YAP promotes the early development of temporomandibular joint bony ankylosis by regulating mesenchymal stem cell function.

To explore the role of YAP, a key effector of the Hippo pathway, in temporomandibular joint (TMJ) ankylosis. The temporal and spatial expression of YAP was detected via immunohistochemistry and multiplex immunohistochemistry on postoperative Days 1, 4, 7, 9, 11, 14 and 28 in a sheep model. Isolated mesenchymal stem cells (MSCs) from samples of the Day 14. The relative mRNA expression of YAP was examined before and after the osteogenic induction of MSCs. A YAP-silenced MSC model was constructed, and the effect of YAP knockdown on MSC function was examined. YAP is expressed in the nucleus of the key sites that determine the ankylosis formation, indicating that YAP is activated in a physiological state. The expression of YAP increased gradually over time. Moreover, the number of cells coexpressing of RUNX2 and YAP-with the osteogenic active zone labelled by RUNX2-tended to increase after Day 9. After the osteogenic induction of MSCs, the expression of YAP increased. After silencing YAP, the osteogenic, proliferative and migratory abilities of the MSCs were inhibited. YAP is involved in the early development of TMJ bony ankylosis. Inhibition of YAP using shRNA might be a promising way to prevent or treat TMJ ankylosis.

Validation of the "obturator functioning scale" for Chinese-speaking patients with obturator prostheses after cancer-related maxillectomy.

Objective: The Obturator Functioning Scale (OFS) is a scale without formal measures of validity in any language. This study aimed to translate and adapt the OFS from English to Chinese and check its reliability and validity in Chinese-speaking patients with obturator prostheses after cancer-related maxillectomy. Methods: The 15-item Chinese preversion of the OFS was completed by 133 patients in three tertiary stomatological hospitals. Of these, 41 completed it again one week after the first measurement. The patients also completed the Chinese version of the University of Washington quality of life scale (UW-QOL, Version 4). Results: Item 12 ("upper lip feels numb") was deleted to achieve a better statistical fit. The 14-item Chinese version of the OFS (OFS-Ch) demonstrated high internal consistency (Cronbach's alpha = 0.908). The test-retest reliability coefficients for most items exceeded 0.90, indicating substantial reproducibility. Confirmatory factor analysis found that the scale consisted of three correlated factors: 1) eating (four items), 2) speech (five items), and 3) other problems (five items). This explained 70.2 % of the total variance using exploratory factor analysis. The scale was significantly convergent and discriminant and could validly discriminate between patients with Brown I and IId maxillary defects. Conclusions: Our results showed that the OFS-Ch scale is a valid tool for evaluating oral dysfunction and satisfaction with appearance for patients with the obturator prosthesis and identifying those at risk of poor obturator function in clinical settings.

HSP27 promotes vasculogenic mimicry formation in human salivary adenoid cystic carcinoma via the AKT-MMP-2/9 pathway.

PURPOSE: To explore the role and mechanism of heat shock protein 27 (HSP27) in SACC VM formation. STUDY DESIGN: Immunohistochemistry and double staining with cluster of differentiation 31 (CD31) and periodic acid-Schiff (PAS) were used to detect HSP27 expression and VM in 70 SACC tissue samples separately. Quantitative real-time polymerase chain reaction (qRT-PCR), western blot analysis, and immunofluorescence were used to detect gene and protein expression. HSP27 in SACC cells were overexpression or downregulated by transfecting HSP27 or short hairpin RNA target HSP27 (sh-HSP27). The migration and invasion abilities of SACC cells were detected using wound healing and Transwell invasion assays. The VM formation ability of the cells in vitro was detected using a Matrigel 3-dimensional culture. RESULTS: HSP27 expression was positively correlated with VM formation and affected the prognosis of patients. In vitro, HSP27 upregulation engendered VM formation and the invasion and migration of SACC cells. Mechanistically, HSP27 upregulation increased Akt phosphorylation and subsequently increased downstream matrix metalloproteinase 2 and 9 expressions. CONCLUSION: HSP27 may plays an important role in VM formation in SACC via the AKT-MMP-2/9 signalling pathway.

