Effects of 4-Hexylresorcinol on Craniofacial Growth in Rats.

4-Hexylresorcinol (4HR) has been used as a food additive, however, it has been recently demonstrated as a Class I histone deacetylase inhibitor (HDACi). Unlike other HDACi, 4HR can be taken through foods. Unfortunately, some HDACi have an influence on craniofacial growth, therefore, the purpose of this study was to evaluate the effects of 4HR on craniofacial growth. Saos-2 cells (osteoblast-like cells) were used for the evaluation of HDACi and its associated activities after 4HR administration. For the evaluation of craniofacial growth, 12.8 mg/kg of 4HR was administered weekly to 4 week old rats (male: 10, female: 10) for 12 weeks. Ten rats were used for untreated control (males: 5, females: 5). Body weight was recorded every week. Serum and head samples were collected at 12 weeks after initial administration. Craniofacial growth was evaluated by micro-computerized tomography. Serum was used for ELISA (testosterone and estrogen) and immunoprecipitation high-performance liquid chromatography (IP-HPLC). The administration of 4HR (1-100 µM) showed significant HDACi activity (p < 0.05). Body weight was significantly different in male rats (p < 0.05), and mandibular size was significantly smaller in 4HR-treated male rats with reduced testosterone levels. However, the mandibular size was significantly higher in 4HR treated female rats with increased growth hormone levels. In conclusion, 4HR had HDACi activity in Saos-2 cells. The administration of 4HR on growing rats showed different responses in body weight and mandibular size between sexes.

Quercetin Decreased Alveolar Bone Loss and Apoptosis in Experimentally Induced Periodontitis Model in Wistar Rats.

BACKGROUND: Quercetin is a flavonoid which has potent anti-inflammatory, antibacterial, and antioxidant effect. Purpose of this study was to evaluate effects of quercetin on alveolar bone loss and histopathological changes in ligature-induced periodontitis in rats. METHODS: Wistar rats were divided into four experimental groups: non-ligated control (C, n=8) group; periodontitis (P, n=8) group; ligature and low dose quercetin group (75 mg/kg/day quercetin, Q75 group, n=8); ligature and high dose quercetin group (150 mg/kg/day quercetin, Q150 group, n=8). Silk ligatures were placed at gingival margin of lower first molars of mandibular right quadrant. Study duration was 15 days, and animals were sacrificed end of this period. Changes in alveolar bone levels were clinically measured and tissues were immunohistochemically examined, matrix metalloproteinase 8 (MMP 8), inducible nitric oxide synthase (iNOS), tissue inhibitor of metalloproteinase 1 (TIMP 1), Cysteine-aspartic proteases 3 (Caspase 3), and tartrate-resistant acid phosphatase (TRAP) positive osteoclast cells, osteoblast, and neutrophil counts were also determined. RESULTS AND DISCUSSION: Alveolar bone loss was highest in P group, and differences among P, Q75, and Q150 groups were significant. Both doses of quercetin decreased TRAP+ osteoclast cells and increased osteoblast cells. Inflammation in P group was also higher than those of C, Q75, and Q150 groups indicating anti-inflammatory effect of quercetin. iNOS, MMP-8, and caspase-3 levels were highest, and TIMP-1 expression was lowest in P group; differences were statistically significant. CONCLUSION: Within limits of this study, it can be suggested that quercetin administration may reduce alveolar bone loss by increasing osteoblastic activity, decreasing osteoclastic activity, apoptosis, and inflammation in an experimental model of periodontitis.

Efficacy of Recombinant Human BMP2 and PDGF-BB in Orofacial Bone Regeneration: A Systematic Review and Meta-analysis.

