Jan Rustemeyer

Bisphosphonate-associated osteonecrosis of the jaw: what do we currently know? A survey of knowledge given in the recent literature

Increasing application of bisphosphonates for therapy of osteopathies has led to reports of the severe associated adverse effects of osteonecrosis of the jaw (ONJ). We reviewed recent literature to assess several aspects of bisphosphonate-associated ONJ, and to provide healthcare professionals with an overview of treatment and preventive options. Literature databases were searched using keywords. Information of 54 articles were discussed and completed by additional literature. High-risk factors were application of nitrogen-containing bisphosphonates, teeth extractions, and ill-fitting dentures. Treatment included non-surgical options and radical surgery. Success and failure were described for all treatment options; further studies investigating long-term recovery and recurrence are warranted. Paying attention to effective prevention of ONJ before, during, and after treatment is essential.

The accuracy of two-dimensional planning for routine orthognathic surgery.

Two-dimensional cephalometric planning software should be helpful for prediction of hard tissue outcome after bilateral sagittal split ramus osteotomy (BSSRO) or bimaxillary osteotomy, but transferring two-dimensional data to three-dimensions (including mock operation and surgery) may result in errors. The objective of this retrospective study was to analyze deviations between predicted results and postoperative outcome using cephalometric analyses, and to evaluate this procedure for daily use. Fifty-four subjects (mean (SD) age 26 (8) years) had a BSSRO (n=21) alone or in combination with Le Fort I osteotomy (n=33). Predictions were made for each case by cephalometric planning software and mock operations done with study models. Postoperative cephalograms were obtained after 14 days and compared with predicted cephalograms for sagittal (SNA, SNB, ANB,) and vertical (ArMeGo, ML-NSL, NL-NSL) measurements. Mean (SD) differences for all measurements varied between 1.3 degrees (1.1 degrees) and 2.2 degrees (1.6 degrees) for BSSRO; and between 1.1 degrees (1.3 degrees) and 2.2 degrees (1.6 degrees) for bimaxillary osteotomy. There were no significant differences between measurements or operations, indicating that the predictions were accurate. A difference of up to 8.5 degrees could be measured in a single case. Cephalometric prediction therefore remains an accurate tool for planning, particularly maxillary rearrangement in the vertical and sagittal dimension for routine operations. If greater shifts in the transversal dimension are necessary, exact planning should be adapted with three-dimensional planning devices to avoid significant differences.

Thermography and thermoregulation of the face

BackgroundAlthough clinical diagnosis of thermoregulation is gaining in importance there is no consistent evidence on the value of thermography of the facial region. In particular there are no reference values established with standardised methods.MethodsSkin temperatures were measured in the facial area at 32 fixed measuring sites in 26 health subjects (7–72 years) with the aid of a contact thermograph (Eidatherm). A total of 6 measurements were performed separately for the two sides of the face at intervals of equal lengths (4 hours) over a period of 24 hours. Thermoregulation was triggered by application of a cold stimulus in the region of the ipsilateral ear lobe.ResultsComparison of the sides revealed significant asymmetry of face temperature. The left side of the face showed a temperature that was on the average 0.1°C lower than on the right. No increase in temperature was found following application of the cold stimulus. However, a significant circadian rhythm with mean temperature differences of 0.7°C was observed.ConclusionThe results obtained should be seen as an initial basis for compiling an exact thermoprofile of the surface temperature of the facial region that takes into account the circadian rhythm, thus closing gaps in studies on physiological changes in the temperature of the skin of the face.

