Le Fort I Internal Distraction Provides Improved Outcomes in Cleft Patients with Severe

Title: Le Fort I Internal Distraction Provides Improved Outcomes in Cleft Patients with Severe Maxillary Deficiency

Authors: Joubin S. Gabbay, MD, Rabin Nikjoo, MD, Anand Kumar, MD, Amir Tahernia, MD, Catherine M. O’Hara, BA, Manisha Sisoda, BS, Jose Garri, MD, Libby Wilson, MD, Henry K. Kawamoto, MD, DDS, and James P. Bradley, MD

Introduction: Dentofacial skeletal deformities are common in patents with cleft lip and palate.1 In 20-25% of patients, orthodontic treatment alone is not sufficient and surgical correction of the class III malocclusion is required. 1-3

Traditional surgical management of maxillary deficiency in patients with cleft lip and palate involves Le Fort I osteotomy and advancement. Patients with mild to moderate maxillary deficiency generally have adequate correction with this management. However, the subset of patients with severe maxillary deficiency (those requiring ≥ 10mm advancement) have high rates of relapse and require secondary procedures. These patients may benefit from gradual distraction osteogenesis of the maxilla for correction of severe maxillary deficiency.

Methods: Nonsyndromic cleft lip and palate patients were divided into Group 1 with mild/moderate deficiency (requiring <10mm advancement) with Le Fort I advancement; Group 2 with severe maxillary deficiency (requiring ≥10mm advancement) with Le Fort I advancement; and Group 3 with severe maxillary deficiency with Le Fort I internal distraction osteogenesis.

Outcome analysis was based on examination, photographs, and cephalometric measurements for preoperative, postoperative, and 1 year follow-up time points. Angular measurements (SNA, SNB, and ANB) as well as linear changes (change in x-axis (horizontal) and y-axis (vertical)) were analyzed.

Speech evaluations were performed using the Pittsburgh speech score for VPI. This is based on nasal emissions, facial grimacing, nasality, phonation problems and misarticulations. A patient with the score of 3 or more without the presence of an oronasal fistula is given to the diagnosis of VPI. A paired student’s t-test was used for comparison.

Results: Patients with moderate maxillary deficiency and Le Fort I advancement (Group 1) had the following findings (means): SNA preop=78.1, postop=83.8, and follow-up=82.8. 77% (10/13) had class I occlusion postop, 1 needed re-advancement, and 3 had VPI. The relapse rate was 8%, re-operation rate 8%, VPI rate 23%.

Patients with severe maxillary deficiency and Le Fort I advancement (Group 2) had the following findings (means): SNA preop=76.5, postop=81.8 and follow-up=79.7. 38% (5/13) had class I occlusion postop, 8 needed re-advancement, and 9 had VPI. The relapse rate was 62%, re-operation rate 62%, and VPI rate 69%.

Patients with severe maxillary deficiency and Le Fort I internal distraction (Group 3) had the following findings (means): SNA preop=74.3, postop= 84.9, and follow-up=84.4. 77% (10/13) had class I occlusion postop, 4 needed re-operation, and 4 had VPI. The relapse rate was 23%, re-operation rate 31%, and VPI rate 31%.

Among those with severe maxillary deficiency, patients undergoing distraction osteogenesis had an increase in SNA of 10.8 compared to 5.5 for traditional advancement. No distraction devices were removed due to patient non compliance. In addition control of multiple segments with elastics and rubber bands assisted with achieving class I dental occlusion.

Discussion: Our data showed that patients with cleft lip and palate requiring large amount of advancements benefit from the internal distraction procedure. The results of this study showed a markedly decreased relapse and revision surgery rate between one step advancement and distraction osteogenesis (80% vs. 20%). The degree of advancement was also significantly greater in the distraction group (10.2 mm vs. 15.7 mm). The low relapse rate (8%) for Group 1 (less than 10 mm advancement) confirms that Le Fort I one step advancement adequately treats patients with mild maxillary deficiency.

Velopharyngeal incompetence was additionally evaluated in this study. Group 1 patients with mild maxillary deficiency manifested VPI post procedure at an incidence of 30%. Group2 patients treated with traditional Le Fort 1 advancement presented with a greatly increased rate of VPI (90%). Group 3 patients treated with distraction osteogenesis showed a lower rate of VPI (40%). The lower rate with DOG may be related to the gradual advancement of the maxilla allowing greater soft tissue expansion through creep and hyperplasia.

Evaluation of patients both clinically and using cephalometric analysis clearly demonstrates improved retained maxillary advancement in patients with severe maxillary deficiency undergoing distraction osteogenesis. Fewer patients experienced relapse and subsequent revision surgery and less VPI in the distraction group compared to one step Le Fort I advancement. The gradual soft tissue expansion associated with DOG may explain the lower rates of relapse and VPI in this group. Le Fort I distraction for severe cleft maxillary deficiency leads to better dental occlusion, less relapse and better speech results. A follow up study with quantitative serial speech evaluations is warranted.

Table 1. Bar graph of the rate of advancement.

Table 2. Bar graph of the rate of relapse (readvancement).

Table 3. Bar graph of the rate of postoperative VPI.

References

1. Ross, R.B. Treatment variables affecting facial growth in complete unilateral cleft lip and palate. Cleft Palate J. 24: 5, 1987.
2. Rosenstein, S., Kernahan, D., Dado, D. et al. Orthognathic surgery in cleft patients treated by early bone grafting. Plast Reconstr Surg. 87: 835, 1991.
3. Guerrero, C.A., Bell, W.H., Meza, L.S. Intraoral distraction osteogenesis: maxillary and mandibular lengthening. Atlas Oral Maxillofac Surg Clin North Am. 7: 111, 1999.