With the rapid development of tissue engineering therapies, there is a growing interest in the application of recombinant human growth factors (rhGFs) to regenerate human orofacial bones. However, despite reports of their ability to promote orofacial bone regeneration in animal experiments, their benefits in human clinical treatments remain unclear. Furthermore, the appropriate concentrations or indications of a specific rhGF remain ambiguous. Therefore it is essential to collect data from diverse clinical trials to evaluate their effects more precisely. Here we reviewed randomized clinical trials (RCT) that focused on the utilization of rhGFs in orofacial bone regeneration. Data from included studies were extracted, pooled and then quantitatively analyzed according to a pre-established protocol. Our results indicate that all current concentrations of rhBMP-2 produces insufficient effect on promoting either tooth extraction socket healing, sinus augmentation or reconstruction of alveolar clefts. However, 0.3 mg/ml rhPDGF-BB promotes the healing of tooth extraction sockets, though the effect does not reach a level of statistical significance. Summarily, we recommend concentrations of 0.3 mg/ml rhPDGF-BB only for the healing of tooth extraction sockets.

Giant Cell Lesions of the Maxillofacial Skeleton Express RANKL by RNA In Situ Hybridization Regardless of Histologic Pattern.

Maxillofacial central giant cell lesions (CGCLs) are often locally aggressive tumors in young patients that may be histologically very similar to or quite distinct when compared with giant cell tumors (GCTs) of long bones. It has been well established that GCTs express high levels of receptor activator of nuclear factor-kappa B ligand (RANKL) and are amenable to treatment with denosumab. To assess the predictive value of morphology, we evaluated CGCLs with GCT-like or non-GCT-like histology for RANKL expression by RNA in situ hybridization. Tumors were classified by clinical and radiographic criteria as aggressive or nonaggressive and histopathologically as resembling GCT or non-GCT-like. RNA in situ hybridization for RANKL mRNA was performed and scored semiquantitatively based on the magnification at which the signal was first detected. There were 17 patients (M:F=8:9) with a median age of 15 years. Nine patients were children under 18 years of age. In 10 patients, tumors were characterized as GCT-like and in 7, non-GCT-like; 6 occurred in the setting of a known associated syndrome. Of the sporadic tumors, 9/11 (82%) were classified as aggressive. Fifteen of 17 (88%) tumors strongly expressed RANKL (8/9 aggressive, 2/2 nonaggressive; 10/10 GCT-like and 5/7 non-GCT-like). Two patients with clinically aggressive CGCL, GCT-like histology and high tumor RANKL expression were identified as candidates for a trial of denosumab with notable clinical response. CGCLs demonstrate strong and diffuse RANKL mRNA expression in mononuclear stromal cells, regardless of histology or presence of an associated syndrome. Denosumab may be clinically beneficial in aggressive CGCLs.

Signals from the brain and olfactory epithelium control shaping of the mammalian nasal capsule cartilage.

Facial shape is the basis for facial recognition and categorization. Facial features reflect the underlying geometry of the skeletal structures. Here, we reveal that cartilaginous nasal capsule (corresponding to upper jaw and face) is shaped by signals generated by neural structures: brain and olfactory epithelium. Brain-derived Sonic Hedgehog (SHH) enables the induction of nasal septum and posterior nasal capsule, whereas the formation of a capsule roof is controlled by signals from the olfactory epithelium. Unexpectedly, the cartilage of the nasal capsule turned out to be important for shaping membranous facial bones during development. This suggests that conserved neurosensory structures could benefit from protection and have evolved signals inducing cranial cartilages encasing them. Experiments with mutant mice revealed that the genomic regulatory regions controlling production of SHH in the nervous system contribute to facial cartilage morphogenesis, which might be a mechanism responsible for the adaptive evolution of animal faces and snouts.

Maternal environment and craniofacial growth: geometric morphometric analysis of mandibular shape changes with in utero thyroxine overexposure in mice.

