The Cleft Palate–Craniofacial Journal 52(5) pp. 574–578 September 2015 Ó Copyright 2015 American Cleft Palate–Craniofacial Association
ORIGINAL ARTICLE Occlusal Classification in Relation to Original Cleft Width in Patients With Unilateral Cleft Lip and Palate Andrew H. Huang, M.D., Kamlesh B. Patel, M.D., Clayton W. Maschhoff, B.S., Donald V. Huebener, D.D.S., M.S., Gary B. Skolnick, B.A., B.S., Sybill D. Naidoo, Ph.D., R.N., C.P.N.P., Albert S. Woo, M.D. Objective: To determine a correlation between the width of the cleft palate measured at the time of lip adhesion, definitive lip repair, and palatoplasty and the subsequent occlusal classification of patients born with unilateral cleft lip and palate. Design: Retrospective, observational study. Setting: Referral, urban, children’s hospital Participants: Dental models and records of 270 patients were analyzed. Interventions: None. Main Outcome Measure: Angle occlusion classification. Results: The mean age at which occlusal classification was determined was 11 6 0.3 years. Of the children studies, 84 were diagnosed with Class I or II occlusion, 67 were diagnosed with Class III occlusion, and 119 were lost to follow up or transferred care. Mean cleft widths were significantly larger in subjects with Class III occlusion for all measures at time of lip adhesion and definitive lip repair (P , .02). At time of palatoplasty, cleft widths were significantly greater at the alveolus (P ¼ .025) but not at the midportion of the hard palate (P ¼ .35) or posterior hard palate (P ¼ .10). Conclusion: Cleft widths from the lip through to the posterior hard palate are generally greater in children who are diagnosed with Class III occlusion later in life. Notably, the alveolar cleft width is significantly greater at each time point for patients who went on to develop Class III occlusion. There were no significant differences in cleft widths between patients diagnosed later with Class I and Class II occlusions. KEY WORDS:
cleft palate width, dental model, occlusion
Patients with cleft lip and palate (CLP) require multidisciplinary care through infancy, childhood, and early adulthood. From a dentofacial perspective, the end goal for treating a patient with CLP is clinically normal occlusion with a proper maxillofacial relationship. Toward that end, these patients will require many interventions beyond their initial lip and palate repair. They often entertain years of orthodontic appliances, and a certain percentage will require orthognathic surgery to correct midface deficiency after final facial growth. It would be ideal if a cleft team could predict the likelihood that a patient with CLP would require orthognathic surgery at skeletal maturity. However, the causes of midface growth disturbance in these patients are multifactorial (Chiu and Liao, 2012). The inherent maxillary deficiency in CLP coupled with the maxillary growth potential is one factor (Dec et al., 2013). Some of the debate centers on the type, timing, and idiosyncrasies of initial palatoplasty (Pigott et al., 2002; Jena et al., 2004; Diah et al., 2007; Liao et al., 2010b). Related interventions, such as lip repair, gingivoperioplasty, and presurgical orthopedics are contributing causes (Normando et al., 1992; Li et al., 2006).
Dr Huang is Staff Surgeon, Division of Plastic Surgery, Stratton Albany Veterans Affairs Medical Center, Albany, New York. Dr. Patel is Assistant Professor, Washington University in St. Louis, School of Medicine, Division of Plastic Surgery, Department of Surgery, St. Louis, Missouri. Mr. Maschhoff is Research Assistant, Washington University in St. Louis, School of Medicine, Division of Plastic Surgery, Department of Surgery, St. Louis, Missouri. Dr. Huebener is Professor, Washington University in St. Louis, School of Medicine, Division of Plastic Surgery, Department of Surgery, St. Louis, Missouri. Mr. Skolnick is Statistical Data Analyst, Washington University in St. Louis, School of Medicine, Division of Plastic Surgery, Department of Surgery, St. Louis, Missouri. Dr. Naidoo is Nurse Practitioner, Washington University in St. Louis, School of Medicine, Division of Plastic Surgery, Department of Surgery, St. Louis, Missouri. Dr. Woo is Assistant Professor, Washington University in St. Louis, School of Medicine, Division of Plastic Surgery, Department of Surgery, St. Louis, Missouri. Drs. Huang and Patel contributed equally to this article and should be considered as first coauthors. Presented at the 12th International Congress on Cleft Lip/Palate and Related Craniofacial Anomalies, Orlando, Florida, May 6–10, 2013. This work was supported in part by the St. Louis Children’s Hospital Foundation – Children’s Surgical Sciences Institute. Submitted October 2013; Revised March 2014; Accepted May 2014. Address correspondence to: Dr. Andrew H. Huang, 113 Holland Avenue, MC 112, Albany, NY 12208. E-mail [email protected]. DOI: 10.1597/13-263 574
Huang et al., OCCLUSAL CLASSIFICATION AND ORIGINAL CLEFT WIDTH
FIGURE 1 Example of a stone model of a patient with cleft lip and palate. Points were used to measure distance of the cleft width at the anterior, midpoint, and posterior aspects of the cleft palate.
