Intracranial volume and whole brain volume in infants with unicoronal craniosynostosis.

OBJECTIVE: Craniosynostosis has been hypothesized to result in alterations of the brain and cerebral blood flow due to reduced intracranial volume, potentially leading to cognitive deficits. In this study we test the hypothesis that intracranial volume and whole brain volume in infants with unilateral coronal synostosis differs from those in unaffected infants. DESIGN: Our study sample consists of magnetic resonance images acquired from 7- to 72-week-old infants with right unilateral coronal synostosis prior to surgery (n  =  10) and age-matched unaffected infants (n  =  10). We used Analyze 9.0 software to collect three cranial volume measurements. We used nonparametric tests to determine whether the three measures differ between the two groups. Correlations were calculated between age and the three volume measures in each group to determine whether the growth trajectory of the measurements differ between children with right unicoronal synostosis and unaffected infants. RESULTS: Our results show that the three volume measurements are not reduced in infants with right unicoronal synostosis relative to unaffected children. Correlation analyses between age and various volume measures show similar correlations in infants with right unicoronal synostosis compared with unaffected children. CONCLUSIONS: Our results show that the relationship between brain size and intracranial size in infants with right unicoronal synostosis is similar to that in unaffected children, suggesting that reduced intracranial volume is not responsible for alterations of the brain in craniosynostosis.

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.

Long-term outcome of cleft lip nasal reconstruction in childhood.

This study documents the pattern of unilateral cleft lip nasal reconstruction in the practice of one surgeon at a tertiary cleft center, evaluating the long-term appearance outcome of single-operation unilateral cleft lip nasal reconstruction in childhood. A retrospective medical record review was performed for all patients with a diagnosis of unilateral cleft lip and age greater than 15 years. Operative notes were reviewed, recording 15 variables identifying specific rhinoplastic maneuvers. Nasal appearance outcome analysis was performed for all patients who underwent only one nasal surgery before 12 years of age (n = 19). Standard frontal whole face photographic images were presented as opposing pairs in a looseleaf binder to two panels, 1 of 10 lay persons and 1 of 10 plastic surgeons. Each pair consisted of photographs of the same patient at different ages in one of three combinations: preoperative-perioperative, perioperative-longest postoperative, or preoperative-longest postoperative. Participants were asked to compare the appearance of the noses in the two photographs and assign a rating based on a 5-point Likert scale. Statistical analyses were performed on the data collected in the aesthetic analysis. The effect of surgery upon nasal appearance was assessed by comparing the preoperative and perioperative photographs. The effect of growth was assessed by comparing the perioperative and long-term postoperative photographs. The combined effect of surgery and growth was assessed by comparing the preoperative and long-term postoperative photographs. The data were assessed by lay and professional evaluators, together and separately, to determine whether differences existed. The majority of patients did not undergo revisional nasal surgery, whereas those who did usually had one nasal operation. Most revisional nasal surgery was performed in conjunction with other cleft-related secondary surgery. A majority of lay and professional evaluators perceived revisional nasal surgery as improving nasal appearance in the short-term and to a lesser degree in the long-term, as compared with the preoperative state. Evaluations of revisional nasal surgery are generally constant between the short-term and long-term postoperative images. Lay evaluations may be contaminated by a general decline in attractiveness with aging. Patient preference should be a major factor in the decision for nasal revision surgery. Multiple means of assessing nasal appearance outcome need to be used to validate results. Nasal appearance outcomes need to be correlated with outcomes with respect to nasal morphology and function as well as patient and parent satisfaction.

The course of the inferior alveolar nerve in the normal human mandibular ramus and in patients presenting for cosmetic reduction of the mandibular angles.

