PubMed Health⌕ Search

Biomedical subjects

I R Munro

Publications and source records attributed to I R Munro.

At least 73 records · Page 4Linked to original sources

Craniofacial surgical techniques for aesthetic results in congenital and acute traumatic deformities.

The first case of congenital orbital hypertelorism presented demonstrates that complex investigations, careful planning, and extensive experience combined with meticulous attention to detail can turn a severe congenital deformity into normality in one operation. The second case of trauma shows that an acute injury (even in the face of potential major contamination) can be initially managed by utilizing all the principles of craniofacial surgery, thus achieving optimal results in one operation. The surgeon must be prepared to utilize extensive exposures to visualize exact fracture sites and the degree of displacement. Bone grafts must be used to provide contour and to replace missing segments. Direct wiring performed with mechanical efficiency can produce a completely stable skeleton without the need of external devices. Probably the most important factor is that the surgeon should endeavor to achieve complete correction during initial operation regardless of the time taken. The concept of doing some things at a later date is never satisfactory in terms of the quality of result.

Adolescent↗

Articulation before and after facial osteotomy.

We examined the articulation in 41 patients before and after facial osteotomies to correct occlusal defects. Both dental occlusion and articulation improved significantly after surgery. Before surgery there was a direct relationship between the degree of prognathia and the severity of the articulation defect; after surgery in the patients with retrognathia there was a direct relationship between the decrease in the occlusion defect. For other types of occlusal defect these relationship were not established.

Adolescent↗

Neurovascular protection in the sagittal split osteotomy.

The Dautrey modification of the sagittal split (cleavage) of the mandible is a safe operation when performed frequently using the correct technique and when wide, lateral ramus retractors are used to give posterior protection to the major neurovascular structures in this region.

Child↗

One-stage reconstruction of the temporomandibular joint in hemifacial microsomia.

In some patients with hemifacial microsomia, the mandibular ascending ramus and condyle are absent. Sometimes the zygomatic arch and glenoid fossa are also absent, and the zygoma and lateral orbital wall are deficient and misplaced. Complete alignment of the facial skeleton with construction of all components of the temporomandibular joint has been performed as a one-stage procedure on 14 patients, aged 6 to 23 years. The principle "first the bone, rarely the soft tissue" has evolved because when the skeleton is correct, the soft tissues assume a normal contour. The dangers of major skeletal surgery in children can be minimized if patients are referred to major craniofacial centers.

Adolescent↗

The management of gigantic benign craniofacial tumors: the reverse facial osteotomy.

A small group of patients is seen because of massive benign facial tumors, which include both soft tissue and bone overgrowth. These people cannot live a normal life because of their facial deformities. Four patients have been chosen to describe a one-stage technique of soft tissue removal and repositioning the facial skeleton utilizing a reverse facial osteotomy. Detailed planning by an experienced craniofacial team, together with preoperative embolization and profound hypotensive techniques have made surgery feasible with minimal blood loss. Rapid and effective rehabilitation of these unfortunate people now can be achieved.

Adolescent↗

Improving results in orbital hypertelorism correction.

Between 1971 and 1977, 40 patients with orbital hypertelorism were operated on by the craniofacial team in Toronto. Results have improved as a result of this experience. Tomography in two planes has revealed four types of medial orbital wall deformity. Cephalographs proved inadequate to understand this three-dimensional problem. Mobilization of the orbits and their correct realignment, with removal of the precise amount of interorbital bone, are only preliminary steps in producing good results. Different techniques for reattachment of the medial canthal ligament, correct orientation of the lateral canthus, changes in methods of nasal excision, and the elimination of other facial or eyelid scars are helping to produce more normal looking patients. Simultaneous major intraoral procedures have been the greatest source of complications. Limitation of this surgery to one team has given sufficient experience to enable a diminution in morbidity and a halving in blood loss and time taken for the operation.

Adolescent↗

Maxillonasal dysplasia (Binder's syndrome).

Eleven patients with Binder's syndrome (nasomaxillary hypoplasia) have been treated by the Toronto Craniofacial Team from 1972 to 1977. The treatment has consisted of onlay bone and cartilage grafts to the nose and perialar region for young children, or when the occlusion is normal. However, cases with severe malocclusion were treated by a Le Fort I and/or Le Fort II osteotomy when the children were older. When the malocclusion was less severe, interceptive orthodontics have been useful. The nose can be significantly lengthened and enlarged through a frontal craniotomy incision connected with an upper buccal sulcus incision, without any incision on the face.

Adolescent↗

Combined report of problems and complications in 793 craniofacial operations.

