Kummoona Chondro-Ossous graft good substitute to condylar growth center and fore correction of facial deformity in chilidren

This theory was accepted by most of the scientist and clinician for many decades till Moss [2], 1962 came with new theory based on, the growth of the face occurred as a functional demand of the periosteal matrix of the facial skeleton and he think there is no growth center in the condyle controlling the growth of the mandible and most of the craniofacial and maxillofacial surgeons with orthodontist were supported Moss theory previously [2].


Introduction
There are a lot of controversial views about the condyle as a growth center, the British pioneer and great scientist John Hunter [1] 1772-1773 who paid attention to the condyle as a growth center in his book the teeth and he mentioned in his book there is a strong relation between the teeth and temporomandibular joint( TMJ). This theory was accepted by most of the scientist and clinician for many decades till Moss [2], 1962 came with new theory based on, the growth of the face occurred as a functional demand of the periosteal matrix of the facial skeleton and he think there is no growth center in the condyle controlling the growth of the mandible and most of the craniofacial and maxillofacial surgeons with orthodontist were supported Moss theory previously [2].
The author came with another idea and supported John Hunter theory [1], his thought was based on his experimental studies by using Rabbits as animal model for his experiments by excision the head of the Rabbit condyle of the mandible of a newly borne animal and three months later he noticed severe deformity of the mandible and mid face ,and the mandible twisted to the effected side and also the author did replaced the TMJ by two part chrome cobalt Kummoona prosthesis [3], for ankylosed joint of 6 year female patient, after three years he noticed this young girl showed excellent function of the mandible during mouth opening without diffi culties during mastication but she had some defi ciency in the growth of the mandible on the of joint replacement side by prosthesis .
The author believed, there is no single theory controlling the growth of the mandible and mid face but both theories working together for growth of the mandible and the face and the condyle work as growth center combined with the Moss theory of functional demand of the periosteal matrix of the facial skeleton [4,5].
During the last 4 decades there were a lot of researchers attempting to use an autologous tissue to replace the damage condyle and the temporomandibular joint (TMJ) by different technique applied clinically on human or experimentally on animal models, these attempts were failed to restore growth and function of the condyle and temporomandibular joint.
A number of different autologous tissues have been used in attempt to restore normal height and reconstruct the TMJ articulation with restoration of function. The attempts of Bardenheur [6] and Gilles [7] both described the use of costochondral graft, this technique has been revised and

Abstract
Kummoona Chondro-Ossous graft is the most popular graft been used for reconstruction of the temporomandibular joint for restoring growth, repair and remodeling and fore correction of facial deformity in children with restoration of functional activity of the damaged temporomandibular joint (TMJ) and graft work as primary growth center. These graft been studied by experiment on Rabbits as an excellent animal model for viability of the graft. clinically 36 cases were reported, they were 25 children including 9 females and sixteen boys with history of ankyloses of the TMJ and ten children of 4 females and 6 boys suffering from milled hemi facial microsomia or fi rst arch dysplasia syndrome and one female case with traumatic hypoplasia of the condyle. subjected to scientifi c scrutiny in the last 4 decades and the pioneers were Johan Kennet [8] and David poswillo 1974 [9,10].
In children the author proposed and advocates a new technique to substitute the costochondral graft with a Chondro-Ossous graft from iliac crest for restoration of growth, repair, remodeling, and height of midface and function of the TMJ.

Material and Methods
Thirty six cases were reported, there were 25 children including 9 female and 16 boys with history of ankyloses of the TMJ and ten children of four females and six boys with history of under developed mandible and milled hemi facial microsomia and one female with hypoplasia of the condyle due to trauma, their age ranged between 4 and 13 years (mean 8.5) and fellow up of the cases ranged from 3-6 years. All these cases were treated in the Surgical Specialty hospital, Medical City and author private clinic (Figures 1 A,

Surgical access
By using a modifi ed question mark full thickness of fascio-cutanous Kummoona fl ap of pre auricular incision with temporal extension, the temporal extension designed to be behind the posterior fi bers of the temporalis muscle. The dissection started in the temporal region down to the zygomatic root of temporal bone and capsule of the TMJ. Another incision was required in the submandibular region for detachment of the masseter and medial pterygoid muscles and for release of the pterygoid-mandibular slink and this incision was used as an access for insertion and fi xation of Chondro-Ossous graft to the ascending ramus after approximating the graft to the glenoid fossa.

