Genetic Analyses of Enamel Hypoplasia in Multiethnic Cohorts.

Enamel hypoplasia causes reduction in the thickness of affected enamel and is one of the most common dental anomalies. This defect is caused by environmental and/or genetic factors that interfere with tooth formation, emphasizing the importance of investigating enamel hypoplasia on an epidemiological and genetic level. A genome-wide association of enamel hypoplasia was performed in multiple cohorts, overall comprising 7,159 individuals ranging in age from 7-82 years. Mixed-models were used to test for genetic association while simultaneously accounting for relatedness and genetic population structure. Meta-analysis was then performed. More than 5 million single-nucleotide polymorphisms were tested in individual cohorts. Analyses of the individual cohorts and meta-analysis identified association signals close to genome-wide significance (P < 510-8), and many suggestive association signals (510-8 < P < 510-6) near genes with plausible roles in tooth/enamel development. The strongest association signal (P = 1.5710-9) was observed near BMP2K in one of the individual cohorts. Additional suggestive signals were observed near genes with plausible roles in tooth development in the meta-analysis, such as SLC4A4 which can influence enamel hypoplasia. Additional human genetic studies are needed to replicate these results and functional studies in model systems are needed to validate our findings.

Early Secondary Alveolar Bone Grafting and Facial Growth of Patients with Complete Unilateral Cleft Lip and Palate.

OBJECTIVE: To investigate the craniofacial growth outcomes of early secondary alveolar bone grafting(ABG) around 6 years of age. DESIGN: Retrospective cohort study. SETTING: 1 North-American and 5 Northern-European cleft centers. SUBJECTS: 33 subjects with CUCLP consecutively treated with secondary ABG around 6 years of age were compared to 105 subjects from 4 centers treated with late secondary ABG and 19 subjects from 1 center with primary ABG. METHODS: Preorthodontic standardized lateral cephalometric radiographs taken after 12 years of age were traced and analyzed according to the Eurocleft Study protocol. Fourteen angular and two proportional measurements were performed. Measurement means from the Study Center(SC) were compared to 5 Northern-European centers using analysis of variance and Welch's modified t-tests, and P < .05 was considered statistically significant. RESULTS: For the SC, the mean age ± SD at the time of bone graft was 5.85 ± 0.71 years and the mean age at the time of the lateral cephalogram was 13.4 ± 1.8 years. The sagittal maxillary prominence of the SC was favorably comparable to the 5 Northern-European centers. The mean SNA (78.1 ± 4.3) for the SC was significantly higher compared to 4 of the 5 Northern-European centers(all P < .05), and the mean ANB angle was comparable to 4 of the 5 centers. Similarly, the mean soft tissue ANB angle was not significantly different to the 5 centers. The soft tissue vertical proportions compared favorably to all 5 Northern-European centers(all P < .01). CONCLUSIONS: Craniofacial growth outcomes of early secondary ABG around 6 years compare favorably to the outcomes of late secondary ABG.

The Effect of Earlier Bone Grafting, Prior to Orthodontic Treatment, on SWAG Ratings of Graft Outcomes.

OBJECTIVE: To compare the outcomes between 2 groups of patients with complete clefts treated with early secondary alveolar bone grafting (ABG) at 2 centers (5-7 years, before orthodontic intervention) and to a third group of patients treated at one of those centers (center 1) who had received later secondary ABG (8-10 years, after orthodontic intervention). DESIGN: Blind retrospective analysis of cleft site radiographs using Americleft Standardized Way to Assess Grafts (SWAG) scale. PATIENTS: A total of 99 patients with complete clefts from 2 North American cleft/craniofacial centers. INTERVENTIONS: Secondary ABG representing 2 protocols: early grafting at a mean age of 6.6 years prior to any orthodontic intervention, and later grafting at a mean age of 10.2 years following pregrafting orthodontic intervention. MAIN OUTCOME MEASURES: Using occlusal radiographs, the SWAG scale from 0 (failed graft) to 6 (ideal) was used. Six trained, calibrated raters scored each radiograph twice, with the average of the 2 ratings used as the final score. Reliability was assessed using the weighted κ statistic. The significance of differences between groups was determined using the Kruskal-Wallis test and Dunn test for pairwise comparisons. RESULTS: Inter-rater reliability of SWAG method was good (0.631). Intra-rater reliability was excellent (0.817). There was a tendency for improved total graft outcome in the early grafted group from center 1 compared to the later grafted group with improvement being significantly different in only the coronal third of the early, preorthodontic grafted group. However, the difference was not statistically significant for the graft overall.

