Lateral incisor agenesis predicts maxillary hypoplasia and Le Fort I advancement surgery in cleft patients.

BACKGROUND: Severe maxillary hypoplasia in cleft patients is caused by a combination of pathogenic and iatrogenic factors. In this work, the authors investigated anatomical deficiencies in dentition for predicting Le Fort I maxillary advancement surgery for severe maxillary hypoplasia in cleft patients. METHODS: Cleft lip-cleft palate and cleft palate patients older than 14 years of age were reviewed for demographics, dental anomalies, and Le Fort I advancement. Chi-square tests, t tests, and multivariate logistic regression analyses were performed to delineate the contribution of quantity and position of dental agenesis to maxillary advancement surgery. RESULTS: In the 114 patients reviewed (mean age, 19.2 years), 64.0 percent were male patients, 71.9 percent had dental agenesis, and 59.6 percent required Le Fort I advancement. In patients who did not exhibit dental agenesis, 18.8 percent required Le Fort I advancement compared with 74.4 percent of patients with dental agenesis (p < 0.0001). Le Fort I advancement surgery was increased to 76.3 percent when dental agenesis was at the lateral incisor position (p < 0.0001) and 86.4 percent when patients were missing two or more teeth (p < 0.0001). Both sella-to-nasion-to-A point angle (p = 0.003) and A point-to-nasion-to-B point angle (p = 0.04) measurements were decreased in patients missing dentition at the lateral incisor position. Adjusting for multiple missing teeth and orthodontic compensations, multivariate logistic regression analyses demonstrated that lateral incisor agenesis is an independent predictor for Le Fort I advancement surgery (OR, 4.4; 95 percent CI, 1.42 to 13.64; p = 0.01). CONCLUSIONS: Lateral incisor agenesis correlated to maxillary hypoplasia and independently predicted the need for Le Fort I advancement in cleft patients, potentially as an anatomical readout of intrinsic growth deficiency. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Maxillary hypoplasia in the cleft patient: contribution of orthodontic dental space closure to orthognathic surgery.

BACKGROUND: Cleft lip and palate surgery in the developing child is known to be associated with maxillary hypoplasia. However, the effects of nonsurgical manipulations on maxillary growth have not been well investigated. The authors present the contribution of orthodontic dental space closure with canine substitution to maxillary hypoplasia and the need for orthognathic surgery. METHODS: Cleft lip/palate and cleft palate patients older than 15 years of age were reviewed for dental anomalies, orthodontic canine substitution, and Le Fort I advancement. Skeletal relationships of the maxilla to the skull base (SNA), mandible (ANB), and facial height were determined on lateral cephalograms. Logistic regression analyses were performed to estimate odds ratios. RESULTS: Ninety-five patients were reviewed (mean age, 18.1 years). In 65 patients with congenitally missing teeth, 55 percent with patent dental spaces required Le Fort I advancement. In contrast, 89 percent who underwent canine substitution required Le Fort I advancement (p = 0.004). Canine substitution is associated with a statistically significant increase in maxillary retrognathia when compared with dental space preservation on lateral cephalograms (mean SNA, 75.2 and 79.0, respectively; p = 0.006). Adjusting for missing dentition, logistic regression analyses demonstrated that canine substitution is an independent predictor for orthognathic surgery (OR, 6.47) and maxillary retrusion defined by SNA < 78 (OR, 8.100). CONCLUSIONS: The coordination of orthodontia and surgery is essential to cleft care. The authors report a strong association between orthodontic cleft closure using canine substitution with maxillary hypoplasia and subsequent Le Fort I advancement, and suggest systematic criteria for management of cleft-related dental agenesis. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.