[Maxillofacial fractures: midface and internal orbit. Part 2: therapeutic options]. / Maxillofaziale Frakturen: Mittelgesicht und interne Orbita. Teil 2: Therapieoptionen.

While the state of the art of clinical assessment and imaging techniques were described in Part 1, this contribution presents a systematic review of the surgical treatment principles in the management of midface and internal orbit fractures from initial care to definitive treatment, including illustrative case examples. New developments and advances are characterized by limited versus extended surgical approaches, by standardization of osteosynthesis principles with regard to three-dimensional buttress reconstruction, by newly developed individualized implants such as titanium meshes and, especially for complex fracture patterns, by critical assessment of anatomical reconstruction through intraoperative endoscopy, as well as intraoperative and postoperative imaging. Newly developed resorbable soft tissue anchors can be used both for ligament and soft tissue resuspension in order to reduce ptosis effects in the cheeks and nasolabial area to achieve facial aesthetics similar to those prior to the injury.

[Maxillofacial fractures: midface and internal orbit : Part 1: classification and diagnosis]. / Maxillofaziale Frakturen: Mittelgesicht und interne Orbita : Teil 1: Klassifikation und Diagnostik.

Fractures of the midface and internal orbit occur isolated or in combination with other injuries. Frequently, the patients are first seen in emergency rooms responsible for the coordination of initial diagnostic procedures, followed by the transfer to specialties for further treatment. It is, therefore, important for all colleagues in traumatology to understand the basic principles of injuries to the midface. Thus, the aim of this article is the description of the anatomy and the current classification systems in use, the related clinical symptoms, and the essential diagnostic measures to obtain precise information about the injury pattern. Issues for treatment will be illustrated and discussed in "Part 2" of this article.

The influence of dexamethasone on postoperative swelling and neurosensory disturbances after orthognathic surgery: a randomized controlled clinical trial.

BACKGROUND: Orthognathic surgery is associated with considerable swelling and neurosensory disturbances. Serious swelling can lead to great physical and psychological strain. A randomized, prospective, controlled clinical trial was realized in order to evaluate the effect of a preoperative intravenous dexamethasone injection of 40 mg on postoperative swelling and neurosensory disturbances after orthognathic surgery. METHODS: Thirty-eight patients (27 male and 11 female) patients, all with the indication for an orthognathic surgery, were enrolled in this study (mean age: 27.63 years, range: 16-61 years) and randomly divided into two groups (study group/ control group). Both groups underwent either maxillary and/or mandibular osteotomies, resulting in three subgroups according to surgical technique (A: LeFort I osteotomy, B: bilateral sagittal split osteotomy (BSSO), C: bimaxillary osteotomy). The study group received a single preoperative intravenous injection of 40 mg dexamethasone. Facial edema was measured by 3D surface scans on the 1st, 2nd, 5th, 14th and 90th postoperative day. Furthermore, neurosensory disturbances on the 2nd, 5th, 14th and 90th postoperative day were investigated by thermal stimulation. RESULTS: Facial edema after LeFort I osteotomy, BSSO and bimaxillary osteotomy showed a significant decrease in the study group compared to the control group (P = 0.048, P = 0.045, P < 0.001). The influence of dexamethasone on neurosensory disturbances was not significant for the inferior alveolar nerve (P = 0.746) or the infraorbital nerve (P = 0.465). CONCLUSIONS: Patients undergoing orthognathic surgery should receive a preoperative injection of dexamethasone in order to control and reduce edema. However, there was no influence of dexamethasone on reduction of neurosensory disturbances. TRIAL REGISTRATION: DRKS00009033 .

Magnetic resonance imaging: a useful tool to distinguish between keratocystic odontogenic tumours and odontogenic cysts.

