Bone regeneration in the hard palate after cleft palate surgery

Evaluation of Secondary Alveolar Bone Grafting for Unilateral Complete Cleft Alveolus: A Retrospective Cone Beam Computed Tomography-Based Study

Background: In patients with cleft lip and palate (CLP), secondary alveolar bone grafting (SABG) with particulate cancellous bone marrow (PCBM) is recommended. Objective: To compare bone graft outcomes in patients with unilateral CLP, when SABG is completed before or after canine tooth eruption (ACE or BCE), as measured by cone beam computed tomography (CBCT). Methods: Patients were allocated into two cohorts, ACE and BCE. The outcomes were evaluated using CBCT, followed by univariate and multifactorial analyses. Results: A total of 468 patients (age 11.61 ± 4.03 years; male/female 288/180) were analyzed, including 282 in the BCE group (9.41 ± 1.59 years, 175/107) and 186 in the ACE group (14.95 ± 4.31 years, 113/73). Although 5-level assessment revealed no significant difference in clinical success rate (>4 points) between the BCE and ACE groups (53.90% vs. 47.85%, p = 0.20), BCE group showed significantly higher rate of bone bridges formation (73.05% vs. 62.90%, p = 0.02), which can be attributed to variations in orthodontic participation and follow-up time. Independent predictors of graft failure were wide cleft, severe oronasal fistula, no palatal bone wall, and insufficient PCBM filling (p < 0.01). Conclusions: SABG should be performed before canine eruption with more aggressive PCBM filling and oral fistula management.

Surgically treated congenital cleft palate in a 4-month-old kitten: medium-term clinical and CT assessment

Case summary

A 4-month-old female domestic shorthair kitten was presented for a congenital cleft palate causing nasal discharge and sneezing episodes. CT revealed a palatal bone defect involving 20% of the palatal area. Surgical correction of both the hard and soft palate defects was performed using the overlapping and medially positioned flap techniques, respectively. Complete healing of the wound and full resolution of the clinical signs occurred within a 1-month period. At 2 months postoperatively, two punctiform oronasal fistulae were observed rostrally without associated clinical signs. Control CT, performed 6 months postoperatively, revealed a 50% enlargement of the palatal bone defect. At 12 months postoperatively, the cat was still in good general condition without any clinical signs.

Relevance and novel information

To the best of our knowledge, this is the first report to describe the treatment of a congenital cleft palate in a kitten using the overlapping flap technique with a successful medium-term clinical outcome, despite the formation of two oronasal fistulae. This suggests that, as in dogs, full restoration of oronasal compartmentation is not mandatory to achieve functional outcome. The increase of the palatal bone defect over time may play a role in late oronasal fistulae formation and should be considered for surgical planning.

Engineered mucoperiosteal scaffold for cleft palate regeneration towards the non-immunogenic transplantation

Cleft lip and palate (CL/P) is the most prevalent craniofacial birth defect in humans. None of the surgical procedures currently used for CL/P repair lead to definitive correction of hard palate bone interruption. Advances in tissue engineering and regenerative medicine aim to develop new strategies to restore palatal bone interruption by using tissue or organ-decellularized bioscaffolds seeded with host cells. Aim of this study was to set up a new natural scaffold deriving from a decellularized porcine mucoperiosteum, engineered by an innovative micro-perforation procedure based on Quantum Molecular Resonance (QMR) and then subjected to in vitro recellularization with human bone marrow-derived mesenchymal stem cells (hBM-MSCs). Our results demonstrated the efficiency of decellularization treatment gaining a natural, non-immunogenic scaffold with preserved collagen microenvironment that displays a favorable support to hMSC engraftment, spreading and differentiation. Ultrastructural analysis showed that the micro-perforation procedure preserved the collagen mesh, increasing the osteoinductive potential for mesenchymal precursor cells. In conclusion, we developed a novel tissue engineering protocol to obtain a non-immunogenic mucoperiosteal scaffold suitable for allogenic transplantation and CL/P repair. The innovative micro-perforation procedure improving hMSC osteogenic differentiation potentially impacts for enhanced palatal bone regeneration leading to future clinical applications in humans.

Spontaneous Palatal Cleft Closure

This case report presents a palatal cleft that healed spontaneously, with complete formation of mucosa and bone. Even though the nasal structures could initially be observed through the cleft palate, a thin membrane sealed any communication between the oral and nasal cavities. The origin of this tenuous membrane cannot be fully understood with current discernment of palate formation, but it probably served as a basis for the formation of the other tissues. No previous record of nonintervened spontaneous closure of a cleft palate has been reported.

