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Biomedical subjects

P E Santiago

Publications and source records attributed to P E Santiago.

6 recordsLinked to original sources
PubMed1999

Treatment planning and biomechanics of distraction osteogenesis from an orthodontic perspective.

As in traditional combined surgical and orthodontic procedures, the orthodontist has a role in the planning and orthodontic support of patients undergoing distraction osteogenesis. This role includes predistraction assessment of the craniofacial skeleton and occlusal function in addition to planning both the predistraction and postdistraction orthodontic care. Based on careful clinical evaluation, dental study models, photographic analysis, cephalometric evaluation, and evaluation of three-dimensional computed tomographic scans, the orthodontist, in collaboration with the surgeon, plans distraction device placement and the predicted vectors of distraction. Both surgeon and orthodontist closely monitor the patient during the active distraction phase, using intermaxillary elastic traction, sometimes combined with guide planes, bite plates, and stabilization arches, to mold the newly formed bone (regenerate) while optimizing the developing occlusion. Postdistraction change caused by relapse is minimal. Growth after mandibular distraction is variable and appears to be dependent on the genetic program of the native bone and the surrounding soft tissue matrix. A significant advantage of distraction osteogenesis is the gradual lengthening of the soft tissues and surrounding functional spaces. Distraction osteogenesis can be applied at an earlier age than traditional orthognathic surgery because the technique is relatively simple and bone grafts are not required for augmentation of the hypoplastic craniofacial skeleton. In this new technique, the surgeon and the orthodontist have become collaborators in a process that gradually alters the magnitude and direction of craniofacial growth.

Biomechanical Phenomena↗
PubMed1999

Presurgical nasoalveolar molding in infants with cleft lip and palate.

Presurgical infant orthopedics has been employed since the 1950s as an adjunctive neonatal therapy for the correction of cleft lip and palate. In this paper, we present a paradigm shift from the traditional methods of presurgical infant orthopedics. Some of the problems that the traditional approach failed to address include the deformity of the nasal cartilages in unilateral as well as bilateral clefts of the lip and palate and the deficiency of columella tissue in infants with bilateral clefts. The nasoalveolar molding (NAM) technique we describe uses acrylic nasal stents attached to the vestibular shield of an oral molding plate to mold the nasal alar cartilages into normal form and position during the neonatal period. This technique takes advantage of the malleability of immature cartilage and its ability to maintain a permanent correction of its form. In addition, we demonstrate the ability to nonsurgically construct the columella through the application of tissue expansion principles. This construction is performed by gradual elongation of the nasal stents and the application of tissue-expanding elastic forces that are applied to the prolabium. Use of the NAM technique has eliminated surgical columella reconstruction and the resultant scar tissue from the standard of care in this cleft palate center.

Acrylic Resins↗
PubMed1998

Reduced need for alveolar bone grafting by presurgical orthopedics and primary gingivoperiosteoplasty.

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.

Alveolar Process↗
PubMed1997

Vector of device placement and trajectory of mandibular distraction.

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.

Cephalometry↗