In contrast to odontogenic cysts, keratocystic odontogenic tumours often recur and require more aggressive surgical treatment, so we tried to find features that distinguished between them on magnetic resonance imaging (MRI). Without knowing the diagnosis, two radiologists reviewed intensity (low, intermediate, or high) and homogeneity (homogeneous or heterogeneous) of signals in short-tau-inversion-recovery (STIR), T1- and T2-weighted, and fat-suppressed, contrast-enhanced MRI in 20 consecutive patients with oval, radiolucent lesions of the mandible on panoramic radiography, and who were subsequently confirmed histopathologically to have either an odontogenic cyst or a keratocystic odontogenic tumour (n=10 in each group). Fisher's exact test was statistically significant at p<0.05. Delineation of a contrast-enhanced wall of a cyst with high signal intensity distinguished odontogenic cysts (9/10 and 8/10, respectively) from keratocystic odontogenic tumours (3/10, p=0.02, and 1/10, p=0.01, respectively). One radiologist found odontogenic cysts were more likely to be homogeneous on unenhanced T1-weighted images (odontogenic cysts 9/10, keratocystic odontogenic tumours 3/10, p=0.02) and one on contrast-enhanced MRI, when the cyst wall was enhanced (odontogenic cysts 7/9, keratocystic odontogenic tumours 0/3, p=0.01). There were no other significant distinguishing features on MRI. In conclusion, the signal intensity of the enhanced wall seems to be a feature on contrast-enhanced MRI that differentiates odontogenic cysts from keratocystic odontogenic tumours.

Photochemically induced experimental ischemic neuropathy: a clinical, electrophysiological and immunohistochemical study.

A new experimental model of focal peripheral nerve infarction is presented. Ischemia was produced in 12 rats by intravascular thrombosis induced by the photochemical reaction of systemically injected rose bengal to the local application of light from a cold light source. Clinical, electrophysiological and immunohistochemical techniques were used to monitor the pathology and the time course of experimental ischemic neuropathy (EIN) of the sciatic nerve. Primary axonal neurofilament disintegration was detectable 4-24 h after illumination and was followed by wallerian degeneration within the first week. At 7 days, there was a secondary disruption of myelin sheaths accompanied by massive infiltration of macrophages and phagocytosis of the necrotic debris. The majority of detected macrophages were derived from circulating blood monocytes which had invaded the nerve. Two weeks after the initial lesions, degeneration had advanced without any signs of regeneration or remyelination. Electrophysiological recordings corroborate the findings of primary axonal degeneration and failure of regeneration up to 2 weeks after the lesion.

The use of flash visual evoked potentials in the early diagnosis of suspected optic nerve lesions due to craniofacial trauma.

Craniofacial trauma encroaching on the orbital apex and optic canal can result in direct or indirect optic nerve lesions, leading to visual impairment or blindness. Early diagnosis of a visual loss and immediate therapy are generally considered crucial for a successful restoration of vision in indirect trauma. However, in comatose or sedated patients the assessment of optic nerve function by testing pupillary reactivity may be severely compromised or impossible because of tensely swollen eyelids, conjunctival oedema, concussion of the ciliary muscle or pharmacological effects. In the event that clinical ophthalmic examination, computer tomography or nuclear magnetic resonance scanning fail to clarify the state of the optic nerve, visual evoked potentials (VEPs) to flash stimulation appear to provide reliable information on function within the visual pathway. On this basis, treatment with corticosteroids and/or surgical decompression can be rapidly initiated. Our results in a preliminary patient series confirm the value of acutely monitored VEPs as an objective test of optic nerve function in cases of suspected optic nerve injury immediately after admission to the emergency care unit. The imaging techniques usually applied may be complemented by VEPs to show the functional significance of structural abnormalities found in the vicinity of the optic nerve.

Relevance of SCC-Ag, CEA, CA 19.9 and CA 125 for diagnosis and follow-up in oral cancer.

The prognosis of oral cavity carcinoma is limited by recurrent disease or lymph node metastasis. Secondary to surgery and radiotherapy, anatomical structures are often severely changed and make early diagnosis of renewed tumour growth by clinical and radiological examination difficult. We studied the course of serum SCC-Ag, CEA, CA 19.9 and CA 125 in 121 patients with untreated squamous cell carcinoma of the head and neck (SCCHN) before and after therapy and evaluated their relevance for diagnosis and follow-up in oral cancer. CA 19.9 and CA 125 seemed to be useless for this tumour entity. CEA resembled more the alcohol consumption and smoking habits of the patients examined than their state of disease. Only SCC-Ag correlated with the tumour burden and represented the disease course. In the event of relapse, half the patients had an exponential increase in SCC-Ag, 1-2 months prior to diagnosis.

Orbital reconstruction with individually copy-milled ceramic implants.

Diagnostic advances such as computed tomography and new surgical techniques have dramatically improved both the functional and aesthetic outcome of orbital reconstructions. Taking a further approach, we designed ceramic implants (Bioverit) on the basis of stereolithographic models. After copy milling a resin template with a commercially available dental unit (Celay), the prefabricated implants were inserted for reconstruction of the lamina papyracea (n = 1), zygomatic complex (n = 2), infraorbital floor (n = 5), and rim (n = 3). Intraoperatively, only slight modifications of the implants had to be performed. The results were encouraging, as all cases showed a good aesthetic and functional postoperative outcome. Preoperative evaluation of the osseous defect and prefabrication of the required implant reduced operating time and patient morbidity significantly.

