September 2019 HSC Section 1 Congenital and Pediatric Problems

Gingivoperiosteoplasty and Alveolar Bone Grafting

has been associated with low rates of VPI, with only 5.7% of patients demonstrating a clearly incompetent velopharyngeal mechanism. 16 Eusta- chian tube dysfunction affects nearly all cleft palate patients. It has been demonstrated that pa- tients undergoing a multilayer closure with intrave- lar veloplasty have significantly improved speech and eustachian tube function outcomes than those undergoing a multilayer closure without the intra- velar veloplasty. 19 MANAGEMENT OF THE ALVEOLAR CLEFT One of the most controversial topics in cleft care is the management of the alveolar cleft, specif- ically the indications for primary GPP. Alveolar clefts exist when there is deficient or absence of bone in the primary palate from the nasal sill to the incisive foramen. When an alveolar cleft is pre- sent one must weigh the risks and benefits of potentially sparing the patient an additional sur- gery against iatrogenic restriction of facial growth and malocclusion. Gingivoperiosteoplasty GPP has been described as a “boneless bone graft.” 20 GPP encourages bone formation in an alveolar cleft through surgical repositioning of the mucosal edges. Goals of the procedure include bony continuity of the alveolar arch, improving alignment and stabilization of the anterior maxilla, nasal symmetry, closing oronasal fistulae, sponta- neous eruption of permanent teeth within and next to the cleft, and avoidance of secondary bone grafting. In 1965, Skoog 20 was the first to describe this technique, which involves forming a mucoper- iosteal bridge across the bridge to promote osseous formation within the subperiosteal tunnel. At that time the lingual and labial aspects of the cleft were approximated with a large transposi- tioned flap from a widely undermined maxillary periosteum, which unfortunately subjected the pa- tient to possible iatrogenic facial growth restriction because of extensive subperiosteal dissection. Since then presurgical infant orthopedics and nasoalveolar molding have been used to narrow the cleft and improve alignment of the alveolar segments before surgical repair. Furthermore, GPP may be broken down into direct and indirect approaches. A direct approach involves using adjacent gingiva, which requires a relatively narrow cleft. Alternatively, during an indi- rect approach a distant periosteal flap is used as previously described. Current data on the use of nasoalveolar molding/GPP are favorable, although long-term outcome studies are required. 21 Prereq- uisites for a GPP include appropriate cleft anatomy

to allow alveolar bony approximation, an optimally molded alveolar cleft and intact mucosa, and no dental eruption. Once these criteria are met, the GPP can usually be scheduled at the time of the primary lip repair, often between 3 and 5 months. Isolated clefts of the primary palate are often not ideal candidates because the alveolar segments of the primary palate are more resistant to parallel presurgical molding. Also in bilateral clefts, consideration is made as to close both or one alve- olar cleft at a time to prevent devascularization of the premaxilla. The initial descriptions of alveolar bone grafting date back to the start of the twentieth century 22 and the most commonly used procedure today was described in 1972 by Boyne and Sands. 23 The goals of alveolar cleft repair include closing nasolabial/palatal fistulae using local mucoperios- teal flaps, restoring maxillary arch continuity, including stabilization of premaxilla in bilateral clefts with cleft bone grafting, providing bone and support for teeth near the cleft, supporting the nasal ala, and providing bone for dental implants. Timing Timing of alveolar cleft repair should aim at mi- nimizing the adverse effects that early repair (<5–6 years old) may have on maxillary growth and avoiding grafting delay until the canine starts to erupt (>10–12 years old). Timing of repair may be classified as primary, early secondary, second- ary, and late. Primary alveolar grafting is done before age 2 and is usually done with the primary lip repair typically with a bone graft harvest from the rib. Advantages include early stabilization of the alveolar segments and improved arch form, although midface growth disturbances have led to abandonment of primary grafting in several cleft centers. 24 Early secondary alveolar grafting falls between 2 and 5 years of age using autogenous bone graft typically from the hip. It has been found that 75% to 90% of maxillary adult dimensions are achieved by age 5. Therefore, it is possible that maxillary growth would not be significantly altered if grafting was performed at that time. 25 Secondary alveolar grafting is done between ages 5 and 13 and specific timing is usually based on dental eruption. Several cleft centers repair between 6 and 10 years of age after orthodontic preparation and maxillary expansion have been completed based on the historical recommendation to pro- ceed with repair once the permanent canine root is one-half to two-thirds formed. This concept fails Alveolar Bone Grafting Introduction

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