Some evidence suggests that a patient’s initial deformity relates to future midface growth (Peltomaki et al., 2001; Liao et al., 2010a; Chiu et al., 2011; Chiu and Liao, 2012). The severity of the cleft palate may be an independent and nonmodifiable factor in the patient’s future dentofacial harmony. Hence, we wished to investigate the occlusal classification of patients who had undergone cleft palate repair to see if there was any relationship between final occlusion class and initial cleft severity. MATERIAL
AND
METHODS
Institutional review board approval was obtained from Washington University in St. Louis. We examined all the available dental impressions of patients with CLP taken from August 1980 to August 2006, the period when dental impressions were routinely taken at our institution. We limited our assessment to patients with a Veau Class III cleft palate, that is, patients with complete unilateral cleft palate and concomitant complete or incomplete cleft lip. To quantify cleft severity, we studied cleft width at the three pivotal surgeries: initial lip adhesion, definitive lip repair, and cleft palate repair. In total, 270 patients had undergone Veau III cleft palate repair and also had dental impressions taken, preserved, and available for study. The dental models of the 270 patients were examined using a 40-mm Castroviejo caliper. The cleft width was measured at three distinct locations: the alveolus, the midportion of the hard palate, and the posterior hard palate (Fig. 1). The alveolar cleft (A-A’) was measured at narrowest portion of the alveolar gap, namely, between the most lateral point of the alveolar process on the greater segment of the cleft (A) to the most mesial point on the lesser segment (A’). The posterior cleft width (P-P’) was measured at the most posterior point of the hard palate cleft. Points M and M’ were marked midway between the
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FIGURE 2 A schematic of a patient with cleft palate. The points were used to measure distances of cleft width.
anterior and posterior points, and the cleft width at the midportion of the hard palate (M-M’) was noted along a line connecting them (Tomita et al., 2012) (Fig. 2). Measurements were made twice, and the average value of the two measures was used in analysis. With patient records, the corresponding time point (lip adhesion, definitive lip repair, or cleft palate repair) for each model was determined. Diagnoses and any secondary palatal surgeries were noted from patient medical records. To determine occlusal classification, we probed the medical records of our cleft palate team from 1984 to 2012 to identify documentation of the patients’ molar occlusal class by a physician or dentist, including participating team orthodontists or pediatric dentists. We also recorded the age at time of occlusal class documentation. In cases of discrepancy of occlusal classification among providers, primacy was given to the pediatric dentist first and the orthodontist second. We grouped Class I and Class II occlusion into a favorable category and Class III as unfavorable. Using two-tailed Student’s t tests, we compared the cleft widths of subjects with unfavorable occlusions to the cleft width of subjects with favorable occlusions at each separate time interval. Intrarater reliability was measured with the intraclass correlation coefficient. For this calculation the cleft width values at each location were pooled across time points. The single measures two-way random effect consistency model was used. Initial data entry was performed using Excel 2010 (Microsoft, Redmond, WA). Statistical analysis was performed using IBM SPSS Statistics version 20 (Chicago, IL). RESULTS Lip adhesion was performed at 4 to 6 weeks of age. Definitive lip repair was conducted at 6 to 8 months of age. Cleft palate repair was performed after 10 months of age.
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TABLE 1
Results of Differences in Cleft Width at Lip Adhesion, Definitive Lip Repair, and Cleft Palate Repair* Alveolar Cleft Width (A-A’) Cleft Width Midportion Hard Palate (M-M’)
Lip adhesion
n Mean (mm) P Definitive lip repair n Mean (mm) P Palate repair n Mean (mm) P
Cleft Width Posterior Hard Palate (P-P’)
Favorable
Unfavorable
Favorable
Unfavorable
Favorable
Unfavorable
50 6.4
41 9.5
45 10.2
42 11.8
44 10.0
41 11.4
47 4.7
43 8.7
37 10.4
36 8.1
41 1.7
24 6.8
24 7.5
18 6.8
.000 56 2.9
.005
.007 44 0.7
.005
.009
.025
29 9.6 .017
.346
19 8.1 .102
* Cleft width is measured at sites along the palate (A-A’, M-M’, P-P’). These are further subdivided into number of dental models analyzed in each group (n), mean cleft width at each interval, and P value of the t tests performed between the favorable (occlusal Class I and II) and unfavorable (Class III) groups.
