Cleft Lip and Palate Repair: Understanding Secondary Bone Grafting
"A Portuguese hospital's experience sheds light on optimizing outcomes in orofacial cleft treatment."
Orofacial clefts, including cleft lip and palate (CLP), are among the most common congenital craniofacial birth defects. These conditions often involve a bone defect in the upper jaw (alveolar cleft), which can impact facial aesthetics, speech, and dental development.
Secondary alveolar bone grafting (SABG) has become a widely accepted surgical technique to correct these bone defects. SABG involves transplanting bone, often from the iliac crest (hip), to the alveolar cleft to provide support for the teeth, close any abnormal openings between the mouth and nose (oronasal fistulas), and improve overall facial structure.
This article explores the experience of a Portuguese tertiary hospital with SABG, analyzing the factors that contribute to successful outcomes and highlighting the importance of a multidisciplinary approach to CLP care.
Outcomes and Complication Rates in SABG
Secondary alveolar bone grafting (SABG) remains a cornerstone intervention for children with cleft lip and palate. A retrospective study found that the long-term postoperative success rate was 91% in patients evaluated at age 16 and at a mean of 7 years postoperatively, with poor oral hygiene significantly associated with surgical failure. Iliac crest bone grafting (ICBG) has long been considered the gold standard for secondary alveolar reconstruction in pediatric patients, though studies continue to investigate complication rates and compare outcomes with alternatives such as Bone Morphogenetic Protein (BMP) and demineralized bone matrix. More recently, research has aimed to estimate the cumulative probability of bone regrafting after SABG and to identify clinical predictive factors that influence outcomes.
Common Techniques and Inherent Challenges
Secondary alveolar bone grafting is widely performed to restore the bony defect in the alveolar ridge, enabling orthodontic tooth movement and periodontal support. The procedure typically involves harvesting autogenous bone — most commonly from the iliac crest — and transplanting it into the cleft site. While effective, this approach carries limitations including donor site morbidity, the need for an additional surgical site, and variable graft resorption over time. Patient age, cleft size, oral hygiene, and surgical technique all contribute to outcome variability, making standardized assessment of success challenging across clinical settings.
Key Milestones in Alveolar Bone Grafting
The modern era of alveolar bone grafting began with Axhausen in 1951, followed by Schmid's description of primary bone grafting in infants in 1955. Through the 1960s and early 1970s, primarily in Europe, additional surgical procedures beyond lip and palate closures were routinely performed within the first year of life. Skoog published an influential technique in 1972, and by 1990, Boyne and Sands introduced further refinements alongside the Millard and Latham approach. These milestones laid the foundation for contemporary secondary alveolar bone grafting protocols, which have since evolved to balance timing, graft source, and regenerative potential.
What Factors Influence Success in Secondary Bone Grafting?
Researchers retrospectively reviewed 29 SABG procedures performed at their institution between 2007 and 2014. The study evaluated the effectiveness of the bone grafts using the Bergland scale, a system that classifies the degree of bone fill achieved after surgery. They also looked for correlations between the success of the graft and various factors related to the patient and the surgical procedure.
- A majority of the grafts (72%) were considered successful, achieving either complete or near-complete bone fill (Bergland types I and II).
- The type of cleft (unilateral, bilateral, pre-foramen, or transforamen) did not significantly impact the outcome of the SABG procedure.
- The presence of a lateral incisor (a tooth next to the cleft) and the stage of canine tooth eruption at the time of surgery also did not show a strong correlation with graft success.
- A notable proportion of patients (17%) required a second bone grafting procedure to achieve adequate correction.
Evolving Evidence and Methodological Advances
Research into secondary alveolar bone grafting continues to evolve, with recent studies focusing on optimizing graft materials, refining surgical timing, and improving long-term outcomes for patients with cleft lip and palate. Advances in imaging and three-dimensional evaluation have enabled more precise assessment of bone volume and integration postoperatively. Ongoing investigations also explore perioperative strategies — including pain control and surgical planning — aimed at reducing complications and enhancing recovery. While no single approach has emerged as universally superior, the collective body of recent literature underscores a trend toward personalized, evidence-based protocols.
