Six year's experience with the zygomatic "sandwich" osteotomy for correction of malar deficiency

PURPOSE: This study discusses the rationale, modifications, and complications of an osteotomy technique used to increase malar projection. PATIENTS AND METHODS: Seventy "sandwich" zygomatic osteotomies were performed in a 6-year period. Hydroxyapatite (HA) blocks were used to stabilize the anterolateral rotation of the zygomatic body in 44 osteotomies, calcium carbonate blocks were used in 23, calvarial bone grafts in three, a piece of bovine cartilage in one, and a bone graft from a chin ostectomy procedure combined with mesh osteosynthesis in one procedure. Fifty-six zygomatic osteotomies were combined with Le Fort I-type osteotomies (eight with a midline split). Nineteen zygomatic osteotomies were performed simultaneously with a Le Fort I-type osteotomy and a rhinoplasty with lateral osteotomies. RESULTS: The increase of malar projection and the stability of the procedure could not be measured on conventional three-plane cephalograms. However, patient's and surgeon's satisfaction were high and remained so during the follow-up period (maximum, 6.5 years; minimum, 6 months). Three patients developed maxillary sinusitis. In two of them, this was clearly related to fragmentation of an HA block. A Treacher-Collins patient developed a chronic fistula in the upper vestibule, caused by leakage of infraorbitally placed HA granules. In two cases, a fracture of the zygomatic arch occurred. Osteosynthesis was performed in one of them. CONCLUSION: With proper technique and care not to fracture the interpositional HA block, complications are rare. The procedure is expedient and provides predictable and stable correction of malar deficiency.     

Animal model of porous polyethylene orbital implants

Ophthalmologists continue to search for the ideal orbital implant for the anophthalmic socket. The successful long-term clinical performance of an implantable prosthesis is highly dependent on the materials from which the device is fabricated. Among the materials issues are chemistry, surface texture, and porosity. Polyethylene, a polymer comprised of simple hydrocarbon chains, is highly resistant to biological degradation and possesses mass and fabrication properties that would be favorable in an orbital implant. In this report, our early experimental experience with porous polyethylene orbital enucleation implants is reported. Our findings are sufficiently encouraging to warrant further exploration and refinement of the polyethylene device examined.     

Paranasal implants for correction of midface concavity

Central midface concavity was corrected with the placement of porous polyethylene implants in the paranasal area. This simulated the effect of skeletal osteotomies and advancement without altering dental occlusion. Implants were placed to correct congenital, posttraumatic, and cleft-related skeletal midface retrusion in nine patients. In seven of the patients, paranasal augmentation was performed in conjunction with rhinoplasty. There have been no implant-related complications during a mean 33-month follow-up (range 5 to 83 months). Screw fixation of these implants ensures stable positioning and allows precise final contouring during surgery.     

Microscrew and microplate systems for select osteotomies in orthognathic surgery

The use of the semirigid screw and plate systems is common place in orthognathic surgery by many oral and maxillofacial surgeons. The size of the screw and plate systems used is commonly designated as mini or osteotomy size. Screw diameter is generally 2.0 mm and plate thickness range is 0.8 mm to 1.2 mm. The systems available perform very well for the majority of osteotomies. There are circumstances when these mini systems are not appropriate. Recently developed microsystems have been applied by us in selected cases of orthognathic surgery. The smallest of the microsystem screws are 0.8 mm diameter and all are available in 2, 3, 4, 5, 6, 8 mm lengths. Some microplates are 0.3 mm thick and available in various shapes including a straight chain. The resultant profile thickness of screw plus plate system becomes 0.8 mm.     

Masticatory function in patients with mandibular prognathism before and after orthognathic surgery

Masticatory function was analyzed in 54 patients with mandibular prognathism before or after orthognathic treatment and in 40 adults with normal occlusion. Masticatory efficiency was evaluated spectrophotometrically by measuring the amount of adenosine triphosphate eluted from masticated adenosine triphosphate granules. Occlusal contact was evaluated by calculating the number and area of occlusal contacts from the illuminated images of a silicone record of the occlusion that was stored in the image analysis system with the aid of a charge-coupled device camera. The mean masticatory efficiency of the preoperative group was approximately half that of the control group. The value for the postoperative group was slightly higher than that for the preoperative group, but there was no statistical difference between the two groups. Likewise, the number and area of occlusal contacts in the preoperative group were also approximately half or less as compared with those of the control group, and they did not show significant changes postoperatively. Statistically, there were correlations between the masticatory efficiency and the number and area of occlusal contacts. The results indicate that although the occlusal relationship of the upper and lower teeth were greatly improved by orthognathic treatment, the postoperative occlusion is not tight enough and may need further adjustment at the end of the treatment.     