During these dates, passive alveolar molding appliances were used at 4 to 8 weeks of age. We did not perform active presurgical orthopedics, gingivoperioplasties or early alveolar bone grafting. Of the 270 patients with available dental models for all three pivotal surgeries, 119 were lost to follow-up or transferred care and, therefore, did not have a final categorization of the occlusal classification in the medical record. The remaining 151 patients had a mean age of 11 6 0.3 years at time of their occlusal classification, as determined by a member of our cleft palate team. Of these 151 patients, 84 were diagnosed with a favorable occlusion (Class I or Class II) and 67 were diagnosed with an unfavorable occlusion (Class III). Table 1 organizes the data into the three time points (lip adhesion, definitive lip repair, and cleft palate repair) and the three palatal measurements (A-A’, M-M’, P-P’). These are further subdivided into the number of dental models analyzed in each group (n), the mean cleft width at each interval (mean 6 standard error of mean), and the P value of the t tests performed between the favorable and unfavorable groups. We noted discrepancies among the number of measurements made per dental model. Specifically, fewer midpalatal and posterior-palatal measurements were made than alveolar cleft width measurements. This related to the reliability of the dental molds. Dental impressions were taken after a gauze throat pack had been inserted. In cases where the gauze interfered with the impression of the edges of the cleft palate soft tissue, measurements could not be reliably taken from the stone model. Because the gauze is placed as posterior into the throat as possible, the gauze throat pack interfered more frequently with the more posterior palatal measurements, although occasionally alveolar measurements were disrupted as well. Only the dental models that, first, had reliable cleft width measurements not disrupted by gauze or other technical issues and, second, corresponded to one of the 151 patients with occlusal classification documented in our medical records were included for analysis in Table 1. As a result, the number of dental models analyzed in each group (n) varies based on time point and measurement point, depending mostly on the quality of the dental impression.
In general, the later time points and more posterior measurements were not as well captured as the earlier time points and more anterior measurements. At the time of lip adhesion and definitive lip repair, we measured the mean cleft widths to be significantly larger in patients who would eventually acquire an unfavorable Class III occlusion (P , .02). These larger cleft widths were noted to be significantly larger at all three locations where we took measurements. Looking at the dental impressions taken at time of cleft palate repair, cleft width was again found to be larger in patients who would later develop unfavorable occlusion, but we only found statistical significance at the alveolar cleft (P ¼ .025). The difference in cleft width between the subject groups at the midpalate (P ¼ .35) and posterior palate (P ¼ .10) was not significant. Unbundling the favorable category into separate Class I and Class II categories, analysis of variance was used to compare all three occlusion classes. Tukey-Kramer post hoc analysis comparing Class I and Class II occlusions showed no statistical difference between any of the measured cleft widths (P . .33). Intrarater reliability of the initial measurements was excellent, with intraclass correlation coefficients ranging from 0.998 to 1.000. DISCUSSION Although the patient’s family often views the surgical repair of the cleft palate as a watershed moment of the patient’s care, in reality long-term follow-up is required to assess speech, occlusion, and midface growth, all of which can be affected for better or worse by the surgeon’s skills. In spite of this, the surgeon’s talent and techniques are only partially responsible for the final outcome. Undoubtedly the presenting deformity and underlying genetic factors also play a role in the ultimate result. From 1986 to 2006, nearly all of our cleft lip and palate patients routinely received passive alveolar molding appliances, necessitating dental impressions. The pediatric dentist on our cleft palate team took these impressions in the operating room immediately before a cleft lip or palate operation began. These dental models allow us to
Huang et al., OCCLUSAL CLASSIFICATION AND ORIGINAL CLEFT WIDTH
retrospectively identify trends and outcomes, at least for the patients who continue to follow up with our team. A significant proportion (44%) of patients for whom we have all three dental models do not have occlusal classification recorded in their medical records at the age of mixed dentition. Though it is possible some of this may be due to poor documentation, many patients were simply lost to follow-up or transferred their care to other institutions. For the remainder (66%) for which we do have documentation, the standard forms filled out by our team orthodontists and pediatric dentist include a spot for occlusal classification. Although occlusal classification at the first molar is possible as soon as the first molars have erupted, the occlusion reaches a more steady state once the primary dentition has exfoliated and the permanent dentition has erupted. This is consistent with the average time of occlusion being documented at 11 6 0.3 years old, at which point most children will have lost their primary teeth. Significant Class III malocclusion may be possible to document earlier, especially if the permanent incisors have erupted and a large negative overjet is recognized. However, final documentation of Class I and II occlusion in this patient population should likely be deferred until the primary molars are exfoliated. We grouped patients with documented occlusal classification into a favorable (Class I and II) or unfavorable (Class III) category. The implication is that patients with unfavorable occlusion will more likely benefit from orthognathic surgery at skeletal maturity, and thus the intervening phase II orthodontics would be used to decompensate the inclinations and set the patient up for a future operation. To help validate the grouping of Class I and Class II occlusions into a single favorable group, we performed a separate analysis of the patients within the favorable group, comparing the cleft widths between patients with Class I occlusion and patients with Class II occlusion. No significant difference was identified in the cleft widths between Class I and Class II occlusions. We then went back to the dental models and compared the cleft width measurements of subjects from the favorable category to subjects from the unfavorable category. We compared the cleft width at three points on the primary and secondary palate (A-A’, M-M’, P-P’) at each time point (lip adhesion, lip repair, palate repair). For the dental impressions taken the time of lip adhesion (around 4–6 weeks of age) and definitive lip repair (around 6 month of age), the subjects with unfavorable occlusion had a significantly larger cleft width at all three places. For the dental impressions taken at the time of palate repair (around 1 year old), the subjects with unfavorable occlusion had a significantly larger alveolar cleft only. Thus, for all time points, the alveolar gap width was significantly wider in patients who went on to develop Class III occlusion compared with that of patients who went on to develop a more favorable occlusion.
