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Biomedical subjects

J L Marsh

Publications and source records attributed to J L Marsh.

At least 91 records · Page 5Linked to original sources
PubMed1997

Results of ankle arthrodesis for treatment of supramalleolar nonunion and ankle arthrosis.

Seven patients with supramalleolar nonunions after tibial plafond fractures underwent ankle arthrodesis combined with surgical treatment of the nonunion. Stabilization of the nonunion and the ankle consisted of medial and lateral plating for two hypertrophic cases and medial external fixation for five atrophic cases. Two of the atrophic nonunions were infected, and the distal tibia below the nonunion was resected and distraction osteogenesis from a proximal level was used to fill the resulting defect. Both the nonunion and ankle arthrodesis healed in six patients in an average of 7.9 months (range, 4-20 months). The nonunion failed to heal in one patient and required a below-knee amputation. The average cost of care was $66,491 per patient. Before surgery, the average patient ankle score was 25 (range, 15-50), and at a median of 35 months' follow-up the average score was 64 (range, 18-79 months). Three patients had scores in the "good" range, two in the "fair" range, one in the "poor" range, and one was rated a treatment failure. The SF-36 scores were significantly lower than age-matched population-based normal subjects. Limb salvage was possible in six of these seven patients, but the treatment times were long, complications frequent, and the cost of care high.

Adult↗
PubMed1997

Need for velopharyngeal management following palatoplasty: an outcome analysis of syndromic and nonsyndromic patients with Robin sequence.

The Robin sequence is a pathogenetically and etiologically heterogeneous condition that can be a nonsyndromic anomaly or one feature of many syndromes. Little information is available regarding the distribution of patients having Robin sequence, with or without associated syndromes, who develop velopharyngeal dysfunction. In order to discern whether patients with Robin sequence, nonsyndromic and/or syndromic, have different velopharyngeal dysfunction rates from those observed among all patients undergoing palatoplasty during the same time period, a retrospective study was undertaken. The charts of 873 patients with overt clefts of the secondary palate managed at a single cleft center between 1978 and 1992 were reviewed. Diagnostic criteria for Robin sequence included cleft palate without cleft lip, microretrognathia, and perinatal respiratory and/or feeding difficulties; 79 such patients (9 percent) were identified from the initial group of 873. Of these, 58 patients (7 percent) were at least 3 years of age and had sufficient follow-up to allow for evaluation of speech outcome by an experienced speech pathologist through a variety of methodologies (videonasendoscopy, speech videofluoroscopy, perceptual speech characteristics). This group comprised the Robin sequence study population. All Robin sequence patients' charts were reviewed by a medical geneticist to confirm the presence or absence of a syndrome. Of the original 873 patients, there were 127 non-Robin sequence patients who were sufficiently cooperative in diagnostic testing to yield definitive information. This group comprised the non-Robin sequence study population. Among nonsyndromic Robin sequence patients, 15 of 34 (44 percent) developed velopharyngeal dysfunction and required velopharyngeal management, while 2 of 24 syndromic patients (8 percent) developed velopharyngeal dysfunction (p = 0.003). Of the 127 non-Robin sequence isolated cleft palate patients, 113 were nonsyndromic, of whom 18 percent (20 of 113) required velopharyngeal dysfunction management, and 14 were syndromic, of whom 64 percent (9 of 14) required velopharyngeal dysfunction management (p = 0.00009). We conclude that nonsyndromic Robin sequence patients have a higher rate of postpalatoplasty velopharyngeal dysfunction than the nonsyndromic non-Robin sequence cleft population. Outcome analysis of velopharyngeal function in cleft patients should take into account patients who have cleft palate in association with Robin sequence, with or without a recognizable syndrome.

Child, Preschool↗
PubMed1997

Current classification of fractures. Rationale and utility.

Fracture classification systems are used on a daily basis in any busy orthopedic clinic. They are an essential means by which physicians communicate, make treatment decisions, estimate prognosis, and report and compare results. Until recently, these classifications have been designed, accepted, and utilized without formal critique. By studying and understanding the shortcomings of previous systems, we can use this knowledge to construct better ones. Ideally, a fracture classification, like any classification, should be reliable, reproducible, all inclusive, mutually exclusive, logical, and clinically useful. The AO/ASIF classification of long bone fractures provides a unified scheme of classification for fractures of the entire skeleton. Despite addressing many of the faults of previous classifications, the observer agreement for this system drops to unacceptable levels at the group and subgroup levels. Further study is warranted to determine how this agreement can be improved.

