secondary alveolar cleft repair
TRANSCRIPT
SECONDARY ALVEOLAR CLEFT REPAIR
Natarajan.c
Any patient born with complete cleft should be considered for alveolar grafting.
Cardinal rule
Classification
Based on the timing of grafting , Primary - less than 2 yrs. Early secondary - 2-5 years. Secondary - 6-15 years. Late secondary - >15 years.
Primary repair – before palatal closure. Secondary repair – after palatal closure.
Pitfalls of primary repair……
“….a surgery that is needless and sometimes barbaric……”
-Pruzansky In , 1963 Convention of American
Cleft Palate Association.
Robertson and Jolly (1968) –first to report
mid-face deficiency and malocclusion due to primary repair.
Transverse maxillary arch collapse is not
completely prevented by primary repair.
Koberg states that, “……most severe maxillary deformities
are to be expected as late results of primary bone grafting , so that late secondary osteoplasty remains the only justifiable form of bone transplantation in cleft surgery……”
Secondary repair -Objectives
.
Max arch stabilization, Bony support to teeth adjacent to cleft, Provision of bone for tooth eruption &
ortho movement, Ridge height for prosthetic rehabilitation, Obliteration of oro-nasal fistula, Support for alveolar base.
Untreated cleft results in…
Palatally displaced alv.ridge on cleft side wit tooth malalingment.
Deficient bone support. Inadequate oral hygiene, due to oro-nasal
fistula. Segmental mobility. Effects on speech.
Various methods of repair.
Grafting. 1.autogenous 2.allogenous 3.alloplastic
Orthognathic surgery.
Intradental distraction osteogenesis.
Periosteoplasty.
Secondary bone grafting of residual alveolar clefts
Phillip J. Boyne & Ned R. Sands journal of oral surgery feb1972, vol 30, 87-92.
CLASSIC ARTICLE. Prefered time for surgery-btwn 9 and 12
years.
But , dental developmental age, and not the chronological age is the foremost consideration.
grafting is done → canine root is 1/4th to 2/3rd
complete.
“delaying grafting beyond the point of canine root development → increased incidence of periodontal defects and fistula.”
Sindet – Pederson - Enmark
But…
When orthognathic surgery is planned …
Secondary grafting is delayed.
Grafting….
In autogenous group , bone is deposited in 2 to 6wk . At 6th mo complete bone fill.
In allogenous group , host bone
induction was not there till 7th wk .At 6 mo only 30% bone filling was evident.
-Marx .et al, JOMS 42 ; 3 ,1984.
Currently alloplasts are indicated for only ridge contouring & not indicated in growing individuals & wit unerupted tooth adjacent to cleft & only wen endosteal implants are not planned.
Optimal sequence…
Transverse expansion of maxilla (in late mixed dentition)
Followed by bone grafting
Graft procurement site selection is based on …
Primarily , size of the defect. Age of the patient. Operator preference. Patients desire.
“best inductor agent…..is natural human bone of cancellous structure in finely divided form , and that the most responsive tissue is the connective tissue closely related to living bone…”
-Collins ,Pathology of Bone.
Various cancellous graft procurement sites …
Illium. Calvarium. Mandibular symphysis.???? Rib. Proximal tibia.
But…
Best cancellous grafts obtained from Trochanter major(femur) -Spiessl, oral & maxillofacial bone
surgery.
PCBM – Particulate Cancellous Bone Marrow
grafts, obtained from illiac crest is the donor material of choice.
-Boyne & Sands 1972
Requisites of ideal bone graft…
Existence in unlimited supply. Provision for immediate osteogenesis for
rapid consolidation. No adverse host rxn. immed. revascularization Osteoinduction Adaptability . No impediment in growth. Framework for osteoconduction. Completely replaceable by bone.
Functions of successful bone graft
Restores normal continuity & functions. Restores appearance and facial esthetics. Forms allostructural framework for new
bone formation. Furnishes osteogenic cells. Precursor for bone induction principle.
Rules for bone grafting-Kazanjian 1952
Adequate blood supply of recipient site. Bone to bone contact ,CREEPING
SUBSTITUTION. Rigid fixation of fragments. Grafts to be placed into only healthy
tissue..
Bone storage-Marx 1994
Cell viability Best maintained in culture media/N.S. 95% viability at room temp for 4 hrs. temp of solution death rate of cells. Temp cooler than room temp small in
cell survival. Avoid hypotonic sols.
10cc loose uncompressed cancellous bone for every 10mm length of reconstruction.