Clinical experience with the application of distraction osteogenesis for airway obstruction.

OBJECTIVES: The objective of this study was to evaluate the long-term success of mandibular distraction osteogenesis in patients with mandibular airway obstruction syndrome (MAOS), defined as obstructive sleep apnea, swallowing abnormalities, and failure to thrive in the presence of micrognathia, glossoptosis, gastroesophageal or laryngeal reflux, and microaspiration. This is a cross-sectional study at the International Craniofacial Institute in the Medical City Hospital, Dallas, TX. From January 1997 to July 2008, a group of 81 patients were examined for MAOS using medical history and physical examination. They all met the criteria for a multidisciplinary team evaluation consisting of upper airway endoscopy, swallowing evaluations, standard overnight polysomnography, and radiologic evaluations of the airway and craniofacial structures. MATERIALS AND METHODS: In the 81 patients examined, Pierre Robin Sequence was diagnosed in 65; micrognathia and glossoptosis without cleft palate, in 13; and micrognathia as a component of a craniofacial syndrome (Treacher Collins syndrome), in 3. A total of 45 patients were documented to have gastroesophageal or laryngeal reflux.Only 41 patients had yet to receive any treatment at the time of evaluation; 40 patients presented with a tracheotomy.Of the 41 untreated patients, 14 responded to conservative treatment; Pierre Robin syndrome was diagnosed in all of them, and they did not require mandibular distraction or other surgical procedure to improve the MAOS.Bilateral distraction osteogenesis of the mandible was performed in 67 patients; 27 were younger than 6 months at the beginning of the distraction, and 40 were older than 6 months (mean age at distraction, 1.2 yr). Of this group, 26 patients did not have any prior surgical treatment, and 41 patients already had a tracheotomy. The distraction devices used were internal in 33 (49.26%) and external in 34 (50.74%) of 67 patients. The distraction protocol consisted of a 24-hour latency period and then a 1-mm/d activation period. The mean activation period was 19.4 days (range, 10-27 d), the mean consolidation period was 73 days, and the mean length of distraction was 22 mm (range, 10-32 mm). RESULTS: Tracheostomy was prevented in 25 (96%) of 26 patients, and decannulation after distraction was possible in 38 (92%) of 41 patients. Success, defined as decannulation within 1 year of the start of distraction or prevention of tracheostomy in a patient otherwise deemed as a candidate, was found in 63 (94%) of 67 patients. Oral feedings have been resumed in 61 (91%) of 67 patients.Complications observed were mostly related to pin site infections requiring antibiotics. Device failure was experienced in 2 (3%) of 66 internal devices and in 7 (10.2%) of 68 external devices.Distraction osteogenesis of the mandible provides an excellent treatment for mandibular airway obstruction in patients younger than 6 years who do not respond to conservative measures and allows for early decannulation in patients who previously underwent tracheotomy.

A novel method for measuring and monitoring monobloc distraction osteogenesis using three-dimensional computed tomography rendered images with the "biporion-dorsum sellae" plane. Part II: comparison of measurements before and after distraction.

The aim was to assess the stability of monobloc distraction osteogenesis using three-dimensional computed tomographic (CT) scan volume-rendered images with the "biporion-dorsum sellae" plane. This was a prospective study of patients undergoing monobloc internal distraction osteogenesis at the International Craniofacial Institute, Dallas, TX. Measurements were made of the perpendicular distance of 8 skeletal facial points to the static "biporion-dorsum sellae" plane. The statistical analyses were performed with the paired-samples t test in SPSS. Three male patients were included in the study. Of these patients, 2 had Apert syndrome (A, B) and 1 had Carpenter syndrome (C). The mean age was 73 (range 30-112) months, and the mean follow up was 14 (range 8-12) months. The consolidation period was 17, 23, and 28 weeks in each patient, respectively. In patient A, the paired-samples t test of matched points was P = 0.022. Further analysis of the three-dimensional lateral profile revealed an obvious relapse, and predistractor removal CT scans (at 17 weeks) also showed deficient bone growth across the distraction gaps at the anterior cranial fossae and the temporal bones. In contrast, patients B and C showed a stable outcome after distraction and after removal of distraction devices. On analysis of the predistractor removal three-dimensional CT scans (23 and 28 weeks, respectively), there was more bone growth across the distraction gaps at the anterior cranial fossa and temporal bones. The "biporion-dorsum sellae" plane was used to assess the results of monobloc distraction osteogenesis. Relapse was associated with inadequate bone growth across the anterior cranial fossa and temporal bone. The findings seem to point the way for an increased consolidation period and more detailed examination of the CT scans before removal of internal distraction devices.

Bone generation in the reconstruction of a critical size calvarial defect in an experimental model.