Oncologic safety of the pedicled submental island flap for reconstruction in oral tongue squamous cell carcinoma: An analysis of 101 cases.

OBJECTIVE: To evaluate whether the pedicle submental island flap (SIF) can be safely used in the oral tongue squamous cell carcinoma (OTSCC) patients with pathologically node-positive (pN+) neck, especially pN+ at level I. METHODS: Retrospectively, 101 OTSCC patients with SIF reconstruction were enrolled. Oncological outcomes included the total locoregional recurrence, the SIF related locoregional recurrence (SRLR) which referred to the local recurrence at flap and ipsilateral neck recurrence at level I, recurrence free survival (RFS), overall survival (OS), and disease specific survival (DSS). RESULTS: Sixty-one patients were pathologically node-negative (pN0) and 40 were pN+. Thirteen patients experienced locoregional recurrence, of which 5 had a SRLR. The pN+ group had a significantly higher locoregional recurrence rate, lower 5-year RFS, OS and DSS than pN0 group (P < 0.05). Patients with pN0 had a significantly higher neck RFS when compared to those with pN+ either at level I (P = 0.005) or at other levels (P < 0.001). However, the neck RFS was similar between the two subgroups of pN+ (P = 0.550). Especially, patients with pN+ at level I had a significantly higher SRLR rate (P = 0.006) compared to those with pN0 at level I. Multivariate analysis showed that pN+ was an unfavorable factor for tumor recurrence and OS. CONCLUSION: Our data did not support the use of SIF in OTSCC patients with pN+ neck at level I due to an significantly increased SRLR rate compared to those with pN0 neck at level I.

Advanced Polymeric Nanoagents for Oral Cancer Theranostics: A Mini Review.

Oral cancer is one of the most common tumours in the world threatening human life and health. The 5-years survival rate of patients with oral cancer has not been improved significantly for many years. The existing clinical diagnostic methods rarely achieve early diagnosis due to deficiencies such as lack of sensitivity. Most of the patients have progressed to the advanced stages when oral cancer is detected. Unfortunately, the traditional treatment methods are usually ineffective at this stage. Therefore, there is an urgent need for more effective and precise techniques for early diagnosis and effective treatment of oral cancer. In recent decades, nanomedicine has been a novel diagnostic and therapeutic platform for various diseases, especially cancer. The synthesis and application of various nanoagents have emerged at the right moment. Among them, polymer nanoagents have unique advantages, such as good stability, high biosafety and high drug loading, showing great potential in the early accurate diagnosis and treatment of tumours. In this review, we focus on the application of advanced polymeric nanoagents in both the diagnosis and treatment of oral cancer. Then, the future therapy strategies and trends for polymeric nanoagents applied to oral cancer are discussed, with the hope that more advanced nanomedical technology will be applied to oral cancer research and promote the development of stomatology.

Quality of life in patients with cancer-related Brown IIb maxillary defect: A comparison between conventional obturation rehabilitation and submental flap reconstruction.

OBJECTIVES: The purpose of this retrospective study was to compare the differences in quality of life (QOL) outcomes between the conventional obturator prostheses (COP) and the pedicled submental artery island flap (SAIF) in the reconstruction of Brown IIb maxillary defects. MATERIALS AND METHODS: The QOL of 116 eligible patients who had a lapse ≥ 12 months after the cancer-related maxilla ablation was evaluated by the University of Washington quality of life scale (UW-QOL), Performance Status Scale for Head and Neck (PSS-HN), and Obturator Functioning Scale (OFS). RESULTS: Patients in the SAIF group reported statistically and clinically significant higher overall QOL scores but lower chewing scores in the UW-QOL scale when compared with those in the COP group (P < 0.05). Clinically significantly higher scores were also observed in the recreation and anxiety domains in the UW-QOL scale for the SAIF group, but there was no statistical significances. The COP group reported more complaints about the nasal leakage when swallowing and the shape of the upper lip, and had a stronger willingness to avoid family or social events in the OFS (P < 0.05). CONCLUSIONS: For patients with Brown IIb defects, SAIF reconstruction can achieve reduced nasal leakage when swallowing, improved upper-lip contour, increased social activity, and superior overall QOL than COP. The inferior chewing function in the SAIF group indicated the need for dental rehabilitation with a conventional denture or osseointegrated implants.

