PEDIATRIC/CRANIOFACIAL Lateral Incisor Agenesis Predicts Maxillary Hypoplasia and Le Fort I Advancement Surgery in Cleft Patients Li Han Lai, B.A. Brian K. Hui, B.A. Phuong D. Nguyen, M.D. Kristen S. Yee, M.D. Martin G. Martz, D.D.S., M.S. James P. Bradley, M.D. Justine C. Lee, M.D., Ph.D. Los Angeles, Calif.
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–tonasion-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. (Plast. Reconstr. Surg. 135: 142e, 2015.) CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.
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axillary hypoplasia in cleft patients is caused by a combination of iatrogenic factors associated with surgical and nonsurgical interventions and pathologic developmental deficiencies. Essentially every surgical intervention for the cleft lip–cleft palate child has been reported to be associated with maxillary hypoplasia, including lip repair,1 palate From the Section of Orthodontics, University of California, Los Angeles School of Dentistry, and the Division of Plastic and Reconstructive Surgery, University of California, Los Angeles, David Geffen School of Medicine. Received for publication April 28, 2014; accepted May 29, 2014.
The first two authors contributed equally to this work.
Copyright © 2014 by the American Society of Plastic Surgeons DOI: 10.1097/PRS.0000000000000779
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repair,2 alveolar bone grafting,1 and gingivoperiosteoplasty.3 Canine substitution, a nonsurgical, orthodontic maneuver to close dental spaces, has also demonstrated a strong association with reduced maxillary growth in the anteroposterior dimension.4 Intrinsic growth deficiency of the maxilla has been debated by multiple groups. Independent case series of unoperated patients found in Third World countries have demonstrated a largely normal growth of the maxilla.5,6 However, other Disclosure: The authors have no financial interest to declare in relation to the content of this article. All sources of funds supporting the completion of this article are under the auspices of the University of California, Los Angeles.
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Volume 135, Number 1 • Lateral Incisor Agenesis investigators have shown that, even in children with unrepaired submucous palates, anteroposterior maxillary deficiencies can be detected when compared with normal children.7 The largest casecontrolled study on adult unoperated isolated cleft palate patients has recently been reported.8 In this work, isolated cleft palate alone showed adverse effects on maxillary growth. Conceptually, perhaps the most compelling evidence for intrinsic deficiencies in growth is the prevalence of dental anomalies in cleft patients.4,9–17 Several investigators have suggested an association between dental agenesis and the severity of clefting.9 A recent two-part study on neonatal cleft patients also suggested that certain dental arches can predict future permanent lateral incisor agenesis and maxillary growth deficiencies.18,19 The clinical utility for identification of clear, anatomical abnormalities in predicting maxillary growth lies in early management with counseling for families on future required surgical therapies. In this work, we investigated our institutional experience with dental agenesis in cleft lip–cleft palate patients and report an association for both quantity and position of dental agenesis and the need for maxillary advancement surgery.
PATIENTS AND METHODS Patients with any type of cleft lip or palate evaluated and treated at the University of California, Los Angeles, Craniofacial Clinic between 2008 and 2013 were identified (n = 114). Patients older than 14 years (at or near skeletal maturity) were reviewed retrospectively for both general demographic information and the following variables: cleft type, number of missing teeth, and site of missing teeth using evaluations and photography at our multidisciplinary University of California, Los Angeles, Craniofacial Center, the orthodontic clinic, and plastic surgery offices. Absence or presence of surgical maxillary advancement or recommendation for orthognathic surgery was recorded. Because of patient compliance and insurance approval issues, the population of patients who received the recommendation for orthognathic surgery during team evaluation and those who underwent surgery were not the same. In this study, we recorded those patients that required a Le Fort I advancement for optimal occlusion based on team recommendations. Lateral Cephalometric Analysis Lateral cephalograms of 52 patients were obtained and traced by three independent
evaluators. Sagittal relationships to the skull base and mandible were determined using the classic sella-to-nasion-to–A point (SNA) and A point– to-nasion-to–B point (ANB) angles in Steiner’s analysis. Relative maxillary vertical height was estimated using the upper facial height (nasion to A point) to lower facial height (A point to menton) ratio. Statistical Analysis Statistical analyses were performed using STATA (StataCorp, College Station, Texas). The primary outcome variable was maxillary hypoplasia, defined by cephalometric measurements and the clinical recommendation for orthognathic surgery. Chi-square tests were used to compare groups based on the quantity and position of missing teeth in relationship to surgery. Independent sample t tests were used to compare the average cephalometric measurements between patients with and without dental agenesis. Chisquare and t tests were considered significant for p < 0.05. Significant variables were subjected to stepwise logistic regression analyses to determine independence.
RESULTS Patients and Descriptive Statistics One hundred fourteen patients were evaluated at or near skeletal maturity with an average age of 19.2 years (range, 14 to 25 years) (Table 1), and 64.0 percent of patients were male patients. Patients carried the diagnoses of isolated cleft palate (10.5 percent), unilateral cleft lip–cleft palate (66.7 percent), or bilateral cleft lip–cleft palate (22.8 percent); 71.9 percent were found to have agenesis of one or more teeth. Of this cohort, Table 1. Demographics Characteristic Age, yr Mean Range Male Cleft type Isolated cleft palate Cleft lip–cleft palate Unilateral cleft lip–cleft palate Right Left Bilateral cleft lip–cleft palate Dental agenesis Surgical patients Age at surgery, yr Mean Range
Value (%) 19.2 14–25 73 (64.0) 12 (10.5) 102 (89.5) 76 (66.7) 27 (23.7) 49 (43.0) 26 (22.8) 82 (71.9) 68 (59.6) 17.7 15.4–21
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Plastic and Reconstructive Surgery • January 2015 46.3 percent were missing one tooth and 53.6 percent were missing two or more teeth. Also, of this cohort, 97.6 percent were missing teeth at the lateral incisor position, 13.8 percent were missing teeth at the central incisor position, 10.0 percent were missing teeth at the bicuspid position, and 8.8 percent were missing teeth at the cuspid position. Le Fort I maxillary advancement was performed or recommended in 59.6 percent of the patients. Cleft Dental Agenesis and Le Fort I Advancement Stratification based on the quantity of missing teeth and clinical recommendations for Le Fort I advancement was performed on the patient cohort (Table 2). In patients without dental agenesis, Le Fort I advancement was required in 18.8 percent of the patients. By contrast, 74.4 percent of patients with dental agenesis required Le Fort I advancement (p < 0.0001). In the cohort of patients with missing teeth, 63.1 percent of patients who were missing only one tooth required Le Fort I advancement (p = 0.001). When patients were missing two or more teeth, 86.4 percent required Le Fort I advancement (p < 0.0001). Stratification based on the position of missing teeth and clinical recommendations for Le Fort I advancement was also performed (Table 3). In patients who were missing teeth at the lateral incisor position, Le Fort I advancement was required in 76.3 percent (p < 0.0001). Le Fort I advancement correlated to agenesis of central incisors Table 2. Quantity of Cleft Dental Agenesis and Le Fort I Advancement No Surgery (%)
Le Fort I (%)
Variable
Total (%)
Without missing teeth Any missing teeth Missing one tooth Missing two teeth
32 (28.1) 26 (81.3) 6 (18.8) 82 (71.9) 20 (24.4) 62 (74.4)