577
Notably, however, the sample size decreases with the posterior cleft width measurements, and with the later time points. This is due to a combination of factors, one of which is the poor quality of dental impressions due to interference from gauze throat pack insertion. The throat pack has a tendency to obscure the more posterior portions of the cleft palate, thus decreasing the ability to measure the posterior cleft width. Also, fewer dental models existed for palatoplasty than for lip adhesion, likely because the purpose of creating dental models was to make passive alveolar molding appliances. Presumably, the need to create new molding appliances decreased as the patients got older and the alveolar ridges responded to molding. Finally, the actual work of pouring stone models is somewhat labor intensive, and a final model that might be good enough to design a molding appliance may not be detailed enough to allow for super-precise cleft palate measurements. Orthognathic surgery is often considered one of the last steps, if not the last step, in a comprehensive treatment plan for patients with CLP. Although malocclusion can be orthodontically compensated, orthognathic surgery is considered the gold standard in restoring midface projection. Indeed, because of the sometimes erratic and often unpredictable growth patterns of the maxilla, many patients with CLP will eventually benefit from midface advancement. Nevertheless, not all patients born with CLP will go on to develop midface retrusion necessitating surgery (Oberoi et al., 2012). Furthermore, not all patients who would benefit from a maxillary advancement will undergo the operation. Patients who decline surgery may be wary of its not insignificant recovery period, which is likely longer than that of any previous operation they remember. Additionally, they may not envision the restoration of midface harmony as being medically necessary. They may also cite surgical fatigue, especially if they have required multiple lip, nose, or palatal revisions. Because most of these patients are late teenagers or young adults at the time of discussion, it behooves the surgeon to take their opinions and desires seriously before proceeding toward orthognathic surgery. These patients may also be conditioned by their parents, who themselves may or may not see the benefit of further operations and would guide their children as such. For all these reasons, it would be helpful to identify such patients—even as neonates—and give parents a reasonable prediction as to whether or not the patient will require orthognathic surgery at skeletal maturity. This may help condition the parents to think through the long-term care of their child, allowing them to realize that the operations will not solely occur in the first year of life but will progress all the way to early adulthood. This study suggests that the width of alveolar cleft is the most important intrinsic and nonmodifiable factor in determining the patient’s final
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occlusion status. Though we are far from creating a predictor model, we hope the data presented here will help future endeavors to do so. REFERENCES Chiu YT, Liao YF. Is cleft severity related to maxillary growth in patients with unilateral cleft lip and palate? Cleft Palate Craniofac J. 2012;49:535–540. Chiu YT, Liao YF, Chen PK. Initial cleft severity and maxillary growth in patients with complete unilateral cleft lip and palate. Am J Orthod Dentofacial Orthop. 2011;140:189–195. Dec W, Olivera O, Shetye P, Cutting CB, Grayson BH, Warren SM. Cleft palate midface is both hypoplastic and displaced. J Craniofac Surg. 2013;24:89–93. Diah E, Lo LJ, Huang CS, Sudjatmiko G, Susanto I, Chen YR. Maxillary growth of adult patients with unoperated cleft: answers to the debates. J Plast Reconstr Aesthet Surg. 2007;60:407–413. Jena AK, Duggal R, Roychoudhury A, Parkash H. Effects of timing and number of palate repair on maxillary growth in complete unilateral cleft lip and palate patients. J Clin Pediatr Dent. 2004;28:225–232. Li Y, Shi B, Song QG, Zuo H, Zheng Q. Effects of lip repair on maxillary growth and facial soft tissue development in patients with a complete unilateral cleft of lip, alveolus and palate. J Craniomaxillofac Surg. 2006;34:355–361.
