J. David

Three-Dimensional Reconstruction of Craniofacial Deformity Using Computed Tomography

The computed tomographic studies obtained routinely in the examination of patients with congenital or acquired defects of the skull and facial bones can be utilized as a substrate to provide an accurate three-dimensional representation of osseous abnormalities. The total dose of x-irradiation is reduced as other means of radiological examination are eliminated. Osseous structures are faithfully reproduced. Complete inspection of the reproduced structure can be made from any viewpoint, including internal inspection.

Mandibular reconstruction with vascularized iliac crest : A 10-year experience

Since 1978, 35 patients have undergone mandibular reconstruction with vascularized iliac crest. During this time, the technique of raising and shaping the iliac crest has undergone a series of modifications. Initially, osteo-cutaneous segments based first on the superficial circum-flex iliac System and later on the deep circumflex iliac System were used. More recently, only the inner table of the ilium has been employed, and where intraoral lining is required, an ulnar forearm free flap has been added. Thirty-two patients were reconstructed successfully. Of the three anastomotic failures, one bony segment was able to survive as a free graft. There were no donor-site complications. With continued experience, operative morbidity has been minimized, while the technique has been modified to tailor the reconstruction to the specific requirements of the patient. It is concluded that vascularized iliac crest provides the most appropriate mandibular reconstruction for a range of congenital and acquired defects.

Hemifacial microsomia: a multisystem classification.

Variability of deformities in hemifacial microsomia has precluded the general acceptance of any classification based on one reference organ. We present a review of hemifacial microsomia classifications and propose a TNM-style multisystem classification. This alphanumeric coding system, SAT, provides cohesion to existing hemifacial microsomia classifications. The acronym SAT is derived as follows: S = skeletal, A = auricle, and T = soft tissue. There are five levels of skeletal deformity (S1 through S5), four levels of auricular deformity (A0 through A3), and three levels of soft-tissue deformity (T1 through T3). Hence a patient with minimal deformity would be classified S1A0T1, whereas a patient with the most severe deformity would be S5A3T3.

Mandibular lengthening by distraction for airway obstruction in Treacher-Collins syndrome.

Mandibular lengthening by distraction was performed in a 6-year-old tracheostomy-dependent Treacher-Collins syndrome patient. Detailed preoperative imaging revealed an occluded retrotongue base pharyngeal airway, which, following mandibular distraction, became patent and permitted tracheostomy removal. Mandibular distraction as a technique must be targeted toward clinical problems—management of upper-airway obstruction may be one such scenario.

Cephaloceles: Treatment, Outcome, and Antenatal Diagnosis

A series of 74 cephaloceles (17 cranial meningoceles and 57 meningoencephaloceles) is reported. Infants born with large meningoencephaloceles containing recognizable cerebral tissue usually did badly despite endeavors to conserve brain function by expanding the cranial capacity (5 cases) or decompressing hydrocephalic ventricles (9 cases). Infants with cranial meningoceles almost all did well, even when there was associated hydrocephalus. The etiological diversity of cephaloceles is emphasized. Frontoethmoidal meningoencephaloceles, which occur with noteworthy frequency in South and Southeast Asia, require separate consideration in both genetic counseling and treatment; the associated facial deformities (hypertelorism and orbital dystopia) can be corrected with a one-stage craniofacial reconstruction. Antenatal diagnosis by ultrasound is now often possible and was achieved in 4 cases; we suggest that neurosurgeons should participate in such antenatal evaluations.

Craniofacial Infection in 10 Years of Transcranial Surgery

Infection following transcranial surgery may be devastating. A review of 170 transcranial operations is presented with a focus on postoperative infection and its relationship to patient age, preoperative microbiology, pattern of operation, length of operation, and the use of antibiotic prophylaxis. The overall postoperative infection rate was 6.5 percent, but the infection rate in adults (23.5 percent) was much higher than in children (2.2 percent). Higher infection rates were found in adults with craniofacial dysostoses undergoing lengthy frontofacial advancements which required tracheostomy airway management. The residual frontal extradural dead space following advancement in adults is a sanctuary to infecting organisms from the respiratory tract--especially Pseudomonas transferred from the tracheostomy site into the upper airway and intracranial dead space by ventilation forces. Operating times for patients who became infected were 2 1/2 hours longer than average operating times for transcranial operations. Preoperative microbiology of the craniofacial region was not a good predictor of subsequent infection. Recommendations include operative intervention at an early age, short preoperative hospital stay, antibiotic prophylaxis to include gram-negative cover, surgical measures to either fill or isolate the dead space, and strict tracheostomy care--preferably with the patient being barrier-nursed.