Near-infrared aggregation-induced emission nanodots for early diagnosis of tongue squamous cell carcinoma and sentinel lymph node mapping.

Fluorescence imaging has been widely used in the biomedical field owing to its merits of high sensitivity, excellent accuracy, high biosafety, etc. However, despite the good performance of fluorescent materials in the diagnosis of subcutaneous tumors or some orthotopic tumors in mice, their potential clinical application for most orthotopic tumors in humans is still limited due to their weak tissue penetration ability and the high thickness of human tissues. Given that the human tongue can extend out of the mouth and is approximately 1 cm thick, the diagnosis of tongue squamous cell carcinoma (TSCC) by fluorescence has great potential for clinical applications. However, to the best of our knowledge, a few studies have been performed to detect tongue tumors using fluorescence imaging, and most of them are administered in a subcutaneous tumor-bearing mouse model and are based on fluorescent materials with aggregation-caused quenching effects. Herein, by developing DPA-TPE-DCM with intense near-infrared fluorescence emission in the aggregation state, aggregation-induced emission materials were used for the first time in the early diagnosis of orthotopic TSCC and sentinel lymph node (SLN) mapping in an immunocompetent mouse model of orthotopic TSCC with a high signal-to-background ratio of 10.2. Moreover, with the guidance of the fluorescence of DPA-TPE-DCM NPs, SLNs smaller than 2 mm in diameter were successfully excised. This study provides new insight and a method for the early diagnosis of TSCC in clinical practice and provides more possibilities to broaden the potential clinical applications of fluorescent materials.

Differences in the biological properties of mesenchymal stromal cells from traumatic temporomandibular joint fibrous and bony ankylosis: a comparative study.

The aim of this study was to compare the functional characteristics of mesenchymal stromal cells (MSCs) from a sheep model of traumatic temporomandibular joint (TMJ) fibrous and bony ankylosis. A sheep model of bilateral TMJ trauma-induced fibrous ankylosis on one side and bony ankylosis on the contralateral side was used. MSCs from fibrous ankylosed callus (FA-MSCs) or bony ankylosed callus (BA-MSCs) at weeks 1, 2, 4, and 8 after surgery were isolated and cultured. MSCs derived from the bone marrow of the mandibular condyle (BM-MSCs) were used as controls. The MSCs from the different sources were characterized morphologically, phenotypically, and functionally. Adherence and trilineage differentiation potential were presented in the ovine MSCs. These cell populations highly positively expressed MSC-associated specific markers, namely CD29, CD44, and CD166, but lacked CD31 and CD45 expressions. The BA-MSCs had higher clonogenic and proliferative potentials than the FA-MSCs. The BA-MSCs also showed higher osteogenic and chondrogenic potentials, but lower adipogenic capacity than the FA-MSCs. In addition, the BA-MSCs demonstrated higher chondrogenic, but lower osteogenic capacity than the BM-MSCs. Our study suggests that inhibition of the osteogenic and chondrogenic differentiations of MSCs might be a promising strategy for preventing bony ankylosis in the future.

Differential regulation of blood vessel formation between traumatic temporomandibular joint fibrous ankylosis and bony ankylosis in a sheep model.

