Bonnie L. Padwa

Cervicofacial Lymphatic Malformation: Clinical Course, Surgical Intervention, and Pathogenesis of Skeletal Hypertrophy

This is a retrospective review of the clinical course and long-term soft-tissue/skeletal problems in 17 patients with large cervicofacial lymphatic malformations. Morbidity included infection (71 percent), airway compromise requiring tracheostomy (65 percent), poor dental health with aggressive caries (53 percent), abnormal articulatory patterns (47 percent), and episodic bleeding (35 percent). All patients underwent soft-tissue excision (mean four procedures per patient). Damage to facial nerve (76 percent) and hypoglossal nerve (24 percent) were common postoperative sequelae. Contour resection did not alter the progression of skeletal hypertrophy. Overgrowth most commonly occurred in the mandibular body, manifesting as anterior open bite deformity and class III occlusion (65 percent). Early mandibular body ostectomy was done in four children with grotesque hypertrophy. Jaw osteotomy was required in 71 percent of the patients to improve the maxillary/mandibular relationship. Histologic examination revealed intraosseous lymphatic malformation in areas of skeletal overgrowth in two-thirds of surgical specimens. The complexity of managing cervicofacial lymphatic malformation underscores the need for an interdisciplinary program in every major referral center. (Plast. Reconstr. Surg. 95: 951, 1995.)

Photoactivation of Endogenous Latent Transforming Growth Factor–β1 Directs Dental Stem Cell Differentiation for Regeneration

Low-power laser–activated endogenous latent transforming growth factor–β1 (LTGF-β1) directs resident dental stem cell differentiation to promote dentin regeneration. Laser Light Encourages Tooth Regeneration A small dose of light may be sufficient to promote new tooth growth, at least in animal models. Arany and colleagues shined low-power laser light on the tooth pulps of rats and saw the formation of tertiary dentin, which is a bone-like substance. Taking this as evidence of tooth regeneration, the authors investigated the mechanism by which light can cause the dental pulp to form bone. Arany et al. discovered that low-power laser activates latent transforming growth factor–β (TGF-β), leading to the generation of reactive oxygen species and the differentiation of dental stem cells into odontoblasts (dentin-forming bone cells). This mechanism was further confirmed in vivo by demonstrating that mice lacking TGF-β or treated with a TGF-β inhibitor were unable to respond to laser therapy. Because lasers are already used in dentistry, it is possible that such light-based treatment could be used in dental regeneration in people. Rapid advancements in the field of stem cell biology have led to many current efforts to exploit stem cells as therapeutic agents in regenerative medicine. However, current ex vivo cell manipulations common to most regenerative approaches create a variety of technical and regulatory hurdles to their clinical translation, and even simpler approaches that use exogenous factors to differentiate tissue-resident stem cells carry significant off-target side effects. We show that non-ionizing, low-power laser (LPL) treatment can instead be used as a minimally invasive tool to activate an endogenous latent growth factor complex, transforming growth factor–β1 (TGF-β1), that subsequently differentiates host stem cells to promote tissue regeneration. LPL treatment induced reactive oxygen species (ROS) in a dose-dependent manner, which, in turn, activated latent TGF-β1 (LTGF-β1) via a specific methionine residue (at position 253 on LAP). Laser-activated TGF-β1 was capable of differentiating human dental stem cells in vitro. Further, an in vivo pulp capping model in rat teeth demonstrated significant increase in dentin regeneration after LPL treatment. These in vivo effects were abrogated in TGF-β receptor II (TGF-βRII) conditional knockout (DSPPCreTGF-βRIIfl/fl) mice or when wild-type mice were given a TGF-βRI inhibitor. These findings indicate a pivotal role for TGF-β in mediating LPL-induced dental tissue regeneration. More broadly, this work outlines a mechanistic basis for harnessing resident stem cells with a light-activated endogenous cue for clinical regenerative applications.