OBJECTIVE: This study was designed to investigate the optimal combination of known osteogenic biomaterials with shape conforming struts to achieve calvarial vault reconstruction, using a canine model. METHODS: Eighteen adolescent beagles were divided equally into 6 groups. A critical size defect of 6 x 2 cm traversed the sagittal suture. The biomaterials used for calvarial reconstruction were demineralised perforated bone matrix (DBM), recombinant human bone morphogenetic protein-2 (rhBMP2) and autogenous platelet-rich plasma (PRP). The struts used were cobalt chrome (metal) or resorbable plate. The groupings were as follows: 1) DBM + metal, 2) DBM + PRP + metal, 3) DBM + PRP + resorbable plate, 4) DBM + rhBMP2 + metal, 5) DBM + rhBMP2 + PRP + metal, and 6) DBM + rhBMP2 + resorbable plate. Animals were euthanised at 3 months post-surgery. There was no mortality or major complications. Analysis was performed macroscopically, histologically, and with computed tomography (CT). RESULTS: There was complete bony regeneration in the rhBMP2 groups only. Non-rhBMP2 groups had minimal bony ingrowth from the defect edges and on the dural surface, a finding confirmed by CT scan and histology. PRP did not enhance bone regeneration. Shape conformation was good with both metal and resorbable plate. CONCLUSION: rhBMP2 but not PRP accelerated calvarial regeneration in 3 months. The DBM in the rhBMP2 groups were substituted by new trabecular bone. Shape molding was good with both metal and resorbable plate.

Preoperative screening for coagulopathy using prothrombin time and partial thromboplastin time in patients requiring primary cranial vault remodeling.

BACKGROUND: The aim of this study was to investigate the prevalence of abnormal preoperative screening prothrombin time and partial thromboplastin time in patients listed for primary cranial vault remodeling that required hematologic workup and their diagnoses and subsequent management. METHODS: This retrospective analysis was performed from January of 2000 to December of 2003 at the International Craniofacial Institute, Dallas, Texas, on a total of 168 patients. RESULTS: All patients had a normal prothrombin time. Abnormally raised partial thromboplastin time was found in six patients (prevalence of 3.57 percent), one who had factor XI deficiency, one who had a borderline factor XI deficiency and circulating inhibitor, one who had an intermittent factor XI deficiency and circulating inhibitor, one who had a borderline von Willebrand's disease with low factor XII, and the remaining two who had a circulating inhibitor of coagulation. Of these six patients, the perioperative management was altered in four of five patients, and one patient declined surgery out of fear of surgical morbidity. The surgery of one patient was aborted intraoperatively because of abnormal bleeding without clot formation after the calvarial burr holes had been drilled. The mean blood loss was 183 ml for the four patients with completed surgery and 100 ml for one patient. CONCLUSIONS: The authors conclude that even though the prevalence of abnormal screening partial thromboplastin time in these patients was low (3.57 percent), detection of an abnormal result required preoperative correction of coagulopathy in 80 percent of cases.

A novel method for measuring and monitoring monobloc distraction osteogenesis using three-dimensional computed tomography rendered images with the 'biporion-dorsum sellae' plane. Part I: Precision and reproducibility.

The results of craniofacial and orthognathic surgery have traditionally been monitored using lateral cephalometry. In the age of computed tomography (CT) and magnetic resonance imaging (MRI), newer methods of measuring surgical outcome have arisen. This has been further enhanced by the use of computer software to render CT images in a three-dimensional format. The authors present a novel method of measuring the outcome of monobloc distraction osteogenesis advancement using the biporion-dorsum sellae plane. The perpendicular distance of eight facial skeletal points to this plane were made automatically using the Vworks 4.0 program. A total of 10 measurements were made against six planes of reference. Planes 1, 2, 3, 1+2 degrees, and 1-2 degrees were constructed, and measurements were made by observer 1. Plane 6 was constructed and measurements were made by observer 2. Plane 1 was used as the denominator on which calculations were made. The results revealed a mean intra- and interobserver percentage difference from plane 1 of less than 5%. In addition, the overall mean intraobserver variance of all eight points from observer 1 was 0.91%, and the mean interobserver variance between observer 1 and 2 was 0.73%. In summary, based on the authors' method, repeated measurements made from the biporion-dorsum sellae plane have proven precision and reproducibility.

Extensive neglected psammomatoid ossifying fibroma with craniofacial deformity.

The psammomatoid ossifying fibroma is a rare and aggressive lesion that usually arises from the sinonasal region. The lesion is well circumscribed with the pathognomonic feature of concentric or laminated spherical ossicles that appear similar to psammoma bodies. The authors report a case of an extensive and neglected psammomatoid ossifying fibroma in a 10-year-old West African girl. She had a 5-year history of a slowly growing tumor, which at presentation was 15 cm in diameter and had resulted in left craniofacial deformity as well as left visual impairment. Due to the large tumor, the surgical resection plan necessitated a cranio-facial neurosurgical approach in combination with autogenous bone grafts for cranofacial reconstruction, and allogenous demineralized bone grafts for donor site coverage. In addition, preoperative embolization was utilized to reduce tumor vascularity. However, this embolization resulted in reduction of pericranial flap vascularity, leading to flap ischemia, infection and subsequent removal of necrotic autogenous bone graft. Ultimately, the objectives of large tumor resection and acceptable aesthetic outcome were met after controlling an episode of postoperative infection.