Genome-Wide Association Study (GWAS) of dental caries in diverse populations.

BACKGROUND: Dental caries is one of the most common chronic diseases and is influenced by a complex interplay of genetic and environmental factors. Most previous genetic studies of caries have focused on identifying genes that contribute to dental caries in specific ethnic groups, usually of European descent. METHODS: The aim of this study is to conduct a genome-wide association study (GWAS) to identify associations affecting susceptibility to caries in a large multiethnic population from Argentina, the Philippines, Guatemala, Hungary, and the USA, originally recruited for studies of orofacial clefts (POFC, N = 3686). Ages of the participants ranged from 2 to 12 years for analysis of the primary dentition, and 18-60 years for analysis of the permanent dentition. For each participant, dental caries was assessed by counts of decayed and filled teeth (dft/DFT) and genetic variants (single nucleotide polymorphisms, SNPs) were genotyped or imputed across the entire genome. Caries was analyzed separately for the primary and permanent dentitions, with age, gender, and presence/absence of any type of OFC treated as covariates. Efficient Mixed-Model Association eXpedited (EMMAX) was used to test genetic association, while simultaneously accounting for relatedness and stratification. RESULTS: We identified several suggestive loci (5 × 10-8 < P < 5 × 10-6) within or near genes with plausible biological roles for dental caries, including a cluster of taste receptor genes (TAS2R38, TAS2R3, TAS2R4, TASR25) on chromosome 7 for the permanent dentition analysis, and DLX3 and DLX4 on chromosome 17 for the primary dentition analysis. Genome-wide significant results were seen with SNPs in the primary dentition only; however, none of the identified genes near these variants have known roles in cariogenesis. CONCLUSION: The results of this study warrant further investigation and may lead to a better understanding of cariogenesis in diverse populations, and help to improve dental caries prediction, prevention, and/or treatment in future.

Patient-Centered Satisfaction After Secondary Correction of the Cleft Lip and Nasal Defect.

OBJECTIVE: To evaluate patient-reported aesthetic and psychosocial outcomes of secondary cleft lip and nose revision procedures. DESIGN: Single-center cohort study. SETTING: Tertiary care pediatric hospital. PATIENTS/PARTICIPANTS: Patients who underwent secondary revision procedures for cleft lip and nasal defect (N = 42). INTERVENTIONS: Patients were administered a survey during a routine postoperative clinic visit. MAIN OUTCOME MEASURE(S): Outcome measures were planned prior to data collection and included improvement in appearance seen in lip and nose, satisfaction with revision procedure, changes in self-confidence, likelihood to participate in social activities, and effect on teasing by peers. RESULTS: Patients agreed that an improvement was seen in the appearance of their lip (1.93) and nose (1.98) following surgery. Overall, patients felt satisfied with the results of their revision procedure (1.76). An improvement in confidence and decrease in feelings of self-consciousness was reported. Patients were teased less by their peers and more likely to participate in social activities. CONCLUSIONS: Secondary revision procedures of the cleft lip and nasal defect provide a patient-reported improvement in appearance and a positive psychosocial impact on patient's lives.

Facial Growth of Patients With Complete Unilateral Cleft Lip and Palate Treated With Alveolar Bone Grafting at 6 Years.

