Faculty Bibliography

The application of distraction osteogenesis in craniofacial surgery has significantly altered the treatment of congenital mandibular deficiencies. However, evaluation of results in both animal studies and clinical cases has revealed deficiencies, particularly in two areas. First, distraction using a uniplanar device in an anteroposterior direction can result in a persistent anterior open bite. Second, the lateralization of the distracted hemimandible was often limited, with insufficient incremental gain in the bigonial distance. To overcome these shortcomings, a multiplanar distraction device was developed and tested in the canine model. This report details canine studies addressing the first problem: combined anteroposterior or sagittal (z-axis) and superoinferior or vertical (y-axis) movements. Six dogs underwent bilateral mandibular distraction with an external (extraoral), multiplanar device and completed sagittal plus vertical distraction. Evaluation included clinical examination (facial form, jaw position, and occlusion), photography, cephalograms (posteroanterior, basilar, and lateral), three-dimensional computed tomography reconstructions, and examination of dry skulls. The dogs averaged 18.5 mm (range, 15-20 mm) of sagittal distraction and 41.0 degrees (range, 21-50 degrees) of vertical distraction. Marked anterior open bites were produced after vertical distraction secondary to premature contact of the maxillary and mandibular molars. Distraction in the vertical direction also had the additive effect of increasing the sagittal gains by approximately 5% to 10%. In conclusion, a multiplanar distraction device (with the potential for distraction in three planes) was effective in increasing mandibular anteroposterior thrust (sagittal distraction) and also in creating an anterior open bite (vertical or superoinferior distraction). Vertical distraction probably requires bilateral osteotomies to obtain optimal results. The preliminary gains in sagittal length are modified (reduced or increased) after distraction in a second plane (vertical and horizontal). Specifically, vertical distraction in the inferior direction (creating an open bite) also leads to isolated increases in the anteroposterior plane. Conversely, vertical distraction in the superior direction (closing an open bite), as seen in a human malocclusion, may lead to isolated decreases in the anteroposterior plane, but this question remains to be investigated in the laboratory

Distraction osteogenesis has been shown to be an effective method of lengthening and augmenting endochondral bone. It has also been applied effectively in the reconstruction of the membranous bones of the craniofacial skeleton. With the accumulation of clinical experience in mandibular distraction, the differences between endochondral and membranous bone distraction have become apparent, especially in the limitations of uniplanar distraction for the three-dimensional reconstruction of the deficient mandible. Distraction of the mandible in a single plane cannot satisfy fully the functional and structural requirements of the patient with malocclusion as well as deficiency of the skeletal and soft tissue. This study reports the development and clinical use of a multiplanar mandibular distraction device with the ability to achieve linear distraction (Z-plane or sagittal), angular distraction (Y-plane or vertical), and transverse distraction (X-plane or coronal). The device contains two independent gear arrangements attached to two arms that extend from the central unit. Therefore, the trajectory of the regenerated bone may be changed during the distraction process. The device also allows manipulation of the various planes of movement independent of each other. Furthermore, the rotational points for the multiplanar distraction devices are located at a single point; therefore only a single osteotomy and two pin sites are required. The multiplanar distraction device allows the surgeon to customize and contour the dimensions of the distraction process by controlling the trajectory of the translation of the regenerated bone

We present 6 patients who do not satisfy the criteria for inclusion into any known diagnostic group, although they share similar physical findings. All had facial findings suggestive of either mild deformational plagiocephaly or craniofacial microsomia; however, hypertrophic and occasionally hyperactive muscles of the face appear to be the unifying and distinctive feature of the group. Contraction of hypertrophic postauricular muscles on the affected side resulted in movement and contraction of the pinna. Hypertrophy of the mentalis and masseter muscles was also frequently observed. Additionally, anomalous neck musculature was seen in 4 of the 6 patients. In 2 patients, the hypertrophy of certain of these muscles produced enough deformity to warrant excision. This is the first report of such an association in the literature. Possible explanations are discussed

We present a new combined approach to primary bilateral cleft lip, nose, and alveolus repair using presurgical nasoalveolar molding combined with a one-stage lip, nose, and alveolus repair. Presurgical alveolar molding is used to bring the protruding premaxilla back into proper alignment with the lateral segments in the maxillary arch. Presurgical nasal molding produces tissue expansion of the short columella and nasal lining. A coordinated surgical approach involves a one-stage repair of the lip, nose, and alveolus. The nasal repair uses a retrograde approach in which the prolabial flap and columella are reflected over the nasal dorsum by continuing the dissection behind the prolabium up the membranous septum and over the septal angle. Tissues are dissected out from between the tip cartilages, and the domes are sutured together in the midline. This method joins a new class of bilateral cleft repairs that place the primary emphasis on correction of the deformity of the nasal tip cartilages