Endoscopically assisted zygomatic fracture reduction and osteosynthesis revisited.

In comminuted fractures of the zygoma open reduction of the malar arch is essential for correct anatomic repair. Avoiding exposure of this landmark may result in severe functional and aesthetic impairment. Exposure of the malar arch necessitated traditionally a coronal incision. However, recently several authors reported good results in malar fracture repair with minimal incisions and endoscopic assistance. To establish this technique a cadaver study was performed. Different approaches to the malar arch, fracture reduction and internal fixation were evaluated. After establishment of a satisfactory technique 12 patients with comminution of the zygoma were treated with endoscopic assistance. Repositioning of the fragments was excellent in nine cases, minimal remaining dislocation was seen in two cases and in one case revision was necessary. Postoperatively the frontal branch of the facial nerve was intact in all patients. Scarring was minimal. In three patients plating of the malar arch on a side table resulted in arch necrosis and resorption in the long-term follow-up. Operating time was remarkably longer than in conventional procedures due to the difficult technique.

Wooden foreign bodies in facial injury: a radiological pitfall.

Foreign bodies can present a diagnostic challenge to the maxillofacial surgeon. Three patients, who suffered from a penetrating injury with a wooden foreign body, were examined and treated. Their preoperative CT and MRI scans were evaluated. In an acute case, the penetrating wooden body mimicked air bubbles. In the other two patients, the wood was retained for several months and appeared with a much higher density on CT. In MRI the wooden foreign bodies gave a low signal intensity. In all injuries removal of the foreign body was delayed, because it was initially radiologically missed or misdiagnosed. In the appropriate trauma setting a penetrating wooden body must always be considered. Its attenuation value increases with time as water is absorbed from the surrounding tissues. Although the radiological appearance may show a great variety, CT imaging is the basic diagnostic technique. MRI is the method of second choice.

The use of TMJ Concepts prostheses to reconstruct patients with major temporomandibular joint and mandibular defects.

Temporomandibular joint (TMJ) reconstruction may be required in complex cases in which there are additional mandibular or zygomatic arch defects. The reconstructive options include autogenous tissue, alloplastic material, or combinations of these. The authors describe 4 cases in which TMJ reconstruction was performed with TMJ Concepts customized joint prostheses. The prosthetic components were designed to restore major defects in the zygomatic arch and the mandibular ramus and body, including one case in which the mandibular component was used to restore total mandibular continuity. The prosthetic components used in these cases provided excellent anatomical reconstruction, and were a viable treatment option in cases in which the pathological process made autogenous grafts unsuitable. The prostheses have been functioning for up to 6 years. In one case a revision operation was required because the lack of a pterygomasseteric sling resulted in the condyle dropping out of the fossa. The authors' clinical experience with these cases suggests that a customized prosthesis combined with TMJ reconstruction can be a reliable treatment alternative for bridging complex, major maxillo-mandibular defects.

Reinnervation-induced alterations in rat skeletal muscle.

Denervation-induced myofiber atrophy can be reversed by reinnervation. Growing reinnervated myofibers upregulate numerous molecules, many of which determine the muscle fiber type. In the present study we aimed at identifying factors that might contribute specifically to myofiber growth after reinnervation. The common peroneal nerve of 15 male Wistar rats was cut and resutured without delay (9 animals) or with a delay of 4 weeks (6 animals). We studied the transcriptional repertoire of intact reinnervated tibialis anterior muscle by microarray gene analysis. We assessed SC activation by immunolabeling using anti-MyoD and -myogenin antibodies. The percentage of SC expressing MyoD reached up to 50% of M-cadherin+ cells whereas the percentage of SC expressing myogenin was normal (<10%) in all muscles examined. The values of ipsi- and contralateral muscles did not differ significantly from one another between right and left leg (p<0.05). Thirteen known genes were differentially regulated after reinnervation compared with contralateral muscles. Five of them determine the slow-twitch fiber type (four and a half LIM domains 3, cardiac beta-myosin heavy chain, calsequestrin 2, troponin C (slow), and heart myosin light chain), and three of them are neurally regulated (thrombospondin 4, transferrin receptor, cardiac ankyrin repeat protein). The results strengthen the notion that reinnervaton affects the molecular repertoire of the myofibers directly, leading to fiber type transformation and partial reversal of the denervation phenotype. By contrast, SC do not appear to be affected by reinnervation directly. They can be activated both in reinnervated and contralateral muscles, and they do not fully differentiate. This makes them unlikely to contribute to myofiber growth.