Communication↗
PubMed1997

Septic arthritis caused by chronic osteomyelitis.

We have treated four cases of previously quiescent osteomyelitis which presented as septic arthritis in an adjacent joint. The osteomyelitic focus was in the bone proximal to the involved joints (zero to ten centimeters above the joint line). Based on the presenting history, physical findings, laboratory tests and cultures of joint fluids, the joint sepsis was low grade in all patients which led to delays in diagnosis and treatment. Aggressive surgical debridement of both bone and joint, followed by a prolonged course of antibiotics led to resolution in all patients. A high index of suspicion combined with adequate radiographs of the surrounding bones should lead to the appropriate diagnosis and treatment.

Adult↗
PubMed1996

Evolutionary changes in the expression pattern of a developmentally essential gene in three Drosophila species.

The hypothesis that morphological evolution may largely result from changes in gene regulation rather than gene structure has been difficult to test. Morphological differences among insects are often apparent in the cuticle structures produced. The dopa decarboxylase (Ddc) and alpha-methyldopa hypersensitive (amd) genes arose from an ancient gene duplication. In Drosophila, they have evolved nonoverlapping functions, including the production of distinct types of cuticle, and for Ddc, the production of the neurotransmitters, dopamine and serotonin. The amd gene is particularly active in the production of specialized flexible cuticles in the developing embryo. We have compared the pattern of amd expression in three Drosophila species. Several regions of expression conserved in all three species but, surprisingly, a unique domain of expression is found in Drosophila simulans that does occur in the closely related (2-5 million years) Drosophila melanogaster or in the more remote (40-50 million years) Drosophila virilis. The "sudden" appearance of a completely new and robust domain of expression provides a glimpse of evolutionary variation resulting from changes in regulation of structural gene expression.

Animals↗
PubMed1996

Long-term studies of metopic synostosis: frequency of cognitive impairment and behavioral disturbances.

Although the occurrence of cognitive impairment and behavioral disturbances in patients with metopic synostosis has been described, the incidence of this dysfunction has not been established. The records of 36 consecutive children with metopic synostosis followed at one craniofacial center from 1978 to 1993 were reviewed and parental questionnaires were completed to establish the frequency of mental retardation, learning disabilities, and behavioral problems associated with this synostosis. Documentation of syndromes, abnormal karyotype, and central nervous system anomalies also was done. The study group consisted of 27 males and 9 females. The average age at most recent follow-up was 7 years and 1 month (range 6 months to 22 years). Two patients had chromosomal abnormalities (9p syndrome and trisomy 21). On the basis of CT and MRI scans, intracranial anomalies were identified for only one patient having an absent corpus callosum. Thirty-two of the study patients had adequate information for longitudinal assessment. Twenty patients have normal development without apparent disability. Of these, those of school age are at appropriate grade level. Eight patients have mild to moderate learning disabilities or behavioral problems, including attention deficit/hyperactivity disorder and impaired language development. Four patients have significant mental impairment. Impaired cognitive development was not limited to children with abnormal karyotype or central nervous system anomaly. Cognitive and behavioral abnormalities occur in at least a third of patients with metopic synostosis. The, at times, subtle nature of these abnormalities mandates longitudinal developmental and neurologic evaluation for infants with metopic synostosis.

Adolescent↗
PubMed1996

Plagiocephaly: differential diagnosis based on endocranial morphology.