An estimated 3% of US pregnancies are affected by maternal thyroid dysfunction, with between one and three of every 1000 pregnancies being complicated by overactive maternal thyroid levels. Excess thyroid hormones are linked to neurological impairment and excessive craniofacial variation, affecting both endochondral and intramembranous bone. Using a geometric morphometric approach, this study evaluates the role of in utero thyroxine overexposure on the growth of offspring mandibles in a sample of 241 mice. Canonical variate analysis utilized 16 unilateral mandibular landmarks obtained from 3D micro-computed tomography to assess shape changes between unexposed controls (n = 63) and exposed mice (n = 178). By evaluating shape changes in the mandible among three age groups (15, 20 and 25 days postnatal) and different dosage levels (low, medium and high), this study found that excess maternal thyroxine alters offspring mandibular shape in both age- and dosage-dependent manners. Group differences in overall shape were significant (P < 0.001), and showed major changes in regions of the mandible associated with muscle attachment (coronoid process, gonial angle) and regions of growth largely governed by articulation with the cranial base (condyle) and occlusion (alveolus). These results compliment recent studies demonstrating that maternal thyroxine levels can alter the cranial base and cranial vault of offspring, contributing to a better understanding of both normal and abnormal mandibular development, as well as the medical implications of craniofacial growth and development.

Facial Bone Reconstruction Using both Marine or Non-Marine Bone Substitutes: Evaluation of Current Outcomes in a Systematic Literature Review.

The aim of the present investigation was to systematically analyse the literature on the facial bone reconstruction defect using marine collagen or not and to evaluate a predictable treatment for their clinical management. The revision has been performed by searched MEDLINE and EMBASE databases from 2007 to 2017. Clinical trials and animal in vitro studies that had reported the application of bone substitutes or not for bone reconstruction defect and using marine collagen or other bone substitute material were recorded following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The first selection involved 1201 citations. After screening and evaluation of suitability, 39 articles were added at the revision process. Numerous discrepancies among the papers about bone defects morphology, surgical protocols, and selection of biomaterials were found. All selected manuscripts considered the final clinical success after the facial bone reconstruction applying bone substitutes. However, the scientific evidence regarding the vantage of the appliance of a biomaterial versus autologous bone still remains debated. Marine collagen seems to favor the dimensional stability of the graft and it could be an excellent carrier for growth factors.

Do we need retarded delivery of bone growth factors in facial bone repair? An experimental study in rats.

The aim of the present study was to evaluate the effect of different dosages of retarded vs. rapid release of bone morphogenic protein 2 (BMP2) at different recipient sites. Porous composite poly(D,L-lactic acid) (PDLLA)/CaCO3 scaffolds were loaded with three different dosages of rhBMP2 (24 µg, 48 µg and 96 µg) and implanted, together with blank controls, both into non-healing defects of the mandibles and into the gluteal muscles of 24 adult male Wistar rats. After 26 weeks, bone formation and expression of bone specific markers [alkaline phosphatase (AP) and Runx2] were evaluated by histomorphometry and immunohistochemistry. Results showed that the mode of delivery had no quantitative effect on bone formation in mandibular sites. Expression of AP and Runx2 showed significant differences among the three dosage groups. There were significant correlations between the expression of both AP and Runx2 as well as the extent of bone formation, with both retarded and rapid release of rhBMP2. In ectopic sites, retarded release significantly enhanced bone formation in the low and medium dosage groups, compared to rapid release. Expression of AP was significantly higher and Runx2 significantly lower in ectopic sites, compared to mandibular sites. Significant correlations between the expression of bone specific markers and bone formation occurred only in the retarded delivery groups, but not in the rapid release groups. Within the limitations of the experimental model, it was concluded that retarded delivery of BMP2 was effective, preferably in sites with low or non-existing pristine osteogenic activity. Expression of bone specific markers indicated that osteogenic pathways might be different in mandibular vs. ectopic sites.

Expression of Dlx-5 and Msx-1 in Craniofacial Skeletons and Ilia of Rats Treated With Zoledronate.

