Comparing the osteogenic capacities of bone substitutes: hydroxyapatite, high-density porous polyethylene, and bone collagen: a biochemical and histological analysis.

Several inorganic materials have been shown previously to hold some osteogenic capacity. The purpose of this study is to compare the bone-forming abilities of hydroxyapatite ceramic, high-density porous polyethylene, and bone collagen within the periosteal island flap of rabbit tibia using histological and biochemical analysis. With this goal, four discrete experimental groups were formed, each comprising 22 New Zealand male rabbits. A sac was created on each rabbit tibial periosteum flap in each of the groups, and each of the previously mentioned materials was placed within this sac separately. One of these groups was thought as a control group without any material being placed inside the periosteal sac. Biopsies were taken at weeks 1, 2, 4, and 8 for biochemical analysis and at weeks 2 and 8 for histological evaluation. Neo-osteogenesis was evaluated quantitatively by determination of alkaline phosphatase and osteocalcin levels biochemically as well as by the percentage of new bone formation inside the periosteal sac histologically. Results show statistically that the osteogenic effect of high-density porous polyethylene is greater than that of the other materials used in this study (P < 0.05).

Reconstruction of congenital absent columella.

A case of congenital absence of the nasal columella accompanying a facial hemangioma is presented. The nose is an important aesthetic unit of the face, and its projection is mainly supported by the columella. The etiology of the absent columella is unclear, and the clinical feature is rare. Reconstruction of the columella remains a challenging problem in plastic surgery, and numerous techniques have been described. The authors discuss several techniques aimed at the correction of the problem and describe a method of reconstruction of the absent nasal columella that was used in the case reported.

Proteus syndrome.

Proteus syndrome is a rare sporadic, hamartoneoplastic disorder of vascular, skeletal, and soft tissues that causes asymmetry of the skull, body, arms, and the legs. The name "Proteus" of the Greek god who had the ability to change his shape was coined to define the variety of deformities including partial gigantism of the hands or feet, asymmetry of the arms and legs, hypertrophy of long bones, plantar hyperplasia, haemangiomas, lipomas, varicosities, linear verrucous epidermal naevi, macrocephaly, and cranial hyperostoses. The basic defect seems to be the focal overgrowth of cellular elements in skin, bone, and other connective tissues. The variable features of the syndrome make differential diagnosis challenging for clinicians. The most important features are the hamartomatous disorders. The long-term prognosis is still not clear. As it is a hamartoneoplastic and incompletely delineated syndrome, the patients must be followed up because of the possible risk of neoplasms.

Van der Woude syndrome.

Van der Woude syndrome (VWS) is an autosomal dominant craniofacial syndrome with variable expression characterised by congenital pits and sinuses in the lower lip together with cleft lip, or palate, or both. We report a case of VWS, which occurred as a new mutation, and review previous reports.

Nasal columella reconstruction with a composite free flap from the root of auricular helix.

Defects of the nasal columella result in significant cosmetic and functional deformities. Over the years, a variety of methods for nasal columella reconstruction have been described in the literature, as have the technical difficulties of reconstructing this subtle structure. Here, a successful reconstruction of a 3.0 x 2.0 cm-wide nasal columella defect, with a chondrocutaneous microsurgical free flap from the root of the auricular helix, is presented.