Spontaneous Bone Regeneration After Closure of the Hard Palate Cleft: A Literature Review

PURPOSE

A wide range of surgical techniques have been described for the treatment of palatal clefts. Some of these surgical procedures result in postoperative osteogenesis at the palatal fissure. The aims of this review were to discuss the current approaches to cleft palate surgery leading to spontaneous bone regeneration and to compare these different procedures. Moreover, the causes of bone regeneration, effects on maxillary growth, and factors affecting bone regeneration on the hard palate are discussed.

MATERIALS AND METHODS

The selected articles were found via MEDLINE and Web of Science. The keywords for the search were "cleft palate," "bone regeneration," "palatoplasty," "reconstructive surgical procedures," and "cleft palate surgery." Studies that examined the effect of primary palatoplasty on spontaneous bone regeneration in the hard palate in children were included in this review. Four articles were analyzed in the qualitative synthesis.

RESULTS

Because of differences in patient characteristics and evaluation methods, it was difficult to compare different surgical procedures. The use of a mucoperiosteal flap in combination with adequate closure of the mucosa is needed to obtain bone formation. The area with the largest amount of regenerated bone was located in the middle of the hard palate. In the literature, it was found that complete closure was considered unfavorable because of the negative effects on maxillary growth, but more studies are needed to confirm this. Of the factors that have been studied, only age turned out to be borderline relevant.

CONCLUSIONS

Only a few studies with small sample sizes have been published on bone regeneration in the hard palate. More research is needed to validate these findings.

Bioactive Sr(II)/Chitosan/Poly(ε-caprolactone) Scaffolds for Craniofacial Tissue Regeneration. In Vitro and In Vivo Behavior

In craniofacial tissue regeneration, the current gold standard treatment is autologous bone grafting, however, it presents some disadvantages. Although new alternatives have emerged there is still an urgent demand of biodegradable scaffolds to act as extracellular matrix in the regeneration process. A potentially useful element in bone regeneration is strontium. It is known to promote stimulation of osteoblasts while inhibiting osteoclasts resorption, leading to neoformed bone. The present paper reports the preparation and characterization of strontium (Sr) containing hybrid scaffolds formed by a matrix of ionically cross-linked chitosan and microparticles of poly(ε-caprolactone) (PCL). These scaffolds of relatively facile fabrication were seeded with osteoblast-like cells (MG-63) and human bone marrow mesenchymal stem cells (hBMSCs) for application in craniofacial tissue regeneration. Membrane scaffolds were prepared using chitosan:PCL ratios of 1:2 and 1:1 and 5 wt % Sr salts. Characterization was performed addressing physico-chemical properties, swelling behavior, in vitro biological performance and in vivo biocompatibility. Overall, the composition, microstructure and swelling degree (≈245%) of scaffolds combine with the adequate dimensional stability, lack of toxicity, osteogenic activity in MG-63 cells and hBMSCs, along with the in vivo biocompatibility in rats allow considering this system as a promising biomaterial for the treatment of craniofacial tissue regeneration.

Long-Term Computed Tomographic Evaluation of Alveolar Bone Formation in Patients with Unilateral Cleft Lip and Palate after Early Secondary Gingivoalveoloplasty

BACKGROUND

The goal of this study was to evaluate with a three-dimensional method the long-term quality of alveolar ossification in unilateral cleft lip and palate patients who underwent early secondary gingivoalveoloplasty according to the Milan surgical protocol.

METHODS

The sample consisted of 63 computed tomographic scans of unilateral cleft lip and palate patients in permanent dentition. The average age at the time of assessment was 15.7 years. Alveolar thickness, nasoalveolar height, nasal floor ossification, and hard palate morphology were evaluated using dental, axial, and coronal cuts on computed tomographic scans and three-dimensional models. All measurements were normalized and ratios of the affected side versus the nonaffected side were provided. Volume measurements and ratios of each hemimaxilla were added. The presence or absence of the permanent lateral incisor on the cleft side was also recorded.

RESULTS

Alveolar thickness and height were ideal or good, respectively, in 89.5 and 91.4 percent of the sample. Insufficient ossification (<25 percent) was found in three patients (5.2 percent), and only one of them (1.7 percent) presented no bone bridging. A statistically significant association was detected between the degree of alveolar ossification, the type of nasal floor ossification, and volume ratio.

CONCLUSIONS

Early secondary gingivoalveoloplasty seemed to allow an adequate ossification of both the alveolar and nasal region. Three-dimensional evaluation of the alveolar cleft ossification provided further information on alveolar bridging and allowed evaluation of the bone availability for implant placement.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Three-dimensional imaging methods for quantitative analysis of facial soft tissues and skeletal morphology in patients with orofacial clefts: a systematic review

Background

Current guidelines for evaluating cleft palate treatments are mostly based on two-dimensional (2D) evaluation, but three-dimensional (3D) imaging methods to assess treatment outcome are steadily rising.