Administration of low-dose FK 506 accelerates histomorphometric regeneration and functional outcomes after allograft nerve repair in a rat model

A substantial loss of peripheral nerves requires grafts for repair. In animal experiments, the use of allografts is successful only when rejection of the transplant is prevented and nerve regeneration is improved by the administration of the immunosuppressant FK 506 used in high doses. In this study, we examined the functional and morphometric outcome after allograft transplantation of the sciatic nerve in rats at low doses of FK 506. Functional recovery and quantitative assessment of myelination were investigated in un-operated controls, in rats receiving isograft transplants without FK 506 treatment and in rats receiving allograft transplants with FK 506 treatment (0.1mg/kg and 0.2mg/kg per day). Walking-track analysis at 4, 8, 12 and 16 weeks post-operation revealed significant functional recovery in allograft with FK 506 (0.1mg/kg) compared with other groups, although levels of the un-operated controls were not reached. At 16 weeks, myelination of nerve sections from FK 506 (0.1mg/kg)-treated and un-operated animals did not differ significantly. There was significantly less effect of the 0.2mg/kg dose than of the 0.1mg/kg dose, both in the histomorphological outcome and in the functional outcome. These findings indicate that higher doses of FK 506 are not necessary for nerve regeneration, and low-dose administration could be acceptable for clinical settings in future.

Allografting Combined with Systemic FK506 Produces Greater Functional Recovery than Conduit Implantation in a Rat Model of Sciatic Nerve Injury

Implantation of allografts or nerve conduits has been used to promote regeneration following peripheral nerve injuries involving substantial axon loss. Both methods provide promising alternatives to autologous grafting and avoid donor site morbidity. We compared the relative efficacies of allografting versus conduit implantation in a rat model of sciatic nerve regeneration. Two rat strains (Lewis and Dark Agouti; n = 30) were employed. Unoperated animals served as controls (group I). Animals in groups II and III underwent left sciatic nerve resection over a distance of 15 mm; group II animals received implants of collagen type I conduits; and group III animals received allografts from the other rat strain and systemic low-dose (0.1 mg/kg/d) administration of FK506. Walking tracks were recorded after 4, 8, 12, and 16 weeks; nerve sections were stained for myelin basic protein after 16 weeks. Functional tests revealed significantly better recovery in group III animals compared with group II even though there was no significant difference in the extent of remyelination. Neither group achieved the functional or histomorphometric values of control animals. Improved functional recovery following allografting plus systemic FK506, in comparison with conduit implantation, underlines the importance of systemic administration of neurotrophic molecules for nerve regeneration.

Correlation of three sciatic functional indices with histomorphometric findings in a rat sciatic nerve allograft repair model.

Walking track analysis was used to measure global functional recovery following sciatic nerve injury. The correlation of morphologic outcome and different sciatic functional indices (SFIs) depends on different variables. The objective of this study was to compare three different SFIs and their correlation with histomorphometric findings in a sciatic nerve allograft repair model in the rat without (group I, n = 8) or with (group II, n = 8) daily intramuscular administration of 0.1 mg/kg FK 506. The correlation of SFIs with each other and with the myelin basic protein (MBP) density of nerve sections proximal, median, and distal to sciatic nerve grafts (1.5 cm) at 4, 8, 12, and 16 weeks postoperation (p.o.) was calculated, and unoperated animals served as controls (n = 8). Significant differences between SFIs calculated for experimental groups I and II at 12 and 16 weeks p.o. suggested that superior functional nerve recovery occurred in group II. However, there were significant differences between all SFIs at 16 weeks p.o. in group II, whereas only differences between SFI 1 and SFI 2 + 3 occurred in group I. SFIs of group II did not reach the values of the unoperated group. There were significant differences between the histomorphometric outcomes of groups I and II. There was no significant difference of MBP density between group II and the unoperated group, suggesting complete morphologic recovery. In conclusion, we found significant correlation between the MBP densities of groups I and II and all SFIs, suggesting a close relationship between histomorphometric and functional findings.

Histomorphological and functional impacts of postoperative motor training in rats after allograft sciatic nerve transplantation under low-dose FK 506.

