy on visual analogue scales. The duration of the osteotomy procedure and the amount of noise were recorded objectively. Learning experience was evaluated in a second run. The Mann-Whitney U-test, Wilcoxon signed rank tests, and Spearman's rank correlation coefficient were used for the statistical analyses. The sonic system was significantly slower, with the worst noise impact (92.9dB; standard deviation (SD) 7.1). However, both user groups improved significantly in the second run (N 7.9, E 7.6). There were no significant differences in handling. The sense of accuracy was evaluated to be significantly best for the sonic system (N 8.4, E 8.4), compared to the ultrasonic system (N 7.1, E 7.1; both P=0.043) and bur system (N 5.5, P=0.002; E 6.0, P=0.006). The practitioners had a promising experience with the application of the ultrasonic system and particularly with the sonic system.

Development and validation of the Burdens in Oral Surgery Questionnaire (BiOS-Q).

Patients' perspective is increasingly re-cognised as an important outcome measure in oral surgery. However, how patients perceive the surgical treatment cannot be assessed currently. This would be an important indicator for process-related quality of care. It was the aim to develop and to validate an instrument for the assessment of patient-based measures of process-related quality of care in oral surgery. The new Burdens in Oral Surgery Questionnaire (BiOS-Q) was developed in two steps in patients undergoing oral surgery. First, an item pool was created using semi-structured interviews in 90 patients. Second, a preliminary version was applied in 297 consecutively recruited patients to assess redundancy, completion rates, face validity, difficulty and distribution. Psychometric properties of the final version of the questionnaire were evaluated. The BiOS-Q consists of 16 items and showed satisfactory internal consistency (Cronbach's alpha = 0·84) and excellent test-retest reliability (ICC = 0·90). The questionnaire's mean score was significantly correlated with dentists' burdens (r = 0·44) and patients' overall satisfaction (r = 0·39) indicating sufficient validity. The BiOS-Q is a reliable and valid instrument for the assessment of patient-based process-related quality of care in oral surgery.

Clinical indication for intraoperative 3D imaging during open reduction of fractures of the mandibular angle.

PURPOSE: This retrospective study investigated 3-dimensional (3D) imaging with intraoperative Cone-Beam Computed Tomography (CBCT) in Mandibular Angle Fractures (MAF) treated by open reduction. The aim of this study was to demonstrate the image quality of intraoperative CBCT in this region and the benefit for the patients. METHODS: 83 patients with 86 MAF were included in this study. 8 patients were female and 75 male. Patient age ranged from 11 to 68 years (average age 26.8 years). All patients were examined with the mobile CBCT scanner ARCADIS Orbic 3D (Siemens Medical Solutions, Erlangen, Germany) directly after surgical treatment of the MAF. RESULTS: As a direct result of intraoperative CBCT four patients (5%) underwent intraoperative revision. The intraoperative acquisition of the data sets was uncomplicated and in all cases it was possible to effectively visualise and assess the MAF in 3D quality. CONCLUSION: The results showed that intraoperative CBCT is a reliable imaging technique for real-time intraoperative assessment of treated MAF. Use of the mobile 3D CBCT scanner is easy to integrate into routine practice and offers the advantage that immediate revision surgery can be performed.

A hematogenous spread brain abscess invading the right damaged temporomandibular joint.

We report a rare case of a brain abscess which drained spontaneously in a temporomandibular joint damaged by osteoarthritis. The female patient presented to our hospital with a severe headache and pain in the temporomandibular joint. She showed elevated inflammatory parameters with unknown cause. Magnetic resonance imaging of her whole body revealed a large temporal brain abscess extending into the glenoid fossa of the temporomandibular joint. The brain abscess was incised and drained by neurosurgeons in our hospital and in the same operation we resected the articular disc and the affected part of the right temporomandibular joint. Histological examination confirmed a chronic arthrosis in the resected bone of the temporomandibular joint and an inflammatory abscess in the resected brain tissue. The patient recovered well and the inflammation resolved as seen in postoperative investigations. Magnetic resonance imaging a month later confirmed local consolidation in the brain with no sign of residual inflammation.