Objective

To identify 3D imaging methods for quantitative assessment of soft tissue and skeletal morphology in patients with cleft lip and palate.

Data sources

Literature was searched using PubMed (1948–2012), EMBASE (1980–2012), Scopus (2004–2012), Web of Science (1945–2012), and the Cochrane Library. The last search was performed September 30, 2012. Reference lists were hand searched for potentially eligible studies. There was no language restriction.

Study selection

We included publications using 3D imaging techniques to assess facial soft tissue or skeletal morphology in patients older than 5 years with a cleft lip with/or without cleft palate. We reviewed studies involving the facial region when at least 10 subjects in the sample size had at least one cleft type. Only primary publications were included.

Data extraction

Independent extraction of data and quality assessments were performed by two observers.

Results

Five hundred full text publications were retrieved, 144 met the inclusion criteria, with 63 high quality studies. There were differences in study designs, topics studied, patient characteristics, and success measurements; therefore, only a systematic review could be conducted. Main 3D-techniques that are used in cleft lip and palate patients are CT, CBCT, MRI, stereophotogrammetry, and laser surface scanning. These techniques are mainly used for soft tissue analysis, evaluation of bone grafting, and changes in the craniofacial skeleton. Digital dental casts are used to evaluate treatment and changes over time.

Conclusion

Available evidence implies that 3D imaging methods can be used for documentation of CLP patients. No data are available yet showing that 3D methods are more informative than conventional 2D methods. Further research is warranted to elucidate it.

Systematic review registration

International Prospective Register of Systematic Reviews, PROSPERO CRD42012002041

The long-term changes of hard palatal bony cleft defects after palatoplasty in unilateral complete cleft lip and palate

There have been few long-term studies regarding the change of bony cleft defects in cleft lip and palate after palatoplasty. The purpose of this study was to evaluate the regenerated bone formed in bony cleft defects and the change in bony cleft width after palatoplasty using computed tomography (CT). Thirty non-syndromic unilateral complete cleft lip and palate patients were retrospectively reviewed. The patients underwent palatoplasty at an average age of 14.32 months. CT was performed at an average age of 9.8 years. The authors evaluated the regenerated bone volume ratio, remnant bony cleft area ratio and change in bony cleft width at the posterior nasal spine. The relative locations of the regenerated bone lesion and the bony cleft to the hard palate were measured. Regenerated bone was observed in all patients. The average regenerated bone volume ratio was 61.1%, and the largest regenerated bone was usually located in the anterior half of the hard palate. The average remnant bony cleft area ratio was 7.6%, and the widest bony cleft was usually located in the anterior 1/3 and the posterior 1/3. The remnant bony cleft and non-regenerated bone lesion were rarely located in the middle 1/3. The bony cleft width at the posterior nasal spine decreased significantly after palatoplasty. Hard palatal bony cleft defects after palatoplasty were decreased by regenerated bone, and possibly by the contracting force of the scar at the midline of the hard palate, and the continuous pressure of the surrounding tissues.

Evaluation and analysis of formation of bone at the palate in patients with cleft lip and palate after palatoplasty based on computed tomograms and three-dimensional data

There are various techniques for palatoplasty, but no studies of postoperative osteogenesis at the palatal fissure. In the cranial and maxillofacial region it is thought to develop from the periosteum, so palatoplasty with mucoperiosteal flaps may encourage new bone to form at the fissure. We evaluated the status of osteogenesis in the hard palate after palatoplasty on computed tomograms (CT). We studied 29 patients (22 boys and 7 girls) with unilateral cleft lip and palate who had pushback palatoplasty with the use of CT obtained between May 2003 and March 2007. Age at the time of operation was recorded. The width of the palatal fissure at the first premolar, the first molar, and the maxillary posterior region were measured on coronal CT. The mean (SD) age at the time of palatoplasty was 16 (2) months. The mean (SD) width of the fissure at the first molar was 3.96 (3.1) mm, and bony union was seen in four patients. The width of the fissure was significantly less at the first molar than at the other sites (p = 0.006). The shape of the margin of the fissure was irregular in nearly all patients. The width of the fissure at the first molar became significantly less, suggesting that osteogenesis had occurred. In some patients the height of the fissure differed. Given the results of previous studies, bony regeneration from the periosteum most likely happens together with regeneration from the margins of the fissure.