PURPOSE: Because of the different embryologic origins of the craniofacial skeleton and ilium, differences in gene expression patterns have been observed between the jaw bones and ilium. Distal-less homeobox (Dlx) genes and Msh homeobox genes, particularly Dlx-5 and Msx-1, play major roles in cell differentiation and osteogenesis. The purpose of this study was to investigate the effects of zoledronate (ZOL) on the craniofacial skeleton and ilium by detecting changes in Dlx-5 and Msx-1 expression at both the protein and messenger RNA levels. MATERIALS AND METHODS: A total of 24 female Sprague-Dawley rats were randomly divided into 2 groups: ZOL group (n = 12), in which the rats were injected intraperitoneally with zoledronic acid for 12 weeks, and control group (n = 12), in which the rats were injected with saline solution for 12 weeks. By use of immunohistochemistry, Western blotting, and real-time reverse transcription polymerase chain reaction, the expression levels of Dlx-5 and Msx-1 in the craniofacial skeleton (including the maxilla, mandible, and parietal bone) and ilium were examined. RESULTS: Dlx-5 expression in the maxilla and mandible was increased at the protein and messenger RNA levels in the ZOL group compared with the control group (P < .01). In addition, Msx-1 expression in the maxilla and mandible was decreased in the ZOL group (P < .01). Furthermore, Dlx-5 and Msx-1 expression in the ilium was decreased in the ZOL group (P < .05). However, no significant difference in Dlx-5 or Msx-1 expression in the parietal bone was observed between the 2 groups (P > .05). CONCLUSIONS: Site-specific differences in the effects of ZOL on the craniofacial skeleton and ilium could be explained by differently altered tendencies in Dlx-5 and Msx-1 expression. The jaw bones were more susceptible to the effects of ZOL than the parietal bone and ilium.

[Toxic phosphorous osteonecrosis of facial bones among drug addicts to desomorphine and pervitin. Part II].

Article describes literature review of "atypical" osteomyelitis--osteonecrosis of facial bones among addicts to synthetic narcotics desomorphine and pervitin, different comorbidities, treatment strategy and prognosis were outlined

Dioxin disrupts cranial cartilage and dermal bone development in zebrafish larvae.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD or dioxin) disrupts craniofacial development in zebrafish larvae. However, the cellular changes responsible for the decreased jaw size remain poorly understood. We show that smaller jaw size is due to a decrease in both the size and number of chondrocytes in the developing craniofacial cartilages. TCDD was found to decrease ossification of osteoblasts in the perichondrium of craniofacial cartilages. We also discovered that TCDD caused clefting of the parasphenoid, an effect with similarity to TCDD-induced cleft palate in mice. Thus, dermal and perichondrial bone development of the craniofacial skeleton are clearly disrupted by TCDD exposure in the zebrafish larvae. This dysmorphic response of the zebrafish craniofacial skeleton after exposure to TCDD is consistent with findings demonstrating disruption of axial bone development in medaka and repression of sox9b in zebrafish.

Langerhans cell histiocytosis: differences and similarities in long-term outcome of paediatric and adult patients at a single institutional centre.

PURPOSE: This study determined the frequency of clinical features, reactivations, sequelae, mortality, and overall survival (OS) and compared paediatric with adult Langerhans cell histiocytosis (LCH) patients. MATERIALS AND METHODS: Ninety patients (60 paediatric and 30 adults) with LCH treated during 28 years were analysed retrospectively. RESULTS: Craniofacial lesion was the most frequent lesion at LCH presentation in children and adults. However, some differences were found. Orbital lesions were more frequent in paediatric than adult patients (P = 0.001). There was a tendency for mandible lesions to be more common in adults than the paediatric group (P = 0.0710). Mucocutaneous lesions were observed in a higher proportion in adults compared to paediatric patients (P = 0.0395). Reactivation episodes (36.8 versus 62.5%) and deaths (10.7 versus 24.0%) occurred in lower proportions in paediatric than adult patients, respectively. The probability of OS in 10 years for both groups was similar (P = 0.137). CONCLUSION: The OS was similar in both groups despite clinical differences between paediatric and adult patients, and higher reactivation and death rates in adults.

Denervation and beta2-adrenoceptor-agonist administration on craniofacial bone density.

