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Alvaro A Figueroa

Publications and source records attributed to Alvaro A Figueroa.

8 recordsLinked to original sources
PubMed2006

Micro-computed tomography evaluation of the glenoid fossa and mandibular condyle bone after bilateral vertical ramus mandibular distraction in a canine model.

The aim of this study was to quantify bone microarchitecture within the glenoid fossa and mandibular condyle following mandibular distraction osteogenesis. Eight 6- to 9-month-old male beagle dogs underwent bilateral vertical mandibular distraction with semiburied distractors (12 days of distraction at 1 mm per day). One unoperated animal served as control. After distraction the animals were divided into two groups (N = 4) and killed after 1 or 2 months of consolidation. Three-dimensional trabecular architecture was analyzed by micro-computed tomography (microCT). At both sites the overall trends were similar. In the glenoid fossa, there was decreased bone volume, trabecular number, and connectivity density and increased trabecular separation at 1 month and decreased trabecular thickness and increased structure model index compared with the control (P < 0.05). In the mandibular condyle, there was decreased bone volume, trabecular number, and connectivity density at both 1 and 2 months, with decreased trabecular thickness and increased structure model index at 2 months only compared with the control (P < 0.05). The bone became less dense and more rodlike. These bone changes are similar to those seen by the effects of aging or impaired normal function. Thus, in the short term, changes occur in the bone microstructure of the glenoid fossa and mandibular condyle after vertical mandibular ramus distraction in the canine model.

Animals↗
PubMed2006

Micro-computed tomography evaluation of the glenoid fossa and mandibular condyle bone after bilateral vertical ramus mandibular distraction in a canine model.

The aim of this study was to quantify bone microarchitecture within the glenoid fossa and mandibular condyle following mandibular distraction osteogenesis. Eight 6- to 9-month-old male beagle dogs underwent bilateral vertical mandibular distraction with semiburied distractors (12 days of distraction at 1 mm per day). One unoperated animal served as control. After distraction the animals were divided into two groups (N = 4) and killed after 1 or 2 months of consolidation. Three-dimensional trabecular architecture was analyzed by micro-computed tomography (muCT). At both sites the overall trends were similar. In the glenoid fossa, there was decreased bone volume, trabecular number, and connectivity density and increased trabecular separation at 1 month and decreased trabecular thickness and increased structure model index compared with the control (P < 0.05). In the mandibular condyle, there was decreased bone volume, trabecular number, and connectivity density at both 1 and 2 months, with decreased trabecular thickness and increased structure model index at 2 months only compared with the control (P < 0.05). The bone became less dense and more rodlike. These bone changes are similar to those seen by the effects of aging or impaired normal function. Thus, in the short term, changes occur in the bone microstructure of the glenoid fossa and mandibular condyle after vertical mandibular ramus distraction in the canine model.

Animals↗
PubMed2006

The pubic bone graft.

We introduce a new technique for harvesting cancellous bone, the pubic bone graft. The pubic bone graft is a predictable and efficient technique that yields an ample harvest of rich cancellous bone. With experience gained from multiple fresh cadaver dissections, we present this technique in detail, including our most recent clinical application to graft alveolar clefts and its advantages over the traditional technique of bone graft harvesting.

Bone Transplantation↗
PubMed2006

Dynamic presurgical nasal remodeling in patients with unilateral and bilateral cleft lip and palate: modification to the original technique.

OBJECTIVE: To present technical modifications to the original presurgical nasal remodeling appliance introduced in 1991. The purpose of the modifications is to improve the cleft nasal deformity before unilateral and bilateral cleft lip repair. METHOD: The principle behind this technique, known as dynamic presurgical nasal remodeling (DPNR), is the use of the force generated during suction and swallowing. A conventional intraoral plate is built with a nasal extension added to the labial vestibular flange. The nasal extension was modified and consists of three components. The palatal plate is left loose in the mouth to generate a discontinuous but controlled impact directed to the affected nasal structures during suction and swallowing. The principle aim of the DPNR technique in unilateral cases is to improve the deformation of nasal structures by straightening the columella, elevating the nasal tip, and remodeling the depressed cleft side alar cartilages. In bilateral cases, the aims are to elongate the columella and to obtain nasal tip projection. CONCLUSIONS: The modifications introduced in the appliance enhance the original DPNR technique and are effective in ameliorating the initial cleft nasal deformity. This facilitates primary surgical cleft lip and nose correction and improves surgical outcomes in patients with complete unilateral and bilateral cleft lip and palate.

Biomechanical Phenomena↗
PubMed2005

Microstructural and strength evaluation of regenerate tissue during the consolidation period after vertical mandibular ramus distraction.

