Trans-sutural distraction osteogenesis for alveolar cleft repair: an experimental canine study

Outcomes of Bifocal Transport Distraction Osteogenesis for Repairing Complicated Unilateral Alveolar Cleft

OBJECTIVES

This study aimed to assess the outcomes of bifocal transport distraction osteogenesis (BTDO) for closure of a wide or previously failed unilateral alveolar cleft.

METHODS

Patient in this study had a large alveolar cleft that had not healed with bone grafts. Bone-borne distraction was used under general anesthesia. Intraoperative complications as bleeding and trauma to neighboring teeth were documented. Postoperative complications as wound dehiscence, paresthesia, infection, and bleeding were recorded. Complications including changes in bone segment movement, activation force loss, and occlusal interferences were observed during the activation phase. During the consolidation phase, problems including gingival recession, pulpal vitality, and cosmetic concerns were evaluated. Postoperative, periapical, occlusal, and orthopantomograms were used to evaluate bone gain and bone generation in the distracted area.

RESULTS

Ten patients (6 males and 4 females) with unilateral alveolar cleft were included, with mean age of 9.5 ± 2.5 years. Average cleft width was 12.25 ± 2.54 mm. There was no intraoperative or postoperative bleeding. Only 1 patient had a wound dehiscence (10%). All patients had mild postoperative pain and edema in upper lip. Only 1 patient complained of numbness in infraorbital nerve's innervated region. Radiographs revealed bone formation in cleft area and bone healing in distracted chamber.

CONCLUSIONS

Bifocal transport distraction osteogenesis improves success rate of an alveolar cleft treatment especially a wide or previously failed one. This technique associated with minimal complications when careful planning and cooperation from a patient are combined. It can be recommended when other modalities for alveolar cleft are failed. Patients also tolerate the device well.

Bone regeneration using composite non-demineralized xenogenic dentin with beta-tricalcium phosphate in experimental alveolar cleft repair in a rabbit model

Background

Alveolar cleft repair is performed via bone grafting procedure to restore the dental arch continuity. A suitable bone substitute materials should possess osteoinductive and osteoconductive properties, to promote new bone formation, along with a slowly resorbable scaffold that is subsequently replaced with functionally viable bone. Calcium phosphate biomaterials have long proved their efficacy as bone replacement materials. Dentin in several forms has also demonstrated its possibility to be used as bone graft replacement material in several studies. The purpose of this study was to evaluate bone regeneration pattern and quantify bone formation after grafting pre-established experimental alveolar clefts defects model in rabbits using composite xenogenic dentin and β-TCP in comparison to β-TCP alone.

Methods

Unilateral alveolar cleft defects were created in 16 New Zealand rabbits according to previously described methodology. Alveolar clefts were allowed 8 weeks healing period. 8 defects were filled with β-TCP, whereas 8 defects filled with composite xenogenic dentin with β-TCP. Bone regeneration of the healed defects was compared at the 8 weeks after intervention. Quantification of bone formation was analyzed using micro-computed tomography (µCT) and histomorphometric analysis.

Results

µCT and histomorphometric analysis revealed that defects filled with composite dentin/β-TCP showed statistically higher bone volume fraction, bone mineral density and percentage residual graft volume when compared to β-TCP alone. An improved surgical handling of the composite dentin/β-TCP graft was also noted.

Conclusions

Composite xenogenic dentin/β-TCP putty expresses enhanced bone regeneration compared to β-TCP alone in the reconstruction of rabbit alveolar clefts defects.

A rabbit model for experimental alveolar cleft grafting

Objectives

The purpose of the present study was to develop an animal model for creating alveolar cleft defects with properly simulated clinical defect environment for tissue-engineered bone-substitute materials testing without compromising the health of the animal. Cleft creation surgery was aimed at creating a complete alveolar cleft with a wide bone defect with an epithelial lining (oral mucosa) overlying the cleft defect.

Methods

A postmortem skull of a New Zealand White (NZW) rabbit skull (Oryctolagus cuniculus) underwent an osteological and imaging survey. A pilot postmortem surgery was conducted to confirm the feasability of a surgical procedure and the defect was also radiologically confirmed and illustrated with micro-computed tomography. Then, a surgical in vivo model was tested and evaluated in 16 (n = 16) 8-week-old NZW rabbits to create in vivo alveolar cleft creation surgery.

Results

Clinical examination and imaging analysis 8 weeks after cleft creation surgery revealed the establishment of a wide skeletal defect extending to the nasal mucosa simulating alveolar clefts in all of the rabbits.

Conclusions

Our surgical technique was successful in creating a sizable and predictable model for bone grafting material testing. The model allows for simulating the cleft site environment and can be used to evaluate various bone grafting materials in regard to efficacy of osteogenesis and healing potential without compromising the health of the animal.