Effect of sucralfate and basic fibroblast growth factor on fibrovascular ingrowth into hydroxyapatite and porous polyethylene alloplastic implants using a novel rabbit model

This study investigated the effects of sucralfate and basic fibroblast growth factor (bFGF) on fibrovascular ingrowth into porous implant materials. Seven white female New Zealand rabbits underwent bilateral abdominal incisions through which porous orbital spherical or and disc-shaped implants were inserted between their abdominal muscles. Eighty hydroxyapatite (HA) and porous polyethylene (PP) implants, each material of different pore sizes, were implanted. These implants were either uncoated or coated with suspensions of polyhydroxymethylmethacrylate (hydron); hydron and sucralfate; or hydron, sucralfate, and bFGF. Implants were harvested after 1, 3, or 6 weeks. Observers classified the extent of fibrovascular ingrowth in a blind manner using light microscopy. All discs and spheres showed fibrovascular ingrowth; at 6 weeks, almost all implants were fully vascularized. Although demonstrating different degrees of fibrovascular maturity, all 3- and 6-week discs showed complete cellular ingrowth. Overall, the most extensive and mature fibrovascularization was found in HA implants, regardless of shape, duration of implantation, or angiogenic enhancing agent used. Thus, this study indicates that fibrovascular ingrowth into porous implants is more greatly affected by implant porosity and composition than by addition of angiogenic enhancing agents. Further in vivo study, using other potential angiogenesis-promoting agents as well as implants with different pore characteristics, is warranted using this reliable and predictable animal model.     

Early prediction of the need for orthognathic surgery in cleft lip and palate patients

OBJECTIVES: To assess the accuracy of Duplex ultrasound in the assessment of aortoiliac disease. DESIGN: Prospective, semi-blind study. SETTING: Vascular laboratory and radiology departments, University Hospital. MATERIALS AND METHODS: Ninety-two patients underwent assessment of the aortoiliac segment by femoral pulse palpation, Duplex ultrasound and biplanar arteriography. Of these 184 aortoiliac segments, 68 were also assessed by intraarterial pressure measurements and 80 by magnetic resonance angiography (MRA). MAIN RESULTS: Femoral pulses were abnormal in all 32 occluded aortoiliac segments. Of 152 patent segments, femoral pulse palpation was misleading in 50 (33%). MRA detected all occlusions and had a sensitivity of 71% and specificity of 68% for stenoses, compared to arteriography. Colour flow Duplex misdiagnosed four occlusions as stenoses. Duplex had a sensitivity of 91% and specificity of 93% for stenoses when compared to arteriography. Two stenoses, detected by Duplex and confirmed by pressure gradients, were missed by arteriography. CONCLUSIONS: Pressure measurements remain the gold standard for aortoiliac examination, arteriography providing only morphological information. The limitations of femoral pulse palpation should be appreciated. Although MRA was faster, Duplex examination proved slightly more sensitive to stenoses. At present, colour Duplex provides the best non-invasive assessment of aortoiliac disease and could prevent unnecessary arteriograms.     

Patients' expectations as predictors of orthognathic surgery outcomes.

109 patients (aged 14–43 yrs) rated their expectations of problems associated with surgery for dentofacial malrelation 6–22 mo before surgery and completed questionnaires 5 more times over the course of 3 yrs, from just before to 2 yrs after surgery. Presurgical expectations of problems were significant predictors of postsurgical reports of experiences, dissatisfaction, and mood disturbances up to 2 yrs after surgery. Contrary to the hypothesis that vigilant copers would have better outcomes than avoidant copers, results suggest that Ss who anticipated few problems with surgery (avoidant copers) reported better psychological outcomes than Ss who expected numerous problems (vigilant copers). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The use of high-density polyethylene implants in facial deformities

OBJECTIVE: To determine the usefulness of porous high-density polyethylene implants (Medpor) in a variety of facial skeletal deformities and subcutaneous defects, excluding those associated with acute maxillofacial trauma. DESIGN: Case series. SETTING: Academic tertiary care referral center in Baltimore, Md. PATIENTS: Thirty-four patients (age range, 20-74 years) with facial deformities requiring skeletal defect reconstruction or augmentation (38 cases), treated between January 1, 1992, and January 1, 1997. Follow-up ranged from 6 months to 40 months. MAIN OUTCOME MEASURES: Age, type and origin of the deformity treated, type of treatment, and complications. RESULTS: Types of deformities and defects treated include 7 patients with orbital defects (secondary traumatic or oncologic deformities), 8 with temporal fossa defects, 8 with frontocranial defects, 4 with maxillary or malar defects, 7 with calvarial bone graft donor site defects, 2 with microtia, and 2 with chin deficiency. Forty implants were placed. Complications included implant exposure in 4 patients and inappropriate augmentation in 1 patient (chin implantation). CONCLUSIONS: High-density polyethylene implants offer an excellent alternative to autogenous and other alloplastic materials in reconstruction of many facial defects and deformities. Advantages include its versatility and relatively ideal pore size that allows for excellent soft tissue ingrowth and coverage. Disadvantages include its rigid nature and difficulty in contouring to the surface of complex skeletal structures.     