Critical time of exposure of the rabbit inferior alveolar nerve to Carnoy's solution.

To reduce the recurrence of keratocysts, tanning of the epithelial lining with modified Carnoy's solution has been advocated as an ancillary procedure. This agent has occasionally been reported to induce long-lasting local neurotoxicity, when the inferior alveolar nerve (IAN) was located within the bony cavity of larger cysts. As the severity of the neurologic damage depends on the tissue penetration of the solution, a critical exposure time must be assumed. To substantiate this hypothesis, rabbit IANs were decorticated over an approximate length of 1 cm and soaked with modified Carnoy's solution for periods from 30 seconds to 10 minutes. Sensory nerve function was monitored using somatosensory evoked potentials. Exposures up to 2 minutes did not result in any electrophysiologic abnormality. Exposure for 3 minutes led to either normal or rudimentary evoked potentials. After exposure of 5 minutes, and invariably after 10 minutes, the evoked potentials from the IAN were absent. Nerve segments were removed for histologic examination and the penetration depth of the Carnoy's solution was identified by staining with the Berlin-blue reaction. The involved areas were morphometrically evaluated and they reflected the electrophysiological findings. Transmission electron microscopy showed morphologic changes confined to the outer nerve sheaths (epineurium and perineurium) after exposure of 3 minutes. Exposure of 5 minutes and longer resulted in involvement of both the nerve sheaths and their axonal contents, with disruption and disintegration of the neural tissue. This study clearly supports the hypothesis that contact of a peripheral nerve (ie, IAN) with Carnoy's solution carries a time-related risk to produce acute sensory impairment.(ABSTRACT TRUNCATED AT 250 WORDS)

Neo-osseous flaps using demineralized allogeneic bone in a rat model.

Surgical reconstruction with revascularized bone grafts can be compromised by donor tissue limitations and may be refined by prefabrication of compound neoflaps using bone substitutes. The principal suitability of demineralized allogeneic bone (DALB) slabs in fabricating neo-osseous flaps based on the inferior epigastric vascular system was studied and compared with neoflaps with autologous bone (AUB). In 45 rats, the histological pattern of bone formation in response to angiogenesis induced by vessel implantation was assessed, and characteristics of vascularization of the neoflap were studied microangiographically at 2, 4, 6, and 8 weeks. Histological techniques included decalcified and nondecalcified sections, as well as intravital polyfluorochrome labeling. Blood flow of the neoflap was also assessed quantitatively using 15-microm microspheres labeled with technetium 99-methylene diphosphate (99-MDP) 8 weeks after flap fabrication. Although the DALB neoflaps showed consistent bone formation and neovascularization, the bone regeneration process was delayed distinctly in comparison with AUB. Microangiographically, however, no differences between the two types of grafts became apparent during all time periods tested. Furthermore, the radioactivity of the DALB neoflap, which means bone blood flow per dry weight, was significantly higher than in AUB grafts and even more than that of intact iliac bone (p = 0.001). The exact meaning of elevated blood flow in DALB and similar degrees of vascularization corresponding to native AUB grafts remains to be determined, but may be a sign of ongoing bone formation resulting in a suitable DALB-containing neo-osseous flap in the long term. The authors findings support that allogeneic bone could be a potential substitute for AUB in creating a prefabricated neo-osseous flap.

[Microneural reconstruction after iatrogenic lesions of the lingual nerve and the inferior alveolar nerve. Critical evaluation]. / Mikroneurale Wiederherstellung nach iatrogenen Läsionen des N. lingualis und des N. alveolaris inferior. Kritische Bestandsaufnahme.