OBJECTIVE: Beta2-agonist medications are thought to have adverse effects on bone density. Surgical denervation and intramuscular beta2-agonist injections appear to have opposing effects on skeletal muscles. The present study has been designed to assess the effects of denervation of the masseter, intramuscular injection of a beta2-agonist and the combination of both procedures, on bone density in the craniofacial skeleton in rats. MATERIALS AND METHODS: Sprague-Dawley rats were prepared as four groups: 1. surgical sham + saline injection into the masseter (sham); 2. surgical denervation of the masseter (den.); 3. surgical denervation of the masseter + intramuscular formoterol injection into the affected muscle (den.+form.); 4. intramuscular formoterol injection into the masseter (form.). All specimens were submitted for CT examination and volumetric calculations of the mineralised bone tissue were performed. RESULTS: The sham and form. groups had a greater volume of mineralised bone in the zygoma on the experimental side compared with the control side. The maxilla on the experimental side had a higher volume of mineralised bone in the den.+form. and form. groups compared with the sham and den. groups. The control side of the maxilla had a higher volume of mineralised bone in the den.+form. and form. groups compared with the den. group only. CONCLUSION: Intramuscular administration of formoterol appears to induce a bilateral increase in bone mineral density in the maxilla and the zygoma, likely explained as a secondary effect of the well-described increase in muscle mass and strength associated with beta2-agonist administration.

Is [F-18]-fluorodeoxy-D-glucose positron emission tomography of value in the management of patients with craniofacial bone sarcomas undergoing neo-adjuvant treatment?

BACKGROUND: We evaluated the role of 18FDG PET/CT used to assess response to preoperative chemotherapy in patients with primary craniofacial bone sarcomas. METHODS: Fourteen patients with craniofacial bone sarcomas (13 osteosarcoma, 1 spindle cell sarcoma) were retrospectively evaluated. All patients received up to 6 cycles of preoperative chemotherapy followed by resection of the primary tumour. Response to treatment was assessed using MRI (RECIST criteria) and 18FDG PET/CT (EORTC guidelines), performed at least at baseline, after 2-4 cycles and pre-operatively. RESULTS: The median baseline 18FDG PET/CT SUV was 10.2 (range 0-41); in 2 patients no uptake was detected. The preoperative 18FDG PET/CT, compared with the baseline, demonstrated a partial metabolic response in 7 patients (59%), complete metabolic response in 2 (16%) and stable metabolic disease in 3 (25%). In contrast, only two patients achieved a RECIST response on MRI: 10 (83%) had stable disease. One patient underwent early resection due to clinical progression after an initial response to treatment. This was confirmed by PET (SUV from 21 to 42) but not on MRI. Twelve of 14 patients (86%) had <90% histological necrosis in the resected tumour. At a median follow-up 23 months, 11 patients (79%) remain disease free, two had metastatic progression (14%) and 1 a local relapse (7%). The median DFS was 17 months. For those patients who achieved a response to preoperative 18FDG PET/CT the median DFS was 19 months (range: 1-66) compared with 3 months (range: 3-13) in those who did not (p = 0.01). In contrast, the median disease free survival (DFS) did not differ according to histological response (19 versus 17 months, >90% versus <90% necrosis, p = 0.45) or resection margins (19 months for R0 versus 18 months for R1, p = 0.2). CONCLUSION: 18FDG PET/CT is more reliable than standard imaging in evaluating response to neo-adjuvant chemotherapy in craniofacial bone sarcomas, changed management in one patient, and in this small series, correlated better with patient outcome than histological response and resection margins. These results warrant prospective validation in a larger cohort of patients.

[Restitution of bioactive ceramic material "Syntekost" by a newly evolved bone in experiment].

Peculiarities of reparative processes of bioactive ceramic material "Syntekost", as well as reaction of structures of internal ear on these material, transplanted on osteal bulla in guinea pigs for experimental model of antromastoidotomy creation, were studied up. The signs of its resorbtion were mild, and these processes not always paralleled the osteal tissue evolvement. A newly formed osteal beams were observed up to 90-th day. In terms up to 12 mo there were preserved practically unchanged groups of granules of ceramic implanted material. New bone have evolved in a kind of foci in a distance from internal surface of osteal bulla. Inflammation or ototoxic impact of the material on structures of internal ear were not observed.

Growth hormone therapy and craniofacial bones: a comprehensive review.