Comparing prospective and retrospective evaluations of temporomandibular disorders after orthognathic surgery

The authors conducted a study to document agreement between prospective examinations performed by trained clinical trial examiners and retrospective surgical chart reviews in identifying signs and symptoms of temporomandibular disorders, or TMD. Only a small fraction of the signs and symptoms identified by clinical trial examiners were documented in the surgical charts. Studies relying on retrospective chart reviews may seriously underestimate signs and symptoms of TMD.     

Reconstruction of saddle nose deformities using porous polyethylene implant

Background: Troglitazone is a new drug for the treatment of type 2 diabetes. Although mild liver injury occurred in 1.9% of participants in controlled trials, the U.S. Food and Drug Administration has received reports of five postmarketing cases of severe liver disease that resulted in death or liver transplantation. OBJECTIVE: To report the clinical and histopathologic characteristics of a patient with troglitazone-associated severe liver injury leading to transplantation. DESIGN: Case report. SETTING: Two university hospitals. PATIENT: A 55-year-old woman taking troglitazone, 400 mg/d, and insulin, 120 U/d. INTERVENTION: Discontinuation of troglitazone therapy, pretransplantation liver biopsy, and liver transplantation. RESULTS: Early nonspecific symptoms were attributed to other causes and were not evaluated. After the patient had used troglitazone for 3.5 months, massive loss of liver parenchyma and symptoms of liver failure developed, necessitating liver transplantation. CONCLUSION: Troglitazone may cause subfulminant liver failure.     

Psychological aspects of orthognathic surgery: a review of the literature

A review of the literature clearly shows that dental and facial disfigurements have significant effects and can be an important social disadvantage. The motivational patterns of patients requesting orthognathic surgery are many and varied, but a desire for improvement in esthetics and alleviation of functional problems are the two most commonly cited reasons. The careful assessment of patients requesting orthognathic surgery is imperative, because the success of surgery may well depend on careful patient selection. Care must be taken with those patients suspected of exhibiting dysmorphophobic tendencies and, if there is any doubt, psychiatric referral should be undertaken. Patient satisfaction following orthognathic surgery has been reported as high overall, as has been the number of patients who have said they would re-elect to have surgery. Many of the studies found that patients had improved self-confidence and social skills after treatment.     

Effects of hypesthesia on oral behaviors of the orthognathic surgery patient

PURPOSE: The purpose of this study was to compare orthognathic surgery patients with and without significant hypesthesia with respect to perceived problems with specific oral behaviors. PATIENTS AND METHODS: Data from 116 patients 6 months after bilateral sagittal split osteotomy (BSSO) and mandibular advancement were analyzed. Tactile sensation in the right and left mental nerve areas was determined using monofilaments and brush strokes (von Frey hairs). The right infraorbital region was used as a control. A difference of 450 mg of force between the control and test sites was considered significant hypesthesia. Patients rated their level of subjective problems with swallowing liquids or solids, smiling, spitting, kissing, speaking, eating, and drooling on a scale from 1 (none to mild) to 7 (extreme). A value of 5 or greater was considered significant impairment. RESULTS: Hypesthesia was shown in 23 patients (19.8%) with the monofilaments and in 29 patients (25.0%) using brush stroke direction. In each of these two groups, a significant correlation was observed between hypesthesia and difficulty in chewing and kissing. No correlation was observed between any of the remaining seven oral behaviors and hypesthesia. CONCLUSION: These findings suggest that only certain oral behaviors are affected by hypesthesia of the mental nerve.     

First 4-years orthognathic surgery audit of a Saudi teaching hospital

The study represents a retrospective audit of the first four years of orthognathic surgery carried out at a Saudi teaching hospital. The results showed that orthognathic surgery was the most common oral and maxillofacial surgery performed in that particular hospital, which is one of two teaching hospitals covered by the division of oral and maxillofacial surgery, faculty of dentistry, King Saud University in Riyadh, Kingdom of Saudi Arabia. The variation in the patients characteristics, treatment provided, and final outcome is presented.     