As microneural repair techniques of the sensory mandibular branches enter the third decade of their clinical use, there are but a few long-term investigations into the value of these procedures in the treatment of iatrogenic injury to the lingual (LN), inferior alveolar (IAN) or mental (MN) nerve. To establish the efficacy of microneural repair in lesions of the LN, IAN or MN with loss of continuity, the outcome of sensory recovery was evaluated in a series of 92 patients (LN: direct coaptation n = 39, coaptation + sural nerve grafting n = 23; IAN: direct coaptation n = 11 coaptation + sural nerve grafting n = 10; MN: direct coaptation n = 11). The minimum duration of follow-up was 14 months postoperatively. The persistent sensory deficit was assessed using standardized neurosensory testing and gustometric stimuli. In addition the patients answered a multiple-choice questionnaire containing a list of complaints. To obtain a numeric estimate for interindividual and intergroup comparison the information from clinical measurements and patient reports was condensed into a 'neurological score' and a 'complaint score', respectively. Furthermore, adequate items from both scores were combined to affirm or deny the return of sensory function in terms of protective and discriminative sensation. The overall results show a broad range of variation in the scores, sometimes reflecting severe degrees of persistent sensory impairment. The lowest scores, corresponding to the best regeneration, were found after direct coaptation of the LN, IAN and NM, but even the best results did not provide sensory recovery to a preinjury level. After direct coaptation of LN 69% of the patients exhibited protective sensation and 41% regained discriminative function. In contrast, LN grafting was ensued from restoration of protective function in 39% and discriminative function in 17% of the patients. More striking differences were found between coaptation and grafting of the IAN (IAN coaptation: 91% protective function; 18% discriminative function; IAN grafting: 60% protective function, 0% discriminative function). In the LN coaptation group low scores and improved taste perception were convincingly associated with short periods since injury (i.e. timing of repair). In conclusion, we feel there is sufficient justification to optimize the potential results of microneural repair by immediate (LN/MN) or early (IAN) reexposure of the injured site in order to clarify the precise nature of the underlying nerve damage and prevent delay, if patients present with complete loss of sensory function subsequent to dentoalveolar or oral surgery. However, clinical and electrophysiologic findings suggesting impairment or partial loss of sensory function are considered a contraindication to microneural intervention, in view of the limited prospects of sensory recovery after surgical repair.

[Endosseous implants after tumor resection of the face]. / Enossale Implantate nach Tumorresektion im Gesichtsbereich.

Endosteal implants after tumor surgery of the face are helpful in reconstructing facial defects. A retrospective study of our patients treated using craniofacial implants was conducted to evaluate long-term results. A total of 128 implants were inserted, 110 implants in the periorbital, 12 implants in the mastoid, and six implants in the paranasal region; 113 implants were short craniofacial Brånemark implants, and 15 implants were dental implants. The success rate for implant survival was 94.5%. Long-term results were promising and more than satisfactory, leading to a large indication for these endosteal implants.

[New applications in maxillofacial surgery: Local injections with botulinum toxin type A]. / Neuerungen in der MKG-Chirurgie: Lokale Injektionsbehandlung mit Botulinumtoxin A.

Intramuscular injections of botulinum neurotoxin type A cause reversible chemodenervation and subsequent paralysis by blocking the presynaptic release of acetylcholine. Botulinum toxin type A has emerged as the most effective form of symptomatic treatment for abnormabilities in muscle movement (blepharospasm, hemifacial spasm, torticollis) and has been approved for use in these conditions. First results in the treatment of patients suffering from oromandibular dystonia, myogenic craniomandibular dysfunction and recurrent dislocation of the temporomandibular joint are presented. In most cases, therapeutic effects occurred within 1-6 days post-injection. Muscular hyperfunction was reliably reduced and involuntary activity patterns gradually ceased. No severe side effects of the local injections were noted.

[The influence of early fronto-orbital advancement on the growth of the frontal sinus and supraorbital region]. / Einfluß von frühem frontoorbitalem Advancement auf das Wachstum von Stirnhöhle und Supraorbitalregion.

In 12 patients with craniosynostosis the influence of early fronto-orbital advancement on the growth of the frontal sinus and supraorbital region was examined. A follow-up examination at the age of 8 years showed a lack of pneumatisation of about 50%. However, there was no correlation between this score and the external contour. The frontal sinus has no dominant influence on the growth of the supraorbital region. In 9 out 12 of cases the very early operation time did not lead to disturbances of growth. A further follow-up examination of the patients after termination of growth at the age of 16 is planned.

[Craniofacial techniques in traumatology]. / Kraniofaziale Techniken in der Traumatologie.

The coronal incision is a versatile approach to midface or skull base fractures. It allows the open reduction of complex fracture sites and facilitates canthopexy, marginotomy or calvarian bone harvesting. By this method, primary treatment can be optimised and the rate of secondary corrective surgery can be reduced. All trauma patients who underwent this kind of intervention were re-examined to check functional and aesthetic results. The complication rate was low and the advantages of these techniques are evident, so that it is suggested that the indication for this operative approach should be extended.