Liao YF, Prasad NK, Chiu YT, Yun C, Chen PK. Cleft size at the time of palate repair in complete unilateral cleft lip and palate as an indicator of maxillary growth. Int J Oral Maxillofac Surg. 2010a;39:956–961. Liao YF, Yang IY, Wang R, Yun C, Huang CS. Two-stage palate repair with delayed hard palate closure is related to favorable maxillary growth in unilateral cleft lip and palate. Plast Reconstr Surg. 2010b;125:1503–1510. Normando AD, da Silva Filho OG, Capelozza Filho L. Influence of surgery on maxillary growth in cleft lip and/or palate patients. J Craniomaxillofac Surg. 1992;20:111–118. Oberoi S, Hoffman WY, Chigurupati R, Vargervik K. Frequency of surgical correction for maxillary hypoplasia in cleft lip and palate. J Craniofac Surg. 2012;23:1665–1667. Peltomaki T, Vendittelli BL, Grayson BH, Cutting CB, Brecht LE. Associations between severity of clefting and maxillary growth in patients with unilateral cleft lip and palate treated with infant orthopedics. Cleft Palate Craniofac J. 2001;38:582–586. Pigott RW, Albery EH, Hathorn IS, Atack NE, Williams A, Harland K, Orlando A, Falder S, Coghlan B. A comparison of three methods of repairing the hard palate. Cleft Palate Craniofac J. 2002;39:383–391. Tomita Y, Kuroda S, Katsura T, Watanabe T, Watanabe K, Fujihara S, Tanaka E. Severity of alveolar cleft before palatoplasty affects vertical maxillofacial growth in 6-year-old patients with complete unilateral cleft lip and palate. Am J Orthod Dentofacial Orthop. 2012;141:S102–S109.
ORIGINAL ARTICLE Occlusal Classification in Relation to Original Cleft Width in Patients With Unilateral Cleft Lip and Palate Andrew H. Huang, M.D., Kamlesh B. Patel, M.D., Clayton W. Maschhoff, B.S., Donald V. Huebener, D.D.S., M.S., Gary B. Skolnick, B.A., B.S., Sybill D. Naidoo, Ph.D., R.N., C.P.N.P., Albert S. Woo, M.D. Objective: To determine a correlation between the width of the cleft palate measured at the time of lip adhesion, definitive lip repair, and palatoplasty and the subsequent occlusal classification of patients born with unilateral cleft lip and palate. Design: Retrospective, observational study. Setting: Referral, urban, children’s hospital Participants: Dental models and records of 270 patients were analyzed. Interventions: None. Main Outcome Measure: Angle occlusion classification. Results: The mean age at which occlusal classification was determined was 11 6 0.3 years. Of the children studies, 84 were diagnosed with Class I or II occlusion, 67 were diagnosed with Class III occlusion, and 119 were lost to follow up or transferred care. Mean cleft widths were significantly larger in subjects with Class III occlusion for all measures at time of lip adhesion and definitive lip repair (P , .02). At time of palatoplasty, cleft widths were significantly greater at the alveolus (P ¼ .025) but not at the midportion of the hard palate (P ¼ .35) or posterior hard palate (P ¼ .10). Conclusion: Cleft widths from the lip through to the posterior hard palate are generally greater in children who are diagnosed with Class III occlusion later in life. Notably, the alveolar cleft width is significantly greater at each time point for patients who went on to develop Class III occlusion. There were no significant differences in cleft widths between patients diagnosed later with Class I and Class II occlusions. KEY WORDS:
cleft palate width, dental model, occlusion
Patients with cleft lip and palate (CLP) require multidisciplinary care through infancy, childhood, and early adulthood. From a dentofacial perspective, the end goal for treating a patient with CLP is clinically normal occlusion with a proper maxillofacial relationship. Toward that end, these patients will require many interventions beyond their initial lip and palate repair. They often entertain years of orthodontic appliances, and a certain percentage will require orthognathic surgery to correct midface deficiency after final facial growth. It would be ideal if a cleft team could predict the likelihood that a patient with CLP would require orthognathic surgery at skeletal maturity. However, the causes of midface growth disturbance in these patients are multifactorial (Chiu and Liao, 2012). The inherent maxillary deficiency in CLP coupled with the maxillary growth potential is one factor (Dec et al., 2013). Some of the debate centers on the type, timing, and idiosyncrasies of initial palatoplasty (Pigott et al., 2002; Jena et al., 2004; Diah et al., 2007; Liao et al., 2010b). Related interventions, such as lip repair, gingivoperioplasty, and presurgical orthopedics are contributing causes (Normando et al., 1992; Li et al., 2006).
Dr Huang is Staff Surgeon, Division of Plastic Surgery, Stratton Albany Veterans Affairs Medical Center, Albany, New York. Dr. Patel is Assistant Professor, Washington University in St. Louis, School of Medicine, Division of Plastic Surgery, Department of Surgery, St. Louis, Missouri. Mr. Maschhoff is Research Assistant, Washington University in St. Louis, School of Medicine, Division of Plastic Surgery, Department of Surgery, St. Louis, Missouri. Dr. Huebener is Professor, Washington University in St. Louis, School of Medicine, Division of Plastic Surgery, Department of Surgery, St. Louis, Missouri. Mr. Skolnick is Statistical Data Analyst, Washington University in St. Louis, School of Medicine, Division of Plastic Surgery, Department of Surgery, St. Louis, Missouri. Dr. Naidoo is Nurse Practitioner, Washington University in St. Louis, School of Medicine, Division of Plastic Surgery, Department of Surgery, St. Louis, Missouri. Dr. Woo is Assistant Professor, Washington University in St. Louis, School of Medicine, Division of Plastic Surgery, Department of Surgery, St. Louis, Missouri. Drs. Huang and Patel contributed equally to this article and should be considered as first coauthors. Presented at the 12th International Congress on Cleft Lip/Palate and Related Craniofacial Anomalies, Orlando, Florida, May 6–10, 2013. This work was supported in part by the St. Louis Children’s Hospital Foundation – Children’s Surgical Sciences Institute. Submitted October 2013; Revised March 2014; Accepted May 2014. Address correspondence to: Dr. Andrew H. Huang, 113 Holland Avenue, MC 112, Albany, NY 12208. E-mail [email protected]. DOI: 10.1597/13-263 574
Huang et al., OCCLUSAL CLASSIFICATION AND ORIGINAL CLEFT WIDTH
FIGURE 1 Example of a stone model of a patient with cleft lip and palate. Points were used to measure distance of the cleft width at the anterior, midpoint, and posterior aspects of the cleft palate.