We report the experiences in 6 major craniofacial centers, with similar teams but in different parts of the world, in a total of 793 craniofacial operations. The mortality rate was 1.6%. Complications developed in 16.5% of the cases (including infections in 4.4%). This surgery has many potential advantages, not least of which is its psychosocial effects on previously disfigured patients. Certain problems seem inherent, however, for there are not yet any satisfactory solutions to them. Some of the factors that reduce morbidity and improve results include the use of hypotensive anesthesia, a reduction in operating time, rigid stabilization of the mobilized bones at the end of the operation, a diminution in the number of incisions, and extensive antibiotic therapy.

Adult↗

The effect of total maxillary advancement on facial growth.

The effect of total maxillary advancement on the growing skull was examined in 25 pigs, subjected to facial operations of varied severity at the age of 5 weeks (elevation of periosteum, simple osteotomy, and osteotomy immobilized by wire fixation, with or without bone grafts) and in controls. When the animals were killed 8 months later, the body weight had increased tenfold and the skull size had doubled. In 5 pigs whose maxillae were advanced 10 mm by bone grafts, the relative increase in length was not maintained. The overall skull length showed no difference from the control measurements. The extent of the growth in the area adjacent to the osteotomy was less than in the controls, but the same as in pigs subjected to periosteal elevation only. Scattered areas of bone damage were seen with no consistent pattern. Incision of the periosteum over the frontal bone decreased the local blood supply, increased the adherence of the periosteum to the bone, and affected bone growth locally.

Adult↗

Velopharyngeal insufficiency after maxillary advancement.

This paper reports velopharyngeal insufficiency after maxillary advancement in a 16-year-old boy. It underlines the need for systematic, quantitative investigation of the effects of this new operation on speech and velopharyngeal function.

Adolescent↗

Problems in cranio-facial surgery.

Four geographically widely separated medical centres with a primary interest in cranio-facial surgery present their combined complications to illustrate the dangers and unsolved problems of this surgery. There wre 149 cases with 2 deaths and 3 other life threatening situations (infections). Approximately 60% of the patients had no complications (90/149). Secondary corrections are often necessary to obtain the desired result or correct problems produced by the surgery. The complexity and rarity of the surgery and supporting disciplines is such that in the interest of the patient and the speciality concentration of this surgery in a few centres is desirable.

Bone Resorption↗

Quantitative assessment of the morphology of the pig's head used as a model in surgical experimentation. Part 1: Methods of Measurements.

Thirty-two surface measurements were described for assessment of the effect of complex surgical operations on the skeleton of the face in pigs. The methods of measurements imitate those of anthropometry. The surface measurements can complement cephalometry with data about the changes in the soft tissue and thus improve the documentation of the effect of surgery. This paper can help in the evaluation of complicated osteotomy procedures using the pig as the animal model, for facial reconstruction research in humans.

Animals↗

Correction of severe facial deformity.

A craniofacial team has been developed to corrdinate the treatment of patients with severe facial deformity and to minimize the surgical risks. Two hundred patients have been evaluated in the last 4 years and more than 100 treated by this team to correct orbital hypertelorism, oxycephaly and plagiocephaly with exophthalmos, features of Crouzon's disease and Apert's and Treacher Collins syndromes, hemifacial microsomia, and severe lower facial deformity and malocclusion. Surgical principles include extensive subperiosteal stripping of bone, osteotomy as necessary, and repositioning maintained by bone grafts. Postoperative evaluation is being maintained for 5 years or to maturity in younger children. Although many of the results are less than perfect, there has been sufficient improvement, especially psychologic and functional, to warrant continuation of the surgical program under closely controlled conditions.

Acrocephalosyndactylia↗

A sudden death associated with the use of sodium nitroprusside for induction of hypotension during anaesthesia.

A death from cyanide poisoning during operation was attributable to the use of approximately 400 mg (10 mg per Kg) sodium nitroprusside as an hypotensive agent. Autopsy cyanide levels of 0.5 mg per cent in blood and 0.3 mg per cent in urine and thiocyanate levels too low to measure in either, suggest an abnormality of cyanide metabolism. The lethal dose of sodium nitroprusside appears to be 7 mg per Kg. A safe regimen would be 3.5 mg per Kg as the anticipated total dose for the period of hypotension. Patients resistant to the full hypotensive effects of sodium nitroprusside, or unable to maintain the level of hypotension, or requiring more than 3.5 mg per Kg to achieve the required effect for the anticipated time, may accumulate toxic levels of cyanide in the blood. Patients with Leber's optic atrophy, tobacco amblyopia and possibly those with other nerve atrophies should not receive sodium nitroprusside or any other cyanide precursor.

Adolescent↗