This study was undertaken to quantify the path of the inferior alveolar nerve in the normal human mandible and in the mandibles of patients presenting for cosmetic reduction of the mandibular angles. The goals were: (1) to provide normative information that would assist the surgeon in avoiding injury to the nerve during surgery; (2) to characterize gender differences in the normal population; and (3) to compare the course of the nerve in the normal population to its course in a group of patients who presented with a complaint of "square face." The study was based upon the computerized tomographic scans of 10 normal patients (six men, four women) and 8 patients (all women) complaining of "square face." Using AnalyzePC 2.5 imaging software, the mandibles were segmented and the position of the nerve was recorded within its osseous canal in the mandibular ramus on each axial slice in which it was identifiable. Distances were calculated between the nerve and the anterior, posterior, lateral, and medial cortices. The positions of the lateral ramus prominence and the lowest point on the sigmoid notch were also recorded. The position of the mental foramen was recorded in relation to the nearest tooth, and the three-dimensional surface distances from the foramen to the alveolar bone, the inferior border of the mandible, and the mandibular symphysis were determined. The distances from the entrance of the nerve into the mandible to the lateral ramus prominence and the lowest point on the sigmoid notch were calculated. Summary statistics were obtained, comparing differences in gender. The nerve was identifiable in each ramus over a mean distance of 12.7 mm. On average, the lateral ramus prominence was 0.3 mm higher on the caudad-cephalad axis than the point at which the nerve entered the bone, whereas the location of the lowest point on the sigmoid notch was 16.6 mm above the nerve. The average distances from the nerve to the anterior, posterior, medial, and lateral cortices were 11.6, 12.1, 1.8, and 4.7 mm, respectively. Gender differences were significant for all of these except the medial cortex to nerve distance. On average, the mental foramen exited the body of the mandible immediately below the second premolar and the average surface distances from the foramen to the symphysis, the most cephalad alveolar bone, and the inferior border of the body were 30.9, 14.2, and 19.3 mm, respectively. With regard to the patients presenting for mandibular angle reduction, there were a few statistically significant but small scalar differences from normal controls.

Relationship between bone and muscles of mastication in hemifacial microsomia.

The relationship between the bone and muscles of mastication in hemifacial microsomia was studied using three-dimensional volumetric computed tomography scans and image processing techniques. High resolution head computed tomography scans were obtained from 31 patients with unilateral hemifacial microsomia and eight normal patients. Using three-dimensional volume renderings of bone, mandibular deformities in patients with hemifacial microsomia were classified using the Pruzansky system. For each patient, specific craniofacial bones (temporal bone, maxilla mandible) and the muscles of mastication (masseter, temporalis and lateral and medial pterygoid) were segmented bilaterally from the image volume for independent display and volume measurement. Volumes were expressed as the ratio of the affected: unaffected sides. For the masseter and temporalis, the relationship between muscular hypoplasia and osseous hypoplasia in its origin and insertion was studied by plotting affected:unaffected bone volume as a function of affected:unaffected muscle volume for each muscle, bone of origin, bone of insertion triplet. The volumes of the pterygoid muscles were compared with hemimandibular volumes. The precision of object segmentations was examined by repetitive definition tasks, whereas the accuracy of volume measurement was tested by scanning custom-made phantom objects and comparing digital to physical object volume measurements. Volume measurements performed using these techniques were both accurate and precise. In hemifacial microsomia, the extent of hypoplasia of specific muscles of mastication predicted the extent of dysplasia in their osseous origin and insertion. However, the reverse was not true. The extent of hypoplasia of the facial bones did not necessarily predict the extent of hypoplasia in the attached muscles of mastication. Pruzansky grade of the mandible described the degree of mandibular hypoplasia on the affected side, but was inconsistent in its prediction of volume decrease of the other facial bones.

Quantification of osseous facial dysmorphology in untreated unilateral coronal synostosis.

Unilateral coronal synostosis results in dysmorphology of the midface in addition to well-characterized cranial and orbital deformities. Because most American infants with this problem have undergone cranio-orbital surgery within their first year of life for the past 25 years, a paucity of data exist regarding the natural history of untreated unilateral coronal synostosis. In an attempt to remedy this void, an international search was conducted to identify computed tomography data sets of living individuals with untreated unilateral coronal synostosis; data were obtained from two European centers and one center in the United States. Results limited to the study of the midface are presented here. Digital data from high-resolution head computed tomography scans of 11 living, white individuals with untreated unilateral coronal synostosis were obtained from three craniofacial centers (in Denmark, The Netherlands, and the United States). Image volumes were constructed from each scan using ANALYZE biomedical imaging software. Fourteen pairs of three-dimensional distances were calculated on the ipsilateral (the side of the synostosis) and the contralateral (the side opposite to the synostosis) hemifaces using 11 osseous landmarks. The resulting measurements were expressed as a ratio of the ipsilateral: contralateral sides. Descriptive statistics were derived for the untreated unilateral coronal synostosis population and compared with analogous measurements performed on dried skulls. Age at computed tomography ranged from 1.1 to 21.1 years (mean, 6.6 years; median, 4.1 years). Twelve of the 14 measured distances differed by greater than 5 percent on the ipsilateral side, and all but one of these measurements were decreased on the ipsilateral side when compared with contralateral values. The results of this study support the following conclusions: (1) There are discrete and measurable differences in the facial morphology between patients with untreated unilateral coronal synostosis and normal skulls. (2) Intercenter and international collaboration can provide a sufficient number of individuals with rare craniofacial anomalies to quantitatively determine group characteristics. (3) Quantitative documentation of rare anomaly natural history is necessary for quantitative outcome assessment of treated patients.