Plagiocephaly is a descriptive term that connotes an asymmetrically oblique or twisted head. Such cranial dysmorphology has a number of etiologies, the most common of which are unicoronal synostosis, unilambdoid synostosis, and plagiocephaly without synostosis. Use of the term plagiocephaly in the literature is often ambiguous in that at times it is used inclusively for all etiologies while at other times it is used exclusively as a synonym for unicoronal synostosis. Although differentiation by physical examination among unicoronal synostosis, unilambdoid synostosis, and plagiocephaly without synostosis usually is possible for an experienced observer, inexperienced observers often have difficulty making an anatomically accurate diagnosis even with the assistance of conventional skull radiographs. High-resolution CT scans, including three-dimensional osseous surface re-formations, have become a standard element in the evaluation of craniofacial anomalies in many centers. We hypothesized that the three major etiologies of plagiocephaly could be unambiguously differentiated by means of endocranial three-dimensional CT osseous surface re-formations. Archival pretreatment CT data on 15 unicoronal synostosis, 4 unilambdoid synostosis, and 15 plagiocephaly without synostosis patients were reviewed to define, qualitatively and quantitatively, the characteristics of the endocranial base morphologies for each group; in addition to visual dysmorphology specific to each group, there was a statistically significant difference in the angle of deviation from the midlines of the anterior and posterior cranial fossae among unicoronal synostosis, unilambdoid synostosis, and plagiocephaly without synostosis. Four radiologists experienced in reading images of craniofacial anomalies were oriented to the group characteristics and then instructed to perform differential diagnosis for each of the 34 patients using only the endocranial three-dimensional CT images. The raters were blind to all other clinical and diagnostic information. The raters correctly diagnosed unicoronal synostosis. Errors were made in differentiation of unilambdoid synostosis and plagiocephaly without synostosis. These errors resulted from the raters' reliance on image inspection rather than quantitation of anteroposterior fossae midline angulation. Such quantitation unambiguously differentiated between unilambdoid synostosis and plagiocephaly without synostosis in the "error" cases. The endocranial base dysmorphology of patients with plagiocephaly is etiology-specific for unicoronal synostosis, unilambdoid synostosis, and plagiocephaly without synostosis. Three-dimensional CT endocranial base images can assist differential diagnosis of plagiocephaly.

Cephalometry↗
PubMed1996

Stability of fronto-orbital advancement in nonsyndromic bilateral coronal synostosis: a quantitative three-dimensional computed tomographic study.

Fronto-orbital dysmorphology in nonsyndromic bilateral coronal synostosis includes frontal flattening, supraorbital recession, and ocular globe protrusion. Surgical advancement of the supraorbital region ("bandeau") is performed to correct these deformities. A retrospective analysis of 10 consecutive patients with nonsyndromic bilateral coronal synostosis was performed to assess the effect of two types of bandeau fixation at the nasion. The advanced bandeau was fixed medially at the nasion with a calvarial bone graft and polyglycolic acid sutures (bone graft/suture group, five patients) or with a microplate (plate group, five patients) and bilaterally at pterion with calvarial bone grafts and polyglycolic acid sutures (all patients). The cranio-orbital dysmorphology and the surgical results were studied using pre-, peri-, and post-operative three-dimensional computed tomographic (CT) data. Reformation, manipulation, editing, and quantitative measurements of the CT data were performed on a computer workstation and Analyze imaging program. Four measurements performed to evaluate the fronto-orbital morphology: the length:width ratio of anterior cranial fossa, ventral globe index, cornea position, and supraorbital rim lag. The ventral globe index assessed the degree of eyeball protrusion out of the orbit cavity. Measurements of the cornea position and supraorbital rim lag were performed on the longitudinal orbit projections of the CT data. Six normal skull CT scans were available for same measurement and comparison. Measurements of the preoperative fronto-orbital dysmorphology in bilateral coronal synostosis were significantly different from those of normal subjects. One year after the surgery, the length:width ratio of the anterior cranial fossa was normalized in both groups. The ventral globe index was improved but not normalized in both groups, whereas the cornea position and supraorbital rim lag were improved in the bone graft/suture group but were normalized in the plate group. Based on the quantitative data, the surgical outcomes in the plate group were significantly better than those in the bone graft/suture group. Major relapse of surgical advancement in the bone graft/suture group seemed to occur in perioperative period. In summary, at 1 year postoperatively, the bandeau advancement improved but did not entirely normalize the fronto-orbital dysmorphology of nonsyndromic bilateral coronal synostosis in either group. We conclude that plate rigid fixation at the nasion provides superior stability for bandeau advancement compared with bone graft/suture fixation.

Bone Plates↗
PubMed1996

Speech outcome following palatoplasty in primary school children: do lay peer observers agree with speech pathologists?

