Electromyographic evaluation of a novel surgical preparation to enhance nerve-muscle specificity that follows mammalian peripheral nerve trunk transection

Previous studies indicated that axons from proximal stumps of transected peripheral nerves "prefer" to grow through Silastic tubes attached to their native (originally associated) rather than foreign (not originally associated) distal stumps. We determined whether or not this specificity is expressed at the level of the neuromuscular junction. Proximal stumps of transected rat sciatic nerves (peroneal and tibial branches) were attached to single inlet ends of 6-mm-long, Y-shape Silastic implants. One outlet was attached to the distal peroneal and the other to the distal tibial stump. Ten weeks later, innervation of the anterior tibialis and interosseous muscles (normally innervated predominantly by peroneal and tibial nerve fibers, respectively) was assessed by measuring compound muscle action potential amplitudes and latencies that follow supramaximal peroneal and tibial nerve stimulation. Results showed higher amplitudes in anterior tibialis muscle, induced by "native" peroneal (vs. tibial) stimulation in four of five animals, and higher amplitudes in interosseous muscles after "native" tibial (vs. peroneal) stimulation in all cases examined. Preparations in which bridges between proximal and distal nerve stumps were bridged with unbranched tubes showed random patterns of muscle innervation. The results suggest that if allowed to express "specificity" at the level of nerve trunk transection, regenerating mammalian peripheral axons can grow into, and form functional connection with, native (vs. foreign) muscle groups. This finding has possible clinical significance.     

ESWL: stone-free efficacy based upon stone size and location

Summary Extracorporeal shock wave lithotripsy was used for the treatment of 1060 patients or 1128 kidneys with solitary stones. There were 528 pelvic stones, 82 upper caliceal stones, 120 middle caliceal stones and 398 lower caliceal stones. These groups were divided into two subgroups of large (>15 mm) and small (15 mm) stones. A total of 1232 treatments were carried out (1.16/patient or 1.09/kidney) and 91% of the patients underwent a single treatment. Auxiliary procedures were required in 5% of the patients and the complication rate was 3%. Overall, 74% of the patients were stone-free after 3 months of follow-up. Of the 26% with residual stones, 18% had sand (2 mm fragments) or match-heads (4 mm), 6% had fragments (5 mm) and 2% had no fragmentation at all. A stone-free result occurred in approximately 87% with small pelvic and upper caliceal stones, whereas large stones in these locations became stone-free in approximately 70% of cases. Both large and small stones in the lower half of the kidney (mid and lower calices) become stone-free less frequently (to a statistically significant degree) than do similar stones located in the pelvis or upper calices.     

Long-Term Results of Surgical Intervention on the Temporomandibular Joint

Between 1973–1987, 40 patients (51 joints) underwent 71 surgical procedures on the temporomandibular joint (TMJ). Indications for surgery included painful TM dysfunction, not alleviated by conservative treatment of at least 12 months' duration, or complete anterior disk dislocation not responding to conservative treatment for three to six months. The incidence of surgical treatment in the period 1983–1987 was 4.1% in a group of 679 patients. The mean follow-up is 5.8 years (range 1–15 years).

At the follow-up examination (37/51) 72.5% of the treated joints appeared to have an excellent or good result; however, 14/51 joints had one or more reoperations (= 14/40 patients: 35%).

The first surgical procedure on the TMJ resulted in an excellent or good result in 29/51 (57%) joints: 6/14 (= 42.9%) high condylectomies; 5/8 (= 62.5%) high condylectomies with a plication procedure; 15/24 (= 62.5%) plication procedure only; 2/2 silastic implants. After one or more reoperations, these figures improved to 10/14 (71%) high condylectomies, 7/8 (87.5%) high condylectomies with a plication procedure, 17/24 (70.8%) plication procedures.

Radiographic changes, including flattening of the condyle, lack of condylar contour, erosion, sclerosis, subcondral cysts, and osteophytes were seen in all (16/16) patients in which a high condylectomy was performed. Out of 22 joints in which only a disk repositioning and plication procedure was performed, only 4/22 showed radiographic changes. The radiographic status was not correlated to the clinical picture at the time of the follow-up examination.     

