Oral rehabilitation with implant-based prostheses of two adult patients treated for childhood rhabdomyosarcoma

A 24-year-old male was treated for a nasopharyngeal rhabdomyosarcoma at the age of four. Treatment consisted of surgical debulking of the tumor, followed by chemotherapy and interstitial radiotherapy (cumulative dose 44 Gy). This therapy resulted in a complete remission of the tumor. No recurrences occurred and neither did the patient develop metastases during a 20-year follow-up period. The late effects of the cancer treatment were delayed growth of the patient, hypoplasia of the midface (Fig. 1a), microdontia with root malformation (Fig. 1c), velopharyngeal insufficiency, and frequent ear infections with impaired hearing.

At the age of 12, a partial prosthesis (both dental and mucosal supported) with a velopharyngeal obturator was made to improve speech. The retention of this prosthesis was impaired due to the conical shape of the teeth and insufficient bone volume to support the prosthesis. The partial prosthesis had to be renewed after 4 years because of the growth of the maxillary complex resulting in a reduced fit of the prosthesis. Orthodontic therapy to correct the midfacial hypoplasia was contraindicated because of the already shortened roots of the teeth.

At the age of 18, i.e., after completion of facial growth, a combined surgical and prosthetic treatment plan was made to improve esthetics by correcting the midface hypoplasia and restoring the oral function. The treatment plan consisted of:

The patient agreed with this treatment and the surgical procedure started at the age of 19. Ten days after placement of the RED frame, the distraction started at a rate of 0.5 mm once daily (Fig. 1a). The vector of distraction osteogenesis (DO) was parallel to the Frankfort horizontal plane. Because of little progression, the rate of DO was increased to 0.5 mm twice a day from day 11. After 25 days, active DO was stopped because a satisfying esthetic result was achieved according to the patient and the surgeon (Fig. 1b). The total advancement measured on lateral radiographs at the central incisors was 15 mm.

After a 3-month consolidation period, the frame was removed. As a result of the forward movement of the maxilla, speech had deteriorated due to worsening of the velopharyngeal insufficiency. Thereupon, the hard and soft palate were reconstructed using a temporalis muscle flap. During that procedure, both coronoid processus were removed to improve mouth opening, and the remaining upper teeth and the maxillary osteosynthesis plates were removed. Because of several nose bleedings that occurred post surgery, a tracheotomy had to be placed for one and a half months.

Fifteen months after the reconstruction of the palate, four dental implants (Brånemark TiUnite regular platform, 13 mm) were placed in the maxilla. Six months later, a maxillary overdenture on a milled titanium superstructure on four implants (Fig. 1d) was made. The patient was very satisfied with the final result and no problems occurred during the 3-year follow-up.

A 25-year-old female had been treated for a rhabdomyosarcoma in her nasal–tonsil region at the age of three. She was first treated with chemotherapy and subsequently with external beam radiotherapy (cumulative dose 59.4 Gy). This treatment resulted in a complete remission of the tumor. No recurrences or metastases were observed during a 22-year follow-up period. The late effects of the oncologic treatment were thin hair, development of cataract, impaired hearing at both sides, trismus, maxillary hypoplasia (Fig. 2a, b), hypodontia, microstomia, and malformation of teeth.

At the age of 20 years, the same combined surgical and prosthetic treatment plan was proposed to this patient as in patient 1 to correct the midface hypoplasia and to restore oral function. The patient, however, did not want to change her facial appearance, needing an alternative surgical treatment plan. This alternative plan consisted of a Le Fort I osteotomy with ventralization and down grafting of the maxilla to improve esthetics and jaw relationship for prosthetic rehabilitation instead of midface distraction with the RED frame. The patient also refused this treatment and asked for dental rehabilitation only. Notwithstanding this suboptimal approach, it was assumed that the patient would greatly benefit from an implant-based prosthetic rehabilitation.

After 20 treatments with HBO, the remaining maxillary teeth were removed. As the bone volume of the maxilla was insufficient for implant placement, 3 months after teeth extraction, bone from the iliac crest was used to lift the nasal floor and to broaden the maxilla to create bone volume allowing for a reliable placement of dental implants at the sites preferred by the prosthodontist. Three months later, four dental implants (Brånemark TiUnite regular platform, 10 and 13 mm) were placed in the anterior maxilla with the help of a template, followed by ten treatments with HBO. After 5 months of osseointegration time, abutment connection was done and an impression was made. During this procedure, one implant appeared not to be osseointegrated and had to be removed. A milled titanium bar superstructure (Fig. 2c) and an overdenture (Fig. 2d) were made on the remaining three implants. The patient was very satisfied with her prosthesis and experienced no problems with her prosthetic rehabilitation during a two and a half-year follow-up.