Five-year follow-up of maxillary distraction osteogenesis on the dentofacial structures of children with cleft lip and palate.

PURPOSE: To determine the long-term outcomes of maxillary distraction osteogenesis (DO) on skeletal and dental structures of growing children with cleft lip and palate. PATIENTS AND METHODS: Severe maxillary deficiencies were treated with a rigid external distractor device followed by a consolidation period. Preoperative and postoperative orthodontic treatment lasted a mean of 14 months and 16 months, respectively. The landmarks on standard lateral cephalometric x-rays were digitized and angular and linear measurements were compared by Student's t test to assess the changes before distraction, after distraction, after consolidation, at 1-year follow-up, and at 2-year follow-up. Long-term follow-up (5 years) was interpreted according to mean values because of the small sample size. RESULTS: During DO, the maxilla was horizontally advanced and moved downward as indicated by the significant changes at the SNA and ANB angles (13 degrees) and at maxillary points A, ANS, and PNS. The increase at the divergence between the maxilla and mandible (ANS-PNS/Me-Go) was found to be significant. The mandible (B, Pg, Me) also moved downward (2-4 mm) and backward (Gn) significantly because of mandibular autorotation. The overjet increased (mean increase, 13.7 mm) and the overbite decreased significantly. The advancement of the upper incisors (13.3 mm) and upper molars (12.3 mm) was slightly more than the skeletal points. In a long-term follow-up (5 years), the ANB angle and horizontal overjet continued to decrease but both values remained positive, indicating a Class I relationship. CONCLUSIONS: This cephalometric study of young adolescents with cleft lips and palates found great improvement in dentofacial structure after maxillary DO and stability in maxillary skeletal advancement. During a 5-year follow-up, the achieved dentoskeletal treatment outcome was partly diminished. The extreme need for maxillary advancement or facial correction because of psychosocial stress and providing an easier approach for finalizing osteotomy are the major 2 indications for DO treatment.

Molar distalization with a pendulum appliance K-loop combination.

SUMMARY: The aim of this study was to evaluate the dentoalveolar effects of a pendulum appliance supported buccally by a K-loop, and to compare these with a cervical headgear (CHG) group. The records of 30 patients with skeletal Class I and dental Class II malocclusions were divided in to two groups: Patients in group 1 (seven females and eight males; mean age, 15.0 +/- 3.4 years) were treated with a pendulum appliance supported with a K-loop buccally, while in group 2 (10 females and 5 males; mean age, 14.2 +/- 2.9 years), the patients were treated with CHG. Standardized lateral cephalograms and study models were taken at the beginning of treatment (T0) and at the end of distal molar movement (T1). T0-T1 changes within the groups were analysed with a paired t-test, and between the groups with a t-test. The mean amount of distalization was 4.53 +/- 1.46 mm in group 1 and 2.23 +/- 1.68 mm in group 2. The mean amount of distal tipping for group 1 was 5.13 +/- 4.90 degrees; the mean amount of mesial tipping for group 2 was 0.80 +/- 2.27 degrees. Intrusion and mesiobuccal rotation of the maxillary molars were achieved in both groups. In group 1, the amount of labial protrusion and tipping of the maxillary incisors was not statistically significant. In group 2, palatoversion and retrusion of the maxillary incisors was statistically significant (P < 0.01 and P < 0.001, respectively). The two major disadvantages of intraoral appliances, which are distal tipping of molars and loss of anchorage at the anterior teeth, were significantly decreased with the use of a pendulum appliance K-loop combination.

Comparison of metal release from new and recycled bracket-archwire combinations.

Most orthodontic brackets and archwires made from stainless steel or nickel (Ni)-titanium (Ti) alloys can release metal ions into the saliva. This study measures the amounts of metal released from simulated fixed orthodontic appliances. Sixty simulated fixed orthodontic appliances were manufactured in different ways and divided into four equal groups as follows: new brackets and new archwires (group 1 controls), new brackets and recycled archwires (group 2), recycled brackets and new archwires (group 3), and recycled brackets and recycled archwires (group 4). The bracket bases coated with adhesives were heated at 350 degrees C for 30 minutes. Recycled archwires were sterilized by autoclaving. Each appliance was soaked in artificial saliva of pH 7 at 37 degrees C for 45 days. At the end of this period, a sample of the artificial saliva was collected for analysis. Concentrations of Ni, chromium (Cr), iron (Fe), manganese, copper (Cu), and Ti ions were measured by atomic absorption and recorded in micrograms per liter. Analysis of variance and the Duncan multiple-range test indicated significant differences among the groups (P < .001). The study revealed the following: (1) group 4 released higher amounts of Cr, Fe, and Ti than any of the other three combinations; (2) Ni release was similar in groups 1 and 2 and in groups 2, 3, and 4; (3) the amounts of Cu, Cr, and Ti ions released from groups 3 and 4 were significantly greater than the amounts released from the other two combinations.