OBJECTIVE: To investigate the effect that alveolar bone grafting (ABG) around 6 years of age has on facial growth by assessing craniofacial growth outcomes. DESIGN: Retrospective cohort study. SETTING: North American cleft centers. PARTICIPANTS: A total of 33 children with complete unilateral cleft lip and palate who were consecutively treated with secondary ABG around 6 years of age were compared to 148 participants from 4 centers with late secondary ABG. METHODS: Preorthodontic standardized lateral cephalometric radiographs were analyzed and traced according to the Americleft Study protocol. Sixteen angular and 2 proportional measurements were performed. The outcomes of all ABG were assessed using the Standardized Way to Assess Graft scale. Measurement means from the study center (SC) were compared to 4 North American centers using analysis of variance and Welch modified t tests, and P < .05 was considered statistically significant. RESULTS: For the SC, the mean age (SD) at the time of bone graft was 5.85 (0.71) years and the mean age at the time of the lateral cephalogram was 13.4 (1.8) years. The sagittal maxillary prominence of the SC was comparable to the 4 other centers. The mean SNA (78.1 [4.3]) for the SC was significantly higher compared to one center that used primary bone grafting ( P = .03). The soft tissue mean ANB (3.52 [4.09]) for the SC was significantly lower compared to 3 of the centers. CONCLUSIONS: Early secondary ABG around 6 years of age did not result in reduced midface projection as assessed by SNA and thus did not compromise anterior maxillary growth.

An Intercenter Comparison of Dental Arch Relationships and Craniofacial Form Including a Center Using Nasoalveolar Molding.

OBJECTIVE: To compare dental arch relationship and craniofacial morphology of patients with CUCLP in pre-adolescence from five cleft centers including a center using NAM. DESIGN: Retrospective cohort study. SETTING: Five cleft centers in North America. PATIENTS: One hundred eighty-two subjects with repaired CUCLP from the five cleft centers participated in the craniofacial form study. One hundred forty-eight subjects from four of the five centers participated in the dental arch relationship study. METHODS: Digital dental models were assessed using the GOSLON Yardstick. Eighteen cephalometric measurements were performed. Measurement means, by center, were compared. Analysis of variance and Tukey-Kramer analysis were used to compare GOSLON scores and cephalometric measurements. RESULTS: The center that performed neither PSOT (including NAM) nor primary bone grafting exhibited the most favorable mean GOSLON score. The same center also showed the highest mean SNA, ANB, and ANS-N-Pg angles. However, the mean ANB and ANS-N-Pg angles were not significantly different from those of the center using NAM. No statistically significant differences were seen for mandibular prominence, vertical dimensions, or dental inclinations. The center with NAM also showed a significantly smaller nasoform angle than two of the four other centers. CONCLUSION: The centers that used NAM and other forms of PSOT did not have better dental arch relationships or craniofacial morphology compared with the centers that performed only primary lip repair. However, this study was not designed to investigate the cause-and-effect relationship between specific outcomes and particular features of those protocols.

Burden of Care of Various Infant Orthopedic Protocols for Improvement of Nasolabial Esthetics in Patients With CUCLP.

OBJECTIVES: 1. To evaluate the orthodontic burden of care of nasoalveolar molding (NAM) and modified McNeil for the treatment of patients with complete unilateral cleft lip and palate (CUCLP). 2. To compare the esthetic outcomes of each with those of centers not utilizing infant orthopedics (IO). DESIGN: Retrospective cohort study. SETTING: Institutional. PARTICIPANTS: Four cohorts with repaired CUCLP (n = 149) from 3 centers. INTERVENTIONS: Two cohorts were treated in the same center and had either traditional infant orthopedics (TIO) or NAM and 2 were treated in centers not employing IO. MAIN OUTCOME MEASURES: Burden of care data for the IO groups were compared using t tests. Frontal and profile photographs at approximately age 5 were collected for ratings of nasolabial esthetics, using a modification of the Asher-McDade method. Intrarater and interrater reliabilities were determined using weighted κ statistics. Median ratings were compared using a Kruskal-Wallis test. RESULTS: The burden of care of NAM was significantly greater than TIO for both the number of visits (9.9 vs 6.6, [ P < .001]); and treatment duration (127 vs 112 days, [ P < .05]). Significant differences in nasolabial esthetic ratings were noted among the 3 centers. No significant differences were observed in the nasolabial esthetic outcomes between the NAM and TIO groups. CONCLUSIONS: 1. NAM required more visits and longer overall duration compared with TIO. 2. The center employing IO showed favorable nasolabial esthetics compared to those not utilizing IO. 3. No significant differences were found in the nasolabial esthetics of patients who have received NAM compared with TIO.

