Anatomy of the facial nerve branching patterns, the marginal mandibular branch and its extraparotid ramification in relation to the lateral palpebral line.

Background: Surgery of face and parotid gland may cause injury to branches of the facial nerve, which results in paralysis of muscles of facial expression. Knowledge of branching patterns of the facial nerve and reliable landmarks of the surrounding structures are essential to avoid this complication. Objective: Determine the facial nerve branching patterns, the course of the marginal mandibular branch (MMB), and the extraparotid ramification in relation to the lateral palpebral line (LPL). Materials and methods: One hundred cadaveric half-heads were dissected for determining the facial nerve branching patterns according to the presence of anastomosis between branches. The course of the MMB was followed until it entered the depressor anguli oris in 49 specimens. The vertical distance from the mandibular angle to this branch was measured. The horizontal distance from the LPL to the otobasion superious (LPL-OBS) and the apex of the parotid gland (LPL-AP) were measured in 52 specimens. Results: The branching patterns of the facial nerve were categorized into six types. The least common (1%) was type I (absent of anastomosis), while type V, the complex pattern was the most common (29%). Symmetrical branching pattern occurred in 30% of cases. The MMB was coursing below the lower border of the mandible in 57% of cases. The mean vertical distance was 0.91±0.22 cm. The mean horizontal distances of LPL-OBS and LPLAP were 7.24±0.6 cm and 3.95±0.96 cm, respectively. The LPL-AP length was 54.5±11.4% of LPL-OBS. Conclusion: More complex branching pattern of the facial nerve was found in this population and symmetrical branching pattern occurred less of ten. The MMB coursed below the lower border of the angle of mandible with a mean vertical distance of one centimeter. The extraparotid ramification of the facial nerve was located in the area between the apex of the parotid gland and the LPL.

Tissue engineering of cartilage with porous polycarprolactone--alginate scaffold: the first report of tissue engineering in Thailand.

OBJECTIVE: To engineer human cartilage with porous polycaprolactone (PCL)-Alginate Scaffold. BACKGROUND: Polycaprolactone (PCL) is a prolonged degradable polymer that has good mechanical strength. The authors fabricated PCL as an ear shaped scaffold. Alginate hydrogel was used to seed chondrocyte into the PCL porous scaffold by a gel-cell seeding technique. MATERIAL AND METHOD: PCL Scaffolds were fabricated like human pinna by particle leaching technique. Chondrocyte was isolated from human rib cartilage and then cultured. The cultured chondrocyte were mixed with 1.2% alginate and b-FGF (basic-fibroblast growth factor) 5 ng/ml at a concentration of 25 x 10(6) cell/ml, then were seeded in porous PCL scaffold to make the constructs. The constructs were cultured in vitro for 1 week. Then they were implanted in subcutaneous plane of the back of six-female nude mice (5 weeks old). Two nude mice were sacrificed at 2, 3, and 6 months. Histological study was done (H&E, Alcian blue, collagen type II). RESULT: Neocartilage was formed in the porous cavity of PCL scaffold. At 2 and 3 months, neocartilage were similar to very young cartilage. At 6 months, they were mature. The delayed maturation until 6 months and the highly vascularization of neocartilage in the early phase was the effect of human b-FGF The growths of neocartilage islands in porous cavity were also observed along with degradation ofPCL inter-porous septum. CONCLUSION: This paper reports the first success of cartilage tissue engineering in Thailand.