Clinical, Histological, and Scintigraphic Comparative Study of the Use of Mandibular Bone Marrow and Peripheral Blood in Bone Neoformation

Background and Purpose. To evaluate the capacity of mandibular bone marrow blood aspirate associated with biomaterials to stimulate bone tissue neoformation compared to the use of peripheral blood aspirate in patients with bone loss in the premaxillary region. Materials and Methods. The study included 16 patients with maxillary atresia. The region was grafted with xenograft blocks associated with the following treatments: G1, the patient’s peripheral blood during surgery, and G2, dripping of mandibular bone marrow blood until the xenograft was completely wet. After 7 and 14 days, scintigraphic images of the regions of interest (ROI) were taken to quantify pixels, which indicate osteogenic activity. Additionally, trephined samples obtained at the time of implant placement were stained in H&E, and newly formed bone tissue was quantified. The data were tabulated and statistically analyzed at a significance level of 5%. Results. Scintigraphic data showed greater osteogenic activity with mandibular bone marrow blood (G2) at all times evaluated p < 0.05 . As for the histomorphometric analysis, a greater amount of bone tissue was observed in samples treated with mandibular bone marrow blood (G2) compared to peripheral blood (G1) p < 0.05 . Conclusions. The appositional bone reconstruction technique in the block associated with mandibular bone marrow blood increased bone neoformation and osteogenic activity compared to conventional graft treatment with peripheral blood.

The chondrocranial key: Fetal and perinatal morphogenesis of the sphenoid bone in primates

The sphenoid bone articulates with multiple basicranial, facial, and calvarial bones, and in humans its synchondroses are known to contribute to elongation of the skull base and possibly to cranial base angulation. Its early development (embryological, early fetal) has frequently been studied in a comparative context. However, the perinatal events in morphogenesis of the sphenoid have been explored in very few primates. Using a cross-sectional age sample of non-human primates (n=39; 22 platyrrhines; 17 strepsirrhines), we used microcomputed tomographic (µCT) and histological methods to track age changes in the sphenoid bone. In the midline, the sphenoid expands its dimensions at three growth centers, including the sphenooccipital, intrasphenoidal (ISS) and presphenoseptal (PSept) synchondroses. Bilaterally, the alisphenoid is enlarged via appositional bone growth that radiates outward from cartilaginous parts of the alisphenoid during midfetal stages. The alisphenoid remains connected to the basitrabecular process of the basisphenoid via the alibasisphenoidal synchondrosis (ABS). Reactivity to proliferating cell-nuclear antigen is observed in all synchondroses, indicating active growth perinatally. Between mid-fetal and birth ages in Saguinus geoffroyi, all synchondroses decrease in the breadth of proliferating columns of chondrocytes. In most primates, the ABS is greatly diminished by birth, and is likely the earliest to fuse, although at least some cartilage may remain by at least one-month of age. Unlike humans, no non-human primate in our sample exhibits perinatal fusion of ISS. A dichotomy among primates is the orientation of the ABS, which is more rostrally directed in platyrrhines. Based on fetal Saguinus geoffroyi specimens, the ABS was initially oriented within a horizontal plane, and redirects inferiorly during late fetal and perinatal stages. These changes occur in tandem with forward orientation of the orbits in platyrrhines, combined with downward growth of the midface. Thus, we postulate that active growth centers direct the orientation of the midface and orbit before birth.

Bone Remodeling Under Screw-Fixed Chin Implants in Patients With Microgenia: A Cross-Sectional Study

