Precision of Simultaneous Guided Dental Implantation in Microvascular Fibular Flap Reconstructions With and Without Additional Guiding Splints.

PURPOSE: Dental rehabilitation in patients receiving free flap reconstructive surgery on the mandible or maxilla is an important part of bringing patients back to normality in both a physical and psychological way. It is therefore important to be able to do this in the fastest way possible. Virtual preplanned reconstructions of jaws with implants placed simultaneously are a good way to expedite this process and have the advantage of allowing true backward planning to achieve bone placement where it prosthetically needs to be. Thus, the precise transfer of the virtually preplanned implant position to the intraoperative situation is crucial for prosthetic rehabilitation. PATIENTS AND METHODS: We compared a control group of patients (4 patients with 15 implants) with preplanned fibular reconstructions of the mandible with implants incorporated in the planning and a trial group of patients (4 patients with 13 implants) with an additional intraoperative splint for the verification of the implants' angulation. The preoperative planning and postoperative computed tomography scans were compared. RESULTS: The average positioning error at bone level was 0.9 mm in the trial group and 1.3 mm in the control group. The average angulation error in the buccolingual plane was 2.9° in the trial group and 5.5° in the control group; axially, the difference was 6.3° in the trial group and 4.1° in the control group. CONCLUSIONS: The use of digitally backward-planned fibula cutting guides with direct dental implant positioning is feasible, and the precision found is comparable with that of standard splint-guided implant placement in the general population. Although the axial angulation error has more to do with anatomic variance and positioning of the bony cutting guide, the trial population clearly profited from the additional splint in the important buccolingual angulation. Overall, we showed a high level of precision over all implants in both groups.

Denosumab as a Treatment Alternative for Central Giant Cell Granuloma: A Long-Term Retrospective Cohort Study.

PURPOSE: Giant cell granuloma (GCG) of the jaw is a rare disease with high morbidity. Various treatment options have been discussed in the past. Since 2010, a pharmaceutical therapy with denosumab seems to have been successful for giant cell tumors of the femur. The authors hypothesized the equally successful use of denosumab for GCGs of the jaws. MATERIALS AND METHODS: In the present retrospective cohort study, 5 patients with large GCGs of the jaws were treated with denosumab with a follow-up of 25 to 49 months. Frequent clinical follow-ups and a radiologic follow-up were performed and systematically analyzed. RESULTS: All patients showed a curative treatment response and complete metabolic resolution of the GCGs under treatment with denosumab. CONCLUSION: A brief review of the relevant literature and a detailed evaluation of current cases led to the conclusion that denosumab therapy should be considered a therapeutic option for large central GCGs of the jaws. The results of this study suggest denosumab is a successful treatment option. A treatment length no shorter than 12 months is recommended and monitoring of treatment response can be well managed by positron-emission tomographic computed tomography or magnetic resonance imaging.

Oral manifestation of Langerhans cell histiocytosis: a case report.

BACKGROUND: Bone necrosis of the jaw is a serious condition with a broad differential diagnosis of pathologies such as cutaneous histiocytosis, bone metastases or malignant tumours. In addition to the most common cause, medication related osteonecrosis of the jaw (MRONJ), one must consider a number of other causes, such as histiocytosis. Langerhans cell histiocytosis (LCH) is a histiocytic disorder with a large spectrum of clinical manifestations and with possible involvement of a variety of organs. This case shows the importance of an early detection of this rare disease in order to prevent further spreading. Even if an initial diagnosis in the oral cavity is rare, dentists should be aware of this disease. CASE PRESENTATION: The presented case describes a patient who was referred for evaluation and treatment due to exposed bone and extensive osteolysis in the region of the upper and lower jaw. After biopsy and diagnosis of LCH, the patient was treated with systemic therapy, achieved remission and is disease free after a 2 year of follow up. CONCLUSIONS: This case report illustrates that when dealing with unclear osteolytic changes of the jawbone, Langerhans cell histiocytosis must be taken into consideration in the differential diagnosis and biopsy must be performed in case of suspicion.

Are virtual planning and guided surgery for head and neck reconstruction economically viable?

PURPOSE: Virtual planning and guided surgery with or without prebent or milled plates are becoming more and more common for mandibular reconstruction with fibular free flaps (FFFs). Although this excellent surgical option is being used more widely, the question of the additional cost of planning and cutting-guide production has to be discussed. In capped payment systems such additional costs have to be offset by other savings if there are no special provisions for extra funding. Our study was designed to determine whether using virtual planning and guided surgery resulted in time saved during surgery and whether this time gain resulted in self-funding of such planning through the time saved. MATERIALS AND METHODS: All consecutive cases of FFF surgery were evaluated during a 2-year period. Institutional data were used to determine the price of 1 minute of operative time. The time for fibula molding, plate adaptation, and insetting was recorded. RESULTS: During the defined period, we performed 20 mandibular reconstructions using FFFs, 9 with virtual planning and guided surgery and 11 freehand cases. One minute of operative time was calculated to cost US $47.50. Multiplying this number by the time saved, we found that the additional cost of virtual planning was reduced from US $5,098 to US $1,231.50 with a prebent plate and from US $6,980 to US $3,113.50 for a milled plate. CONCLUSIONS: Even in capped health care systems, virtual planning and guided surgery including prebent or milled plates are financially viable.

