Biomedical subjects

D E Altobelli

Publications and source records attributed to D E Altobelli.

5 recordsLinked to original sources

PubMed1996

The concept of the sagittal orbital-globe relationship in craniofacial surgery.

Euophthalmos, the normal relationship of the orbital rims to the eyes, is critical to planning and to surgical correction of craniofacial deformities. The four most easily localized anthropometric (soft tissue) landmarks for the sagittal orbital-globe relationship are orbitale superius (os), orbitale inferius (oi), orbitale laterale (ol), and nasion (n), all referenced to apex corneae (acor). The normal adult values for os, oi, ol, and n were extracted from the literature. Age-specific anthropometric landmarks were computed from age-specific Bolton cephalometric templates. A vernier caliper was used to measure preoperatively the surface orbital landmarks in patients with various syndromic and nonsyndromic craniosynostotic disorders. Preoperative measurements were compared with the derived normative data to determine the necessary sagittal orbital translocation for frontal advancement (n=19) and frontal-midfacial advancement (n=2). Postoperative orbital anthropometry documented the degree of normalization of the sagittal orbital-globe relationship. The problems with current instrumentation for orbital anthropometry are discussed.

Adolescent↗

PubMed1995

Frontonasal suture expansion in the rabbit using titanium screws.

PURPOSE: This study investigated the ability to use titanium screws to provide stable skeletal points in the growing craniofacial region of the rabbit for suture expansion. These screws provided sites for direct application of external forces to alter growth and anatomic form. MATERIAL AND METHODS: Twenty-one rabbits (30 days old) were divided into three groups: control (n = 9), experimental (n = 9, and sham (n = 3). Four four-holed AO/ASIF commercially pure titanium craniofacial plates were contoured into an L-shape with a 90 degree angle at the midpoint. The plates were placed bilaterally in the frontal and nasal bone sites and secured with 2.0-mm diameter, 4-mm long, commercially pure titanium screws in both the sham and experimental groups. After 4 week of healing, a spring mechanism with a distraction force of 55 g was activated between ipsilateral plates and across the frontonasal sutures bilaterally in the experimental group for 5 weeks. No force was applied between the plates in the sham group. A preliminary evaluation of the bone-implant interface and the changes in the suture was done histologically. Morphologic changes were measured using cephalometric radiographs and direct anatomic measurements. RESULTS: The experimental group showed a significant increase in growth across the frontonasal suture in comparison with the sham group (P < .05). In addition, an increase in the length of the nasal and frontal bones in the expanded group was observed in comparison with the control and sham groups (P < .05). Histologically, a mixture of woven and lamellar bone was seen in the suture region and lamellar bone was seen in the screw-bone interface. CONCLUSION: This study indicates that titanium screws in the developing rabbit skull can provide stable sites for the direct application of external forces, producing secondary changes in skeletal morphology. This laboratory models provides a useful system for the further study of growth modification using such external mechanical forces.

Animals↗

PubMed1993

Computer-assisted three-dimensional planning in craniofacial surgery.

Three-dimensional surface reconstruction from computed tomographic (CT) data has been used to plan craniofacial operations. Cephalometric and anthropometric databases were integrated with three-dimensional CT reconstructions to quantitate the skeletal deformity and to assist in the design of the surgical procedure. Interactive techniques were developed to simulate osteotomies and skeletal movements in three dimensions on the computer-generated surface images. The ocular globes were referenced to position the orbital segments; i.e., the osteotomized segments were transposed into normal anatomic relationship with respect to the eyes. The measurements from the computer graphic simulation were used intraoperatively to establish the correct position of the skeletal segments.

Adolescent↗

PubMed1993

Enophthalmos following orbital transposition for craniofacial malformations.

This is a retrospective study of the frequency and factors that portend enophthalmos following orbital osteotomies and transposition for craniofacial malformations. Clinically obvious postoperative enophthalmos (POE) was noted in 23 (37.7 percent) of 61 patients undergoing such procedures. Postoperative enophthalmos was observed in 86 percent of Apert patients who had combined anteromedial orbital transposition and in 48 percent of patients with hypertelorbitism who had standard 360-degree osteotomies. In contrast, the incidence of postoperative enophthalmos was 21 percent following frontofacial (monobloc) or subcranial (Le Fort III) advancement. Postoperative enophthalmos also correlated with the occurrence of orbital fracture/fragmentation and with disruption of the periorbita. This study underscores the importance of establishing the correct relationship of the globe to the orbital rim (euophthalmos) while maintaining the spatial position of the eye, especially its anterior projection. Postoperative enophthalmos can be prevented by inserting bone grafts into orbital osteotomy gaps, correcting orbital volume/morphology following floor or wall outfracture/fragmentation, and preserving the periorbital supporting system.

Acrocephalosyndactylia↗

PubMed1987

Free and microvascular bone grafting in the irradiated dog mandible.

Microvascular and free rib grafts were placed in 4.5 cm defects in an edentate mandibular body defect 18 to 28 days after completion of 50 Gy of irradiation from a 60Co source. The animals were sacrificed from two to forty weeks postoperatively and evaluated clinically, radiographically, and histologically. There was a marked difference in the alveolar mucosal viability with the two grafts. Mucosal dehiscence was not observed over any of the microvascular grafts, but was present in seven-eighths of the free grafts. Union of the microvascular bone graft to the host bone occurred within six weeks. In contrast, after six weeks the free graft was sequestered in all the animals. An unexpected finding with both types of graft was the marked subperiosteal bone formation. This bone appeared to be derived from the host bed, stabilizing and bridging the defects bilaterally. The results suggest that radiated periosteum may play an important role in osteogenesis.

Animals↗