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Biomedical subjects

I T Jackson

Publications and source records attributed to I T Jackson.

At least 55 records · Page 3Linked to original sources
PubMed1997

Surgical management of velopharyngeal insufficiency following uvulopalatopharyngoplasty: report of three cases.

Uvulopalatopharyngoplasty is a surgical procedure that has a role in the management of obstructive sleep apnea and chronic snoring. A recognized complication of the procedure is postoperative velopharyngeal insufficiency. In this paper, three patients who have required corrective surgery for this problem are presented, and their management is discussed. The rehabilitation discussion was tailored to the clinical findings being either a pharyngeal flap in one case and a modified sphincter pharyngoplasty in the other two. The condition of all three patients was considerably improved, but two had mild residual velopharyngeal incompetence.

Adult↗
PubMed1997

Distraction osteogenesis for lengthening of the hard palate: Part I. A possible new treatment concept for velopharyngeal incompetence. Experimental study in dogs.

Many procedures have been described to correct velopharyngeal incompetence. Significant complications can occur, and the results may not be satisfactory. If the short soft palate has satisfactory muscle function and if it could be moved toward the posterior pharyngeal wall by distraction osteogenesis of the hard palate, an entirely new concept of treatment for velopharyngeal incompetence would be available. The object of the present study was to explore the possibility of osteogenesis occurring in the hard palate in dogs after gradual distraction (callus distraction). Six adult, mix-bred dogs were anesthetized, and the palatal mucosa was elevated. A midpalatal transverse osteotomy and two lateral osteotomies were performed. Tantalum bone markers for cephalometric analysis were placed, and an individually fabricated, orthodontic-like distraction device with an expansion screw in the sagittal direction was inserted. The device was stabilized on the premolars and fixed to the palatal bone with titanium miniscrews. Gradual distraction began after a latency period of 10 to 18 days. The rate of the distraction varied from 0.25 to 0.75 mm per day. The device was left in place for 6 to 8 weeks after expansion to allow for bony consolidation. Assessment was by direct examination, cephalograms, computed tomography, and histology with bone labeling. Impressions of the jaws were taken preoperatively and after device removal to examine plaster cast changes in the dental occlusion. Cephalometric and computed tomographic scan analysis demonstrated a distraction of up to 8 mm. All gaps were filled with de novo osteogenesis. Comparison of the plaster casts revealed no change in the occlusion. At 1 month after distraction, the computed tomographic scan showed the first signs of ossification of the experimental gap from the anterior and posterior bone ends. After 4.5 months ossification was almost complete with a small translucent zone in the middle of the experimental gap. After 7 months ossification was complete.

Animals↗
PubMed1997

Distraction osteogenesis for lengthening of the hard palate: Part II. Histological study of the hard and soft palate after distraction.

To correct velopharyngeal incompetence, a new treatment concept was proposed in Distraction Osteogenesis for Lengthening of the Hard Palate: Part I (using lengthening of the hard and soft palate by distraction osteogenesis). Cephalometry and computed tomography showed successful elongation of the posterior hard palate with gradual calcification. Here the sequential use of fluorochrome markers (oxytetracycline, xylenol orange, DCAF [2,4-bis-N-N'-dicarboxymethyl aminomethyl fluorescein], and alizarin complexone) during the distraction and retention period is reported together with the histologic investigations using light and laser scan microscopy without prior demineralization. The experimental gap showed de novo osteogenesis in all dogs. The new bone was always in continuity with the original anterior and posterior palatal bone margins. It either bridged the experimental gap fully or left a small central zone of fibrous tissue, in which eventual ossification occurred. Several distinct zones could be distinguished: A small central zone was found with parallel strains of collagen fibers, oriented longitudinally in the direction of the distraction. Next to this zone a layer of undifferentiated mesenchymal precursor cells was seen in direct contact to newly formed bone. The next zone was coarse woven bone, showing a transition to mature lamellar bone through remodeling. No evidence of endochondral bone formation was found, i.e., all dogs showed exclusively intramembranous bone formation. The soft tissues showed no signs of alteration: in particular, there was no necrosis or scar formation. The soft tissues were not thinned but appeared to have followed the longitudinal displacement. In conclusion, gradual distraction osteogenesis of the hard palate could be a possible method for lengthening the palate to treat velopharyngeal incompetence.

Animals↗
PubMed1997

Fistula formation and repair after palatal closure: an institutional perspective.

