Basnayake S1 , Karunathilaka S2, Rajaganesh A3 , De Alwis S4
- Department of Orthodontics, Lady Ridgeway Hospital for Children, Colombo
- Oral and Maxillofacial Unit, Colombo South Teaching Hospital
- Department of Orthodontics, DGH Negombo
- Department of Orthodontics, Lady Ridgeway Hospital for Children, Colombo
Introduction :Alveolar bone grafting (ABG) is an essential intervention in the management of cleft lip and palate. The precise timing of the ABG surgery had been debated for many years. Secondary ABG carried out prior to the eruption of the permanent canine has become a widely accepted procedure since it was first introduced in 1972. It is carried out in the mixed dentition stage to create an intact and continuous alveolar arch.
Objective: To evaluate the success rate of alveolar bone graft surgeries in cleft lip and palate patients at Lady Ridgeway Hospital for Children Colombo.
Methods and Materials: This Retrospective analytical study used a sample population of 100 patients who underwent Alveolar bone graft surgeries carried out by a single operating surgeon. Kindelan scoring system was applied to maxillary occlusal radiographs taken at least 6month after surgery.
Results: 55% were Grade 1. 20% were grade 2 and 11% were Grade 3 No complete bony fill was seen in 5% of cases.
Conclusion: Our figures revealed a clinical success rate of 75% (Type I and II).
Cleft lip and palate, Alveolar bone graft, Kindelan score, Sri Lankan
Cleft lip and palate conditions are common congenital deformities of the oro-pharyngeal region. Management of such conditions require involvement of multiple specialties who should intervene at various stages of a child’s development from birth to adulthood.
Alveolar bone grafting is one such essential intervention which has various benefits that have been well documented. The precise timing of the ABG surgery had been debated for many years.
Secondary alveolar bone grafting carried out prior to the eruption of the permanent canine has become a widely accepted procedure since it was first introduced by Boyne and Sands in 1972 i. It is carried out in the mixed dentition stage to create an intact and continuous alveolar arch. This allows proper eruption of the permanent dentition and also facilitates orthodontic tooth movements into previous cleft sites, there by minimizing the need for prosthetic replacement of teeth. It also helps to stabilize the pre maxilla in bilateral cleft patients. In addition to the aforementioned benefits, alveolar bone grafting also improves the contour of the alar base and facilitates fistula closureii.
Secondary alveolar bone grafting is now an essential part of the cleft lip and palate treatment protocol. The optimum time is decided individually. Usually its between 9-11 years when the unerupted cleft canine root is one-half to 2/3 rds developed and sometimes between 7-8 years if a well formed lateral incisor is present.
The advantages of a successful Alveolar bone graft are clear but various factors play a role in establishing whether or not the grafted bone survives. The type of cleft, whether unilateral or bilateral has been shown to affect the outcome of alveolar bone graft surgeries in some studiesiii. The status of the cleft canine at the time of ABG surgery has been proved by various authors to be a major factor in determining the success of the graftiv. Having a tooth erupt through the newly grafted bone or moving a tooth orthodontically into it ensures its survival. In addition to that, the size of the cleft, presence of supernumeraries and decayed teeth in the cleft and pre surgical orthodontic expansion of the cleft site are also considered be factors which affect the outcome of ABG. Infection control and experience of the surgeon also plays a major role in the success of ABG. A protocol was developed jointly by the Department of Orthodontics LRH and the Oral Maxillofacial unit of the Teaching Hospital Kalubowila to cover all aspects, which contribute to the success of this surgery. Therefore it was essential to evaluate the success rate of alveolar bone grafts of our patients.
Various centers around the globe have carried out such researches and reported them accordingly. A radiographic tool is necessary to visualize the grafted site, and the type of tool used in previous studies vary from 3-Dimentional CTs, Intra Oral Periapical Radiographs or Occlusal radiographs. The indices used to analyze the grafted site also varied among previous studies with the Berglund scorev being the most commonly used. The Kindelan scorevi and the Chelsea scorevii were also used in certain studies.
According to CSAG (Clinical Standards Advisory Group) the success rate of Alveolar bone grafts in England and Wales had improved from 58% in 1998 to 95% in 2006 following implication of centralizationviii,ix. Such a study carried out in Sri Lanka would provide results which can be compared with international standards to identify shortcomings and to improve future care. Therefore the purpose of this study is to establish the radiographic outcome of Alveolar Bone grafts carried out in cleft palate patients registered in Lady Ridgeway Hospital for Children, Colombo. To the best of my knowledge similar studies have not been carried out in Sri Lanka previously
To establish the radiographic outcome of Alveolar Bone grafts carried out in cleft palate patients registered in Lady Ridgeway Hospital for Children, Colombo
Methods and Materials
Study designA: Retrospective analytical study
Setting: Lady Ridgeway Hospital for Children
Sample population: Consecutive alveolar bone graft surgeries carried out by a single operating surgeon between October 2009- September 2012 at the Oral and Maxillo Facial unit in the Colombo South Teaching Hospital.