Video imaging--a computer facilitated approach to communication and planning in orthognathic surgery

The role of connective tissue in the aetiology of female stress incontinence has been investigated. Collagen content and extractability as well as estrogen receptor concentration in vesico-vaginal fascia were measured after small tissue biopsies had been obtained during vaginal repair surgery in cases of urinary incontinence. The mean concentration of estrogen receptor in vesico-vaginal fascia among incontinent women was 49.4 +/- 14.8 fmol/mg of protein as compared to 29.6 +/- 13.1 in continent control group (P < 0.03; t-test). The mean hydroxyproline concentration in vesico-vaginal fascia of incontinent women was 13.8 +/- 2.6 micrograms/mg wet weight, whereas in the control group it was significantly higher 20.6 +/- 2.4 (P < 0.001). The role of connective tissue components in the aetiology of female stress incontinence is discussed.     

Blood flow changes after orthognathic surgery: maxillary and mandibular subapical osteotomy

Subapical osteotomies were performed in the left quadrant of the mandibles and maxillas of five dogs and six monkeys. Two indirect methods, the isotope fractionation (diffusible tracer) and particle distribution (nondiffusible tracer--15mu microspheres) were used to quantitate local blood flow. To examine the effect of the surgery, blood flows in the alveolar bone, mucosa, and dental pulp of the segmented left quadrant and the corresponding tissues in the right quadrant were calculated and compared. It was assumed that the blood flows to the nonoperated right quadrant could serve as the controls to those observed in the osteotomized segment. The fractional decrease in blood flows to tissues in the operated sides were similar in both experimental animals. The decrease was largest in the dental pulp, ranging from 54% to 82% on the average, and least for the mucosal tissue, ranging from 18% to 40%. Blood flows decreased by 48% to 74%, on the average, in the alveolar bone. In some animals, blood flow to mucosal tissue that served as the pedicle was actually greater than the blood flow in the corresponding tissue on the right side. After surgery, the cardiac output in the dogs averaged about 156 ml/min/kg as calculated from both the diffusible and nondiffusible data. In the monkeys in which only the microspheres were injected, the cardiac output averaged 99 ml/min/kg. The arterial blood pressure dropped 8 to 13 mm Hg on the average (dog, 108 to 100 mm Hg; monkeys, 94 to 81 mm Hg). The heart rate also decreased slightly in dogs, 158 to 139 beats/min on the average; however, it increased slightly after the surgery in the monkeys, 144 to 161 beats/min. Blood losses during surgery were replaced wtih lactated Ringer's solution and the transient decreases in blood pressure of about 20 to 35 mm Hg were not sufficient to produce any shut down of renal blood flow.     

Changes in bite force and occlusal contacts in patients treated for mandibular prognathism by orthognathic surgery

PURPOSE: The purpose of this study was to evaluate changes in bite force and occlusal contacts before and after orthognathic surgery in patients with mandibular prognathism and to compare the findings with those in controls with normal occlusion. PATIENTS AND METHODS: Bite force and occlusal contacts were analyzed in 23 (7 male and 16 female) patients with mandibular prognathism before and after sagittal split ramus osteotomy, and in 20 (10 male and 10 female) controls with normal occlusion. The bite force and occlusal contacts were simultaneously measured by a computerized occlusal analysis system, the T-Scan system, immediately before surgery, and at 6 weeks, 3 months, 6 months, and 1 year postoperatively. RESULTS: Both the bite force and occlusal contacts in the patients were significantly less than those in the controls before surgery. Although both the bite force and occlusal contacts in the patients were improved by the orthognathic surgery, neither approached the level in the controls within 1 year. Bite force was correlated with the number of occlusal contacts in both patient and control groups. CONCLUSION: The postoperative masticatory function does not reach control levels even 1 year after the orthognathic surgery for mandibular prognathism. Therefore, further adjustment of the occlusion should be considered before the end of treatment.     

Selenium deficiency in patients with cardiovascular diseases and its correction with the drug "selena"

Blood selenium concentrations, erythrocytic glutathione peroxidase (GPO) activity, and plasma lipid peroxides were investigated in patients with ischemic heart disease (IHD) and dilated cardiomyopathy (DCMP). Patients with IHD and DCMP displayed depressed activity of GPO with activation of lipid peroxides associated with lower blood selenium. The daily intake of 300 micrograms of selenium from Selena during a month treatment augmented selenium concentrations by 71% in IHD and DCMP patients. This augmentation showed an inverse correlation with primary plasma selenium concentrations. Plasma malonic dialdehyde levels decreased by 17%. The findings suggest that selenium is involved in the pathogenesis of DCMP and IHD, which may be a ground for selecting patients with selenium deficiency for its correction with Selena.