Cleft palate

Orthodontic treatment of cleft palate in childhood can pose many difficulties and an interdisciplinary approach is essential. Tooth related anomalies include abnormalities in the size, shape, location and eruption of teeth. Both deciduous and permanent teeth are involved. The affected lateral incisor occurs on the distal side of the cleft. The tooth can also be missing or divided into two. Central and lateral incisors adjacent to the cleft can be peg shaped (very small) and have poor enamel (hypoplasia). With small or missing upper lateral incisors, the decision must be made whether to close spaces or open spaces for prosthodontic replacement (prosthodontic referring to false teeth which may be an implant where a metal structure imitating a tooth root is placed in the bone). The usual evaluations of arch length deficiency in both arches are made and the level of crowding or spacing will determine the best approach, also keeping in mind the comments regarding the avoidance of excessive Class III (where the lower jaw projects forward of the upper jaw; can be a small upper jaw, large lower jaw or a combination of both) camouflage below. However, the current alveolar grafts do mean space closure is a more realistic objective (alveolar bone is the bone in which the teeth are contained). Where space dictates a prosthodontic option, an implant can also be used with reasonable success. A supplemental bone graft may be required.

Orthodontic maxillary expansion in childhood is usually required (the maxilla is the upper jaw). Although there exists a transverse anterior dentoalveolar maxillary deficiency, the skeletal transverse dimensions are unaffected. As the common pattern is medially collapsed anterior portions, a fan type expansion appliance can be employed. A suitably adjusted expansion appliance known as a Quad Helix is commonly employed. With posterior crossbites, the normal technique of palatal expansion with separation at the midpalatal suture cannot be utilised. As there is not an equivalent midpalatal suture, and the soft tissues are already stretched, the expansion will be dental expansion, with appropriate retention considerations (probably long-term). The use of a protraction facemask has also been advocated. Although effective in the short term, there is a lack of evidence supporting long-term benefits. Early orthodontic treatment should also correct any rotations, malpositions and crossbites involving the central incisors. This stage aims to establish a favourable arch form with improvement in function and aesthetics. Care must be taken not to tip roots of teeth out of the supporting bone.

The expansion phase can as appropriate be completed prior to alveolar bone grafting, assisting in providing a wider site for the graft and subsequent canine tooth eruption (third tooth from the front). Alveolar bone grafting is now aimed to be performed between 8 to 10 years of age (when canine root one third to one half developed). The canine is able to erupt through the graft, bring additional bone support and inducing favourable bone remodelling. Canines can erupt without a graft having been placed, however, the periodontal status is often compromised. Although bone grafts have been placed across the alveolus shortly after the presurgical orthopaedics, with the objective of stabilising the segments, contemporary practice avoids this early grafting due to the disruption of local growth.

Comprehensive orthodontic therapy with full fixed appliances can be undertaken in the late teens. Due to the Class III pattern, treatment is must often be undertaken following the adolescent growth spurt. The restriction of forward maxillary growth means even greater than usual consideration must be given to the possibility of mandibular growth re-establishing the Class III pattern. Treatment for a significant Class III pattern involves a combined orthognathic-orthodontic approach; camouflage should be avoided in these cases. Estimates of the number of patients requiring orthognathic-orthodontic treatment range from about 10% in some centres to 25 % in others. A feature is the maxillary hypoplasia (small upper aw). Restriction of maxillary growth results from surgical ankylosis, where the scars of the earlier required surgery limit forward maxillary development. Mandibular prognathism (large mandible = lower jaw) can be present in cleft cases just as in non-cleft cases; retrognathia (small lower jaw) can also be present. Bimaxillary (both jaws, maxilla and mandible)  surgery with mandibular setback may be required in cases without mandibular excess due to the extent of the sagittal discrepancy. Overcorrection provides a margin for some relapse. A surgically repaired upper lip results in a limiting soft tissue barrier to the dentition. The ability to procline maxillary incisors is reduced. The temptation to compensate by keeping the upper dentition forward and simply extracting lower premolars and retracting the lower incisors should be avoided in most instances. A far superior result in these more pronounced Class III cases can usually be obtained with orthognathic surgery (jaw surgery). Due to missing teeth, osseointegrated implants may also be indicated, and if inadequate bone is present, then a supplemental bone graft may be required.

REFERENCES

Bardach,J. and Morris,H.L. (1990). Multidisciplinary Management of Cleft Lip and Palate. W.B. Saunders Company, Philadelphia.

Berkowitz,S. (1996). Cleft Lip and Palate: Perspectives in Management. Singular Publishing. San Diego.

Berkowits,S. (1996). A comparison of treatment results in complete bilateral cleft lip and palate using a conservative approach versus Millard-Latham PSOT procedure. Semin. Orthod.,2:169-194.

Grayson,B.H., Cocarro,P.J. and Valauri,A.J. (1990). Orthodontics in cleft lip and palate children. In: Plastic Surgery. Volume 4. Cleft Lip and Palate and Craniofacial Anomalies. W.B. Saunders. Philadelphia.

Posnick,J.C. (1996). Orthognathic surgery for the cleft lip and palate patient. Semin. Orthod.,2:205-214.

Proffit,W.R., White,R.P. and Sarver,D.M. (2003). Contemporary Treatment in Dentofacial Deformity. Mosby, St. Louis.

Vargervik,K. (1981). Orthodontic management of unilateral cleft lip and palate. Cleft Palate J.,18:256270.

Vlachos, C.C. (1996). Orthodontic treatment for the cleft palate patient. Semin. Orthod.,2:197-204.

Waite,P.D. and Waite,D.E. (1996). Bone grafting for the alveolar cleft defect. Semin. Orthod.,2:192-196.