OBJECTIVES: Clinical and experimental studies show that the etiology of traumatic temporomandibular joint (TMJ) fibrous ankylosis and bony ankylosis are associated with the severity of trauma. However, how the injury severity affects the tissue differentiation is not clear. We tested the hypothesis that angiogenesis affects the outcomes of TMJ trauma, and that enhanced neovascularization after severe TMJ trauma would promote the development of bony ankylosis. METHODS: Bilateral condylar sagittal fracture and discectomy were performed for each sheep, with the glenoid fossa receiving either severe trauma to induce bony ankylosis or minor trauma to induce fibrous ankylosis. At days 7, 14, 28, and 56 after surgery, total RNA was extracted from the ankylosed callus. Temporal gene expressions of several molecules functionally important for blood vessel formation were studied by real-time PCR. RESULTS: Histological examination revealed a prolonged hematoma phase and a lack of cartilage formation in fibrous ankylosis. mRNA expression levels of HIF-1α, VEGF, VEGFR2, SDF1, Ang1, Tie2, vWF, CYR61, FGF2, TIMP1, MMP2, and MMP9 were distinctly lower in fibrous ankylosis compared with bony ankylosis at several time points. CONCLUSIONS: Our study indicates that inhibition of angiogenesis after TMJ trauma might be a promising strategy for preventing bony ankylosis in the future.

A gene signature associated with prognosis and immune processes in head and neck squamous cell carcinoma.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) has a poor prognosis that has not significantly improved in the past several decades. A prognostic-related signature was needed. METHODS: The Cancer Genome Atlas and GSE41613 databases were downloaded as a training and validation set, respectively. We identified 12 genes that demonstrated progression and prognostic value, and then, a gene signature was constructed. RESULTS: This classification could reflect distinct characteristics, phenotypically and molecularly, among HNSCC tumors. It could stratify patients with significantly different survival rates (median survival: 2083 days vs 927 days; P = 3.85E-08) in the training cohort and validation cohort (P = 0.007) and was significantly involved in immune/inflammatory response and tumor progression processes. CONCLUSIONS: This bioinformatics-based signature suggested the presence of two distinct populations of patients with HNSCC with distinguishable phenotypic characteristics and clinical outcomes and might provide insight for new types of immune therapy.

Removal of the articular fibrous layers with discectomy leads to temporomandibular joint ankylosis.

OBJECTIVE: The aim of this study was to investigate whether direct damage of the articular fibrous layers without condylar fracture, combined with discectomy, was enough to induce temporomandibular joint (TMJ) ankylosis. STUDY DESIGN: Bilateral TMJ surgery was performed in 8 growing sheep. Disk removal (DR) was performed in the lateral two-thirds on the control side, and disk and articular fibrous layers removal (DFLR) was performed in the lateral two-thirds on the experimental side. Four animals were sacrificed for each side at 1 and 3 months postoperatively. RESULTS: Fibrous ankylosis was achieved on the DFLR side in 2 of 4 sheep and fibro-osseous ankylosis in the other 2 sheep at 1 month after surgery. Fibro-osseous ankylosis developed on the DFLR side in 4 sheep at 3 months postoperatively. On the DR side, pathologic characteristics of TMJ osteoarthritis could be seen; however, no evidence of ankylosis was observed. The scores of TMJ ankylosis for the DR side were significantly lower than those for the DFLR side at different time points (P < .05). CONCLUSIONS: This study demonstrated that removal of articular fibrous layers combined with discectomy can lead to traumatic TMJ ankylosis.

Bioinformatic Analysis Reveals an Immune/Inflammatory-Related Risk Signature for Oral Cavity Squamous Cell Carcinoma.

High-throughput gene expression profiling has recently emerged as a promising technique that provides insight into cancer subtype classification and improved prediction of prognoses. Immune/inflammatory-related mRNAs may potentially enrich genes to allow researchers to better illustrate cancer microenvironments. Oral cavity squamous cell carcinoma (OC-SCC) exhibits high morbidity and poor prognosis compared to that of other types of head and neck squamous cell carcinoma (HNSCC), and these differences may be partially due to differences within the tumor microenvironments. Based on this, we designed an immune-related signature to improve the prognostic prediction of OC-SCC. A cohort of 314 OC-SCC samples possessing whole genome expression data that were sourced from The Cancer Genome Atlas (TCGA) database was included for discovery. The GSE41613 database was used for validation. A risk score was established using immune/inflammatory signatures acquired from the training dataset. Principal components analysis, GO analysis, and gene set enrichment analysis were used to explore the bioinformatic implications. When grouped by the dichotomized risk score based on the signature, this classifier could successfully discriminate patients with distinct prognoses within the training and validation cohorts (P < 0.05 in both cohorts) and within different clinicopathological subgroups. Similar somatic mutation patterns were observed between high and low risk score groups, and different copy number variation patterns were also identified. Further bioinformatic analyses suggested that the lower risk score group was significantly correlated with immune/inflammatory-related biological processes, while the higher risk score group was highly associated with cell cycle-related processes. The analysis indicated that the risk score was a robust predictor of patient survival, and its functional annotation was well established. Therefore, this bioinformatic-based immune-related signature suggested that the microenvironment of OC-SCC could distinguish among patients with different underlying biological processes and clinical outcomes, and the use of this signature may shed light on future OC-SCC classification and therapeutic design.

