John Daskalogiannakis

The Americleft Study: An Inter‐Center Study of Treatment Outcomes for Patients With Unilateral Cleft Lip and Palate Part 4. Nasolabial Aesthetics

Objective To compare the nasolabial aesthetics for individuals with nonsyndromic complete unilateral cleft lip and palate between the ages of 5 and 12 years. Design Retrospective cross-sectional study. Setting Four cleft centers in North America. Subjects A total of 124 subjects with repaired complete unilateral cleft lip and palate who were treated at the four centers. Methods After ethics approval was obtained, 124 preorthodontic frontal and profile patient images were scanned, cropped to show the nose and upper lip, and coded. Using the coded images, four nasolabial features that reflect aesthetics (i.e., nasal symmetry, nasal form, vermilion border, and nasolabial profile) were rated by five examiners using the rating system reported by Asher-McDade et al. (1991). Intrarater and interrater reliabilities were determined using weighted kappa statistics. Mean ratings, by center, were compared using analysis of variance. Results Intrarater reliability scores were good to very good and interrater reliability scores were moderate to good. Total nasolabial scores were Center B = 2.98, Center C = 3.02, Center D = 2.80, and Center E = 2.87. No statistically significant differences among centers were detected for both total aesthetic scores and for any of the individual aesthetic components. Conclusion There were no significant differences in nasolabial aesthetics among the centers evaluated. Overall good to fair nasolabial aesthetic results were achieved using the different treatment protocols in the four North American centers.

The Americleft study: an inter-center study of treatment outcomes for patients with unilateral cleft lip and palate. Part 2. Dental arch relationships.

Objective To compare maxillomandibular relationships for individuals with nonsyndromic complete unilateral cleft lip and palate using the Goslon Yardstick for dental models. Design Retrospective cohort study. Setting Five cleft palate centers in North America. Subjects A total of 169 subjects with repaired complete unilateral cleft lip and palate who were consecutively treated at the five centers. Methods Ethics approval was obtained. A total of 169 dental models of patients between 6 and 12 years old with complete unilateral cleft lip and palate were assessed using the Goslon Yardstick. Weighted kappa statistics were used to assess intrarater and interrater reliabilities; whereas, analysis of variance and Tukey-Kramer analysis was used to compare the Goslon scores. Significance levels were set at p < .05. Results Intrarater and interrater reliabilities were very good for model ratings. One center that incorporated primary alveolar bone grafting showed especially poor Goslon scores that were significantly poorer than the remaining centers. The surgery protocols used by the other four centers did not include primary alveolar bone grafting but involved a number of different lip and palate closure techniques. Using the Goslon Yardstick assumptions, the center with the best scores would be expected to require end-stage maxillary advancement orthognathic surgery in 20% of its patients; whereas, the center with the worst scores would be likely to require this surgery in 66% of its patients. Conclusions The Goslon Yardstick proved capable of discriminating among the centers’ dental arch relationships. Possible explanations for the differences are discussed.

The Americleft study: an inter-center study of treatment outcomes for patients with unilateral cleft lip and palate part 1. Principles and study design

Objective The Americleft study is a North American initiative to undertake an intercenter outcome study for patients with repaired complete unilateral cleft lip and palate from five well-established North American cleft centers. Design Retrospective cohort study. Setting Five cleft palate centers in North America. Methods This is the first paper in a series of five that outlines the overall goals of the study and sets the basis for the clinical outcome studies that are reported in the following four papers. The five centers’ samples and treatment protocols as well as the methods used for each study are reported. The challenges encountered and possible mechanisms to resolve them and reduce methodological error with intercenter studies are also reviewed.

The americleft study: An inter-center study of treatment outcomes for patients with unilateral cleft lip and palate part 3. Analysis of craniofacial form

Objective To compare craniofacial morphology for individuals with nonsyndromic complete unilateral cleft lip and palate between the ages of 6 and 12 years. Design Retrospective cohort study. Setting Four North American cleft palate centers. Subjects A total of 148 subjects with repaired complete unilateral cleft lip and palate who were consecutively treated at the four centers. Methods The 148 preorthodontic lateral cephalometric radiographs were scanned, scaled, digitized, and coded to blind the examiners to radiograph origin. On each radiograph, 18 (angular and ratio) cephalometric measurements were performed. Measurement means, by center, were compared using analysis of variance and Tukey-Kramer analysis. Results Significant differences were found for sagittal maxillary prominence among the four centers. The most significant difference was seen between Center B (lowest SNA) and Center C (highest SNA). Similar differences were seen at the soft tissue level, with Center C showing a significantly larger ANB angle compared with Centers B and D. Center C was also shown to have statistically greater mean soft tissue convexity than Centers B, D, and E. The mean nasolabial angle in Center B was significantly more acute than in Centers C, D, and E. No statistically significant differences were seen for mandibular prominence, vertical dimensions, or dental inclinations. Conclusion Significant differences were seen among the centers for hard and soft tissue maxillary prominence, but not for mandibular prominence, vertical dimensions, or dental inclinations. A modest but statistically significant (p < .001) negative correlation was found between Goslon scores and ANB angle (r = –.607).