An Intercenter Comparison of Nasolabial Appearance Including a Center Using Nasoalveolar Molding.

OBJECTIVE: To compare nasolabial appearance outcomes of patients with complete unilateral cleft lip and palate (CUCLP) in preadolescence from 4 cleft centers including a center using nasoalveolar molding (NAM) and primary nasal reconstruction. DESIGN: Retrospective cohort study. SETTING: Four cleft centers in North America. PATIENTS: 135 subjects with repaired CUCLP. METHODS: Frontal and profile facial pictures were assessed using the Asher-McDade rating scale. Intra- and interrater reliability were tested using weighted Kappa statistics. Median scores by center were compared with Kruskal-Wallis statistics. RESULTS: Intrarater reliability scores were moderate to good. Interrater reliability scores were moderate. Significant differences ( P < .05) among centers were found. For nasal form, center G (median = 2.83) had better scores than centers C and D (C median = 3.33, D median = 3.17). For nose symmetry, center G had better scores (median = 2.33) than all other centers (B median = 2.67, C median = 2.83, D median = 2.83). For vermillion border, center G had better scores (median = 2.58) than centers B and C (B median = 3.17, C median = 3.17). For nasolabial profile, center G (median score = 2.67) had better scores than center C (median = 3.00). For total nasolabial score, center G (median = 2.67) had better scores than all other centers (B median = 2.83, C median = 3, D median = 2.83). CONCLUSION: The protocol followed by center G, the only center that performed NAM and primary nasal reconstruction, produced better results in all categories when compared to center C, the only center that did not perform presurgical orthopedics or lip/nose revisions. When compared to centers that performed traditional presurgical orthopedics and surgical revisions (B and D), center G was not consistently better in all categories. As with other uncontrolled, retrospective intercenter studies, it is not possible to attribute the outcomes to a specific protocol component.

Active Presurgical Infant Orthopedics for Unilateral Cleft Lip and Palate: Intercenter Outcome Comparison of Latham, Modified McNeil, and Nasoalveolar Molding.

OBJECTIVE: To compare dental arch relationship, craniofacial form, and nasolabial aesthetic outcomes among cleft centers using distinct methods of presurgical infant orthopedics (PSIO). DESIGN: Retrospective cohort study. SETTING: Four cleft centers in North America. PATIENTS: One hundred ninety-one children with repaired complete unilateral cleft lip and palate (CUCLP). MAIN OUTCOME MEASURES: Dental arch relationship was assessed using the GOSLON Yardstick. Craniofacial form was assessed by 12 cephalometric measurements. Nasolabial aesthetics were assessed using the Asher-McDade system. Assessments were performed between 6 and 12 years of age. RESULTS: The center that used no PSIO achieved the most favorable dental arch relationship and maxillomandibular relationship, with a median GOSLON score of 2.3 ( P < .01) and an ANB angle of 5.1° ( P < .05). The proportion of children assigned a GOSLON score of 4 or 5, predictive of the need for orthognathic surgery in adolescence, was 16% at the center that used no PSIO and no secondary surgery, compared to 76% at the centers that used the Latham appliance and early secondary lip and nose surgery ( P < .01). The center that used no PSIO and no secondary surgery achieved significantly less favorable nasolabial aesthetic outcomes than the centers using Latham appliance or nasoalveolar molding (NAM) ( P < .01). CONCLUSIONS: Effects of active PSIO are multifaceted and intertwined with use of revision surgery. In our study, centers using either the Latham appliance combined with early revision surgery or the NAM appliance without revision surgery achieved better nasolabial aesthetic outcomes but worse maxillary growth, compared to a center using no PSIO and secondary surgery.