Mandibular ramus height restoration by distraction osteogenesis (DO) is a key procedure in mandibular hypoplasia reconstruction. The objective of this study was to evaluate short-term skeletal changes in the regenerated bone after vertical mandibular ramus DO using a buried distraction device. Eight subadult beagle dogs underwent bilateral vertical mandibular ramus DO. After a 7-day latency period, distraction was performed at a rate of 0.5 mm twice a day for 12 days. Four dogs were killed at 1 month and four dogs at 2 months after the end of distraction. One intact beagle was included as an unoperated control. After sacrifice, micro computed tomography (muCT) and mechanical testing of distracted sites were used to measure bone volume (BV), total volume (TV), and mechanical peak load strength, respectively. The muCT images showed wide variation in the response, with some animals demonstrating considerable bone formation and reconstitution of the canal for the inferior alveolar nerve. Quantitatively, BV was no more than 67% and BV/TV was less than 25% of the intact control, and strength was approximately 33% of the intact control value. The 1 and 2 month values were similar. These results suggest that internal distractors can successfully reconstitute bone but that the regenerated tissue did not regain structural and mechanical characteristics of native bone within the 2 month study period.

Animals↗
PubMed2005

Cephalometric craniofacial characteristics in patients with temporomandibular joint ankylosis.

BACKGROUND: The sequelae of temporomanibular joint (TMJ) ankylosis include limitation of jaw movement, interference of oral function and affects on the craniofacial growth. Analysis of the craniofacial form of TMJ ankylosis offers guidelines for managing this disease. METHODS: Forty-five patients with intraarticular TMJ ankylosis were collected from the files at the Chang Gung Craniofacial Center. There were 21 male and 24 female patients, aged 3 to 47 years. Thirty-seven patients were unilaterally affected and eight had bilateral involvement. Patients were grouped according to gender and age. Both the medical history and onset of the disease were investigated in all patients. The pretreatment lateral cephalograms were used for analysis. The variables were compared with the Chinese norms with corresponding sex and age groups. RESULTS: The etiology included 48.9% facial trauma history, 17.8% traumatic delivery or birth injury, 15.6% middle ear or dental infection, 2.2% chronic arthritis and 15.6% unknown causes. The onset of mouth opening limitation was under 16 years of age. The average total mandibular length was less than the norm by 30 mm. Each patient presented with a mandible that had backward rotation with chin recession. Accentuated antegonial notch and inferiorly located condyle were observed on the affected side. The maxilla was shorter and the ANB was larger than the norm by 10 degrees but the overbite and overjet were within normal ranges. CONCLUSIONS: The facial growth was severely disturbed in terms of dimension, morphology and direction of growth in patients with TMJ ankylosis. Better management of mandibular fractures, good infection control and early treatment intervention are ways to reduce the influence on craniofacial growth.

Adolescent↗
PubMed2004

Long-term skeletal stability after maxillary advancement with distraction osteogenesis using a rigid external distraction device in cleft maxillary deformities.

Rigid external distraction is a highly effective technique for correction of maxillary hypoplasia in patients with orofacial clefts. The clinical results after correction of sagittal maxillary deformities in both the adult and pediatric age groups have been stable. The purpose of this retrospective longitudinal cephalometric study was to review the long-term stability of the repositioned maxilla in cleft patients who underwent maxillary advancement with rigid external distraction. Between April 1, 1995, and April 1, 1999, 17 consecutive patients with cleft maxillary hypoplasia underwent maxillary advancement using rigid external distraction. There were 13 male patients and four female patients, with ages ranging from 5.2 to 23.6 years (mean, 12.6 years). After a modified complete high Le Fort I osteotomy and a latency period of 3 to 5 days, patients underwent maxillary advancement with rigid external distraction until proper facial convexity and dental overjet and overbite were obtained. After active distraction, a 3- to 4-week period of rigid retention was undertaken; this was followed by removable elastic retention for 6 to 8 weeks using, during sleep time, an orthodontic protraction face mask. Cephalometric radiographs were obtained preoperatively, after distraction, at 1 year after distraction, and 2 or more years after distraction. The mean follow-up was 3.3 years (minimum, 2.1 years; maximum, 5.3 years). The following measurements were obtained in each cephalogram: three linear horizontal and two linear vertical maxillary measurements, two angular craniomaxillary measurements, and one craniomandibular measurement. Differences between the preoperative and postoperative cephalometric values were analyzed by paired t tests (p < 0.05). The cephalometric analysis demonstrated postoperatively significant advancement of the maxilla. In addition, the mandibular plane angle opened 1.2 degrees after surgery. After the 1- to 3-year follow-up period, the maxilla was stable in the sagittal plane. Minimal anteroposterior growth was observed in the maxilla compared with that exhibited in the anterior cranial base. However, there was significant vertical maxillary growth over the 3-year observation period. The mandibular plane angle tended to decrease during the follow-up period. The cephalometric data from this study support the clinical impression of maxillary stability after maxillary advancement with rigid external distraction in cleft patients. This effective and stable technique is now considered for all pediatric patients with severe cleft maxillary hypoplasia and for adolescent and adult patients with moderate to severe deformities.

Abnormalities, Multiple↗