ELIMINATION OF TRAUMATIC OCCLUSION

A stable maxilla is necessary for bone graft healing. Thus, traumatic occlusion of teeth in the cleft region should be eliminated, when possible, through alignment of the offending (usually maxillary incisor) teeth. Great care must be used to prevent moving the roots into the cleft site, and adequate retention is recommended to allow reformation of the cortical bone along the root prior to surgical exposure. It is often best to delay orthodontic alignment until after the graft because commonly there is only a thin layer of bone along the cleft side of the roots of adjacent teeth (Fig. 21-5, A). Denudation of roots during grafting can result in periodontal defects, ankylosis, root resorption, and/or decreased alveolar bone mass upon healing. If traumatic occlusion cannot be eliminated prior to graft placement, a full-time bite splint can prevent traumatic occlusion while the graft heals.

FIG 21-5 Examples of expansion appliances in cleft-affected patients. A, Radiograph of a “W”-arch; note the thin layer of bone on the lateral aspect of the central incisor in the cleft edge. B, Removable maxillary expansion appliance; note the lingual shelf of acrylic on the side of the greater segment to utilize the lower arch to reinforce anchorage and provide greater expansion of the lesser segment. Inverted “W” stainless-steel wire spring provides for expansion anteriorly. C, Bonded “fan” appliance in a patient with bilateral cleft lip and palate. The appliance uses posterior occlusal coverage to prevent traumatic occlusion of the incisors, since the premaxilla is flared by the lingual wires. Note that this appliance preferentially expands the anterior portion of the collapsed palatal shelves.

PRE-GRAFT EXPANSION

The amount and timing of pre-graft expansion should be planned in consultation with the surgeon. Whereas expansion is valuable before bone grafting to optimize surgical access, segments must not be expanded beyond the limits of surgical closure. The ideal expansion would provide coordinated maxillary and mandibular arch forms. If this interferes with the graft prognosis, three options are posed: delay the graft until adolescence and unite the segments with orthognathic or distraction surgery; perform the graft with little or no expansion and attempt expansion later (which may require surgical assistance); or accept the crossbite. If the patient is expected to need orthognathic maxillary advancement later, less expansion is indicated. Delaying the graft until adolescence may negatively affect the eruption or orthodontic movement of adjacent teeth, which could cause periodontal defects, caries, and social stigmata. In unilateral cleft-affected patients, further expansion is fairly predictable after alveolar bone grafting, although arch form may be compromised. However, post-graft expansion is less predictable in the bilateral situation, with the increased scarring and lack of a functional maxillary midline suture.

There are several appliance designs that can be used for expansion: fixed-spring appliances (e.g., quad-helix, W-arch or combinations; see Fig. 21-5, A); removable appliances with jackscrew devices or wire springs (Fig. 21-5, B); or fixed jackscrew devices (e.g., “fan” appliance; Fig. 21-5, C). Bilateral clefts with a posteriorly displaced premaxilla may require a separate appliance first to buccalize the premaxilla (Fig. 21-6), followed by the expander (see Fig 21-5, C). The selection of appliances is based on several variables: the direction and extent of expansion needed, the teeth present, the expected resistance, access to the cleft area needed by the surgeon, and the compliance anticipated by the patient. Removable appliances are preferred for optimal hygiene but lend themselves to compliance problems and loss. Fixed appliances cause fewer such problems, but they cause greater hygiene problems that may lead to decalcification and caries. Spring appliances apply lighter forces, under the control of the orthodontist, and the quad-helix provides lighter forces over a greater range than the W-arch. They can also be activated to expand segments differentially, which is quite useful because the lesser segment (or posterior segments in a bilateral cleft) is generally collapsed more anteriorly than posteriorly. However, repeated reactivation of spring-loaded appliances may be necessary to achieve the desired expansion. Jackscrew appliances are very rigid and generate high forces, resulting in rapid movement, but they require activation by the patient or a parent. They provide a specific amount and direction of expansion. Any fistulae present (including those unknown to the patient and/or clinician) will tend to be enlarged during the expansion. Such fistulae are generally closed at the time of the alveolar bone graft. Ideally the appliance should allow unimpeded surgical access. If it is in a position to interfere with surgery, the appliance can be modified beforehand or removed and replaced in the operating room. The appliance should be conducive to good oral hygiene in order to prevent bone graft failure.¹⁴ For proper graft healing, expansion should be maintained for 4 to 6 months after surgery, either by retaining the passive expansion appliance or by replacing it with a removable acrylic retainer or fixed lingual arch (Fig. 21-7). With complete bilateral clefting, it is important to stabilize a mobile premaxilla through the time that the graft is incorporated into the host bone.¹⁴ This will require 6 weeks to 6 months, depending on graft size, tissue stretch and/or scarring, occlusal stability, and individual bone and soft-tissue healing capacity. A full-time maxillary splint or heavy labial or lingual fixed appliance can provide this stability.

FIG 21-6 A “trombone”-style appliance uses elastic chain to advance the premaxilla out of crossbite. A separate expansion appliance is then used posteriorly followed by alveolar ridge bone grafting.

FIG 21-7 A, A fixed lingual arch maintains expansion after placing an alveolar bone graft and incorporating two finger springs to flare the central incisors. B, A modified “W” or lingual arch maintains the expansion obtained, while allowing surgical access for the alveolar bone graft.

An alternative approach advocates alveolar bone grafting at a younger age (5–7 years) followed by orthodontic stimulation of the graft by rapid expansion with a fixed-expansion (e.g., jackscrew type) appliance (see Fig. 21-5, C).¹⁵ Proponents of this method claim shorter orthodontic treatment time and prevention of maxillary horizontal hypoplasia. In theory, rapid expansion could elicit an effect similar to distraction osteogenesis at the cleft site. Initial maxillary incisor alignment can be done with fixed orthodontic appliances immediately after the graft. Generally, the patient then takes a break from active treatment and is placed in retention. If necessary, missing or unerupted teeth may be masked with a removable acrylic retainer with plastic pontics, and a temporary bonded lingual retainer (0.0175-inch multi-strand archwire) can be used to retain spaced incisors until comprehensive orthodontic treatment is begun.

MAXILLARY PROTRACTION

Following graft stabilization and initial incisor alignment, an orthodontic assessment is indicated to evaluate the patient’s pattern of maxillary and mandibular growth. Discordant monozygotic twin studies have revealed differences based on the type and severity of the cleft.¹⁶ Growth is essentially unaffected in patients with clefts of only the lip and alveolus. Cleft palate can result only in a shorter posterior face height, a steeper mandibular plane angle, and retrognathia. Complete unilateral cleft lip and palate can lead to failure of anterior maxillary growth, resulting in posterior and inferior displacement. Patients with very flat profiles, increased face heights, and/or Class III skeletal relationships will generally exhibit a worsening of their condition with further growth. Significant skeletal deformities are often best treated with combined orthodontics and surgery, possibly in multiple stages. Young (∼8 years^17–19) patients with mild maxillary deficient clefts may benefit from orthopedic forces for maxillary protraction via bonded full occlusal coverage acrylic splints¹⁹ or fixed banded^17–18 intraoral appliances, with extraoral protraction force applied via elastic force to a facial mask. These masks differ in their various pads, bands, and frame styles, and even include an American football-style helmet.^17–20 This treatment can effectively correct anterior crossbites and improve the prognathic profile through a limited maxillary skeletal advancement (1–3 mm), maxillary denta/>