Free radial forearm flap and anterolateral thigh flap for reconstruction of hemiglossectomy defects: A comparison of quality of life.

OBJECTIVES: The purpose of the retrospective study was to compare the differences of quality of life (QOL) outcomes 2 or more years postoperatively between the free radial forearm flap (FRFF) and anterolateral thigh flap (ALTF) in reconstruction of defects of a hemiglossectomy. METHODS: Ninety patients who had a lapse ≥2 years since the reconstructive flap surgery were evaluated by the University of Washington quality of life scale (UW-QOL), and Performance Status Scale for Head and Neck (PSS-HN). RESULTS: Patients in the FRFF group reported statistically and clinically significantly better scores in the recreation, swallowing, chewing and speech domains of the UW-QOL compared with those in the ALTF group (P < .05). Similarly, FRFF provided better results in the understandability of speech and normalcy of diet of the PSS-HN, than the ALTF (P < .05). CONCLUSIONS: FRFF had the advantage of oral functions, such as chewing, speech and swallowing, over the ALTF for reconstruction of defect of half of the tongue. These results may provide useful information for surgeons to select a suitable free flap for tongue reconstruction.

Preserving the Fibrous Layer of the Mandibular Condyle Reduces the Risk of Ankylosis in a Sheep Model of Intracapsular Condylar Fracture.

PURPOSE: The aim of this experimental study was to investigate the role of the fibrous layer of the condylar head in the formation of temporomandibular joint (TMJ) ankylosis in a sheep model of intracapsular condylar fracture. MATERIALS AND METHODS: Six growing Xiao-wei Han sheep were used in the study, and bilateral TMJ surgery was performed in each sheep. In the left TMJ, sagittal fracture of the condyle, removal of the fibrous layer of the condylar head, excision of two thirds of the disc, and removal of the fibrous zone of the glenoid fossa were performed. In the right TMJ, the same surgical management was performed, except that in each sheep, the fibrous layer of the condylar head was preserved. Three sheep were killed humanely at 1 month postoperatively, and the other 3 sheep were killed humanely at 3 months postoperatively. The TMJ complexes were examined by histologic evaluation. RESULTS: Fibrous ankylosis was observed on the left side in 3 sheep at 1 month postoperatively and in 2 of 3 sheep at 3 months postoperatively. Fibro-osseous ankylosis was achieved on the left side in 1 sheep at 3 months postoperatively. In the right TMJ, the main postoperative histologic findings included condylar fracture healing, topical rupture or exfoliation of the fibrous layer of the condyle, and fissure between the fibrous layer and the proliferative zone of the condyle. However, no evidence of ankylosis was observed. The TMJ ankylosis scores on the right side were significantly lower than those on the left side at different time points (P < .05). CONCLUSIONS: This study showed that the presence of the fibrous layer of the condylar head prevented the development of TMJ ankylosis in a sheep model of intracapsular condylar fracture.

Quality of life in long-term oral cancer survivors: an 8-year prospective study in China.