This study aimed to determine the effect of motor training on recovery after nerve transplantation under low‐dose FK 506. Rats (n = 30) of two strains were randomly assigned to three groups. Group I served as untreated controls; groups II and III received allograft transplants for reconstruction of the sciatic nerve and FK 506 (0.1 mg/kg/d). Nonoperated limbs served as intra‐animal controls. Group III received postoperative motor training. Functional and histomorphological outcomes were assessed by walking track analysis and by blob analysis for myelinization of nerve sections. Regeneration occurred in both groups II and III. The control sections of the nonoperated limbs in group III showed significantly higher myelinization compared with group I and II; regeneration of the operated side was superior in group II. With regard to postoperative motor training, no benefit could be seen; however, the impact of postoperative motor training on the nonoperated limb were identified. Muscle Nerve, 2009

Prefabricated nerve conduits advance histomorphological and functional outcomes in nerve regeneration of the sciatic nerve of the rat.

Bridging a nerve defect is sometimes necessary to achieve nerve regeneration after injury. Different methods and conduit designs have been considered, but only isograft transplants or prefabricated conduits are available. This study presents a comparison of prefabricated conduits and isograft transplants in rats, with the aim of making suggestions for clinical settings. In rats of inbred strains LEW and DA, a 1.5cm defect of the sciatic nerve was reconstructed by isograft (n=10) or conduit (n=10). Untreated rats (n=10), sham-operated rats (n=10) and nerves of the non-operated contralateral limb served as controls. Regeneration was evaluated by histomorphological examination and with walking track analysis of the ankle stance angle (ASA) and the sciatic functional index (SFI). After 16 weeks, myelinization and ASA in the conduit group were significantly superior to that in the isograft group. There was no significant difference in SFI between the groups. Reconstruction in the isograft group showed a negative impact on the non-operated side. Conduits and isografts did not reach the morphological or functional levels of untreated or sham-operated animals. The results suggest preferential conduits should be used for nerve reconstruction.

A strategy to avoid facial mutilation in orbital embryonal rhabdomyosarcoma

IntroductionAn orbital embryonal rhabdomyosarcoma (RMS) is a rare malignancy in children, but clinical findings are typical. We detail the case of an 8-year-old female with orbital RMS and discuss the therapeutic options.Case reportOrbital RMS was apparent with painless exophthalmos of the right globe and diplopia. Head MRI showed tumor masses behind and inferior to the globe. Open biopsy led to the histological diagnosis. Metastasis or infiltration of orbital bone was not observed. Chemotherapy was carried out in accordance with the Cooperative Weichteilsarkom Studie (CWS) 2002 protocol. Tumor regression was detected after the first course of chemotherapy; we decided to excise the residual tumor with preservation of the globe. The CWS 2002 protocol was subsequently completed. Radiotherapy was not done. One year after treatment, RMS recurrence was not observed.ConclusionAfter interdisciplinary treatment, mutilation was avoided after exenteration of the orbit or radiation treatment to the growing facial skeleton. That was possible due to excision of the residual tumor in a second step, leading to down-staging of the RMS.

Total mandibular reconstruction following diffuse sclerosing osteomyelitis

BackgroundDiffuse sclerosing osteomyelitis (DSO) is a non-purulent chronic recurrent inflammation and affects the mandible in many cases. Belonging to the group of autoinflammatory diseases, in children and in cases with various additional symptoms including synovitis, acne, pustulosis, hyerostosis, and osteitis (SAPHO syndrome), therapy usually consists of non-surgical treatment. Against this background, we present an unusual course of DSO in an adult female patient.Case reportA 50-year-old female suffering from DSO without SAPHO syndrome was pretreated for years with conservative drug regimens and local surgery. Previous therapy was not successful, and subsequently, multiple surgical procedures were carried out focused on recurrent acute exacerbations of DSO. Surgery resulted in a total resection and alloplastic and autoplastic reconstruction of the mandible including both temporomandibular joints. Prosthetic rehabilitation was possible after dental implant loading, and the final outcome was very satisfactory.ConclusionIn the event that non-surgical options are not successful in DSO, an extended surgical therapy becomes necessary. Even if surgery results in complete resection of the mandible, a satisfactory rehabilitation can be achieved after complex reconstruction.