Objective:To explore the function of the bridging epithelium between maxillary process and nasal process in the devel-opment of lip and palate.Methods:The fertilized white leghorn chick eggs incubated to the appropriate Hamburger and Hamilton(H-H)stages were examined by tissue histologic studies,scanning electron microscopy observation,BrdU assay and TUNEL assay re-spectively.Results:At H-H stage 24,the epithelia between maxillary,lateral nasal and globular process were juxtaposed.At H-H stage 26-27,string-like filopodia appeared and the bridging epithelium formed,then in the bridging epithelium cell proliferation was decreased and the apoptotic cells appeared.At H-H stage 28,the apoptosis of the bridging epithelium cells increased,the full fusion of the processes was completed.Conclusion:The occurrence of bridging epithelium between maxillary process and nasal process plays an important role in the development of lip and palate.

BACKGROUND: The aim of this study was to present three-dimensional (3D) structural characteristics of the mandible in the hemifacial microsomia. The mandible has six distinct functional units, and its architecture is the sum of balanced growth of each functional unit and surrounding matrix. METHODS: In order to characterize the mandibular 3D architecture of hemifacial microsomia, we analyzed the mandibular functional units of four hemifacial microsomia patients using the 3D reconstructed computed tomography (CT) images. And we compared the functional unit size between affected and non-affected side. RESULTS: The length of condyle and angle showed significant differences between affected and non-affected sides. However, the length of mandibular body showed insignificant differences. The size differences between affected and non-affected side were observed at the condyle, angle, and body in descending order. CONCLUSIONS: This preliminary study suggests that the main etiopathogenic units are condyle and angle in the hemifacial microsomia mandible. Further investigation with the increased number of subjects will be helpful to establish treatment modality by etiopathogenic targeting of hemifacial microsomia.
Goldenhar Syndrome* ; Humans ; Mandible

Although the head and neck region is recognized as the most common location for peripheral nerve sheath tumors, central involvement, particularly in the jaw bones, is quite unusual. Neurofibroma is one of the most common nerve sheath tumors occurring in the soft tissue and generally appears in neurofibromatosis 1 (NF1 or von Recklinghausen's disease). Malignant peripheral nerve sheath tumors (MPNSTs) are uncommon sarcomas that almost always arise in the soft tissue. Here, we report four cases of intraosseous peripheral nerve sheath tumors occurring in the jaw bones and compare the clinical, radiologic, and pathologic findings in order to make a differential diagnosis.
X-Rays ; Sarcoma/*diagnosis ; Neurofibromatoses/pathology ; Neurofibroma/*pathology ; Nerve Sheath Neoplasms/*diagnosis ; Male ; Jaw/*radiography ; Humans ; Female ; Diagnosis, Differential ; Child ; Bone Neoplasms/*diagnosis ; Adult ; Adolescent

BACKGROUND: The porion (Po) is used to construct the Frankfort horizontal (FH) plane for cephalometrics, and the external auditory meatus (EAM) is to transfer and mount the dental model with facebow. The classical assumption is that EAM represents Po by the parallel positioning. However, we are sometimes questioning about the possible positional disparity between Po and EAM, when the occlusal cant or facial midline is different from our clinical understandings. The purpose of this study was to evaluate the positional parallelism of Po and EAM in facial asymmetries, and also to investigate their relationship with the maxillary occlusal cant. METHODS: The 67 subjects were classified into three groups. Group I had normal subjects with facial symmetry (1.05 +/- 0.52 mm of average chin deviation) with minimal occlusal cant (<1.5 mm). Asymmetry group II-A had no maxillary occlusal cant (average 0.60 +/- 0.36), while asymmetry group II-B had occlusal cant (average 3.72 +/- 1.47). The distances of bilateral Po, EAM, and mesiobuccal cusp tips of the maxillary first molars (Mx) from the horizontal orbital plane (Orb) and the coronal plane were measured on the three-dimensional computed tomographic images. Their right and left side distance discrepancies were calculated and statistically compared. RESULTS: EAM was located 10.3 mm below and 2.3 mm anterior to Po in group I. The vertical distances from Po to EAM of both sides were significantly different in group II-B (p = 0.001), while other groups were not. Interside discrepancy of the vertical distances from EAM to Mx in group II-B also showed the significant differences, as compared with those from Po to Mx and from Orb to Mx. CONCLUSIONS: The subjects with facial asymmetry and prominent maxillary occlusal cant tend to have the symmetric position of Po but asymmetric EAM. Some caution or other measures will be helpful for them to be used during the clinical procedures.
Chin ; Dental Models ; Facial Asymmetry* ; Maxilla ; Molar ; Orbit

Dental Models ; Linear Energy Transfer ; Orthognathic Surgery

Cell Proliferation ; Chimera ; Embryonic Development ; Epithelium ; Female ; Fibroblast Growth Factors ; Mandible ; Maxilla ; Neural Crest ; Phosphotransferases ; Pregnancy ; Tretinoin ; Vertebrates