Long-Term Failures and Underexplored Outcomes
Despite its established role, secondary alveolar bone grafting is not without failures. Long-term outcomes beyond the first decade remain poorly documented, as highlighted by a 30-year longitudinal evaluation of SABG in patients with complete unilateral non-syndromic cleft lip and palate. Retrospective analyses of consecutive patient cohorts have identified variable success rates, with graft resorption, infection, and inadequate bone volume contributing to poor outcomes. These limitations challenge the assumption that SABG alone guarantees lasting maxillary continuity and underscore the need for more rigorous long-term follow-up studies.
Autologous vs. Alloplastic Graft Materials
Systematic reviews and meta-analyses have compared autologous bone grafting — traditionally iliac crest autograft — with alloplastic materials and bone substitutes for secondary alveolar reconstruction. A 2019 systematic review and meta-analysis found that autologous bone and recombinant human bone morphogenetic protein-2 (rh-BMP2) grafts showed similar effectiveness in maxillary alveolar reconstruction for patients with unilateral cleft lip and palate when assessing bone graft volume. More recent comparative studies have expanded the analysis to include combined approaches using autogenous bone alongside substitutes, evaluating key radiographic outcomes such as bone fill and integration. These findings suggest that while iliac crest autograft remains the benchmark, alternative materials may offer comparable results with potentially reduced donor site morbidity.
Why a Multidisciplinary Approach is Key
The study emphasizes the importance of a multidisciplinary team in the management of CLP. This team typically includes surgeons, orthodontists, speech therapists, and other specialists who work together to provide comprehensive care for patients.
Integrating Evidence into Clinical Practice
Secondary alveolar bone grafting remains an essential component of the multidisciplinary care pathway for individuals with cleft lip and palate, bridging the gap between early soft tissue repair and long-term dental rehabilitation. Expert consensus continues to emphasize the importance of individualized treatment planning, taking into account patient age, cleft type, and oral health status. While the evidence base has grown substantially, clinical judgment — informed by surgical experience and patient-specific factors — still plays a central role in determining optimal timing and technique. Continued collaboration between surgeons, orthodontists, and speech therapists is critical to achieving the best functional and aesthetic outcomes.
Novel Materials, Timing, and Extended Follow-Up
Emerging research is expanding the horizon of alveolar cleft bone grafting through novel graft materials, advanced perioperative optimization, and refined surgical and radiographic evaluation techniques. A 2025 review of current concepts highlights progress in identifying the ideal timing for grafting, improving pain control protocols, and leveraging imaging to guide surgical planning. The growing recognition that long-term outcomes beyond the first decade remain poorly documented has prompted calls for extended follow-up studies spanning decades rather than years. These frontiers point toward a future in which SABG is increasingly guided by personalized data, from preoperative imaging to molecular-level graft assessment.
Rethinking the Timing of Bone Grafting
One of the most significant systemic debates in cleft care concerns the optimal timing for secondary alveolar bone grafting. Traditionally performed between 9 and 11 years of age — coinciding with the eruption of the permanent canine — recent evidence and clinical experience have increasingly supported performing SABG earlier, specifically between 4 and 6 years of age. This shift reflects a growing body of evidence suggesting that earlier intervention may improve dental and periodontal outcomes while simplifying the overall treatment timeline. However, adopting earlier grafting protocols requires careful consideration of the child's skeletal development and the availability of adequate donor tissue.
Patient-Reported Outcomes and Compliance
Beyond surgical metrics, the real-world impact of secondary alveolar bone grafting is increasingly measured through patient and parent reported outcome measures (PROMs). A pioneering PROMs study evaluated 40 consecutive cleft lip and palate children between 8 and 14 years old, marking the first investigation of patient-reported outcomes in those who had or had not undergone SABG. Complementing this, research assessing outcomes at age 16 has identified poor oral hygiene as a significant predictor of surgical failure, highlighting the critical role of patient compliance. Together, these findings underscore that successful bone grafting depends not only on surgical technique but also on the patient's engagement with long-term oral health maintenance.
The optimal timing for SABG is a critical decision, requiring careful consideration of the patient's dental development, facial growth, and overall health. A multidisciplinary team can best assess these factors and determine the most appropriate time for intervention.
Long-term follow-up is also essential to monitor the success of the bone graft and address any potential complications. The Portuguese hospital's experience underscores the need for continued research and collaboration to improve outcomes for individuals with cleft lip and palate.