Some evidence suggests that a patient’s initial deformity relates to future midface growth (Peltomaki et al., 2001; Liao et al., 2010a; Chiu et al., 2011; Chiu and Liao, 2012). The severity of the cleft palate may be an independent and nonmodifiable factor in the patient’s future dentofacial harmony. Hence, we wished to investigate the occlusal classification of patients who had undergone cleft palate repair to see if there was any relationship between final occlusion class and initial cleft severity. MATERIAL
AND
METHODS
Institutional review board approval was obtained from Washington University in St. Louis. We examined all the available dental impressions of patients with CLP taken from August 1980 to August 2006, the period when dental impressions were routinely taken at our institution. We limited our assessment to patients with a Veau Class III cleft palate, that is, patients with complete unilateral cleft palate and concomitant complete or incomplete cleft lip. To quantify cleft severity, we studied cleft width at the three pivotal surgeries: initial lip adhesion, definitive lip repair, and cleft palate repair. In total, 270 patients had undergone Veau III cleft palate repair and also had dental impressions taken, preserved, and available for study. The dental models of the 270 patients were examined using a 40-mm Castroviejo caliper. The cleft width was measured at three distinct locations: the alveolus, the midportion of the hard palate, and the posterior hard palate (Fig. 1). The alveolar cleft (A-A’) was measured at narrowest portion of the alveolar gap, namely, between the most lateral point of the alveolar process on the greater segment of the cleft (A) to the most mesial point on the lesser segment (A’). The posterior cleft width (P-P’) was measured at the most posterior point of the hard palate cleft. Points M and M’ were marked midway between the
575
FIGURE 2 A schematic of a patient with cleft palate. The points were used to measure distances of cleft width.
anterior and posterior points, and the cleft width at the midportion of the hard palate (M-M’) was noted along a line connecting them (Tomita et al., 2012) (Fig. 2). Measurements were made twice, and the average value of the two measures was used in analysis. With patient records, the corresponding time point (lip adhesion, definitive lip repair, or cleft palate repair) for each model was determined. Diagnoses and any secondary palatal surgeries were noted from patient medical records. To determine occlusal classification, we probed the medical records of our cleft palate team from 1984 to 2012 to identify documentation of the patients’ molar occlusal class by a physician or dentist, including participating team orthodontists or pediatric dentists. We also recorded the age at time of occlusal class documentation. In cases of discrepancy of occlusal classification among providers, primacy was given to the pediatric dentist first and the orthodontist second. We grouped Class I and Class II occlusion into a favorable category and Class III as unfavorable. Using two-tailed Student’s t tests, we compared the cleft widths of subjects with unfavorable occlusions to the cleft width of subjects with favorable occlusions at each separate time interval. Intrarater reliability was measured with the intraclass correlation coefficient. For this calculation the cleft width values at each location were pooled across time points. The single measures two-way random effect consistency model was used. Initial data entry was performed using Excel 2010 (Microsoft, Redmond, WA). Statistical analysis was performed using IBM SPSS Statistics version 20 (Chicago, IL). RESULTS Lip adhesion was performed at 4 to 6 weeks of age. Definitive lip repair was conducted at 6 to 8 months of age. Cleft palate repair was performed after 10 months of age.
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TABLE 1
Results of Differences in Cleft Width at Lip Adhesion, Definitive Lip Repair, and Cleft Palate Repair* Alveolar Cleft Width (A-A’) Cleft Width Midportion Hard Palate (M-M’)
Lip adhesion
n Mean (mm) P Definitive lip repair n Mean (mm) P Palate repair n Mean (mm) P
Cleft Width Posterior Hard Palate (P-P’)
Favorable
Unfavorable
Favorable
Unfavorable
Favorable
Unfavorable
50 6.4
41 9.5
45 10.2
42 11.8
44 10.0
41 11.4
47 4.7
43 8.7
37 10.4
36 8.1
41 1.7
24 6.8
24 7.5
18 6.8
.000 56 2.9
.005
.007 44 0.7
.005
.009
.025
29 9.6 .017
.346
19 8.1 .102
* Cleft width is measured at sites along the palate (A-A’, M-M’, P-P’). These are further subdivided into number of dental models analyzed in each group (n), mean cleft width at each interval, and P value of the t tests performed between the favorable (occlusal Class I and II) and unfavorable (Class III) groups.
