Mark Egbert

Lymphatic malformations: Review of current treatment:

Objective: Summarize current knowledge of lymphatic malformation medical, sclerotherapy, and surgical treatment; and highlight areas of treatment controversy and treatment difficulty that need improvement. Methods: Panel presentation of various aspects of lymphatic malformation treatment. Results: The mainstay of lymphatic malformation treatment has been surgical resection, which has been refined through lesion staging and radiographic characterization. Intralesional sclerotherapy in macrocystic lymphatic malformations is effective. Suprahyoid microcystic lymphatic malformations are more difficult to treat than macrocystic lymphatic malformations in the infrahyoid and posterior cervical regions. Bilateral suprahyoid lymphatic malformations require staged treatment to prevent complications. Lymphatic malformation treatment planning is primarily determined by the presence or possibility of functional compromise. Problematic areas include chronic lymphatic malformation inflammation, dental health maintenance, macroglossia, airway obstruction, and dental malocclusion. Conclusions: Lymphatic malformation treatment improvements have been made through radiographic characterization and staging of lymphatic malformations. Direct malformation involvement of the upper aerodigestive tract can cause significant functional compromise that is difficult to treat.

Stability of Le Fort I osteotomy with maxillary advancement: A comparison of combined wire fixation and rigid fixation☆

PURPOSE This study compares two types of fixation: intraosseous wires, skeletal suspension wiring, and maxillomandibular fixation (combined wire fixation; CWF) with rigid internal fixation (RIF) in patients who underwent Le Fort I osteotomy to correct maxillary hypoplasia. MATERIALS AND METHODS All patients were operated on by the same surgeon using a standard technique, which included bone grafting. The 12 patients in group A were treated with CWF for 4 weeks. Group B was made up of 13 patients who had RIF and training elastics for 4 weeks. Cephalometric analysis using a commercial software package was performed on radiographs that were taken immediately preoperatively (T1), 1 day postoperatively (T2), and at least 1 year postoperatively (T4). The position of the maxilla in relation to the cranial base and Frankfort plane at each time interval was compared. RESULTS Postsurgical horizontal change (maxillary position change from T2 to T4) for both groups was in the posterior direction. In group A, six patients had less than 1 mm change, three had 1 to 2 mm change, and three had > 2 mm change. In group B, 10 patients had less than 1 mm change, three had 1 to 2 mm change and 0 had > 2 mm change. Comparison of mean values of groups A and B suggested improved stability with rigid versus wire fixation in the horizontal plane; however, statistical analysis of adjusted mean values showed no significant difference. Vertical changes in maxillary position were also measured from postoperatively to 1 year (T2 to T4). The vertical changes were minimal in those cases of maxillary advancement where no vertical changes were planned; however, there was a statistically significant (P = .0024) improved stability with RIF versus combined wire fixation cases. Comparison of adjusted means showed double the amount of vertical setting 1 year postoperatively in the CWF group. CONCLUSION Overall, 22 of 25 patients with horizontal maxillary advancement had excellent stability at 1 year. Observed trends suggest that RIF may have improved stability over CWF.

Lymphatic malformations: Current cellular and clinical investigations

Objective: Summarize current knowledge of lymphatic malformation development, biology, and clinical outcome measures. Methods: Panel presentation of lymphatic malformation biology and measurement of head and neck malformation treatment outcomes. Results: Characterization of lymphatic malformation endothelial and stromal cells may lead to biologically based treatment. Traditionally, lymphatic malformation treatment outcomes have been measured according to reduction of malformation size. Currently, methods to measure functional outcomes following lymphatic malformation treatment are lacking. This is particularly apparent when the malformation directly involves the upper aerodigestive tract. Conclusions: The etiology and pathogenesis of head and neck lymphatic malformations are poorly understood, but understanding is improving through ongoing investigation. Reduction of lymphatic malformation size is generally possible, but further work is necessary to optimize methods for measuring therapeutic outcomes in problematic areas.

Orbital abscess of odontogenic origin. Case report and review of the literature

A case is discussed of a patient with an orbital cellulitis and a post septal abscess secondary to infection from an upper molar tooth. Spread of infection was to the maxillary sinus and thence to the orbit via a defect in the orbital floor. The clinical presentation, differential diagnosis, value of CT scanning, treatment and possible complications are reviewed.

Bupivacaine administration and postoperative pain following anterior iliac crest bone graft for alveolar cleft repair.

Objective: To determine whether placement of a bupivacaine-soaked absorbable sponge (BAS) in addition to bupivacaine infiltration at the anterior iliac crest (AIC) donor site alters postoperative pain for children undergoing alveolar bone grafting (ABG) for cleft lip with or without cleft palate (CL±P). The comparison group received only bupivacaine infiltration (NO BAS) at the AIC. Design: Retrospective cohort. Medical records were abstracted by one investigator, blinded to BAS versus NO BAS use. Setting and Patients: Consecutive patients with CL±P who underwent ABG between 2000 and 2006 at one large U.S. craniofacial center. Intervention: BAS was used in 118 procedures and NO BAS in 89. Outcome Measures: Postoperative pain score, total and opioid pain medication requirement, length of hospital stay (LOS), and time to initial ambulation. Results: One hundred eighty-two patients underwent 207 ABG procedures. Mean pain scores were significantly lower when BAS was used compared with NO BAS (1.3 versus 1.8; p  =  .01). Patients who received BAS required significantly less pain medication than NO BAS patients: opioids (0.14 versus 0.20 mg/kg; p  =  .01) and total (0.60 versus 0.71 mg/kg; p  =  .02). Relative to the NO BAS group, those who received BAS had a shorter LOS (30.9 versus 42.4 hours; p < .0001) and less time to initial ambulation following surgery (14.4 versus 20.6 hours; p < .0001). Conclusion: Use of BAS at the AIC donor site significantly reduced postoperative pain score, pain medication requirement, LOS, and time to ambulation relative to children who did not receive BAS following ABG.