The use of alloplastic chin implants has been associated with a risk of bone resorption. The aims of this study were to evaluate, in patients with microgenia, the association between chin implants and bone resorption and identify the associated risk factors for such resorption. The sample consisted of 51 patients with microgenia: 17 with chin implants (group A, placed over the course of a 15-year period [2002-2017]) and 34 without implants (group B). Cone-beam computed tomography was used to evaluate bone erosion in different areas of the chin. The patients were evaluated, and their medical records were reviewed to identify risk factors. A chi-square or Fisher exact test and the Mann-Whitney test were used to compare groups; resorption sites were compared with Friedman test. Linear regression models were used to evaluate associations between potential risk factors and resorption. Bone resorption was higher in group A than in group B (mean ± SD: 0.98 ± 0.63 mm vs 0.03 ± 0.12 mm; P < .0001). Symphyseal buccal cortical bone in group A was thinner (1.66 ± 0.34 mm) than it was in group B (2.07 ± 0.45 mm), P < .001. Group A showed appositional bone growth and no cortical bone perforation. The mean of the amount of bone resorption of chin implant patients compared with that of those without implants was, on average, 0.99 mm greater (95% confidence interval: 0.64-1.35; P < .001). Although statistically significant differences in bone resorption were observed between groups, these differences were not clinically significant. Thinning of symphyseal buccal cortical bone without perforation and appositional bone growth occurred in chin implant patients, suggesting bone remodeling. Our results suggest that bone that is in contact with chin implants remodels and remains stable throughout the years, instead of undergoing progressive resorption.

Thickness of the bone-cartilage unit in relation to osteoarthritis severity in the human hip joint

ObjectiveBone formation is a hallmark of osteoarthritis (OA). It has been speculated that bone formation may occur because of ossification at the bone-cartilage unit, that is, bone formation directly involving the calcified cartilage (CC). This study aimed to investigate the thickness of the CC and subchondral bone (SCB) in relation to the severity of the overlying articular cartilage (AC) degeneration.DesignWe investigated femoral heads from 20 patients with OA and 15 healthy subjects with design-based stereology using systematic uniform random sampling of the entire joint surface. This was combined with the Osteoarthritis Research Society International (OARSI) OA cartilage histopathology assessment system, thus obtaining focal OARSI grades paired with thickness measurements of AC, CC and the SCB.ResultsThe patients with OA had thicker CC (mean 159; 95% CI 144 to 177 µm) compared with the healthy subjects (mean 132; 95% CI 113 to 1550 µm; p=0.036), and this difference was even higher in areas without loss of AC thickness (OARSI grade ≤3); 187 (95% CI 164 to 214) µm vs 132 (95% CI 113 to 155) µm (p=0.001). In the patients with OA, a thicker SCB was observed in areas with loss of AC thickness (OARSI grade ≥4), but not in areas without loss of AC thickness (OARSI grade ≤3).ConclusionThe study showed that thicker CC is present in early stages of OA, suggesting that bone formation by endochondral ossification is an early phenomenon of OA. Thickening of the SCB was present, but only in areas with denuded bone. Suggesting that also appositional bone growth occurs and that it may be a consequence of changed biomechanics.

Lateralization Technique and Inferior Alveolar Nerve Transposition

Bone resorption of the posterior mandible can result in diminished bone edge and, therefore, the installation of implants in these regions becomes a challenge, especially in the presence of the mandibular canal and its contents, the inferior alveolar nerve. Several treatment alternatives are suggested: the use of short implants, guided bone regeneration, appositional bone grafting, distraction osteogenesis, inclined implants tangential to the mandibular canal, and the lateralization of the inferior alveolar nerve. The aim was to elucidate the success rate of implants in the lateralization technique and in inferior alveolar nerve transposition and to determine the most effective sensory test. We conclude that the success rate is linked to the possibility of installing implants with long bicortical anchor which favors primary stability and biomechanics.

Osteonecrosis of the Femoral Head with Collapsed Medial Lesion

A 60-year-old female experienced the gradual onset of left hip pain without any triggering event. Radiographs showed vertical sclerosis in the center of the femoral head and the lesion inside the boundary demonstrated diffuse bony sclerosis. No collapse was observed at the weight-bearing portion on radiograph. However, computed tomography showed a subchondral collapse at the medial lesion. On T2-weighted magnetic resonance imaging, the necrotic lesion showed diffuse high-intensity signals that indicated a prominent repair process. Bone biopsy diagnosed osteonecrosis with associated prominent appositional bone and vascular granulation tissue.