Differences in hard and soft tissue profile after orthodontic treatment with and without extraction

Aims and Background

Premolar extraction is often associated with variations in the soft tissue profile that lead to considerable improvements in the facial profile. This study compared the changes in the facial profile of hard and soft tissues and investigated possible differences in the various facial parameters between patients who were treated with and without premolar extraction.

Materials and Methods

A total of 98 orthodontically treated patients were divided into two groups with an equal number of participants. Premolar extraction was performed in the test group only. A total of 33 landmarks were identified on each cephalometric radiograph. The intraclass correlation coefficient was calculated. We evaluated changes in measurements between pre- and post-treatment by performing the signed-rank test. We used the Kruskal-Wallis test to compare changes between the groups.

Results

No significant differences were observed in the treatment outcomes of skeletal and soft tissue variables in class I and class II participants between the test and control groups (P > 0.01). However, significant differences were noted in the treatment outcomes of dental variables in class II participants between the groups. Dental variables did not show any significant difference in class III patients between the groups.

Conclusion

This study showed that skeletal and soft tissue changes were similar in skeletal except for few dental parameters following orthodontic treatment with and without premolar extraction.

The prevalence of CCR5-Δ32 mutation in a cohort of Saudi stem cell donors

CCR5 is a chemokine receptor that was found to be used by HIV as a co-receptor for entering target cells. A 32 bp deletion was described in certain people that rendered CCR5 non-functional. The mutant allele CCR5-Δ32 has been shown to prevent HIV infection. In addition, stem cell transplantation with the CCR5-Δ32 homozygous genotype can lead to clearance of HIV infection. In this study, our aim was to investigate the frequency of CCR5-Δ32 mutation in a cohort of stem cell donors from cord blood bank and stem cell donor registry. A total of 3025 samples were collected from healthy stem cell donors (2625) and from cord blood units (400). DNA was extracted and the CCR5 gene was amplified by polymerase chain reaction (PCR) in a light cycler system using SYBR Green dye. The mutated gene was further confirmed by direct gene sequencing. We found 38 heterozygous for CCR5-Δ32 and one homozygous CCR5 mutation (Δ32/Δ32) out of the 3025 tested individuals. We conclude that the protective CCR5-Δ32 allele appears to be rarely present in Saudi Arabia.

Neutrophils and lymphoid chimerism after adult living-related liver transplantation from a homozygous donor

Chimerism and graft-versus-host disease (GVHD) pose significant risks to liver transplant patients. The risk of chimerism and GVHD is higher among cases of living-related liver transplant (LRLT). Donors homozygous at all HLA loci carry a higher risk for GVHD. Herein we present a case of LRLT. The recipient suffered from end-stage liver disease and received a right lobe graft from his son. After 8 months posttransplant, the patient developed profound bone marrow depression. The patient was negative for CMV, Brucella, HHV6, HHV8, HBV, HCV, and parvovirus. No skin or GI signs of GVHD were noted. The patient and donor were HLA typed by SSP. The donor was homozygous for all HLA loci while the patient shared the class II homozygosity and was class I heterozygous. Chimerism studies were prompted after noting that the neutrophil compartment of the patient was homozygous for all HLA loci. This initiated further studies of the PMN and lymphocytes by microsatellite analysis. A total 15 microsatellites were analyzed. The results suggest that the majority (75%) of the PMNs and 45% of the lymphocytes were of donor origin. The patient was treated with G-CSF; his WBC counts returned to normal. At 2.5 years posttransplant the patient had not developed GVHD, despite the large number of donor lymphocytes circulating in his bloodstream. The only complaint he had was severe arthritis, which was treated with steroids. It must be investigated whether this was the result of GVHD.