Isolated bilateral zygomatic arch fracture: an unusual pattern.

Isolated fractures of the zygomatic arch represent 5% to 14% of all zygomatic complex fractures. Bilateral isolated zygomatic arch fractures, which are defined as fractures of both zygomatic arches without any other facial fracture, are extremely rare. In this case report, we present a rare case of this facial fracture pattern.

[Conduction anesthesia of the infraorbital nerve - A guide to intraoral nerve block anesthesia of the infraorbital nerv]. / Leitungsanästhesie des Nervus infraorbitalis.

In order to be able to perform major oral surgery in the upper jaw, sufficient local analgesia is indispensable. While the inferior alveolar nerve is often blocked for dental treatments in the lower jaw, block anesthesia in the upper jaw is less common. This article gives pragmatic advice on how to block the infraorbital nerve. By using this method patients comfort is significantly improved and the surgeon can focus on the treatment at hand.

Classification of potential risk factors for trigeminocardiac reflex in craniomaxillofacial surgery.

PURPOSE: Trigeminocardiac reflex (TCR) in craniomaxillofacial surgery can lead to severely life-threatening situations. At least mild forms are probably much more common than the existing surgical literature suggests. Therefore, the aim of this presentation of cases and literature review was to evaluate the predisposing factors leading to a classification of risk factors for potential TCR and to give information concerning preventive measures and management procedures. PATIENTS AND METHODS: All surgery reports from the Department of Cranio-Maxillofacial and Oral Surgery in the University Hospital in Zurich between 2003 and 2008 were searched for severe intraoperative cardiovascular complications, and a literature review was performed for publications concerning asystole or bradycardia during maxillofacial surgical procedures. RESULTS: Three incidents were revealed in which severe bradycardia--in 2 cases followed by asystole--had occurred. All incidents were successfully managed. CONCLUSION: All craniomaxillofacial surgeons involved in orbital surgery in general and in the treatment of midface fractures, eyelid surgery, and orthognathic procedures in particular should be aware of the possibility of the TCR and should be familiar with its prevention and therapy.

Intraoperative 3-dimensional cone beam computed tomographic imaging during reconstruction of the zygoma and orbit.

OBJECTIVE: Fractures of the zygoma and orbit are common facial skeleton injuries. Inadequate reduction and internal fixation may result in functional and aesthetic impairment. The aim of this study was to assess the use of intraoperative 3-dimensional (3-D) cone beam computed tomography (CBCT) for determining the intraoperative revision rate and the need for additional reconstruction of the orbit. STUDY DESIGN: We conducted a retrospective analysis of 48 consecutive patients (15 females, 33 males) suffering from simple or complex zygomatic fractures, seen between June 2015 and October 2016. Intraoperative 3-D CBCT (Xoran Technologies, Ann Arbor, MI) was performed, and the intraoperative image was overlaid on the preoperative image by using iPlan software (Brainlab, Feldkirchen, Germany) for quality control. Categorical variables were cross-tabulated and compared using Fisher's exact test. P values and 95% confidence intervals were assessed. RESULTS: In 6 of 48 patients, intraoperative revision was deemed necessary on the basis of the superimposition on the preoperative images. Five of these 6 patients had comminuted fractures (P = .001). In 7 patients, the indication for orbital reconstruction was revised after intraoperative 3-D CBCT. CONCLUSIONS: Intraoperative 3-D CBCT allows for immediate revision and prevents unnecessary orbital reconstruction.

Plasmon-resonant gold nanorods as low backscattering albedo contrast agents for optical coherence tomography.

Plasmon-resonant gold nanorods are demonstrated as low backscattering albedo contrast agents for optical coherence tomography (OCT). We define the backscattering albedo, a', as the ratio of the backscattering to extinction coefficient. Contrast agents which modify a' within the host tissue phantoms are detected with greater sensitivity by the differential OCT measurement of both a' and extinction. Optimum sensitivity is achieved by maximizing the difference between contrast agents and tissue, |a'(ca) - a'(tiss)|. Low backscattering albedo gold nanorods (14x 44 nm; lambda(max) = 780 nm) within a high backscattering albedo tissue phantom with an uncertainty in concentration of 20% (randomized 2+/-0.4% intralipid) were readily detected at 82 ppm (by weight) in a regime where extinction alone could not discriminate nanorods. The estimated threshold of detection was 30 ppm.