The aim of this study was twofold: (1) to test the ability of normal children to discriminate the speech of children with repaired cleft palate from the speech of unaffected peers and (2) to compare these naive assessments of speech acceptability with the sophisticated assessments of speech pathologists. The study group (subjects) was composed of 21 children of school age (aged 8 to 12 years) who had undergone palatoplasty at a single cleft center and 16 matched controls. The listening team (student raters) was composed of 20 children who were matched to the subjects for age, sex, and other variables. Randomized master audio-tape recordings of the children who had undergone palatoplasty were presented in blinded fashion and random order to student raters who were inexperienced in the evaluation of patients with speech dysfunction. The same sound recordings were evaluated by an experienced panel of extramural speech pathologists whose intrarater and interrater reliabilities were known; they were not direct care providers. Additionally, the master tape was presented in blinded fashion and random order to the velopharyngeal staff at the cleft center for intramural assessment. Comparison of these assessment methodologies forms the basis of this report. Naive raters were insensitive to speech differences in the control and cleft palate groups. Differences in the mean scores for the groups never approached statistical significance, and there was adequate power to discern a difference of 0.75 on a 7-point scale. Expert raters were sensitive to differences in resonance and intelligibility in the control and cleft palate groups but not to other aspects of speech. The expert raters recommended further evaluation of cleft palate patients more often than control patients. Speech pathologists discern differences that the laity does not. Consideration should be given to the utilization of untrained listeners to add real-life significance to clinical speech assessments. Peer group evaluations of speech acceptability may define the morbidity of cleft palate speech in terms that are most relevant to the patients themselves and may safeguard against the possibility of offering treatment that may be unnecessary.

Child↗
PubMed1996

Developmental territories created by mutual antagonism between Wingless and Decapentaplegic.

Drosophila appendages develop from imaginal discs which become subdivided into distinct regions during normal patterning. At least 3 axes of asymmetry are required to produce a chiral appendage such as a leg. The A/P compartments provide one axis of asymmetry in all discs. In leg and antennal discs, the anterior compartment becomes asymmetric in the D/V axis with decapentaplegic (dpp) expression defining dorsal anterior leg, and wingless (wg) expression defining ventral anterior leg. However, unlike wing discs, no D/V compartment has been demonstrated in legs or antennae. How are the dorsal anterior and ventral anterior territories defined and maintained? Here we show that wg inhibits dpp expression and dpp inhibits wg expression in leg and eye/antennal discs. This mutual repression provides a mechanism for maintaining separate regions of wg and dpp expression in a developing field. We propose the term 'territory' to describe regions of cells that are under the domineering influence of a particular morphogen. Territories differ from compartments in that they are not defined by lineage but are dynamically maintained by continuous morphogen signaling. We propose that the anterior compartment of the leg disc is divided into dorsal and ventral territories by the mutual antagonism between WG and DPP signaling.

Animals↗
PubMed1996

Acute obstructive sleep apnea as a complication of sphincter pharyngoplasty.

This report describes postoperative airway compromise following sphincter pharyngoplasty (SP) for treatment of post-palatoplasty velopharyngeal dysfunction. A retrospective review of 58 SPs performed for post-palatoplasty velopharyngeal dysfunction, on 30 male, and 28 female patients, over a 5-year study period was undertaken at a tertiary referral academic institution (Washington University School of Medicine), at the St. Louis Children's Hospital, Cleft Palate and Craniofacial Deformities Institute. Eight patients were identified who had the following inclusion criteria: overt perioperative and/or postoperative airway dysfunction, identifiable syndromes, or microretrognathia. Items reviewed were patient demographic factors, associated medical problems, genetics evaluations, nasendoscopic characteristics of velopharyngeal closure, anesthetic evaluation of the patients, and the incidence and severity of perioperative complications. Particular attention was paid to factors contributing to the airway obstruction. Of the eight subjects with perioperative and/or postoperative upper airway dysfunction following SP, five patients had Pierre Robin sequence/micrognathia, while three patients had a history of perinatal respiratory and/or feeding difficulties without micrognathia or an identified genetic disorder. All but two episodes of airway dysfunction resolved within 3 days postoperatively. These patients were discharged home with apnea monitors; both were readmitted with recurrent airway dysfunction. Continuous positive airway pressure (CPAP) was utilized successfully in all instances, and no patients required take-down of the SP to relieve airway dysfunction. CPAP is an effective, noninvasive treatment strategy for management of iatrogenically induced apnea following SP, without sacrificing the surgical benefit of improved speech intelligibility.

Adolescent↗
PubMed1996

Orbital dysmorphology in unilateral coronal synostosis.