The craniosynostoses : causes, natural history, and management

I Causes and Effects.- 1 The Concept of Craniosynostosis and the Evolution of Craniofacial Surgery.- 2 The Growth of the Skull and the Role of the Sutures.- 3 Aetiology and Pathogenesis.- 4 Pathology.- 5 Incidence.- II Symptoms and Strategies.- 6 Symptomatology.- 7 Principles of Investigation.- 8 Principles of Treatment.- III Simple Calvarial Deformities.- 9 Classification.- 10 Scaphocephaly.- 11 Trigonocephaly.- 12 Turricephaly.- 13 Plagiocephaly.- 14 Oxycephaly and Related Conditions.- IV Complex Craniofacial Deformities.- 15 Craniofacial Syndromes.- Crouzon Syndrome.- Apert Syndrome.- Saethre-Chotzen Syndrome.- Pfeiffer Syndrome.- Carpenter Syndrome.- Cohen Syndrome.- Other Craniofacial Syndromes.- 16 Surgical Management.- 17 Results and Complications.- 18 Psychosocial Aspects of Craniofacial Surgery.- Appendices.- A: Organisation of a Craniofacial Unit.- B: Syndromes Associated with Craniosynostosis.- References.

CT-determined intracranial volume for a normal population.

Intracranial volume comparisons of patients with craniosynostosis and normal have been contrary to expectations, leading to questioning of the validity of the current normal reference material. Computed tomography-determined intracranial volume is presented for a white normal population. Specifically, intracranial volumes for 157 subjects (82 female and 75 male) were measured from computed tomography data using the Cavalieri estimator: volume determination was based on measuring the area in each computed tomography section. Monomolecular and Gompertz models were applied to find curves of best fit to the intracranial volume as a function of the age. The best fit was obtained using the monomolecular model when the response variable was the logarithmically transformed intracranial volume, and the independent variable was the logarithm of the age from conception. For example, the mean (standard deviation) for male subjects at 1 year and 20 years were 1,125.6 (89.6) ml and 1,472.9 (117.2) ml, respectively, and for female subjects 1,024.9 (84.0) ml and 1,321.7 (108.3) ml, respectively. Although the shape and rate of increase of the female and male curves is similar, the female mean is 1.3 standard deviations below the male mean at 20 years. These curves were compared with the commonly referenced curves of Blinkov (1941), Lichtenberg (1960), and Dekaban (1977). Our male curve is substantially higher than these curves in the age range 8 months to 4 years. Our female curve, however, is approximately 1 standard deviation below Lichtenbergs curve from birth to 7 months. There are then only minor differences between our female curve and Lichtenbergs curve until his curve crosses ours at 41 months, where they significantly diverge from approximately 4.5 years. Our curves indicate that 95% of the final intracranial volume has been attained by 42 months for girls and 46 months for boys.

Obstructive sleep apnea in Apert's and Pfeiffer's syndromes: more than a craniofacial abnormality.

Nine acrocephalosyndactyly type I patients (Aperts syndrome) and three acrocephalosyndactyly type V patients (Pfeiffers syndrome) were evaluated for the relative importance of upper and lower airway abnormalities in the generation of obstructive sleep apnea. All patients were found to have a combination of upper and lower abnormalities. The influence of lower pathology was greater in the infants, and the influence of upper airway, specifically pharyngeal, was greater in the adults. A comparison between preoperative and postoperative polysomnography revealed little improvement with standard craniofacial advancements. Furthermore, three patients are described who succumbed to pulmonary death despite tracheostomy. Conservative treatment with prone or lateral positioning and medical pulmonary regimens is advocated. Finally, the pathogenesis of this diffuse airway pathology is discussed.

Fronto-ethmoidal meningoencephaloceles: morphology and treatment.

Twenty-five cases of fronto-ethmoidal meningoencephaloceles have been studied. The relationship to other sincipital meningoencephaloceles is explored. In all cases the exit holes from the anterior cranial fossa are at the site of the foramen caecum. The facial component of the defect determines the sub-classification: naso-frontal, naso-ethmoidal and naso-orbital. The cranio-facial deformity may consist of hypertelorism, orbital dystopia, elongation of the face and dental malocclusion. These reflect the distorting influence of the extruded intracranial contents on facial growth. Early removal of the meningoencephalocele by the cranio-facial route is recommended to allow normal growth forces to be re-established. In older patients with established deformities translocation of the orbits may be necessary.