We retrospectively reviewed 119 consecutive patients who underwent cleft palate repair at the Mayo Clinic to determine the incidence of postoperative fistula formation, to assess possible contributing factors, and to review the methods of surgical management. Fistulas of the secondary palate were included, but nasal-alveolar fistulas and intentionally unrepaired anterior palatal fistulas were excluded. Six patients whose repairs were performed after 2.5 years of age were excluded to ensure a more uniform patient population. Cleft palate fistulas occurred in 13 of the 113 patients (11.5 percent). The median age at repair was 8.2 months, and the median follow-up period was 5.2 years. Several variables were analyzed by means of the log-rank test to determine their significance in postoperative fistula formation. Sex, extent of clefting (as estimated by the Veau classification), and type of palatal closure did not significantly affect the rate of fistula formation. However, patients who had palatal closure at an age younger than 12 months had a lower incidence of fistula formation (7.8 percent) than children whose closures were performed between the ages of 12 and 25 months (19.4 percent) (p = 0.058). The strongest predictor of the occurrence of a cleft palate fistula was the surgeon performing the procedure (p = 0.008). Fistula repair was deemed necessary in 11 of 13 patients, and 91 percent of these fistulas were healed with a single operation. Most of these fistulas were closed by using local flaps and two-layered closures. Cleft palate repair carries a significant but acceptable risk of fistula formation, which can be managed with local flaps. Fistula occurrence is related most to the experience level of the operating surgeon.

Child, Preschool↗
PubMed1997

Local flap reconstruction of defects after excision of nonmelanoma skin cancer.

Reconstruction of facial defects poses the interesting challenge of finding the most satisfactory flap both aesthetically and functionally. It requires not just a knowledge of the flap, but an ability to think and plan in three dimensions. Not all individuals possess this; thus, what is obvious and simple to one surgeon, poses a great and worrisome problem for another. This can be made easier by considering certain rules. First, excise the lesion properly and then think about the reconstruction. The presence of the defect crystallizes the thought process. Next, consider the topographic and functional anatomy of the face, the differences in skin color, presence of hair, and the "idea" lines for position of scars. The flap options are rotation, transposition, and advancement. The latter, on occasions, may be as an island. These movements must be fitted into the aforementioned requirements. In this way the best choice usually is reached. Remember, there is always a way out using a skin graft or tissue expansion.

Basal Cell Carcinoma↗
PubMed1997

[A method for true nose lengthening].

There are various methods of lengthening the nose after trauma or for congenitally short noses. Forehead flaps and bone and cartilage grafts to the nasal dorsum are routinely performed. Bone grafts to the dorsum are onlay grafts that can show resorption. In craniofacial procedures, e.g., after Le Fort II/III osteotomies, the nose is brought forward and downward as necessary. This principle for nasal lengthening has been applied to 11 patients with congenitally short noses or after trauma. A coronal incision was made, an extensive subperiosteal skin undermining above the entire nasal bones and the piriform aperture was performed. Then a naso-frontal osteotomy was carried out, which runs downward to the piriform aperture. It runs either anteriorly to the lacrimal sac or it runs behind it through the medial orbital wall. It then crosses the inferior orbital rim and runs from there into the nasal floor. The nasal lining is released and the osteotomized fragment mobilized and moved caudally and anteriorly. This results in a deviation of the nasal septum, requiring a septoplasty. Cranial bone grafts (outer table) are interposed in the osteotomy gaps and fixed with microplates. This method of nose lengthening was applied to 11 patients with good results.

Adult↗
PubMed1996

Galeo-pericranial flaps in the forehead: a study of blood supply and volumes.

Despite their extensive use in anterior cranial base reconstruction, very little is understood about the blood supply of galeo-pericranial flaps derived from the forehead region. The goal of this study was to define the extent of the reliable axial blood supply and to determine the volumes of these flaps. The blood supply to anteriorly based galeo-pericranial flaps depends entirely upon the deep branches and a variable component of the superficial branches of the supraorbital and the supratrochlear vessels. The axial component of the blood supply to these flaps is 20-70 mm. The extent of "random' pattern blood supply distal to this could not be adequately assessed. The volumes of various galeo-pericranial flaps range from 3 to 48 cc. The well vascularized proximal portions of galeo-pericranial flaps may well serve the reconstructive needs of the anterior cranial base. Use of more distal portions of these flaps should be undertaken with caution. Some increase in bulk and vascularity may be achieved if the pericranial and the galeal-frontalis myofascial flaps are harvested as a single unit, the composite galeal-frontalis-pericranial flap. Due to the vascular and volume limitations of galeo-pericranial flaps, consideration should be given to the use of microvascular free tissue transfers in instances where large soft tissue defects and a large "dead space' occur.

Angiography↗
PubMed1996

An anatomical classification of maxillary ameloblastoma as an aid to surgical treatment.

Maxillary ameloblastoma is a different entity from its mandibular counterpart. It is reported to behave more aggressively and have a poorer prognosis. Eleven maxillary ameloblastomas (three recurrent) are reported with a follow-up ranging from 1 month to 12 years with no recurrences. It is proposed that radical treatment of these tumours, with good reconstruction, can give satisfactory function and survival. To that end, the tumours have been classified as to their position in the maxilla and surgical resection related to this.

Adult↗
PubMed1996

Multiple segmental gradual distraction of facial skeleton: an experimental study.

The method of distraction osteogenesis was used to move several facial segments in different directions with formation of new bone. On 3 young adult sheep a Le Fort II osteotomy, combined with circumferential orbital osteotomies, was performed. The periosteum over the osteotomies was preserved. Titanium bone screws were placed as bone markers. The segments were fixed with pins and plates to a combined distraction apparatus in order to advance the segments in different directions. By a gradual distraction, the midface was advanced forward by 30 mm. The left orbit was moved laterally 20 mm and the right orbit was moved forward 20 mm. In both orbits there was a concomitant globe movement. New bone formation in the distracted area was obvious radiographically, clinically, and histologically. In conclusion, multiple segmental distraction is possible in the adult sheep face and may offer three-dimensional (3D), controlled correction of complex face deformities.