OBJECTIVES: The purpose of the prospective study was to evaluate the long-term changes in quality of life (QOL) in patients with oral cancer and to examine the potential factors that predicted QOL at 8 years after treatment. STUDY DESIGN: Seventy-one patients were evaluated by the University of Washington quality of life scale. QOL in 30 long-term survivors was assessed at diagnosis and at the 3-month, 1-year, and 8-year follow-up. RESULTS: QOL was found to be better among survivors compared with nonsurvivors at the 1-year follow-up. Levels of pain, mood, and anxiety showed clinically and statistically significant improvements between diagnosis and at 8 years following treatment, whereas problems with chewing, speech, shoulder mobility, and taste worsened during this interval (P < .05). From 1 to 8 years, patients reported clinically significant improvements with regard to appearance, recreation, speech, saliva, and anxiety. Among the 11 sociodemographic, disease-, or treatment-related factors, age and tumor site were associated with long-term QOL. CONCLUSIONS: Although the QOL among patients with oral cancer was generally favorable in the long term, the changed patterns in different domains over time should be noted. Improved QOL between the 1-year and the 8-year follow-up demonstrated the dynamics of QOL after 1 year and justified ongoing follow-up beyond the 1-year observation point.

Imaging and histologic features of traumatic temporomandibular joint ankylosis.

OBJECTIVE: We aimed to study the pathology underlying traumatic temporomandibular joint ankylosis (TMJA). STUDY DESIGN: Specimens from 10 patients with traumatic TMJA were categorized using the Sawhney classification and were decalcified and stained with hematoxylin-eosin, alcian blue/periodic acid-Schiff, alizarin red, and Masson stains. Immunostaining with anti-CD34 antibody was performed. Computed tomography and pathologic findings were compared. RESULTS: Ankylosed areas consisted of fibrocartilaginous tissues. Bone formation occurred by osteophyte extension from the osteochondral surface toward the mass center. Endochondral ossification and osteophyte proliferation, alone or simultaneously, participated in bony ankylosis. Sequestra in the cartilaginous ankylosis preferentially formed bony bridges. Newly formed capillaries participated in ossification from the bony surface of the bone-cartilage junction; bone formed around the capillaries. Osteoclasts were present at the capillary tips. CONCLUSIONS: Types II and III were cartilaginous-bony ankylosis, with similar components. Bony traumatic TMJA was formed by osteophyte proliferation and endochondral ossification.

A pilot trial on the molecular pathophysiology of traumatic temporomandibular joint bony ankylosis in a sheep model. Part I: Expression of Wnt signaling.

OBJECTIVE: To preliminarily investigate the temporal patterns of the endogenous mRNA expression for members of the Wnt signaling and a series of genes regulating bone formation during the development of traumatic temporomandibular joint (TMJ) bony ankylosis in a sheep model. METHODS: Six sheep were used for the induction of bony ankylosis of TMJ. We performed a condylar fracture, excision of the lateral 2/3 disc and serious injury to the glenoid fossa to induce bony ankylosis on the right TMJ. An isolated condylar fracture was performed on the left side. Two sheep were sacrificed at 1 month, 3 months, and 6 months after surgery, respectively. The specimens from the ankylosed joint and the condylar fracture were harvested for RNA extraction respectively. In this report (Part I), only the bony ankylosed samples were used for analysis of gene expressions. The specimens 1 month postoperatively were taken as the control, and the changes of expression of target genes over time were examined by real-time PCR. RESULTS: mRNA expression of Wnt1, Wnt2b, Wnt3a, ß-catenin, Sfrp1, Lrp6, Lef1, CyclinD1, and Runx2 was up-regulated at 3 and 6 months compared with 1 month. The expression of Wnt5a, Sox9, and Osterix was up-regulated with a peak at 3 months, and then fell back to the basal levels at 6 months. The expression of Ocn began to up-regulate until 6 month postoperatively. CONCLUSION: Our findings suggested that Wnt signaling was involved in the formation of traumatic TMJ bony ankylosis and thus may be a potential therapeutic target for the treatment of the disease in the future.

A pilot trial on the molecular pathophysiology of traumatic temporomandibular joint bony ankylosis in a sheep model. Part II: The differential gene expression among fibrous ankylosis, bony ankylosis and condylar fracture.