During these dates, passive alveolar molding appliances were used at 4 to 8 weeks of age. We did not perform active presurgical orthopedics, gingivoperioplasties or early alveolar bone grafting. Of the 270 patients with available dental models for all three pivotal surgeries, 119 were lost to follow-up or transferred care and, therefore, did not have a final categorization of the occlusal classification in the medical record. The remaining 151 patients had a mean age of 11 6 0.3 years at time of their occlusal classification, as determined by a member of our cleft palate team. Of these 151 patients, 84 were diagnosed with a favorable occlusion (Class I or Class II) and 67 were diagnosed with an unfavorable occlusion (Class III). Table 1 organizes the data into the three time points (lip adhesion, definitive lip repair, and cleft palate repair) and the three palatal measurements (A-A’, M-M’, P-P’). These are further subdivided into the number of dental models analyzed in each group (n), the mean cleft width at each interval (mean 6 standard error of mean), and the P value of the t tests performed between the favorable and unfavorable groups. We noted discrepancies among the number of measurements made per dental model. Specifically, fewer midpalatal and posterior-palatal measurements were made than alveolar cleft width measurements. This related to the reliability of the dental molds. Dental impressions were taken after a gauze throat pack had been inserted. In cases where the gauze interfered with the impression of the edges of the cleft palate soft tissue, measurements could not be reliably taken from the stone model. Because the gauze is placed as posterior into the throat as possible, the gauze throat pack interfered more frequently with the more posterior palatal measurements, although occasionally alveolar measurements were disrupted as well. Only the dental models that, first, had reliable cleft width measurements not disrupted by gauze or other technical issues and, second, corresponded to one of the 151 patients with occlusal classification documented in our medical records were included for analysis in Table 1. As a result, the number of dental models analyzed in each group (n) varies based on time point and measurement point, depending mostly on the quality of the dental impression.
In general, the later time points and more posterior measurements were not as well captured as the earlier time points and more anterior measurements. At the time of lip adhesion and definitive lip repair, we measured the mean cleft widths to be significantly larger in patients who would eventually acquire an unfavorable Class III occlusion (P , .02). These larger cleft widths were noted to be significantly larger at all three locations where we took measurements. Looking at the dental impressions taken at time of cleft palate repair, cleft width was again found to be larger in patients who would later develop unfavorable occlusion, but we only found statistical significance at the alveolar cleft (P ¼ .025). The difference in cleft width between the subject groups at the midpalate (P ¼ .35) and posterior palate (P ¼ .10) was not significant. Unbundling the favorable category into separate Class I and Class II categories, analysis of variance was used to compare all three occlusion classes. Tukey-Kramer post hoc analysis comparing Class I and Class II occlusions showed no statistical difference between any of the measured cleft widths (P . .33). Intrarater reliability of the initial measurements was excellent, with intraclass correlation coefficients ranging from 0.998 to 1.000. DISCUSSION Although the patient’s family often views the surgical repair of the cleft palate as a watershed moment of the patient’s care, in reality long-term follow-up is required to assess speech, occlusion, and midface growth, all of which can be affected for better or worse by the surgeon’s skills. In spite of this, the surgeon’s talent and techniques are only partially responsible for the final outcome. Undoubtedly the presenting deformity and underlying genetic factors also play a role in the ultimate result. From 1986 to 2006, nearly all of our cleft lip and palate patients routinely received passive alveolar molding appliances, necessitating dental impressions. The pediatric dentist on our cleft palate team took these impressions in the operating room immediately before a cleft lip or palate operation began. These dental models allow us to
Huang et al., OCCLUSAL CLASSIFICATION AND ORIGINAL CLEFT WIDTH
retrospectively identify trends and outcomes, at least for the patients who continue to follow up with our team. A significant proportion (44%) of patients for whom we have all three dental models do not have occlusal classification recorded in their medical records at the age of mixed dentition. Though it is possible some of this may be due to poor documentation, many patients were simply lost to follow-up or transferred their care to other institutions. For the remainder (66%) for which we do have documentation, the standard forms filled out by our team orthodontists and pediatric dentist include a spot for occlusal classification. Although occlusal classification at the first molar is possible as soon as the first molars have erupted, the occlusion reaches a more steady state once the primary dentition has exfoliated and the permanent dentition has erupted. This is consistent with the average time of occlusion being documented at 11 6 0.3 years old, at which point most children will have lost their primary teeth. Significant Class III malocclusion may be possible to document earlier, especially if the permanent incisors have erupted and a large negative overjet is recognized. However, final documentation of Class I and II occlusion in this patient population should likely be deferred until the primary molars are exfoliated. We grouped patients with documented occlusal classification into a favorable (Class I and II) or unfavorable (Class III) category. The implication is that patients with unfavorable occlusion will more likely benefit from orthognathic surgery at skeletal maturity, and thus the intervening phase II orthodontics would be used to decompensate the inclinations and set the patient up for a future operation. To help validate the grouping of Class I and Class II occlusions into a single favorable group, we performed a separate analysis of the patients within the favorable group, comparing the cleft widths between patients with Class I occlusion and patients with Class II occlusion. No significant difference was identified in the cleft widths between Class I and Class II occlusions. We then went back to the dental models and compared the cleft width measurements of subjects from the favorable category to subjects from the unfavorable category. We compared the cleft width at three points on the primary and secondary palate (A-A’, M-M’, P-P’) at each time point (lip adhesion, lip repair, palate repair). For the dental impressions taken the time of lip adhesion (around 4–6 weeks of age) and definitive lip repair (around 6 month of age), the subjects with unfavorable occlusion had a significantly larger cleft width at all three places. For the dental impressions taken at the time of palate repair (around 1 year old), the subjects with unfavorable occlusion had a significantly larger alveolar cleft only. Thus, for all time points, the alveolar gap width was significantly wider in patients who went on to develop Class III occlusion compared with that of patients who went on to develop a more favorable occlusion.