Unilateral coronal synostosis (UCS) produces overt craniofacial dysmorphology. UCS surgery in infancy aims to release the osseous restriction and normalize the fronto-orbital deformity. The quantitative effect of this surgery on the orbit and its contents is unknown. This study was conducted to quantify the preoperative orbital dysmorphology and its surgical outcome in patients with unilateral coronal synostosis. Twenty-eight UCS patients had preoperative three-dimensional computerized tomographic (CT) scans (at mean age 4.0 months), cranio-orbital reconstructive surgery (at 4.7 months), and postoperative scans (at 18.1 months). The CT data were analyzed using a computer workstation and AnalyzeTM biomedical imaging software. Four measurements were performed on both ipsilateral (same side as synostosis) and contralateral (opposite to synostosis) orbits of each scan: orbital index (OI, 100 x height/width of orbit), orbital cavity volume (OV), ocular globe volume (GV), and ventral globe Index (VGI, 100 x globe volume ventral to the anterior surface of orbital cavity/GV). The data were analyzed for statistical significance using Student's ttest. Preoperatively, the OI was significantly greater on the ipsilateral than on the contralateral side (113.7 vs. 87.3). There was a significant improvement on both sides of the orbit postoperatively, with ipsilateral 99.1 and contralateral 92.1. However, the difference between both sides remained significant. The OV was smaller in the ipsilateral orbits both pre- and postoperatively, with ipse/contralateral ratios of 95.8 and 95.2, respectively. Importantly, the GV was consistently smaller in the ipsilateral orbits preoperatively, with an ipse/contralateral ratio of 93.3. The ratio increased to 97.1 postoperatively, a statistically significant change. In the ipsilateral orbits, the preoperative VGI was significantly greater. The VGI improved postoperatively. These data indicate that UCS affects the development of the osseous orbit as well as its soft-tissue contents. After cranio-orbital surgery, there is diminution of asymmetry of both the bony orbit and its soft-tissue contents. Partial normalization of orbital dysmorphology occurred during the first postoperative year. UCS surgery in infancy does not prevent growth of orbital hard or soft tissues, and it seems to permit normalization of previously impaired growth.

Cephalometry↗
PubMed1996

Mandibular dysmorphology in unicoronal synostosis and plagiocephaly without synostosis.

Patients with unicoronal synostosis (UCS) or plagiocephaly without synostosis (PWS) have distinctive skull dysmorphologies. Associated mandibular dymorphologies have been suspected but not quantified. This study was performed to test the hypothesis that discrete mandibular dysmorphology exists in both UCS and PWS. All patients at a tertiary referral center at a medical school-affiliated children's hospital with confirmed diagnosis of UCS or PWS with adequate pretreatment CT data were included in the study population, which population was comprised of 20 UCS, 23 PWS, and 8 normal infants. Each patient had a head CT scan using 2-mm slices. 3-D images were created using Analyze, a biomedical imaging program. The mandibles were isolated, and the coordinates of 8 landmarks were sampled from each mandible by a single investigator: a single volume value was measured, and 9 linear distances and 4 angles were calculated. Corresponding measurements from each hemimandible were expressed as ratios of ipsilateral/contralateral side. In UCS, the affected side was defined as the side ipsilateral to the synostosis; In PWS, the affected side was defined as the side ipsilateral to the occipital flattening. The results from both groups were t tested for statistical significance. For UCS, statistically significant (p < .001) findings included: ipsilateral hemimandibular volume 5% smaller than contralateral; affected hemimandibular body length 1.9% shorter; affected gonial angle 2.6% more acute; affected coronoid process tilted anteriorly 2.5%; and distances from condylion and tip of the coronoid process to the chin landmarks 4% shorter on the affected side. For PWS, significant findings included: affected hemimandibular volume 3.8% larger; ramal height 3.5% shorter; mandibular body length 3% longer; and coronoid process tilted anteriorly by 2.3% on the affected side. In the UCS/PWS comparison, findings included: affected hemimandibular volume in UCS 8.7% less; affected gonial angle in UCS 3% more acute; affected mandibular corpus length in UCS 5% shorter; distances from the condylion and the tip of the coronoid process to the chin landmarks 4% shorter on the affected side in UCS. The hypothesized presence of diagnosis specific mandibular dysmorphology in UCS and PWS is confirmed. This analysis forms the baseline for study of the effects of unperturbed growth or therapeutic interventions upon the dentoskeletal dysmorphology of these anomalies.

Cephalometry↗
PubMed1996

Surgical imaging systems.

