KIT-related piebaldism in a Chinese girl.

Piebaldism is a rare, autosomal dominant and congenital pigmentary disorder characterized by stable depigmentation of the skin and white forelock. Mutations in KIT or SNAI2 genes result in piebaldism. Most individuals with piebaldism have a family history of the disorder. Herein, we report a 5-month-old Chinese girl with severe piebaldism but no family history thereof. She has white forelock and large patches of depigmentation in the jaw, central anterior trunk, perineum and extremities. We performed whole-exome and Sanger sequencing and identified a de novo KIT mutation (NM_000222.2: c.2657G>A, p.Gly886Val) in exon 18 of KIT in the proband. Currently, this mutation is located in the most extreme C-terminal of the tyrosine kinase domain 2 of the KIT gene amongst all reported mutations and causes a severe clinical phenotype. We further reviewed literature on piebaldism and summarized 79 KIT gene mutations that lead to this disease. Our study may expand knowledge on the genotype-phenotype correlation in piebaldism and serve as a reference for genetic counseling and prenatal diagnosis of affected families.

[Clinical application of mandibular osteomuscular flap pedicled with temporalis to repair maxillary bone defect].

OBJECTIVE: To evaluate the clinical effect of mandibular osteomuscular flap pedicled with temporalis to repair maxillary defect. METHODS: From March 2008 to May 2010, ten cases of maxillary defects resulted from malignant tumor resection were treated with mandibular osteomuscular flap pedicled with temporalis. Ten cases of malignant tumor included six cases of Squamous cell carcinoma,one case of duct carcinoma, osteosarcoma, chondrosarcoma and malignant melanoma. One case was repaired by mandibular osteomuscular flap only, nine cases were repaired by mandibular osteomuscular flaps combined with other soft tissue flaps. RESULTS: All the 10 mandibular osteomuscular flaps survived completely with no complication. The patients were followed up for 12 to 36 months, with an average of 18 months. Satisfactory appearance and complete functional restoration were achieved except for one case of chondrosarcoma recurrence. CONCLUSIONS: The mandibular osteomuscular flap pedicled with temporalis is safe and easily performed with less complication. It is an ideal method for repairing the maxillary defect.

[Anatomic study of mandibular bone flap pedicled with temporal muscle for midface bone defect].

OBJECTIVE: To study the anatomy of mandibular bone flap pedicled with temporal muscle for midfacial bone defects. METHODS: The shape and blood supply of the temporal muscle and mandibular ramus, as well as their relationship, were observed and measured in 30 sides of adult head specimens. RESULTS: The temporal muscle has a fan-shaped main portion, then is scattered into three bundles as anterolateral, anteromedial, posterior bundles, which end respectively at anterior border of ramus, the temporal ridge and posterior portion of coronoid process. Then the muscle goes downward until it reaches the distal side of the third medial surface molar and attaches the 3/4 of medial surface of anterior portion of ramus. The blood supply of temporal muscle includes the medial temporal artery with external diameter of (0.76 +/- 0.20) mm, the anterior deep temporal arteries with external diameter of (0.79 +/- 0.21) mm, posterior deep temporal arteries with external diameter of (0.98 +/- 0.64) mm, the accessory deep temporal artery formed by many little branches. The anterior part of ramus is supplied by the periosteal arteries and the bony perforator of the deep temporal arteries. Rectangular ramus of mandible was divided into anterior portion and posterior portion by the line linking the lowest point of mandibular notch, mandibular foramen and mandibular canal. Anterior portion can supply a bone flap with a size of (46.67 +/- 6.85) mm x (17.98 +/- 2.64) mm x (11.49 +/- 0.99) mm. CONCLUSIONS: The mandibular bone flap pedicled with temporal muscle has a reliable blood supply and abundant bone volume. It is feasible to design a mandibular bone flap pedicled with temporal muscle for midfacial bone defect.