Canine retraction with rare earth magnets : an investigation into the validity of the constant force hypothesis

The objective of this study was to test the hypothesis that a prolonged constant force provides more effective tooth movement than an impulsive force of short duration. Six human subjects were selected, the main criterion being a need for extraction of their upper first premolars. Canine retraction on these subjects was executed on one side with the application of a force rapidly declining in magnitude, produced by a vertical loop, and on the other side with the application of a relatively constant force. This type of force was achieved by a similar vertical loop which was constantly activated by three parylene-coated neodymium-iron-boron (Nd2Fe14P) block magnets. The vertical loop on the control side was reactivated 6 weeks after the initial activation. No reactivation was necessary on the experimental side for the duration of the experiment. The rate of tooth movement on the two sides was compared over a period of 3 months, on the basis of maxillary impressions taken at frequent intervals during the course of the study. The canines retracted with a constant force moved statistically significantly more than the control canines (p < 0.05) during the experimental period. The average differences in the mean rates of tooth movement between the two sides were in the order of 2:1 in favor of the experimental side. There were no statistically significant differences in the changes of angulation (tipping) or rotation about the y axis between the two sides. The duration of force application seems to be a critical factor in regulating rate of tooth movement. Conversely, magnitude of the applied force did not appear to be of primary significance.

The need for orthognathic surgery in patients with repaired complete unilateral and complete bilateral cleft lip and palate.

Objective: To determine the percentage of patients with complete unilateral cleft lip and palate and complete bilateral cleft lip and palate treated at SickKids since birth who would benefit from orthognathic surgery. Design: Retrospective cohort study. Subjects: The review comprised records of 258 patients with complete unilateral cleft lip and palate and 149 patients with complete bilateral cleft lip and palate born from 1960 to 1989. Of these, 211 and 129 patients, respectively, had been treated at SickKids since birth. Patients with syndromes or associated anomalies were excluded. Methods: Patients who had undergone orthognathic surgery were recorded. For the remaining patients, arbitrarily set cephalometric criteria were used in order to identify the “objective” need for surgery. Lateral cephalometric radiographs taken beyond the age of 15 years were digitized using Dentofacial Planner cephalometric software. Results: Of the 211 patients with complete unilateral cleft lip and palate, 102 (48.3%) were deemed to benefit from orthognathic surgery. For the complete bilateral cleft lip and palate sample, the percentage was 65.1% (84 of 129). Definitive information on presurgical orthopedics was available for a small subsample (101 patients) of the complete unilateral cleft lip and palate cohort. The need for orthognathic surgery for this group was slightly higher (59.4%, or 60 of 101). Conclusion: These results suggest that a considerable percentage of patients with a history of complete cleft lip and palate at our institution require orthognathic surgery. Factors that need to be considered in the interpretation of these results include the quest for improvement in the profile aesthetics; the fact that the Canadian health care system covers the costs of surgery, making it more accessible to the patients; and the inclusion in the above figures of patients who had orthognathic surgery solely for reasons of closure of previously ungrafted alveolar clefts and associated fistulae.

The Americleft Study: An Inter‐Center Study of Treatment Outcomes for Patients With Unilateral Cleft Lip and Palate Part 5. General Discussion and Conclusions

Objective To summarize the Americleft study regarding treatment outcomes for patients with complete unilateral cleft lip and palate (CUCLP). Setting Five cleft palate centers in North America. Subjects One hundred sixty-nine subjects, between the ages of 6 years and 12 years, with repaired CUCLP who were consecutively treated at the five centers. Methods Study consisted of model comparisons assessing maxillomandibular relationship using the GOSLON Yardstick (169 patients from all 5 centers), soft and hard tissue craniofacial morphologic comparisons using lateral cephalometric analyses (148 patients from four of the centers), and nasolabial esthetics assessments (125 patients from four of the centers). Results Significant differences were found between the center with the best GOSLON scores and the remaining centers. These differences also corresponded to those found in the craniofacial morphologic cephalometric assessment. Sagittal maxillary prominence was found to be significantly better for the center with the best GOSLON scores, while no significant differences were seen among the centers for mandibular prominence, vertical dimensions, or dental inclinations. No differences were seen for nasolabial esthetics between the centers. Conclusions Challenges experienced while undertaking the inter-center retrospective study are reviewed. Aspects of treatment that could potentially make the outcome of treatment less optimal included primary alveolar bone grafting and extensive treatment protocols. Differences in the outcomes identified between the centers were restricted to the maxilla, and no differences were identified for mandibular prominence, vertical dimensions, or dental inclinations.