Scapular Free Vascularised Bone Flaps for Mandibular Reconstruction: Are Dental Implants Possible?

OBJECTIVES: Free fibula flap remains the flap of choice for reconstruction of mandibular defects. If free fibula flap is not possible, the subscapular system of flaps is a valid option. In this study, we evaluated the possibility of dental implant placement in patients receiving a scapular free flap for oromandibular reconstruction. MATERIAL AND METHODS: We retrospectively reviewed 10 patients undergoing mandible reconstruction with a subscapular system free-tissue (lateral border of the scapula) transfer at the University Hospital Zürich between January 1, 2010 and January 1, 2013. Bone density in cortical and cancellous bone was measured in Hounsfield units (HU). Changes of bone density, height and width were analysed using IBM SPSS Statistics 22. Comparisons of bone dimensions as well as bone density were performed using a chi-square test. RESULTS: Ten patients were included. Implantation was conducted in 50%. However, all patients could have received dental implants considering bone stock. Loss of bone height and width were significant (P < 0.001). There was a statistical significant increase in bone density in cortical (P < 0.001) and cancellous (P = 0.004) bone. CONCLUSIONS: Dental implants are possible after scapular free flap reconstruction of oromandibular defects. Bone height and width were reduced, while bone density increased with time.

Facial Pain Associated with CPAP Use: Intra-Sinusal Third Molar.

Objective. This paper describes a patient with left hemifacial pain elicited by the use of a CPAP mask. Case Report. A 74-year-old man was referred with a history of pain in the left maxillary sinus related to the use of his CPAP interface, thereby prohibiting the use of the latter. Computed tomography revealed an intra-sinusal ectopic third molar in the left maxillary sinus floor corresponding to the painful area. After removal of the ectopic tooth under local anesthesia by a Caldwell-Luc approach, the patient was relieved of his symptoms. Conclusion. Although an ectopic tooth in the maxillary sinus is rare, this case points out the importance of actively looking for a regional problem if patients cannot tolerate the CPAP interface since this can lead to issues of incompliance and medical complications due to the untreated obstructive sleep apnoea syndrome.

Unilateral facial swelling in an infant.

The melanotic neuroectodermal tumour of infancy (MNTI) is an uncommon, usually benign neoplasm which is most commonly found in the maxilla. We describe the case of a 6-month-old boy who was referred with a swiftly increasing swelling of the left cheek. After imaging and biopsy, MNTI was confirmed, and surgical resection was performed. Literature demonstrates that most MNTIs occur in the head and neck area and most of those occur in the maxilla. Although most cases are benign, 6.5% are malignant with metastatic disease. Treatment and outcome are discussed in detail. The case highlights the importance of making the diagnosis MNTI early on in order to achieve an optimal outcome.

Sulfide-Arrested Growth of Gold Nanorods.

The growth of gold nanorods can be arrested at intermediate stages by treatment with Na(2)S, providing greater control over their optical resonances. Nanorods prepared by the seeded reduction of AuCl(4) in aqueous cetyltrimethylammonium bromide solutions in the presence of AgNO(3) typically exhibit a gradual blueshift in longitudinal plasmon resonance, over a period of hours to days. This "optical drift" can be greatly reduced by adding millimolar concentrations of Na(2)S to quench nanorod growth, with an optimized sulfur:metal ratio of 4:1. The sulfide-treated nanorods also experience a marked redshift as a function of Na(2)S concentration to produce stable plasmon resonances well into the near-infrared. Sulfide treatment permitted a time-resolved analysis of nanorod growth by transmission electron microscopy, revealing two distinct periods: an initial growth burst (t < 15 min) that generates dumbbell-shaped nanorods with flared ends and a slower phase (t > 30 min) favoring growth around the midsection, leading to nanorods with the more familiar oblate geometry. The blueshift in plasmon resonance that accompanies the dumbbell-to-oblate shape transition correlates more strongly with changes in the length-to-midsection (L/D(1)) ratio rather than the length-to-end width (L/D(2)) ratio, based on the empirical relationship introduced by El-Sayed and co-workers.

In vitro and in vivo two-photon luminescence imaging of single gold nanorods.

Gold nanorods excited at 830 nm on a far-field laser-scanning microscope produced strong two-photon luminescence (TPL) intensities, with a cos(4) dependence on the incident polarization. The TPL excitation spectrum can be superimposed onto the longitudinal plasmon band, indicating a plasmon-enhanced two-photon absorption cross section. The TPL signal from a single nanorod is 58 times that of the two-photon fluorescence signal from a single rhodamine molecule. The application of gold nanorods as TPL imaging agents is demonstrated by in vivo imaging of single nanorods flowing in mouse ear blood vessels.