Surgery involved Autogenous bone grafts from Anterior illiac crest.
Sample size: 113
Study instrument: Maxillary occlusal radiographs taken at 6 month intervals as a routine, to assess the viability of the bone graft.
These radiographs were taken at 70 degree angulations to the vertical and centered through the cleft
The follow up time varied from being 6 months to 2 years
- Patients who have undergone Alveolar bone graft (ABG) surgery between October 2009 – September 2012.
- Minimum period of 6 months since the ABG surgery. Therefore allowing time for the bone to be integrated and calcified
- Patients who do not have minimum 6 months post operative period.
Criteria of evaluation.
Anonymous, standardized photographs were taken of each maxillary occlusal radiograph. These were then transferred to Microsoft power point slides for scoring. Two examiners in Glasgow did scoring independently. The examiners scored the postoperative radiographs under standardized conditions on two separate occasions.
The Kindelan scoring system was used as an audit tool to assess the amount of bony fill at the cleft site. It has four grades (Table1 & figure 1). Grade 1 indicates more than 75% bony fill at the cleft site. Grade 2 shows 50-75% bony fill and anything less than 50% is scored as Grade 3. Cases with no complete bony fill are classified as Grade 4. The kindelan scoring system is frequently used and is easy to apply. The main advantage over the other scoring systems is that it does not require the permanent canine adjacent to the cleft to be fully erupted. This can take a significant amount of time following the graft.
Table 1 Kindelan scoring system
|4||No complete bony fill||Failure|
Being a two dimensional assessment is a drawback as plain radiographs are susceptible to distortion and superimposition of adjacent structures. Although plain radiographs have various limiting factors, they are cheaper, easily accessible and give a low dose of radiation. Previous studies have shown that measuring outcome from a single postoperative radiograph using the Kindelan scoring system is a reliable methodx.
The two examiners (Examiner A and B) scored the postoperative radiographs under standardized conditions on two separate occasions. According to the Kindelan scoring system Grade 1 and 2 were considered as successful outcome of treatment, Grade 3 was borderline and Grade 4 was a failure.
A Kappa statistic was used to measure intra-examiner and inter-examiner reliability as this was ordered categorical data. Bland Altman system was used measure the strength of agreement for the Kappa coefficient.
Ethical clearance obtained form Ethical review committee, Lady Ridgeway Hospital for Children. Radiographs taken as a routine during follow up visits were considered. Patients were not subjected to additional radiation for the purpose of this study.
Table 2 shows the results of the analysis done by the two examiners on two separate rounds, and Table 3 displays the average.
Table 2 Results
|Round 1 Examiner 1||Round 1 Examiner 2||Round 2 Examiner 1||Round 2 Examiner 2|
Table 3 Results
|Grade 1||55%||Clinically successful|
|Grade 2||20%||Clinically successful|
Out of the 113 radiographs scored using the kindelan scale, 55% were classified as Grade 1 and 20% were Grade 2. Grades 1 and 2 are considered as clinically successful outcome. 11% were classed as Grade 3. 5% of the cases showed no complete bony fill and therefore scored as Grade 4. 10% of the cases could not be assessed.
According to the Bland Altman system the strength of agreement for the Kappa coefficient (very good 0.81-1.00; good 0.61-0.90; moderate 0.41-0.60; fair 0.21-0.40 and poor <0.21). ranging from 0.412-0.766 was obtained by the examiners which was acceptable.
Discussion & Conclusion
This study recorded 75% success rate of Alveolar bone graft surgeries carried out in cleft lip and plate patients registered in Lady Ridgeway Hospital for Children Colombo.
There was a 5% failure rate. The causes of failure may have been due to ABG surgeries not being carried out in the optimum time due to late presentation.
Success rates of other similar studies around the globe varied from 58% – 100%. This audit provided us with valuable insight into the ABG surgeries carried out in our patients and it also gave us an opportunity to compare our results
Three dimensional volumetric assessment by cone beam CT can be a very accurate and a reliable method in the future.
Patients and Staff of Lady Ridgeway Hospital for Children Colombo.
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