A study of the frictional characteristics of four commercially available self-ligating bracket systems

The objective of this investigation was to assess and compare the in vitro tribological behaviour of four commercially available self-ligating bracket systems. The frictional characteristics of the Damon3, Speed, In-Ovation R, and Time2 bracket systems were studied using a jig that mimics the three-dimensional movements that occur during sliding mechanics. Each bracket system was tested on the following stainless steel archwires: 0.016 x 0.022, 0.019 x 0.025, 0.020 round, and 0.021 x 0.021 inch Speed D-wire. An Instron testing machine with a 50 N load cell was used to measure the frictional resistance for each bracket/tooth assembly. The crosshead speed was set at a constant rate of 1 mm/minute, and each typodont tooth was moved along a fixed wire segment for a distance of 8 mm. Descriptive statistical analysis for each bracket/archwire combination with regard to frictional resistance was performed with a two-way, balanced analysis of variance for bracket type and wire size. The Damon3 bracket consistently demonstrated the lowest frictional resistance to sliding, while the Speed bracket produced significantly (P < 0.001) more frictional resistance than the other brackets tested for any given archwire. The self-ligation design (passive versus active) appears to be the primary variable responsible for the frictional resistance generated by self-ligating brackets during translation. Passively ligated brackets produce less frictional resistance; however, this decreased friction may result in decreased control compared with actively ligated systems.

Treatment of dental anomalies in children with complete unilateral cleft lip and palate at SickKids hospital, Toronto.

Objective: To quantify dental anomalies in permanent dentition associated with complete unilateral cleft lip and palate and to survey treatment modalities used to address these problems. Method: Retrospective study of 116 children with complete unilateral cleft lip and palate treated at SickKids since birth. Presence and morphology of lateral incisors and second premolars were determined. Orthodontic, surgical, and/or prosthetic procedures were analyzed. Results: The cleft-side lateral incisor was absent in 93.1% of finished cases. The lateral incisor mesial to the cleft was present in 4.3%, absent due to agenesis in 75.9%, and extracted in 19.8% of cases. The lateral distal to the cleft was present in 2.6%, absent due to agenesis in 33.6%, and extracted in 63.8% of cases. Of 105 lateral incisors, only one had normal morphology. Noncleft-side lateral incisors were absent in 16% of finished cases. Absence was due to agenesis in 12.1% of cases and extraction in 4.3%. When the lateral incisor was missing, closure of the dental space occurred by orthodontic tooth movement after alveolar bone grafting (45%); surgical closure with simultaneous alveolar bone grafting (35%); prosthetic closure (17%); and 3% were failures. Agenesis of premolars occurred in 12.1% of cleft-side and 10.3% of noncleft-side maxillary second premolars. Conclusions: The cleft-side lateral incisor is rarely present at the conclusion of orthodontic and surgical treatment of complete unilateral cleft lip and palate. Often absent due to agenesis, when present it is typically abnormal in size and bone support and is commonly extracted in favor of canine substitution.

The Americleft Project: A Proposed Expanded Nasolabial Appearance Yardstick for 5- to 7-Year-Old Patients With Complete Unilateral Cleft Lip and Palate (CUCLP)

Objective To develop a yardstick of reference photographs for nasolabial appearance assessments of 5- to 7-year-old patients with complete unilateral cleft lip and palate (CUCLP). Design Blind retrospective analysis of clinical records and comparison to historical controls. Patients Subjects were two groups of 6- to 12-year-olds (n = 124 and n = 135) and one group of 5- to 7-year-olds (n = 149) with nonsyndromic CUCLP from three previous Americleft studies, including cohorts from seven different cleft/craniofacial centers. Interventions All patients received the infant management protocols of their respective centers. Eleven trained and calibrated judges (five participated in all three studies) did blind ratings of nasolabial appearance using the Asher-McDade method. Main Outcome Measures Patients receiving the most consistent ratings between judges, selected first from the groups of 6- to 12-year-olds, were used to create a pilot yardstick for eventual use in the third study of 5- to 7-year-olds. For each of the Asher-McDade categories, 8 of the 5- to 7-year-old patients receiving the most consistent scores between raters were ranked by 10 judges for a final elimination to leave three per category. Results Using this method of successive changes in rating methods, a new reference yardstick for nasolabial appearance rating was established and linked to the original Asher-McDade method as well as the single examples in a previously published yardstick for patients with CUCLP. Pilot testing using the yardstick improved reliabilities. Conclusions Use of an expanded nasolabial yardstick of reference photographs representative of the range of possibilities of each of the five Asher-McDade categories is now available to see if reliability of these ratings can be improved.