Frequency of Le Fort I Osteotomy After Repaired Cleft Lip and Palate or Cleft Palate

Objective: Diminished maxillary growth is a consequence of labiopalatal repair, and many patients with cleft lip and palate require Le Fort I advancement. The goal of this study was to determine the frequency of maxillary hypoplasia as measured by need for Le Fort I. Subjects: Retrospective cohort study of males born before 1987 and females before 1989. Records of 173 patients with cleft lip and palate and 34 with cleft palate were reviewed. Methods: Documented age, gender, cleft type, and need for Le Fort I. Pearson chi-square and Fischers exact analyses were performed to evaluate the frequency of Le Fort I. Results: Of 217 patients with cleft lip and palate or cleft palate, 40 were syndromic; of the remaining 177 patients, 69 had cleft lip, 78 had cleft lip and palate, and 30 had cleft palate. Thirty-seven of 177 patients (20.9%) required Le Fort I, subcategorized by cleft type: 0/69 for cleft lip, 37/78 for cleft lip and palate, and 0/35 for cleft palate (p < .0001). Of the 37/78 (47.4%) cleft lip and palate patients, the frequency of Le Fort I correlated with severity: 5/22 unilateral incomplete cleft lip and palate; 16/33 unilateral complete cleft lip and palate; 1/2 bilateral incomplete cleft lip and palate; 2/4 bilateral asymmetric complete/incomplete cleft lip and palate; 13/17 bilateral complete cleft lip and palate (p < .05). Conclusion: Overall frequency of Le Fort I was 20.9% in patients with cleft lip and palate and cleft palate. Of those with cleft lip and palate, 47.7% required maxillary advancement, but none with isolated cleft lip or cleft palate required correction. Frequency of Le Fort I osteotomy correlated with the spectrum of severity of labiopalatal clefting.

Repair of bilateral cleft lip: review, revisions, and reflections.

Rarely does the appearance of a child with a repaired bilateral cleft lip compare favorably with that of a child with a repaired unilateral cleft lip. However, there has been a major change in operative strategy during the past decade, and as a result, the typical bilateral cleft nasolabial stigmata are no longer so obvious. The senior author restates the principles for correction of bilateral cleft lip and nasal deformity, and underscores the essential role of preoperative premaxillary positioning. He reviews his method of single-stage closure of the cleft primary palate, including three-dimensional adjustments based on predicted four-dimensional changes. Operative modifications are described for variations of bilateral cleft lip. The authors emphasize the surgeons obligation for periodic assessment. In a consecutive series of 50 patients with repaired bilateral complete cleft lip/palate, the revision-rate was 33% as compared with 12.5% if the secondary palate is intact. No revisions were necessary for philtral size or columellar length. The authors propose that nasolabial appearance and speech are the priorities in habilitation of the child with bilateral cleft lip/palate rather than the traditional emphasis on maxillary growth.

Progression of facial asymmetry in hemifacial microsomia.

Hemifacial microsomia is a common craniofacial anomaly, variably affecting structures derived from the first and second pharyngeal arches. Correction of the skeletal deformity in children has been advocated to improve growth potential and reduce secondary deformity. However, contrary reports have suggested that facial asymmetry in hemifacial microsomia does not increase with growth; therefore, skeletal correction can be postponed, even until adolescence. The purpose of this study was to test the hypothesis that facial asymmetry in hemifacial microsomia is progressive. This is a retrospective evaluation of 67 patients with untreated hemifacial microsomia. The patients were categorized as: group I (mandible type I, IIa), n = 38, and group II (mandible type IIb, III), n = 29. Pretreatment posterior-anterior cephalometric radiographs were used to analyze asymmetry by measuring the angle between the true horizontal and the following planes: piriform rim, maxillary occlusal plane, and intergonial angle. Angular measurements were averaged for patients in the deciduous (<6 years), mixed (≥6<13 years), and permanent dentition (≥13 years). In group I, angle piriform rim, maxillary occlusal plane, and intergonial angle increased from 7.0, 4.3, and 4.4 to 8.4, 6.6, and 6.1 degrees, respectively [mean age, 4.1 (deciduous) to 8.6 (mixed) to 21.0 (permanent) years]. In group II, angle piriform rim, maxillary occlusal plane, and intergonial angle increased from 9.5, 6.2, and 5.3 to 11.7, 7.6, and 8.0 degrees, respectively [mean age, 3.4 (deciduous) to 8.0 (mixed) years]. These data demonstrate that hemifacial microsomia is progressive and underscores the importance of early surgical correction of mandibular asymmetry in this disorder. (Plast. Reconstr. Surg. 105: 492, 2000.)