Imaging i.n.surgery. is used for diagnosis, planning, intraoperative navigation and post-operative evaluation, DIgItal medical imaging modalities mclude computed tomography (CT), magnetic resonance Imaging (MRI), MR therapy (MRT), fluoroscopy and ultrasound.t These modalities are applied singly or jointly (multimodality) Surgical requirements differ according to the nature of intervention, and real-time guidance? is sometimes needed such that a sequence of images is generated and displayed as acquired, Soft copy display on CRTscreens is satisfactory for intraoperative use, while hardcopy film images or physical replica modeling may be needed in other cases. Computed tomography/ developed more than 20 years ago, remains important in craniofacial'v" and orthopedic surgery." Newer imaging systems, especially ultrasound, magnetic resonance imaging,'6 and digital fluoroscopy are used for neurosurgery, oncology, cardiothoracic and abdominal surgery. Each modality offers specific qualities that subserve specific needs in diagnosis, planning, intraoperative navigation and evaluation (Table 1).

Journal Article↗
PubMed1996

Observations on a recent increase in plagiocephaly without synostosis.

OBJECTIVE: To verify and determine the cause of an increase in the referral of infants with plagiocephaly without synostosis (PWS) to a single tertiary craniofacial center. DESIGN: A chart review was performed for 269 infants with a diagnosis of PWS who presented to a single tertiary craniofacial center between 1979 and 1994. The pattern of referral for PWS was analyzed using both simple linear regression and time series regression analyses. In addition, the referral pattern for PWS was compared with that for infants seen at the same center who received a diagnosis of synostotic plagiocephaly. Changes in the distribution of several demographic, perinatal, and clinical variables during the study period were also assessed. Finally, in an effort to identify correlates of the risk of PWS developing, characteristics of patients who were Missouri residents and presented between 1992 and 1994 were evaluated and compared with those of the 1993 Missouri live birth cohort. SETTING: The Cleft Palate and Craniofacial Deformities Institute, St Louis Children's Hospital, Washington University Medical Center. RESULTS: The average annual number of referrals to our center for PWS in the period 1992 to 1994 was more than sixfold greater than that for the preceding 13 years. There was a statistically significant increase in the annual number of referrals to our center during the 16-year study period. Moreover, there was evidence that the average annual increase in referrals was significantly greater during the last 3 years (1992 through 1994) of the study than in the first 13 years. This shift in the referral patterns is roughly contemporaneous with the American Academy of Pediatrics recommendations regarding infant sleep position. There was no evidence that either the mean number of referrals or the average annual increase in referrals for patients with synostosis changed during the study period. Among patients with PWS, the average age at presentation did not change during the study period. There were also no significant changes in the distribution of other demographic, perinatal, and clinical variables. When compared with the Missouri birth cohort, infants with PWS were significantly more likely to be boys and to have been delivered by forceps. There was also some evidence that patients with PWS were more likely to be born prematurely and to be products of multiple-gestation pregnancies. These associations were, however, of only borderline statistical significance. CONCLUSION: Referrals to our center for PWS increased markedly in 1992 relative to previous years. The temporal coincidence of this increase with the American Academy of Pediatrics recommendation to avoid the prone sleeping position, to reduce the risk of sudden infant death syndrome, suggests a possible causal relationship. If this association is causal, education regarding the need for head position rotation coupled with that for sudden infant death syndrome should obviate positional PWS.

Craniosynostoses↗
PubMed1996

Three-dimensional imaging, surgical planning, and image-guided therapy.

Three-dimensional imaging is now widely available and used often to aid in the comprehension and application of volumetric data to diagnosis, planning, and therapy. CAS comprises visualization of complex anatomy, planning of interventions, image-based guidance for diagnosis and therapy, evaluation of results, and follow up. CAS-networked workstations have interactive pointing devices and specialized software that support simulation, navigation, and follow-up functions. Volumetric and real time digital imaging are used to plan procedures, for intra-operative guidance, and to monitor progress. Monitoring with real time ultrasound, fluoroscopy, and MR imaging is performed to assess local effects of specific therapeutic modalities. Normative data bases, especially digital stereotactic atlases, allow incorporation of a priori anatomic knowledge in CAS. Computer-assisted planning and simulation of complex craniofacial surgery is feasible with commercially available software and hardware using CT scan and MR images. This can be performed by an operator with low-level computer skills on a graphics workstation. The outcome of computer-simulated surgery can be validated quantitatively. Computer-simulated surgery does affect the choice of intervention for patients with complex craniofacial anomalies. Further evaluation of the process is needed to determine the influence of surgical simulation and planning on outcome.

Computer Simulation↗