PubMed Health⌕ Search

PubMed · 4532388

[Embryology].

Abstract

The source did not provide an abstract. Follow the original record for more information.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

G Sterzik. 1974. [Embryology].. https://pubmed.ncbi.nlm.nih.gov/4532388/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

The Le Fort III osteotomy: to distract or not to distract?

Treatment of the craniofacial dysostoses (e.g., Crouzon, Apert, Pfeiffer, Saethre-Chotzen syndromes) is critically dependent on the successful advancement of the midface with a Le Fort III procedure. The purpose of this retrospective clinical outcome study was to evaluate a new technique for distracting the Le Fort III procedure and to compare its results in growing children with those of the standard Le Fort III osteotomy. The records of 22 children were reviewed; 10 patients (mean age, 6.5 years) underwent a standard Le Fort III procedure, and 12 patients (mean age, 7.5 years) underwent a Le Fort III distraction procedure. The distraction group included two separate techniques, bilateral buried distraction (n = 2) and halo distraction (n = 10). Preoperative and 2- to 3-month postoperative cephalograms were analyzed. The average horizontal advancement achieved in the standard Le Fort III group was 6 mm, compared with 19 mm of advancement in the distraction group (p </= 0.005). Complications were evenly distributed between the two groups (one infection and one tracheostomy in each group), and the lengths of hospitalization were similar. No documented improvement in sleep apnea was identified in the standard Le Fort III group. However, in the distraction group two patients experienced normalization of sleep studies postoperatively as measured by respiratory disturbance index, and two patients underwent successful decannulation of tracheotomies. For aesthetic reasons, halo distraction was preferred over bilateral buried distraction. With halo distraction the vector of traction is focused in the facial midline, which helps to reposition the concave midface and to provide a more convex facial profile. In growing children, the ideal vector for distraction is determined by the malar position and not by dental occlusion. The amount of overcorrection can be calculated from tables of normal anthropologic data. On this preliminary review, it was concluded that the use of halo distraction, in combination with a modified Le Fort III osteotomy, provided a significantly further forward-positioned midface and seemed to offer a better correction of sleep apnea than did the standard Le Fort III osteotomy.

Cephalometry↗

Re-creating ancient hominid virtual endocasts by CT-scanning.

Probably the first radiographic study of human fossils, that by D. Gorganovic-Kramberger on Neandertal remains from Krapina, Croatia, was published in 1906, only 11 years after Röntgen announced the discovery of X-rays. Many subsequent studies on fossil hominids used regular clinical diagnostic radiological apparatus, as depicted in Atlas of Radiographs of Early Man by M.F. Skinner and G.H. Sperber (1982). Some specimens such as crania filled with heavily calcified matrix proved intractable. Ordinary radiographs of such specimens usually failed to reveal endocranial structure, as fossilized bone and calcified endocast were approximately equally radio-opaque. Thus, neither endocranial volume nor structural details were detectable. The only invasive method that could have been employed involved mechanical removal of the solid matrix, but this entailed hazards to the cranial vault and the destruction of the natural endocranial cast. In 1983--1984, G.C. Conroy and M. Vannier utilized recent advances in high-resolution computed tomography to produce non-invasive, intracranial capacity measurements of matrix-filled fossil skulls. They tried the method on two fossil mammal skulls filled with hard sandstone matrix (1984, Science 26:456-458), and then successfully applied it to a South African, matrix-filled cranium of the ancient hominid (hominin) species, Australopithecus africanus from Makapansgat (Conroy et al. 1990, Science 247:838-841). Details of the morphology of the endocranial surface of the braincase were revealed, including the pattern of venous sinus drainage in the posterior cranial fossa. A group based in St. Louis, Vienna, Paris, Rome, and Johannesburg has taken such studies further. Beautiful "virtual endocasts" have been produced on a large male specimen of A. africanus from Sterkfontein, South Africa, and the endocranial capacity has been determined (1998). The methods make it possible to re-create "virtual endocasts" of ancient hominids.

Cephalometry↗