The use of buccal fat pad (BFP) as a pedicled graft in cleft palate surgery.

The buccal fat pad (BFP) as pedicled graft was originally used in reconstructing medium sized intraoral defects. Promising results concerning the use of BFP in cleft palate surgery have been published recently. The aim of this article is to report on the use of BFP as a pedicled graft in cleft palate surgery and to discuss promising results for this reconstructive surgical concept. A retrospective evaluation of 24 patients who had BFP pedicled flaps used for the prevention and repair of Type III (Pittsburgh Fistula Classification) cleft palate fistulas, to obstruct the retromolar space of Ernst and in case of wide clefts, from 2005 to 2010, was conducted. In all cleft palate patients, the recipient area fully epithelialized within 4 weeks or less. No recurrence was seen and the donor site healed well without aesthetic or significant functional impairment. This series confirms the excellent and predictable healing of BFP intraorally and the minimal morbidity associated with the use of such grafts. The results of this study allow the authors to recommend that the BFP pedicled flap is considered as a reliable alternative procedure to expand the therapeutic options. The BFP graft provides an advantage in reconstructive cleft palate surgery.

Diagnostic and therapeutic aspects in the treatment of gunshot wounds of the viscerocranium.

Gunshot wounds of the viscerocranium are a rare occurrence during times of peace in Europe. The removal of projectiles is recommended; in some cases, however, this is controversial. The material properties of projectiles and destruction of anatomical landmarks make it difficult to determine their precise location. Therefore, navigation systems and cone-beam computed tomography (CT) provide the surgeon with continuous intraoperative orientation in real-time. The aim of this study was to report our experiences for image-guided removal of projectiles, the use of cone-beam computed tomography and the resulting intra- and postoperative complications. We investigated 50 patients with gunshot wounds of the facial skeleton retrospectively, 32 had image-guided surgical removal of projectiles in the oral and maxillofacial region, 18 had surgical removal of projectiles without navigation assistance and in 28 cases we used cone-beam CT in the case of dislocated projectiles and fractured bones. There was a significant correlation (p = 0.0136) between the navigated versus not navigated surgery and complication rate (8 vs. 32%, p = 0.0132) including major bleeding, soft tissue infections and nerve damage. Furthermore, we could reduce operating time while using a navigation system and cone-beam CT (p = 0.038). A high tendency between operating time and navigated surgery (p = 0.1103) was found. In conclusion, there is a significant correlation between reduced intra- and postoperative complications including wound infections, nerve damage and major bleeding and the appropriate use of a navigation system. In all these cases we were able to present reduced operating time. Cone-beam CT plays a key role as a useful diagnostic tool in detecting projectiles or metallic foreign bodies intraoperatively.

Long-term follow-up of blowout fractures of the orbital floor reconstructed with a polyglactin 910/PDS implant.

PURPOSE: Resorbable alloplastic materials are used in many surgical applications. This retrospective study evaluated the clinical outcome after reconstruction of traumatic orbital floor defects using a polyglactin 910/PDS implant (Ethisorb™). PATIENTS AND METHODS: Seventy patients with isolated blowout fractures of the orbital floor resulting in defect sizes of up to 2.5 cm(2) were included in this study. All patients were clinically examined 5 days after surgery at the time of suture removal (T1) and 18 months postoperatively (T2). Diplopia was graded as significant diplopia or diplopia in extreme gaze. RESULTS: At T1, diplopia was observed in 9% of the patients, swelling of the periorbital region in 6%, and enophthalmus in none of the patients. No persistent complications were observed at T2. CONCLUSION: Reconstructive surgery of the orbit is one of the most demanding challenges in maxillofacial surgery. For traumatic defects of the orbital floor, reconstruction using a polyglactin 910/PDS implant (Ethisorb(™)) seems to be a reliable method for the repair of small-to-moderate defects.