The biomechanical effects of deep tissue support as related to brow and facelift procedures

The adverse effects of increased tension across a healing wound are well known. However, the effect of closing a wound in layers in order to decrease tension on the epidermis has been a source of controversy. It is hypothesized that deep tissue support decreases skin tension upon wound closure. In order to clarify this issue, a two-part study was designed to address the immediate effects of deep tissue support in vitro using fresh-frozen cadavers and in vivo on patients undergoing scheduled surgery. Closing skin tension was measured at standard reference points in coronal brow lift and rhytidectomy procedures performed with and without galeal closure and superficial musculoaponeurotic system (SMAS) procedures, respectively. Deep tissue support was found to significantly (p less than 0.05) decrease skin tension at the time of skin closure at standard reference points in coronal brow lift and rhytidectomy procedures performed on fresh-frozen cadavers. Similar significant (p less than 0.05) decreases in closing skin tension also were found in vivo in patients undergoing similar surgical procedures. Stress relaxation was not found to play a significant role in contributing to this immediate decrease in closing skin tension. It would appear, therefore, that deep tissue support, in the form of galeal closure and an SMAS procedure in coronal brow lift and rhytidectomy procedures, respectively, provides increased viscoelastic support, producing immediate significant decreases in closing skin tension in these procedures. The beneficial effects on wound healing, scar formation, tension-related trophic skin changes, and possible improved long-term results are discussed.     

Complex maxillary fractures: role of buttress reconstruction and immediate bone grafts

Between 1978 and 1984, 558 patients with complex facial fractures have been treated. One hundred and seventy-one of these patients have had complex Le Fort fractures of the maxilla. In this group of patients, the importance of direct anatomic reconstruction of the anterior maxillary buttresses has been assessed. Complete exposure of the injured buttresses will facilitate assessment of the exact fracture pattern. Direct fixation of the medial and lateral maxillary buttresses on each side, in combination with immediate bone-graft reinforcement or replacement of comminuted or missing buttresses, will facilitate the reconstruction of even the most severely injured maxilla in one stage. This approach is combined with similar reconstructive techniques in other areas of the craniofacial skeleton. Associated mandibular fractures are managed with rigid internal fixation utilizing A-O techniques. The use of these techniques dramatically facilitates airway management and simplifies the treatment of the edentulous patient, the patient with bilateral condylar neck fractures, and those patients with sagittal splitting of the maxilla and palate. The use of both internal craniofacial suspension wires and external craniofacial suspension devices has become largely unnecessary, and reconstruction of even the most complex injuries in one stage with minimal complications and secondary deformities is made possible.     

Interaction of distinct nuclear proteins with sequences controlling the expression of polyomavirus early genes.

The interaction between cellular factors and polyoma virus (Py) DNA was investigated by using a gel retention assay. Nuclear extracts from various cell lines (NIH 3T3, NIH 3T6, LTK-, F9) contained proteins that formed specific and distinct complexes with Py B enhancer fragments of either wild-type or F9-1 mutant origin. The presence of an excess amount of other well-characterized DNA sequences, including the Py A enhancer, the murine sarcoma virus enhancer, and the simian virus 40 enhancer-promoter region, did not interfere with this protein-DNA interaction. However, a fragment previously defined as containing the lymphotropic papovavirus enhancer shares the binding of some common factor. This observation, in combination with the results of retention gel assays at different Mg2+ concentrations, indicates the interaction of several nuclear factors and Py DNA. The assay systems that were used allowed a distinction between some factors on the basis of their different biochemical and sequence requirements. The contact sites of these complexes were mapped to the B enhancer region of Py with Bal 31-derived mutant restriction fragments and ExoIII nuclease and are compatible with the functional domains determined in vivo.