Condylar changes after orthognathic surgery for class III dentofacial deformity: a systematic review

After orthognathic surgery for class II dentofacial deformity, remodelling of the mandibular condyle will take place. In a number of cases, this may evolve towards a phenomenon of condylar resorption. Yet, studies on the occurrence of this complication after the correction of a class III deformity are scarce. A systematic review of the literature was performed with the aim of identifying reports on condylar resorption or remodelling after orthognathic surgery for class III dentofacial deformity. A search of the international databases yielded 12 eligible studies. Eight studies reported some degree of postoperative condylar remodelling, while symptoms of condylar resorption were only described in a limited group of patients. Thus, the literature may show evidence of condylar remodelling after orthognathic treatment of class III patients, and anecdotal reports of condylar resorption exist. The small sample sizes, heterogeneity in methods and outcomes, and use of two-dimensional radiographs indicate the need for updated long-term research. In the future, the use of cone beam computed tomography data for volumetric and morphological condylar analysis in combination with three-dimensional cephalometry may provide the opportunity to further elucidate this phenomenon and better characterize its aetiology.     

CBCT-based predictability of attachment of the neurovascular bundle to the proximal segment of the mandible during sagittal split osteotomy

Injury to the inferior alveolar nerve (IAN) during surgery is an important complication of bilateral sagittal split osteotomy. With cone beam computed tomography, the course of the nerve and its relationship to the surrounding structures can be assessed in three dimensions. This study aims to determine whether tomography can predict attachment of the neurovascular bundle to the proximal segment of the mandible during sagittal split osteotomy (SSO). Bilateral linear measurements were taken on cross-sectional tomography images. During osteotomy, it was noted for each patient whether the neurovascular bundle was attached to the proximal segment during the split. If attached, a bone-cutting instrument or a blunt instrument was needed to free the nerve. The nerve was attached at more than one-third of operation sites (170 sites). Of these, over 65% of attached nerves (108 sites) required a bone-cutting intervention to free them from the mandible. After correcting for confounding factors, the linear distances from the buccal cortical margin of the IAN canal to the inner and outer buccal cortical margins of the mandible were important predictors of whether the IAN will be attached to the proximal segment of the mandible during SSO.     

Receptor binding and growth-promoting activity of insulin-like growth factor-I in a bovine mammary epithelial cell line (MAC-T3).

Insulin-like growth factor-I (IGF-I) has been known to be mitogenic to a variety of cell types, although a growth-regulatory role for IGF-I on bovine mammary epithelial cells has not been fully investigated. In the present study, we examined the receptor binding of IGF-I and its effect on growth in a bovine mammary epithelial cell line (MAC-T3). Specific receptors for IGF-I were detected on cultured bovine mammary epithelial cells. Competitive binding revealed that half-maximal inhibition of 125I-labelled IGF-I binding by IGF-I was approximately 3 micrograms/l. Dissociation rate constant of the IGF-I receptor was 3.10 +/- 0.06 nmol/l (S.E.M.) with a receptor site concentration of 366 +/- 8 fmol/mg protein for the average of three experiments. IGF-I exerted a positive mitogenic effect on MAC-T3 cells according to both direct DNA assay and thymidine incorporation assay. Moreover, the mitogenic effect of IGF-I on MAC-T3 cells was enhanced by the addition of fetal calf serum in the culture media. The present results suggest that the bovine mammary epithelial cell line (MAC-T3) provides a useful model system with which to study the biological actions of insulin-like growth factors on the bovine mammary secretory tissue in vitro.     

Magnetic resonance neurography of the head and neck: state of the art,anatomy, pathology and future perspectives

Magnetic resonance neurography allows for the selective visualization of peripheral nerves and is increasingly being investigated. Whereas in the past, the imaging of the extracranial cranial and occipital nerve branches was inadequate, more and more techniques are now available that do allow nerve imaging. This basic review provides an overview of the literature with current state of the art, anatomical landmarks and future perspectives. Furthermore, we illustrate the possibilities of the three-dimensional CRAnial Nerve Imaging (3D CRANI) MR-sequence by means of a few case studies.