The craniofacial anomalies archive at St. Louis Children's Hospital: 20 years of craniofacial imaging experience.

This article describes how the Craniofacial Imaging Laboratory at the Cleft Palate and Craniofacial Deformities Institute, St. Louis Children's Hospital, Washington University Medical Center, has developed an electronic archive for the storage of computed tomography image digital data that is independent of scanner hardware and independent of units of storage media (i.e., floppy disks and optical disks). The archive represents one of the largest repositories of high-quality computed tomography data of children with craniofacial deformities in the world. Archiving reconstructed image data is essential for comparative imaging, surgical simulation, quantitative analysis, and use with solid model fabrication (e.g., stereolithography). One tertiary craniofacial center's experience in the establishment and maintenance of such an archive through three generations of storage technology is reported. The current archive is housed on an external 35-GB hard drive attached to a Windows-based desktop server. Data in the archive were categorized by specific demographics into groups of patients, number of scans, and diagnoses. The Craniofacial Imaging Laboratory archive currently contains computed tomography image digital data for 1827 individual scans. The earliest scan was done in 1980; the most recently stored scan for the purposes of this report occurred in May of 2000. The average number of scans archived per complete year was 94, with a range of 59 to 138. Of the 1827 total scans, 74 percent could be classified into specific diagnostic categories. The majority of the archive (55 percent) is composed of the following five diagnoses: sagittal synostosis (17 percent), unilateral coronal synostosis (11 percent), hemifacial microsomia (10 percent), plagiocephaly without synostosis (10 percent), and metopic synostosis (7 percent). Storage of computed tomography image data in a digital archive currently allows for continuous upgrading of image display and analysis and facilitates longitudinal and cross-sectional studies, both intramural and extramural. Internet access for clinical and research purposes is feasible, but contingent on protection of patient confidentiality. The future of digital imaging regarding craniofacial computed tomography scan storage and processing is also discussed.

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).

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.

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.

The effect of hamulus fracture on the outcome of palatoplasty: a preliminary report of a prospective, alternating study.

OBJECTIVE: To determine whether, in performing palatoplasty, fracture of the pterygoid hamulus is beneficial, detrimental, or neutral with respect to intraoperative and perioperative complications, hearing outcome, and speech outcome. DESIGN: Prospective, alternating. SETTING: Institutional, tertiary cleft palate center, Chang Gung Memorial Hospital, Taipei, Taiwan. PARTICIPANTS: A total of 173 patients enrolled in the study, of whom 161 had charts available for analysis. INTERVENTIONS: During the performance of palatoplasty, 85 patients received hamulus fracture and 76 patients did not. All palatoplasties were performed by the same surgeon. MAIN OUTCOME MEASURES: (1) Surgical outcomes, including patient demographic data, palatoplasty type and duration, blood loss, incidences of oronasal fistulae, temporary mucosal dehiscence, and postoperative bleeding; (2) otolaryngological outcomes, including hearing results as judged by auditory brainstem response testing, myringotomy tube data describing rates of tube extrusion, and culture results from sampled effusions; and (3) preliminary speech outcomes as described by judgments of overall velopharyngeal function from perceptual speech samples. RESULTS: No statistically significant differences in any of the measured surgical, otolaryngological, or preliminary speech outcomes were found between the groups who did and did not receive hamulus fracture. CONCLUSIONS: On the basis of these results, we are unable to advocate the performance of hamulus fracture as an operative maneuver during the performance of primary palatoplasty. The historical rationale and theoretical advantage of this maneuver have not been demonstrated here nor have any detrimental effects of the maneuver been measured.