The result of the experiments
In the fi rst experiment after excision of the head of condyle three months later, we noticed severe deformity of the mandible in the operated side and the mandible twisted to the effected side ( Figure 4).

Postmortems macroscopic examination
the Chondro-Ossous grafts were nicely adapted to the new function of hard masticatory process, the union between the graft and the ascending ramus was excellent and there was no resorption in the head or in the shaft of the graft and the stainless steel used for fi xation of the graft show no changes in color or presence of corrosive property and the graft formed a neck and condyle similar to normal condyle in the opposite side ( Figure 5 A,B).

Microscopic examinations
The cytological features of the newly reconstructed Chondro-Ossous graft resemble the histology of non-operated condyle with 4 distinct zone layers. The staining by (H&E).

Clinical Results
Clinical cases were reported were thirty six cases, there    There are two successful biological techniques widely used now a day for reconstruction of the TMJ, the fi rst by Costa-Chondral graft and the second by Kummoona Chondro-Ossous graft [4,12]. The studies that carried by David Poswillo on nonhuman primates have showed and stated that, costochondral graft that replaced the mandibular condyle can rapidly adapt to the adaptive functional demands of the site.
The author objection about the costochondral graft, the cap easily displaced from the rib and perforation of the pleura might happened also an over growth of the graft might occur, this procedure required inter maxillary fi xation for 6 weeks, these patients showed diffi culties in opening the mouth after releasing the jaws from inter maxillary fi xation after six weeks due to spasm of muscles of mastication while in application of Chondral-Osseous graft for reconstruction of TMJ, no long fi xation required and active mobilization of the jaw started in the fallowing days not only for restoration of function but for restoration of growth based on Moss theory of functional demand of periosteal matrix of the facial skeleton [2]. Recently this phenomena of an over growth of costochondral graft was reported after fi ve years in a child previously treated for ankyloses of the TMJ, the growth pattern was unpredictable and more troublesome than the lack of growth [5].
In children the author proposed and advocates a new technique to substitute the Costo-Chondral graft by the use of Chondral-Osseous graft for restoration of function and growth and remodeling of the condyle and TMJ, the graft proved successful for reconstruction of TMJ ankyloses, hemi facial microsomia or fi rst arch dysplasia and traumatic hypoplasia of the condyle.
The success of the results by using this technique was very optimistic in all diseases for restoration of function, growth and aesthetic of the mandible and mid face and the graft does not show any ossifi cation or chondrofi cation in the long term and the graft has the ability to restore growth because of presence of intrinsic growth potential due to presence of mesenchymal stem cells to grow in multidirectional pattern through a stable Chondro-Ossous junction.
Recently researchers on connective tissue for cell differentiation found the value of chondro osseous junction of the graft to maintain growth, repair and remodeling of the graft due to intrinsic potential and the presence of mesenchyme stem cells during endo chondral bone formation in the Chondro-Ossous graft, chondrocyte cells undergoes differentiation towards hyper trophy before they replaced by bone and bone marrow [5].
In this study they did found that a G-protein coupled receptor (CXCR4) predominantly expressed in hypertrophic chondrocyte, while its ligand chemokine stromal cells derived factor (SDF-1) is expressed in the bone marrow adjacent to hypertrophic chondrocyte [3,5].
The Chondro-Osseous graft proved to be a good substitute to the Costo-Chondral graft and as condylar growth center through its clinical application and experimental studies for restoration of growth, remodeling and repair of the condyle and TMJ.