OBJECTIVE: The purpose of the study was to preliminarily explore the differential expressions of a series of genes regulating bone formation in temporomandibular joint (TMJ) fibrous ankylosis, bony ankylosis and condylar fracture healing. METHODS: The cDNA from either the bony ankylosed callus or fracture callus of the 6 sheep, as described in the part I, were both used in the study. The differences of gene expressions between bony ankylosis and condylar fracture at 1, 3, and 6 months postoperatively were measured by real-time PCR, with 2 samples at each time point. In addition, another 2 sheep were added to have fibrous ankylosis induced on the right TMJ, and 1 sheep was sacrificed at 3 and 6 months after surgery, respectively. The differences of gene expressions between fibrous and bony ankylosis at 3 and 6 months postoperatively were measured by real-time PCR. RESULTS: Bony ankylosis showed higher mRNA expression trends in Wnt2b, Wnt5a, ß-Catenin, Lef1, CyclinD1, Runx2, Osterix, Sox9, Col10a1, Alp, Ocn, Bmp2, and Bmp7 compared to fibrous ankylosis, although no statistical analysis was performed due to the very small sample size. Whereas bony ankylosis showed a significant lower expression of Wnt5a, ß-Catenin, Lef1, Runx2, Osterix, Sox9, Col10a1, Alp, Ocn and Bmp4 compared to condylar fracture at several time points (P < 0.05). CONCLUSION: Our data provided a preliminary molecular evidence for the hypothesis that the development of traumatic TMJ bony ankylosis was the course of delayed bone healing or hypertrophic nonunion, and deserved to be further studied.

Surgical induction of TMJ bony ankylosis in growing sheep and the role of injury severity of the glenoid fossa on the development of bony ankylosis.

OBJECTIVE: The purpose of this paper is to summarize our experiences in creating an animal model of TMJ bony ankylosis based on 2 sequential experiments. METHODS: Two sequential experiments were performed with the aim of creating a model of TMJ bony ankylosis. Seven growing sheep were used in the first experiment, in which 1 was served as a control animal. Condylar fracture with disc preservation was performed on the control side. On the contralateral side, condylar fracture, excision of the lateral 2/3 disc and injury to the glenoid fossa were performed to induce bony ankylosis. Three animals were sacrificed respectively at 3 and 6 months after surgery. In the second experiment, 7 growing sheep were used. The only difference of modeling between the 2 experiments was that more serious injury to the glenoid fossa was made in the ankylosis-induced side in experiment 2. Three, 2, and 2 animals were sacrificed respectively at 1, 3, and 6 months postoperatively. The TMJ complexes were examined by computed tomography (CT) and histological evaluation. RESULTS: In experiment 1, only fibrous ankylosis was observed in the ankylosis-induced side both at 3 and 6 months postoperatively. In experiment 2, CT and histological evaluation showed that the outcomes of the ankylosis-induced side were fibrous-bony ankylosis, fibrous-bony ankylosis, and bony ankylosis respectively at 1, 3, and 6 months after surgery. CONCLUSION: Through summarizing the differences of the modeling and the different outcomes in the 2 experiments, we concluded that severe damage to the glenoid fossa played an important role in the development of TMJ bony ankylosis.

Ankylosing spondylitis associated with bilateral ankylosis of the temporomandibular joint.

OBJECTIVE: The objective of this study was to analyze the clinical and laboratory features, treatments, and prognosis of ankylosing spondylitis (AS) associated with bilateral temporomandibular joint ankylosis (TMJA). METHODS: A PubMed search was conducted from 1966 to date, and the references of published studies were also checked to identify additional cases. Information from these reports and our report were compared and analyzed. RESULTS: Published literature in the past 36 years, which included 8 cases, were reviewed. The mean (SD) age at diagnosis of AS and bilateral TMJA was 21.00 (6.35) and 32.50 (13.43) years, respectively. Ankylosis of cervical vertebra was described in all patients. Total alloplastic joints and artificial condyle replacements were also reported in recent years. The slices of ankylotic mass showed the marrow was infiltrated by eosinophilic granulocytes. CONCLUSION: Evaluating temporomandibular joint (TMJ) function is strongly recommended in patients who have a long history of AS, particularly in cases involving cervical vertebrae disease.