Synostotic frontal plagiocephaly : anthropometric comparison of three techniques for surgical correction

&NA; Surgical correction of synostotic frontal plagiocephaly (“unilateral coronal synostosis”) focuses on distortions of the forehead and orbits. Technical variations include unilateral versus bilateral fronto‐orbital positioning. Surgical alignment of the deviated nasal root was introduced in our unit. Anthropometry was used to assess anatomic outcome, and results were compared in 22 children with synostotic frontal plagiocephaly who had either (1) unilateral fronto‐orbital advancement (“canthal advancement”) (n = 8), (2) bilateral fronto‐orbital advancement/ modeling without nasal straightening (n = 7), or (3) bilateral fronto‐orbital advancement/modeling with closing wedge nasal osteotomy (n = 7). Postoperative frontoorbital asymmetry was most marked in the group I patients wherein the ipsilateral supraorbital rim was retruded 3.9 mm and elevated 2.6 mm, on average relative to the corneal apex, compared with the normal side. Group II children averaged 2‐mm orbital retrusion and 2.2‐mm elevation. Group III patients averaged 1.4‐mm orbital retrusion and 2.9‐mm elevation. These differences in orbital rim measurements among the three groups were not statistically significant. Postoperative nasal root angulation of 4 degrees or more was found in more than 50 percent of children who had either a unilateral or a bilateral procedure, without nasal correction. In contrast, primary nasal osteotomy resulted in a nasal cant of 3 degrees or less in all children. This difference in nasal angulation among the three groups was statistically significant (p = 0.035). Group III had a straighter nasal angle than groups II and I (in that order). Measurement of the distances from nasion to inner and to outer canthi also reflected persistent deviation of the nasal root. Group III children had a more central radix than either group I or II (p = 0.05). The data in this study support an operative strategy of bilateral (parallelogrammic) positioning of the forehead/ superior orbits with primary correction of nasal root angulation. (Plast. Reconstr. Surg. 100: 1387, 1997.)

Simultaneous maxillary and mandibular distraction osteogenesis with a semiburied device

Distraction osteogenesis is a technique utilizing natural healing mechanisms to generate new bone; it is commonly used to lengthen the hypoplastic mandible. Distraction of the maxilla and mandible as a unit is an obvious extension of the technique. We describe the application of a semiburied distractor to simultaneously lengthen the mandible and maxilla and level a canted occlusal plane in three cases. The indications for bimaxillary distraction are reviewed, including its advantages, disadvantages and limitations.

Midfacial growth after costochondral graft construction of the mandibular ramus in hemifacial microsomia

PURPOSE The purpose of this study was to document vertical midfacial growth after costochondral graft mandibular ramus construction in children with type IIB and type III hemifacial microsomia (HFM). METHODS This is a retrospective study of 33 children who underwent costochondral graft (CCG) construction for mandibular type IIB (abnormal, small, and medially displaced ramus, n = 19) and mandibular type III (absent ramus and glenoid fossa, n = 14) HFM, between 1980 and 1990. Types I and IIA patients were not included because their milder mandibular deformities were lengthened by osteotomy. Mean age at operation was 6.2 (2 to 10) years, and the mean follow-up period was 5.5 (1 to 13.5) years. Occlusal cant, piriform angle, and intergonial angle were measured on the most current posteroanterior (PA) cephalogram. The ratio of unaffected to affected ramus length was determined on the most current panoramic radiograph. Patient outcomes were classified based on the occlusal cant at the latest follow-up: group 1, successful result with a symmetrical maxilla (occlusal cant of <5 degrees); group 2, acceptable result (occlusal cant > or =5 degrees but <8 degrees), and Group 3, failure (occlusal cant > or = 8 degrees). OMENS scores were calculated for each patient: each of the five major anatomic deformities of HFM (orbital, mandibular, auricular, neural, and soft tissue) were graded 0 to 3 and summed. The mean differences in age at operation and OMENS scores between groups were calculated (ANOVA). RESULTS At the end of follow-up, patients defined as having a successful result (group 1) had a mean occlusal cant of 2 degrees, a mandibular length ratio of 1.0, and an intergonial angle of 2 degrees. However, the final piriform angle was 7 degrees, indicating less vertical midfacial growth than maxillary alveolar growth. These patients were older at the time of operation (mean age, 6.7 years), and their mean OMENS score (6.3) was significantly lower (P = .004) than in patients in group 2 (mean age at operation, 6.3 years; mean OMENS score, 6.8) and group 3 (mean age at operation, 5.8 years; mean OMENS score, 7.8). In group 2, the occlusal cant, mandibular length ratio, and intergonial and piriform angles did not improve. In group 3, the occlusal cant and piriform angle became worse during the follow-up period. CONCLUSIONS The results of this study indicate that after construction of the ramus and condyle in type IIB and III HFM patients, vertical midface growth is secondary to a combination of midfacial and alveolar growth. Patients operated on at an older age were more likely to have a successful long-term result. Finally, the severity of the overall deformity, as reflected in a higher OMENS score, appeared to be an important factor in the response to early correction.