Growth hormone (GH) has significant effects on linear bone growth, bone mass and bone metabolism. The primary role of GH supplementation in children with GH deficiency, those born small for gestational age or with other types of disorders in somatic development is to increase linear growth. However, GH therapy seems to elicit varying responses in the craniofacial region. Whereas the effects of GH administration on somatic development are well documented, comparatively little is known of its effects on the craniofacial region. The purpose of this review was to search the literature and compile results from both animal and human studies related to the impact of GH on craniofacial growth.

The effects of C-type natriuretic peptide on craniofacial skeletogenesis.

C-type natriuretic peptide (CNP) is a potent stimulator of long bone and vertebral development via endochondral ossification. In the present study, we investigated the effects of CNP on craniofacial skeletogenesis, which consists of both endochondral and membranous ossification. Morphometric analyses of crania from CNP knockout and transgenic mice revealed that CNP stimulates longitudinal growth along the cranial length, but does not regulate cranial width. CNP markedly increased the length of spheno-occipital synchondrosis in fetal murine organ cultures, and the thickness of cultured murine chondrocytes from the spheno-occipital synchondrosis or nasal septum, resulting in the stimulation of longitudinal cranial growth. Mandibular growth includes endochondral and membranous ossification; although CNP stimulated endochondral bone growth of condylar cartilage in cultured fetal murine mandibles, differences in the lengths of the lower jaw between CNP knockout or transgenic mice and wild-type mice were smaller than those observed for the lengths of the upper jaw. These results indicate that CNP primarily stimulates endochondral ossification in the craniofacial region and is crucial for midfacial skeletogenesis.

Parathyroid hormone applications in the craniofacial skeleton.

Parathyroid hormone (PTH) is known for its ability to 'build' bone, with research in this area centered on its use as an osteoporosis therapeutic. Recent interest has developed regarding its potential for regenerative applications such as fracture healing and osseous defects of the oral cavity. Many years of investigation using murine gene-targeted models substantiate a role for signaling at the PTH/PTH-related protein (PTHrP) receptor (PPR) in intramembranous bone formation in the craniofacial region as well as in tooth development. Pre-clinical studies clearly support a positive role of intermittent PTH administration in craniofacial bones and in fracture healing and implant integration. A few human clinical studies have shown favorable responses with teriparatide (the biologically active fragment of PTH) administration. Favorable outcomes have emerged with teriparatide administration in patients with osteonecrosis of the jaw (ONJ). New delivery strategies are in development to optimize targeted application of PTH and to help maximize local approaches. The promising host-modulating potential of PTH requires more information to further its effectiveness for craniofacial regeneration and osseous wound-healing, including a better delineation of cellular targets, temporal effects of PTH action, and improved approaches for local/targeted delivery of PTH.

Ontogenetic changes of craniofacial complex in Turner syndrome patients treated with growth hormone.

OBJECTIVE: The present study assessed changes of craniofacial complex in Turner syndrome (TS) patients treated with growth hormone (GH) during development. The objective was to examine the growth rate and pattern of craniofacial structures and to establish effects of GH on craniofacial development. MATERIALS AND METHODS: The study population consisted of 15 TS patients treated with GH aged 5-18.5 years (13.3 ± 4.4) and corresponding control group of 45 females aged 6.8-18.7 (11.4 ± 2.6). According to the stage of cervical vertebral maturation, subjects were categorized into pre-growth (5 TS and 15 controls) and growth (10 TS and 30 controls) subgroups. The cephalometric analysis comprised angular and linear variables, measured on lateral cephalometric radiographs. RESULTS: The mandibular corpus/anterior cranial base ratio increased significantly only in controls during development. In growth period, ramus/corpus ratio was significantly larger in TS group. SNA and SNB angles were significantly smaller in TS growth subgroup compared to corresponding controls. Among other variables, no statistically significant differences were revealed. CONCLUSIONS: In TS patients treated with GH, growth capacities of cranial base and maxilla are adequate which can be attributed to GH treatment. Shape of mandible is altered due to decreased growth of corpus and overdeveloped ramus. Both maxillary and mandibular retrognathism are becoming more expressed during development. CLINICAL RELEVANCE: Favorable influence of GH on craniofacial complex growth rate and altered growth pattern revealed in this study should be considered while planning both orthodontic treatment and retention.