The Americleft Project: Plaster Dental Casts Versus Digital Images for GOSLON Yardstick Ratings When Used in Intercenter Comparisons.

The purpose of this investigation was to determine reliability and validity of GOSLON Yardstick ratings using plaster casts versus photo galleries of digital images in actual intercenter comparisons. The dental arch relationships of 112 patients with complete unilateral cleft lip and palate from 3 North American cleft/craniofacial centers were rated in 2 separate studies. In the first, plaster casts were used. For a later intercenter comparison, the same dental casts were scanned, digital bases added, and two-dimensional photographic galleries (6 views) were created for each set of casts. Three raters experienced with the GOSLON Yardstick carried out 2 separate ratings of the plaster casts in the first study, then of the photographic gallery of scanned digital images of the same casts in the second study. Inter- and intrarater reliabilities were calculated using the Weighted Kappa statistic. Average scores for each patient were calculated and compared between methods with correlation statistics and a Bland-Altman plot. Kruskal-Wallis test was used to compare results between centers using both media. Reliability using both methods was very good and comparable between methods. Mean weighted Kappas were: inter-rater = 0.815 (plaster) versus 0.891 (photo); and intrarater = 0.866 (plaster) versus 0.891 (photo). There was a highly significant correlation (r = 0.920). Mean difference between centers was 0.033 of a GOSLON category. The level of significance of the differences found between centers with both methods was identical, confirming the interchangeability of both media presentations.

Reliability of the SWAG-The Standardized Way to Assess Grafts Method for Alveolar Bone Grafting in Patients With Cleft Lip and Palate.

OBJECTIVE: The objective of this study was to test a new method, a Standardized Way to Assess Grafts (SWAG), to rate alveolar bone graft (ABG) outcomes for patients with cleft lip and palate. DESIGN: This was a retrospective comparison using the SWAG scale. SETTING: This study took place in four cleft palate centers with different treatment protocols. METHODS: A total of 160 maxillary occlusal radiographs taken 3 to 18 months post-ABG for sequentially treated patients with cleft lip and palate were assessed using the SWAG scale. Radiographs were scanned, standardized, blinded, and rated by 6 calibrated orthodontists to assess vertical thirds, bony root coverage, and complete bony fill. All radiographs were rated twice, 24 hours apart, by the same raters. MAIN OUTCOMES: Intra- and interrater reliabilities were assessed. RESULTS: Intrarater reliability was good to very good (.760; .652-.834), and interrater reliability was moderate to good (.606; .569-.681), comparable to previously published methods. CONCLUSIONS: Rater reliabilities were shown to be comparable to or better than existing methods. The SWAG method was validated for ABG assessments in the mixed and permanent dentitions based on reliabilities in an intercenter outcome comparison.

A Multicenter Study Using the SWAG Scale to Compare Secondary Alveolar Bone Graft Outcomes for Patients With Cleft Lip and Palate.

Objective To assess secondary alveolar bone graft (ABG) outcomes using the standardized way to assess grafts, or SWAG scale, for patients with cleft lip and palate (CLP). Design Retrospective cohort study. Setting Four cleft centers with different protocols. Methods One hundred sixty maxillary occlusal radiographs taken 3 to 18 months after secondary ABG for sequentially treated patients with CLP were assessed using the SWAG scale. Radiographs were scanned, standardized, blinded, and rated by six orthodontists using the SWAG scale. Randomized radiographs were rated twice, 24 hours apart, by the same raters. Main Outcomes Intrarater and interrater reliabilities were assessed. Means and SDs were calculated for ABG ratings using analysis of variance and Tukey tests (P < .05). Result The mean ABG age was 9.1 years (range = 7 to 10.1 years) and the mean follow-up age was 12.4 years (range = 8.2 to 20.4 years). Intrarater and interrater reliabilities were good (intrarater = 0.788, interrater = 0.705), and higher than published methods. Mean ABG ratings for the cleft centers were 4.53, 2.9, 3.63, and 5.0 and differed significantly. The two centers with the highest ABG ratings showed higher ratings for all thirds decreasing from apical to coronal. The two centers with lower ABG ratings showed poorer ABG ratings for all thirds, and the middle third received the highest ratings. Conclusions The SWAG scale overcomes the challenges of age and bone location. The SWAG method was validated for showing intercenter differences for overall bone fill as well as in vertical thirds. Surgical technique, timing, and expertise/volume were identified as possible factors related to outcome.