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Notably, however, the sample size decreases with the posterior cleft width measurements, and with the later time points. This is due to a combination of factors, one of which is the poor quality of dental impressions due to interference from gauze throat pack insertion. The throat pack has a tendency to obscure the more posterior portions of the cleft palate, thus decreasing the ability to measure the posterior cleft width. Also, fewer dental models existed for palatoplasty than for lip adhesion, likely because the purpose of creating dental models was to make passive alveolar molding appliances. Presumably, the need to create new molding appliances decreased as the patients got older and the alveolar ridges responded to molding. Finally, the actual work of pouring stone models is somewhat labor intensive, and a final model that might be good enough to design a molding appliance may not be detailed enough to allow for super-precise cleft palate measurements. Orthognathic surgery is often considered one of the last steps, if not the last step, in a comprehensive treatment plan for patients with CLP. Although malocclusion can be orthodontically compensated, orthognathic surgery is considered the gold standard in restoring midface projection. Indeed, because of the sometimes erratic and often unpredictable growth patterns of the maxilla, many patients with CLP will eventually benefit from midface advancement. Nevertheless, not all patients born with CLP will go on to develop midface retrusion necessitating surgery (Oberoi et al., 2012). Furthermore, not all patients who would benefit from a maxillary advancement will undergo the operation. Patients who decline surgery may be wary of its not insignificant recovery period, which is likely longer than that of any previous operation they remember. Additionally, they may not envision the restoration of midface harmony as being medically necessary. They may also cite surgical fatigue, especially if they have required multiple lip, nose, or palatal revisions. Because most of these patients are late teenagers or young adults at the time of discussion, it behooves the surgeon to take their opinions and desires seriously before proceeding toward orthognathic surgery. These patients may also be conditioned by their parents, who themselves may or may not see the benefit of further operations and would guide their children as such. For all these reasons, it would be helpful to identify such patients—even as neonates—and give parents a reasonable prediction as to whether or not the patient will require orthognathic surgery at skeletal maturity. This may help condition the parents to think through the long-term care of their child, allowing them to realize that the operations will not solely occur in the first year of life but will progress all the way to early adulthood. This study suggests that the width of alveolar cleft is the most important intrinsic and nonmodifiable factor in determining the patient’s final
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occlusion status. Though we are far from creating a predictor model, we hope the data presented here will help future endeavors to do so. REFERENCES Chiu YT, Liao YF. Is cleft severity related to maxillary growth in patients with unilateral cleft lip and palate? Cleft Palate Craniofac J. 2012;49:535–540. Chiu YT, Liao YF, Chen PK. Initial cleft severity and maxillary growth in patients with complete unilateral cleft lip and palate. Am J Orthod Dentofacial Orthop. 2011;140:189–195. Dec W, Olivera O, Shetye P, Cutting CB, Grayson BH, Warren SM. Cleft palate midface is both hypoplastic and displaced. J Craniofac Surg. 2013;24:89–93. Diah E, Lo LJ, Huang CS, Sudjatmiko G, Susanto I, Chen YR. Maxillary growth of adult patients with unoperated cleft: answers to the debates. J Plast Reconstr Aesthet Surg. 2007;60:407–413. Jena AK, Duggal R, Roychoudhury A, Parkash H. Effects of timing and number of palate repair on maxillary growth in complete unilateral cleft lip and palate patients. J Clin Pediatr Dent. 2004;28:225–232. Li Y, Shi B, Song QG, Zuo H, Zheng Q. Effects of lip repair on maxillary growth and facial soft tissue development in patients with a complete unilateral cleft of lip, alveolus and palate. J Craniomaxillofac Surg. 2006;34:355–361.
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