The Assessment of Digital Study Models Using the GOSLON Yardstick Index.

Objective : To investigate the reproducibility and repeatability of digital models of patients with a unilateral cleft lip and palate (UCLP) using the GOSLON yardstick. Design : Reproducibility and repeatability study. Method : Two examiners used the GOSLON yardstick to assess the intermaxillary dentoalveolar relationship of 30 consecutive UCLP patients by analyzing their 9-year (±3 months) dental study casts and digital study models. The records were rated 1 week apart to avoid bias. The process was repeated 1 month later as a measure of reproducibility. Reliability was assessed by comparing the GOSLON score achieved between the two modalities. Patient dental study casts were sent to 3M Unitek Australia to be scanned using the 3M Unitek Lava(TM) system to produce digital study models. The accuracy of the dental study cast occlusal registration was assessed by both raters prior to sending the study models for scanning. Statistical analysis : The Linear Weighted Kappa statistic and Kendall's Coefficient of Concordance statistic were used to determine the levels of agreement within and between raters. Results : The linear weighted Kappa statistic for intrarater repeatability of digital study models scores were very high (0.89 and 0.97). This compared favorably to the intrarater repeatability of study model casts scores (0.86 and 0.97). There was very good agreement for interrater digital study model scores (0.80 and 0.87) and also for the interrater study model casts scores (0.80 and 0.90). Kendall's Coefficient of Concordance statistic (0.99) and Correlation Coefficient (0.86) support the weighted Kappa results of the digital study model scores. Conclusion : Digital models can be used for GOSLON scoring with a high degree of reproducibility and repeatability.

The influence of orthodontic treatment on the Goslon score of unilateral cleft lip and palate patients.

OBJECTIVE: To assess the effect of orthodontic treatment on Goslon Yardstick outcome. DESIGN: Retrospective study. PATIENTS: A series of 66 consecutive patients born with a complete unilateral left lip and palate. Patients were sorted into a nontreatment group (n  =  47) and a treatment group (n  =  19). METHOD: Three assessors trained in the use of the Goslon Yardstick ranked the dental arch relationships of study casts taken at 6 and 9 years. RESULTS: There was only a fair agreement (κ  =  .33) between 6- and 9-year Goslon Yardstick scores for the cohort of 66 patients, with a significant (p < .05) difference in the mean score at 6 years (3.17 ± 0.8) and at 9 years (2.88 ± 1.0). Removal of 19 subjects who had orthodontic inventions prior to taking of the 9-year-old study cast improved the agreement to moderate (κ  =  .52). There was no significant difference (p > .05) in mean scores at 6 and 9 years (3.13 ± 0.9 and 3.17 ± 1.03, respectively). The treatment group exhibited significant differences (p < .001) with mean Goslon Yardstick scores of 3.0 ± 0.9 at 6 and 2.25 ± 0.45 at 9 years. CONCLUSIONS: The inclusion of patients who had received orthodontic treatment prior to taking of study casts being used for Goslon Yardstick scoring can result in a more favorable outcome. Patients who have received active orthodontic treatment prior to taking of dental casts should be excluded or accounted for in audits to assess primary cleft surgical outcome in patients with a unilateral cleft lip and palate.

Dental arch relationship outcomes in children with complete unilateral cleft lip and palate treated at Princess Margaret Hospital for Children, Perth, Western Australia.

OBJECTIVES: To (1) audit dental arch relationships of all children born between 1982 and 1999 with complete unilateral cleft lip and palate (UCLP) treated at the Cleft Lip and Palate Unit, Princess Margaret Hospital for Children (PMH), Perth, Western Australia, (2) assess the distribution of GOSLON ratings from dental casts taken at 9 years, (3) compare the 9-year GOSLON ratings for "High" and "Low" caseload surgeons, and (4) compare the 9-year PMH GOSLON ratings with published ratings from other units. DESIGN: Retrospective audit of dental casts and medical charts. PATIENTS: Dental casts were retrieved for 71 children (47 boys and 24 girls) at 9 years of age. MAIN OUTCOME MEASURES: GOSLON ratings. RESULTS: Sixty-eight percent of patients had an excellent to satisfactory dental arch relationship (GOSLON Yardstick ratings 1 to 3) at 9 years with a mean rating of 2.85. High caseload surgeons achieved statistically better mean GOSLON ratings than low caseload surgeons (2.72 and 3.33, respectively). CONCLUSIONS: PMH Cleft Unit's dental arch relationship outcomes are comparable to published series of units using similar treatment protocols. High caseload surgeons achieved better dental arch relationships than low caseload surgeons.

Mandibular distraction osteogenesis and maxillary osteotomy in a class II division 1 patient with chronic juvenile arthritis.

A patient with juvenile chronic arthritis presented with a malocclusion characterized by mandibular hypoplasia, symphysial deficiency, and an increased mandibular occlusal plane angle. Correction of the mandibular defect required both the horizontal advancement of the mandible and a counterclockwise rotation of the proximal segment to reduce the mandibular occlusal plane angle. This was achieved by a combination of distraction osteogenesis to horizontally advance the mandible (14 mm), followed by manipulation of the postdistraction regenerate to reduce the mandibular occlusal plane and increase the symphysial projection. The counterclockwise rotation of the mandibular body resulted in the creation of a posterior open bite. After a three-month period to allow consolidation of the mandibular distraction osteogenesis, secondary maxillary surgery at the Le Fort 1 level was performed to reestablish maxillary occlusal contact at the new mandibular occlusal plane. A genioplasty was also performed to improve chin projection.