The Effect of Cleft Size in Infants With Unilateral Cleft Lip and Palate on Mixed Dentition Dental Arch Relationship.

OBJECTIVE: To determine the relationship between infant cleft size and dental arch relationship in the mixed dentition in patients with complete unilateral cleft lip and palate. DESIGN: Retrospective analysis of mixed longitudinal records. PATIENTS: A total of 29 consecutively enrolled patients with unilateral cleft lip and palate participated in a longitudinal study that included dental casts prior to lip surgery (T1: age 1 month), prior to palate surgery (T2: age 10 months), and in mixed dentition (T3: age 9 years). INTERVENTIONS: All infants were managed with lip repair (2.5 months), hard palate repair (12 months), and soft palate repair (16 months) but without any presurgical orthopedic treatment and no orthodontic intervention prior to mixed dentition records. MAIN OUTCOME MEASURES: The outcome measures included determination of an infant cleft severity ratio, defined as the ratio of palatal cleft area to palatal surface area, at both T1 and T2, and the 9-year-old (T3) dental arch relationship as determined using the GOSLON Yardstick. The correlation between the infant cleft severity ratio at T1 and T2 and the later GOSLON Yardstick score at T3 was determined using Pearson r. The intrarater reliability of the infant cleft severity ratio was assessed with Pearson r and the interrater reliability of the GOSLON Yardstick ratings, by weighted kappa. RESULTS: Reliability for the infant cleft severity ratio method was r = .92 to .95, and for GOSLON ratings κ = .81 to .91. There was no significant correlation between 1-month infant cleft severity ratio and GOSLON (r = .3) and 10-month infant cleft severity ratio and GOSLON (r = .1). CONCLUSIONS: Cleft size versus the amount of palatal tissue available for repair and concern over more scarring with a greater infant cleft severity ratio were not factors in affecting the eventual dental arch relationship.

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.

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 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).

Prevalence of Torus Palatinus and association with dental arch shape in a multi-ethnic cohort.

Objectives: Torus Palatinus (TP) is a bony projection located on the oral surface of the hard palate. The trait is typically benign, has an unknown etiology, and varies widely in phenotypic expression. Prior studies suggest differences in TP prevalence by sex and ancestry, but the reported rates vary, even within a single ancestral group. We assessed the prevalence of TP and its association with palatal shape in a large multi-ethnic cohort of normal individuals. Methodology: 1102 adults were included (625 with European ancestry, 377 with West African anscestry, and 100 with East Asian ancestry). 3D digital dental casts were obtained and rated. TP frequencies were compared between sexes and/or ethnicities using Chi-squared tests. Dental cast models were then landmarked, and canonical variates analysis was performed to test for shape differences between those with and without TP. Results: Females had a significantly higher rate of TP than males across all three ancestral groups (p≤0.004). In males, no significant differences were found among ethnicities. Ancestral differences in TP frequency were driven by females, with East Asians having the highest rate (34.69%), followed by Europeans (24.88%) and West Africans (15.22%). Shape differences were found only in Asians and Africans, indicated a shorter and wider palate in presence of TP. Conclusions: Ethnic differences in TP frequency were present only in females. Further, females have considerably higher rates of TP than males in each population tested. Further studies of TP at earlier time-points and in connection to other aspects of craniofacial growth may shed light on these sex and ethnic differences.