Doğan Dolanmaz | PubMed Health

PubMed2006

Experimental evaluation of the effects of zoledronic acid on regenerate bone formation and osteoporosis in mandibular distraction osteogenesis.

PURPOSE: The aim of this study was to evaluate the effects of systemically administered zoledronic acid (ZA) on the bone mineral density (BMD) and bone mineral content (BMC) at mandibular distraction sites in rabbits. MATERIALS AND METHODS: Eighteen New Zealand white rabbits were randomly divided into 2 groups. Bone lengthening was performed in the left portion of the mandible through distraction osteogenesis at a rate of 0.5 mm every 12 hours for 5 days. While the experimental group rabbits were administered intravenous 0.1 mg/kg ZA, control group rabbits were given only saline infusion during operation. All animals were sacrificed at the end of the consolidation period of 28 days. The mandibles of all animals were removed and both the anterior and posterior pin regions of the regenerate and regenerate region were evaluated by dual energy x-ray absorptiometry (DEXA). BMD and BMC data were statistically analyzed. RESULTS: Except for 1 rabbit from the experimental group that had an infection at the external pin region, all animals showed complete clinical healing. When the values in the group receiving ZA were compared with those of the control group, it was observed that the BMD values of the anterior pin region of regenerate, regenerate region, and posterior pin region increased by 23%, 20%, and 31%, respectively; and BMC values increased by 22%, 24%, and 32%, respectively. When data of these regions were compared, both BMD and BMC were found statistically different in all regions (P < .05). CONCLUSION: Results of this study showed that ZA had positive effects on new bone formation at and around the distraction gaps of the lengthened rabbit mandibles by distraction osteogenesis.

Absorptiometry, Photon↗

PubMed2004

Intraosseous screw-supported upper molar distalization.

The aims of the present study were to investigate (1) the efficiency of intraosseous screws for anchorage in maxillary molar distalization and (2) the sagittal and vertical skeletal, dental, and soft tissue changes after maxillary molar distalization using intraosseous screw-supported anchorage. Twenty-five subjects (18 girls and seven boys; 11.3 to 16.5 years of age) with skeletal Class I, dental Class II malocclusion participated in the study. An anchorage unit was prepared for molar distalization by placing an intraosseous screw behind the incisive canal at a safe distance from the midpalatal suture following the palatal anatomy. The screws were placed and immediately loaded to distalize upper first molars or the second molars when they were present. The average distalization time to achieve an overcorrected Class I molar relationship was 4.6 months. The skeletal and dental changes were measured on cephalograms and dental casts obtained before and after the distalization. In the cephalograms, the upper first molars were tipped 8.8 degrees and moved 3.9 mm distally on average. On the dental casts, the mean distalization was five mm. The upper molars were rotated distopalatally. Mild protrusion (mean 0.5 mm) of the upper central incisors was also recorded. However, there was no change in overjet, overbite, or mandibular plane angle measurements. In conclusion, immediately loaded intraosseous screw-supported anchorage unit was successful in achieving sufficient molar distalization without major anchorage loss.

Adolescent↗