Vascularized fibular graft for pediatric mandibular reconstruction.

Background: Although vascularized bone grafts have become well accepted in adults, especially following ablative head and neck procedures, there are few long-term reports of their use in pediatric patients. Methods: In this study, the authors analyzed the outcomes of 18 free fibula grafts in 16 patients aged 10 months to 21 years (mean, 12 years) with an average follow-up of 5 years. Eleven patients had cancer-related defects, four had craniofacial anomalies, and one had a posttraumatic deformity. All patients with congenital malformations had been followed since birth, and the others had been followed from the time of their original cancer diagnosis or injury. Results: Of the 16 patients, seven underwent irradiation and seven underwent chemotherapy. The most severe deformities were seen in those with cancer resection and radiation therapy. Most defects were hemimandibular; there was one total mandibular defect (a child with Ewing sarcoma). Ten patients had had previous failed nonvascularized bone grafts. Eleven flaps were osteocutaneous with either intraoral or extraoral components; most had multisegmental osteotomy and had one arterial and two venous anastomoses. All free fibula transfers were successful; there were no vascular problems and only two minor complications. Conclusion: A number of lessons are learned from careful analysis of this unique group of patients, and an algorithm of pediatric mandibular reconstruction is proposed.

Children with repaired bilateral cleft lip/palate: effect of age at premaxillary osteotomy on facial growth.

This study compared facial growth in three groups of patients with bilateral complete cleft lip/palate: those who had (1) no premaxillary osteotomy, (2) premaxillary osteotomy before age 8 years, and (3) premaxillary osteotomy after age 8 years. Of 24 children with bilateral complete cleft lip/palate, 7 had early premaxillary osteotomy (mean age, 6.1; range, 3.7 to 7.6 years), 10 had late osteotomy (mean age, 11.2; range, 8.3 to 20.7 years), and 7 did not require premaxillary repositioning and served as controls (mean age, 12.4; range, 6.4 to 17.8 years). Presurgical and postsurgical lateral cephalograms were digitized using the Dentofacial Planner software; most current lateral cephalograms comprised the control group. Forty-one bony and 25 soft-tissue landmarks were digitized, and 8 angles were measured: SNA, (sella-nasion-A point), SNPg (sella-nasion-pogonion), ANB (A point-nasion-B point), NAPg (nasion-A point-pogonion), ST convexity (glabella-subnasale-soft-tissue pogonion), Sn-G vertical (line perpendicular to the horizontal plane dropped from glabella and distance measured from subnasale to this vertical), Cm-Sn-Ls (columella-subnasale-abial superioris), and Sn-Gn-C (subnasale-soft-tissue gnathion-chin point). Statistical difference in mean preoperative and postoperative values were measured with analysis of variance. Tests of significance were adjusted for multiple comparisons using the Bonferroni correction. Mean age at follow-up for early, late, and control groups was 11.8, 14.0, and 12.4 years, respectively. Mean follow-up for early and late groups was 5.7 and 2.8 years. There was a significant preoperative difference among the three groups for mean SNA (p < 0.01), ANB (p < 0.01), and NAPg (p < 0.01). Bonferroni analyses revealed that the early group had significantly greater SNA, ANB, and NAPg angles than the late (p < 0.01) and control groups (p < 0.05). There was a significant postoperative difference among groups for ANB (p < 0.05); Bonferroni analyses also showed that the control group had a significantly greater ANB than the late group (p < 0.05). The t test for equity of means established postoperative change for SNA (p < 0.01), ANB (p< 0.01), NAPg (p < 0.01), and ST convexity (p < 0.01) for the early group was significantly greater than for the late group. Children who required early premaxillary positioning had more significant preoperative deformity; however, this groups postoperative profile was not, on average, significantly different from either the late or control groups. Our findings that the early group had more significant change with premaxillary osteotomy than the late group suggest that premaxillary positioning can be done before completion of facial growth without compromise.