Deformation of Nasal Septal Cartilage During Mastication

The cartilaginous nasal septum plays a major role in structural integrity and growth of the face, but its internal location has made physiologic study difficult. By surgically implanting transducers in 10 miniature pigs (Sus scrofa), we recorded in vivo strains generated in the nasal septum during mastication and masseter stimulation. The goals were (1) to determine whether the cartilage should be considered as a vertical strut supporting the nasal cavity and preventing its collapse, or as a damper of stresses generated during mastication and (2) to shed light on the overall pattern of snout deformation during mastication. Strains were recorded simultaneously at the septo‐ethmoid junction and nasofrontal suture during mastication. A third location in the anterior part of the cartilage was added during masseter stimulation and manipulation. Contraction of jaw closing muscles during mastication was accompanied by anteroposterior compressive strains (around −1,000 με) in the septo‐ethmoid junction. Both the orientation and the magnitude of the strain suggest that the septum does not act as a vertical strut but may act in absorbing loads generated during mastication. The results from masseter stimulation and manipulation further suggest that the masticatory strain pattern arises from a combination of dorsal bending and/or shearing and anteroposterior compression of the snout. J. Morphol., 2009.

Sleep disturbances in 22q11.2 deletion syndrome: a case with obstructive and central sleep apnea.

The 22q11.2 deletion syndrome is characterized by wide phenotypic variability, frequently involving characteristic craniofacial features, cardiac malformations, and learning difficulties. Skeletal anomalies are also common and include an obtuse angle of the cranial base, retrognathia, and cervical spine abnormalities. Despite these anomalies, sleep-disturbed breathing is not reported frequently in patients with 22q11.2 deletion syndrome. We describe a patient with an obstructive sleep disturbance that was successfully treated with a tonsillectomy followed by mandibular distraction osteogenesis. She also had central sleep apnea, initially attributed to spinal cord impingement from cervical instability. Posterior cervical fusion was associated with a decrease in the number of central apneic events.

Real-time monitoring of the growth of the nasal septal cartilage and the nasofrontal suture.

INTRODUCTION The nasal septum is thought to be a primary growth cartilage for the midface and, as such, has been implicated in syndromes involving midfacial hypoplasia. However, this internal structure is difficult to study directly. The aims of this study were to provide direct, continuous measurements of the growth of the nasal septal cartilage and to compare these with similar measurements of the nasofrontal suture to test whether the growth of the cartilage precedes the growth of the suture and whether the growth of the septal cartilage is constant or episodic. METHODS Ten Hanford minipigs were used. Linear displacement transducers were implanted surgically in the septal cartilage and across the nasofrontal suture. Length measurements of the cartilage and suture were recorded telemetrically each minute for several days. RESULTS The growth rate of the nasal septal cartilage (0.07% ± 0.03% length/h) was significantly higher than that of the suture (0.03% ± 0.02% length/h) (P = 0.004). The growth of both structures was episodic with alternating periods of growth (5-6 per day) and periods of stasis or shrinkage. No diurnal variation in growth of the cartilage was detected. CONCLUSIONS These results are consistent with the notion that growth of the septal cartilage might drive growth of the nasofrontal suture. Growth of the midface is episodic rather than constant.

The effects of tooth extraction on alveolar bone biomechanics in the miniature pig, Sus scrofa

OBJECTIVE This study investigated the role of occlusion in the development of biomechanical properties of alveolar bone in the miniature pig, Sus scrofa. The hypothesis tested was that the tissues supporting an occluding tooth would show greater stiffness and less strain than that of a non-occluding tooth. DESIGN Maxillary teeth opposing the erupting lower first molar (M(1)) were extracted on one side. Occlusion developed on the contralateral side. Serially administered fluorochrome labels tracked bone mineralisation apposition rate (MAR). A terminal experiment measured in vivo buccal alveolar bone strain on occluding and non-occluding sides during mastication. Ex vivo alveolar strains during occlusal loading were subsequently measured using a materials testing machine (MTS/Sintech). Whole specimen stiffness and principal strains were calculated. RESULTS MAR tended to be higher on the extraction side during occlusion. In vivo buccal shear strains were higher in the alveolar bone of the occluding side vs. the extraction side (mean of 471 microvarepsilon vs. 281 microvarepsilon, respectively; p=0.04); however, ex vivo shear strains showed no significant differences between sides. Stiffness differed between extraction and occlusion side specimens, significantly so in the low load range (344 vs. 668 MPa, respectively; p=0.04). CONCLUSIONS Greater in vivo shear strains may indicate more forceful chews on the occluding side, whereas the similarity in ex vivo bone strain magnitude suggests a similarity in alveolar bone structure and occlusal load transmission regardless of occlusal status. The big overall change in specimen stiffness that was observed was likely attributable to differences in the periodontal ligament rather than alveolar bone.

The Oral and Maxillofacial Surgery Anesthesia Team Model

Oral and maxillofacial surgeons have been providing safe anesthesia to their patients using the anesthesia team model; this has allowed access to care for patients that have significant anxiety. The AAOMS strives to maintain the excellent safety record of the anesthesia team model by creating simulation programs in anesthesia, regularly updating the office anesthesia evaluation program, convening anesthesia safety conferences and strengthening the standards in our training programs. Through these efforts, our delivery of anesthesia to our patients will remain safe and effective.