Histomorphologic characteristics of bisphosphonate-related osteonecrosis of the jaw.

BACKGROUND: Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a known side effect of the therapy with bisphosphonates. No specific pathologic aspects or histological features are included in the most current definition. This study investigates characteristics of BRONJ with a special emphasis on histomorphologic aspects, evaluating the role of Actinomyces spp. as well as other disease-promoting factors in a formal pathogenetic context. METHODS: We investigated 23 patients (14 female, nine male; mean age: 66 ± 11.8 years) who received bisphosphonates with a gender- /age-matched control group. Tissue specimens were treated according to local standards and analyzed histologically. RESULTS: In 18 (78.3%) BRONJ cases, we found Actinomyces spp. colonies. Bone remodeling could be found in three specimens (13%). Eight specimens (34.8%) showed signs of epithelial proliferation. Analysis of dental treatment before the onset of BRONJ did not reveal significant differences (P > 0.20). In 10 patients (83%; P > 0.05) of the reported cases a relationship between dental treatment and the occurrence of a purulent bone necrosis could be observed. Statistically significant differences in thickness of trabeculae were detected between the two study groups (P = 0.04). CONCLUSIONS: This study demonstrates the important influence of the osteoblast-osteoclast balance in a histomorphologic analysis. Together with cofactors, which are able to trigger the onset of BRONJ, a new pathogenesis model was developed.

Reliability and validity of a modified lateral cephalometric analysis for evaluation of craniofacial morphology and growth in patients with clefts.

In previous intercenter studies on craniofacial morphology in patients with unilateral cleft lip and palate, probable surgical-induced changes in mandibular morphology and spatial position related to posterior vertical maxillary morphology were identified by our group. These changes could not be detected in other cephalometric cleft studies because posterior vertical maxillary height and vertical mandibular ramus length were not measured simultaneously. This study presents a modified digital lateral cephalometric hard and soft tissue analysis (Onyx Ceph software, version 2.5.6.; Image Instruments GmbH, Chemnitz, Germany) to evaluate craniofacial morphology and growth patterns in patients with clefts. Forty controls without clefts were used to evaluate the accuracy, reliability, and validity of this analysis for future cleft research. Measurement error according to the method of Bland and Altman was less than 1.00 degrees and 1.00 mm, whereas squared correlation coefficients (r) according to the method of Sackett et al showed a high reliability. Method comparison tests according to the method of Bland and Altman clearly showed that the modified digital cephalometric analysis ("test") was valid for future cleft research compared with the "gold standard" (conventional cephalometry).

Functional, electrophysiologic, and morphometric evaluation of nerve regeneration from coaptation on regenerated nerve fibers: experimental study in rabbits.

The importance of a sufficient number of nerve fibers at a proximal coaptation site is indisputable for the successful repair of nerves; however, the quality of nerve fibers required at this site has yet to be defined. The present study deals with the question of whether it is necessary to trim nerves back to unaffected neuronal tissue or whether the coaptation on recently regenerated nerve fibers, commonly believed to produce a poor quality of repair can, in fact, produce adequate nerve regeneration. Twenty New Zealand White rabbits received a standardized crush lesion on the peroneal nerves of both hind legs. Four weeks later, the nerves of the left hind legs (n = 20) were transected 10 mm distal to the previous crush lesion and coapted to the freshly regenerated nerve fibers. For comparison, on 10 right hind legs, the nerves were transected at the site of previous crushing (Group A, superimposition) or 10 mm proximal to the site of crushing on unscathed nerve fibers (Group B). Eleven weeks later, the quality of nerve regeneration was assessed by the toe-spreading reflex, electrophysiologic data, muscle weight, and histomorphologic evaluation. In the animals of Group A, the quality of nerve regeneration following coaptation on the regrown axons did not differ in any of the examined parameters from the quality of nerve fibers outgrown from the site of the superimposed lesion. Both lesions led to a completely functional reinnervation. Also in Group B, nerve action potential recording and histologic data on both sides did not reveal a significant difference between the number and maturation of nerve fibers equidistant from the suture site, shortly before muscle entrance. With this coaptation model, it could be demonstrated in the peroneal nerve of rabbits, that coaptation to recently regenerated nerve fibers leads to a significant functional regeneration.

Nasalance measures in German-speaking cleft patients.

The purpose of this study was to evaluate nasalance measures in German-speaking patients with different types of repaired cleft lip and palate and to find out if significant nasalance gender differences exist in the different cleft groups. A total of 125 German-speaking cleft patients (74 male and 51 female) were included in this study: 18 patients with isolated unilateral cleft lip (UCL; mean age: 13.00 +/- 2.03 years), 66 patients with complete unilateral cleft lip and palate (UCLP; mean age: 14.80 +/- 3.45 years), 25 patients with isolated cleft palate (CP; mean age: 14.60 +/- 3.48 years), and 16 patients with complete bilateral cleft lip and palate (BCLP; mean age: 14.30 +/- 3.61 years). Nasalance data were collected and computed using the NasalView hardware/software system (Fa. Tiger Electronics, Seattle, WA). Speech stimuli according to a modified Heidelberg Rhinophonia Assessment Form (sustained vowels "a," "e," "i," "o," and "u"; oral and nasal sentences; and three oral-nasal reading passages) were used to obtain nasalance scores. Nasalance distance and ratio were also calculated for the oral and nasal sentences and for one of the oral-nasal reading passages. Unpaired t tests showed no significant gender nasalance differences in each cleft group. Analysis of variance showed no significant differences in mean nasalance distance and ratio. For the nasal sentence, a significant difference (P = 0.032) in mean nasalance scores was found between the UCL and UCLP groups.