OBJECTIVE: The purpose of this study was to evaluate if narrowing and approximation of the alveolar cleft through presurgical alveolar molding followed by gingivoperiosteoplasty (GPP) at the time of lip repair reduces the need for a bone-grafting procedure. DESIGN: This was a retrospective blind study of patients with unilateral or bilateral alveolar clefts who underwent presurgical infant alveolar molding and GPP by a single surgeon. Alveolar bone formation was assessed prior to the eruption of the maxillary lateral incisor or canine by clinical examination, panoramic and periapical radiographs, and/or a dental CT scan. The criterion for bone grafting was inadequate bone stock to permit the eruption and maintenance of the permanent dentition. SETTING: This study was performed at the Institute of Reconstructive Plastic Surgery by the members of the Cleft Palate Team. PATIENTS: All patients with unilateral (n = 16) or bilateral (n = 2) alveolar clefts who underwent presurgical infant alveolar molding and GPP by a single surgeon from 1985 to 1988 were studied. The control population consisted of all alveolar cleft patients (n = 14) who did not undergo alveolar modeling or GPP during the same time period. INTERVENTIONS: Presurgical alveolar modeling was performed with an intraoral acrylic molding plate. This plate was modified on a weekly basis to align the alveolar segments and close the alveolar gap. The surgical intervention consisted of a modified Millard GPP. MAIN OUTCOME MEASURES: The primary study outcome measure was the elimination of the need for a secondary bone graft in patients who underwent presurgical alveolar molding and GPP. RESULTS: Of the 20 sites in the 18 patients who underwent GPP, 12 sites did not require an alveolar bone graft. Of the 8 sites requiring a bone graft, 4 presented minimal bony defects. All 14 patients in the control group required bone grafts. CONCLUSIONS: In this series of 20 alveolar cleft sites treated with presurgical orthopedics and GPP, 60% did not need a secondary alveolar bone graft in the mixed dentition

The role of preoperative planning, the geometric changes, and the long-term effects of mandibular distraction have not been previously reported. This study included 10 patients who underwent unilateral (5 patients) or bilateral (5 patients) mandibular distraction. Preoperative, postdistraction, and yearly radiographs (panoramic, posteroanterior, and lateral cephalograms) were reviewed. Postdistraction follow-up ranged from 12 to 70 months. Postdistraction, the mandibles showed evidence of anticipated growth without relapse. This growth rate was variable and dependent on the genetic program of the native bone. Previously reported improvement in temporomandibular joint morphology was maintained in the long term. The resulting shape of the neomandible was most influenced by the vector of placement of the distraction device. When placed vertically, ramal elongation was observed. When placed horizontally, anterior projection of the mandibular body occurred. When placed obliquely, ramal and body elongation occurred with preservation of the gonial angle. After 2 to 5 years of follow-up, continued growth of the neomandible was observed

Distraction osteogenesis has become an accepted method of treatment for patients requiring reconstruction of hypoplastic mandibles. We present a quantitative analysis of volumetric changes after distraction osteogenesis in a series of 10 patients. Group I (n = 5 patients, 3 unilateral craniofacial microsomia, 1 Goldenhaar syndrome, and 1 bilateral craniofacial microsomia) underwent unilateral distraction of the mandible. Group II (n = 5 patients, 1 Nager syndrome, 1 bilateral craniofacial microsomia, 1 developmental micrognathia, and 2 Treacher Collins syndrome) underwent bilateral distraction of the mandible. Predistraction and postdistraction axial and three-dimensional computed tomographic (CT) scans were digitized and transferred to a computer for analysis with image-processing software to determine the changes in volume of the mandible and bony regenerate. The CT-derived volume method was validated by scanning three dry cadaver mandible specimens and comparing the volume data with those derived from a water-displacement method. The difference between the two methods was less than 5 percent. The mean distracted length, as recorded from the calibrated device, was 22.6 mm in the 10 patients. In the unilateral distraction group, the mean increase in hemimandibular bone volume was 2.8 cc, with a mean percentage increase of 27 percent in the distracted hemimandible. In the bilaterally distracted patients, the mean increase in total mandibular volume was 7.9 cc, with a mean percentage increase in bone volume of 25 percent. This study represents the first attempt to quantify the increase in bone volume resulting from distraction osteogenesis. Quantitative volumetric analysis of CT scans is an accurate method to measure the amount of bone regenerate in patients undergoing distraction osteogenesis of the mandible or the extremities. The concept and utility of quantifying the volumetric changes in bone following distraction osteogenesis may become more important as multiplanar devices are developed and used in other areas of the craniofacial skeleton

The objective of this study was to report the effect of gingivoperiosteoplasty on growth of the midfacial skeleton 6 years following primary surgical repair. Patients with complete unilateral cleft lip and palate who underwent primary cleft lip and nose repair with and without gingivoperiosteoplasty (GPP) were retrospectively compared by means of a lateral cephalogram. Mean age at the time of evaluation was 5.7 years. All patients were treated at the Institute of Reconstructive Plastic Surgery, New York University Medical Center. All surgery and presurgical orthopedics was performed by the same surgeon and the same orthodontist. Twenty-five consecutively treated patients who presented with complete unilateral clefts of the primary and secondary palate were included in the study. Of these, 20 patients were available for 6-year follow-up cephalometric documentation and review. All patients received preoperative orthopedics with passive molding appliances, followed by repair of the lip, alveolus, and nose in a single stage at the age of 3 months. The repair was performed using the rotation/advancement technique. The difference between the two groups was whether or not gingivoperiosteoplasty was performed. The reason for not performing gingivoperiosteoplasty was incomplete approximation of the alveolar segments usually due to a late start in beginning therapy. Lateral cephalograms (68.5 months post primary surgery) were obtained and traced. Cranial base (S-N), maxilla (ANS-PNS), and mandible (Go-Pg) were digitized for shape coordinate analysis. No significant difference in the mean position of ANS-PNS was found between groups (with or without gingivoperiosteoplasty). There was, however, a significant difference in the variance of position for the points ANS-PNS between the groups (p < .002). We were unable to observe any difference (anteroposterior or supero-inferior) in the average position of the hard palate (ANS-PNS) between groups. We conclude that gingivoperiosteoplasty results in a more uniform position of the hard palate (ANS-PNS) relative to patients that did not receive gingivoperiosteoplasty. We were unable to demonstrate any clear impairment of maxillary growth in the patients treated with gingivoperiosteoplasty when compared to patients treated without gingivoperiosteoplasty