Animals↗
PubMed1996

A new design of a cross-lip vermilion flap.

A new technique is described for the treatment of major vermilion defects using a cross-lip vermilion flap as a multistaged procedure. There is minimal disfigurement of the lip. The reconstruction is achieved using tissue of similar quality, texture, and color. The advantages of this method over the currently available techniques are discussed.

Esthetics↗
PubMed1996

Vascular anatomy of the galeal occipitalis flap: a cadaver study.

The vascular anatomy of the galeal occipitalis flap was studied in 10 fresh cadavers by an intraarterial dye injection technique. The scalp flap was based posteriorly, incorporating both the occipital and posterior auricular arteries. A good transmidline anastomosis was demonstrated between the two occipital arteries in the full-thickness scalp flap. However, in the isolated galeal flap, although the axial distribution of the occipital artery was maintained, fewer transmidline connections were seen between the two occipital arteries. The posterior auricular artery was consistently visualized in all dissections, and it showed good connections with the ipsilateral occipital artery. However, there were very few anastomoses between the two posterior auricular arteries across the midline. The rich anastomotic network between the occipital artery and the posterior auricular artery extended well beyond the vertex. This study showed that a large flap can be raised if both the occipital artery and the posterior auricular artery are included in its base. The occipital artery is a vessel of satisfactory size and is potentially a good vascular source for a thin galeal free flap. It is recommended that the flap be raised at the subperiosteal level for ease of dissection and protection of the vessels, which are initially in the subgaleal plane and then arborize in the galea.

Arteries↗
PubMed1996

The effect of insulin-like growth factor 1 on craniofacial bone healing.

Human insulin-like growth factor 1, a known regulator of bone formation, was investigated for its possible effect on membranous bone formation in a rat model. Full-thickness bone defects (10 x 10 x 1 mm) were created in the rat calvarium, and insulin-like growth factor 1 was administered by an osmotic minipump directly into the defect enclosed by the periosteum and dura mater. The dose of insulin-like growth factor 1 was 100 micrograms every 2 weeks. The defects were studied radiographically, macroscopically, and microscopically at 3, 6, 9, and 12 weeks. The group treated with insulin-like growth factor 1 showed qualitative and quantitative differences when compared with the control group. The amount of new bone formation in the group treated with insulin-like growth factor 1 was significantly larger than that of the control group. In the insulin-like growth factor 1 group, the location of new bone formation occurred in the center and at the margin of the bone defect. In the control group, bone was formed only around the margin of the bone defect. This study suggests that insulin-like growth factor 1 improved membranous bone healing in vivo and that insulin-like growth factor 1 makes mesenchymal precursor cells of bone differentiate directly into bone-forming cells.

Animals↗
PubMed1996

Histopathology of apocrine bromhidrosis.

A histologic study of axillary skin taken from 20 Korean bromhidrosis patients and 10 normal Korean subjects without axillary odor was undertaken. Under light microscope, the skin specimens, stained with hematoxylin and eosin, were examined. Compared with the controls, the apocrine glands were numerous and the gland size large in the bromhidrosis skin. The decapitated epithelial cell-lined contracted glands were seen intermixed with the nondecapitated cell-lined distended glands in the bromhidrosis skin. By comparison, in the normal controls, the apocrine glands were atrophic and lined with flat epithelial cells and showed no decapitation. It appears that histologic change of apocrine glands may contribute more to bromhidrosis than bacterial decomposition of apocrine sweat. Surgical removal of apocrine glands may thus be the most satisfactory and logical method of treatment.

Adult↗
PubMed1996

Assessment and treatment of facial deformity resulting from radiation to the orbital area in childhood.

Children who receive radiation for malignant tumors in the orbital area frequently develop widespread craniofacial deformities. These affect the skull, orbit, maxilla, and mandible. When these patients seek treatment at a later age, they require careful assessment using cephalometrics and three-dimensional imaging. It is recommended that the four levels of skeletal deformity be corrected in a single procedure, that is frontotemporal expansion with repositioning of the skull base area, orbital expansion and repositioning together with maxillary and mandibular surgery. Bone grafts should be inlay rather than onlay and soft tissue should be supplied by free-tissue transfer. This counteracts any residual ischemia related to the previous radiation therapy. The second surgical stage is designed to reconstruct the socket and the eyelids to allow more satisfactory rehabilitation with an ocular prosthesis. In patients who have a globe present, the usual enophthalmos can be corrected by repositioning of the eye as part of the first procedure by reducing the anteroposterior dimensions of the socket. In bilateral cases, the deformity is hourglass in nature and requires correction in the frontal and temporal area with lateral displacement of the orbits. A bimaxillary procedure is also indicated. It is emphasized that to formulate a satisfactory operative plan an in-depth three-dimensional analysis of the deformity is mandatory.

Child↗