Three-dimensional assessment of the nasopharyngeal airway in Down syndrome during the mixed dentition period: a case-control study.

OBJECTIVE: In this retrospective case-control study, we aimed to evaluate the nasopharyngeal airway volume of children with Down syndrome (DS) and compare the results with those of control participants well matched for sex and age. MATERIALS AND METHODS: Fifteen children with DS (mean age = 9.43 ± 0.38 years; 8 boys, 7 girls) and 15 control participants (mean age = 9.51 ± 0.40 years; 8 boys, 7 girls) were enrolled. The nasopharyngeal airway volume and the cross-sectional morphology were measured with cone-beam computed tomography taken for orthodontic treatment. All measurements were assessed by analysis of covariance (ANCOVA) using Bonferroni post hoc pairwise comparison tests. Covariates were body height and body weight, and the ANB angle and the mandibular plane angle. Significance was set at P < .0019. RESULTS: Nasal airway, superior airway, and total airway volumes of DS participants were significantly smaller than those of the control participants in ANCOVA results adjusted for ANB angle and mandibular plane angle (P = .000). In ANCOVA results adjusted for body height and body weight, no statistically significant differences in the volume measurements were found. CONCLUSION: The results indicate that the nasopharyngeal airway volume differs between children with and without DS and that the airway volume tends to be smaller in DS children than in children without DS.

Comparison of Maxillofacial Morphology Between Modified Furlow's and Modified two-Flap Palatoplasty in Orofacial Clefts During the Primary Dentition Period.

OBJECTIVE: To assess the effect of two palatoplasty procedures, modified Furlow's palatoplasty (F procedure) and modified two-flap palatoplasty (T procedure), on the maxillofacial morphology of unilateral cleft lip and palate (UCLP) and bilateral cleft lip and palate (BCLP) during the primary dentition period. DESIGN: Retrospective cohort study. SETTING: Department of Orthodontics, School of Dentistry, Showa University. PARTICIPANTS: We enrolled 106 pediatric patients (63 boys, 43 girls; aged 4.43 ± 0.34 years) with non-syndromic orofacial clefts who underwent cheiloplasty and palatoplasty. INTERVENTIONS: Patients were divided into four groups according to cleft type (BCLP or UCLP) and palatoplasty procedure type (F or T procedure). MAIN OUTCOME MEASURES: Maxillofacial morphology was assessed by examining parameters on lateral cephalograms. RESULTS: Multiple comparisons revealed significant differences among N-A, N-ANS, and ANS-PNS distances and SNA and ANB angles among the groups. There were significant differences in N-A, N-ANS, ANS-PNS, SNA, and SNB among the UCLP and BCLP groups. The calculated effect sizes were all within 0.3-0.5. The statistical power was as follows: N-A, 86.41%; N-ANS, 79.77%; ANS-PNS, 97.49%; SNA, 96.88%; and ANB, 99.25%. CONCLUSIONS: Although UCLP and BCLP both exhibited differences in craniofacial distances and angles, the procedure type (either F or T procedure) had no significant effect on the maxillofacial morphology (as determined by lateral cephalograms). However, to rule out additional bias, patient-specific factors should be considered that may be affected by maxillofacial development when deciding surgical approaches.

Effects of Anti-Receptor Activator of Nuclear Factor Kappa B Ligand Antibody and Zoledronic Acid on Periapical Lesion Development in Mice.

INTRODUCTION: Antiresorptive drugs are widely used to treat osteoporosis and other systemic bone diseases, although their efficacy for local bone resorption after localized inflammation has not been fully elucidated. We examined the effects of an anti-receptor activator of nuclear factor kappa B ligand (RANKL) antibody and the bisphosphonate zoledronic acid (ZOL) on periapical lesion (PL) development in mice. METHODS: Dental pulp of lower first molars in mice was removed, with the exposed dental pulp chambers left open to the oral environment to induce apical periodontitis. An anti-RANKL antibody or ZOL was intraperitoneally injected once per week until postoperative day 21, and then micro-computed tomographic imaging and histologic analyses were performed. RESULTS: PL enlargement was inhibited by both the anti-RANKL antibody and ZOL in a dose-dependent manner, and a reduction of inflammatory cell infiltration in apical tissues inhibited periapical bone resorption. The anti-RANKL antibody decreased the number of osteoclasts in periapical tissues, whereas ZOL suppressed periapical bone resorption with osteoclast numbers maintained. Although the administration of each of the antiresorptive drugs increased femoral bone mass, femoral bone mineral density in the PL group was lower compared with the sham-operated group. CONCLUSIONS: These results suggest that an antiresorptive drug administered systemically is distributed to areas of local inflammation in the jaw can prevent PL development.

Three-Dimensional Assessment of Craniofacial Features in Patients With Down Syndrome During the Mixed Dentition Period: A Case-Control Study.

OBJECTIVES: Down syndrome (DS) is a common congenital chromosomal disorder related to trisomy 21. Lateral cephalometric radiography studies have shown that patients with DS have characteristic craniofacial morphology; however, no 3-dimensional analysis studies have been performed to investigate the craniofacial features, including volumetric aspects, of patients with DS. The present study was performed to evaluate the craniofacial features, including volumetric aspects, of patients with DS and to compare these findings with control participants using cone beam computed tomography (CBCT). MATERIALS AND METHODS: The study sample consisted of 12 patients with DS and 12 control participants. All participants were examined by means of CBCT; the resulting images were used for evaluation of maxillary and mandibular volume, cranial base, and craniofacial measurements. Differences between patients with DS and control participants were statistically analyzed using Student t test. RESULTS: Compared to control participants, patients with DS exhibited statistically significant reductions in maxillary and mandibular volumes. Both sagittal and axial cranial base linear measurements were shorter in patients with DS than in control participants. In contrast, the cranial base angle was enhanced in patients with DS, compared with control participants. Moreover, condylion (Co)-gnathion, anterior nasal spine-menton, and Co-subspinale (point A) measurements were shorter in patients with DS than in control participants; the sella-nasion-mandibular plane angle was significantly reduced in patients with DS, compared with control participants. CONCLUSION: Our results suggest that patients with DS have distinct skeletal volume and craniofacial morphology features, relative to individuals without DS.

Neural crest-derived cells possess differentiation potential to keratinocytes in the process of wound healing.

Neural crest-derived cells (NCDCs), which exist as neural crest cells during the fetal stage and differentiate into palate cells, also exist in adult palate tissues, though with unknown roles. In the present study, NCDCs were labeled with EGFP derived from P0-Cre/CAG-CAT-EGFP (P0-EGFP) double transgenic mice, then their function in palate mucosa wound healing was analyzed. As a palate wound healing model, left-side palate mucosa of P0-EGFP mice was resected, and stem cell markers and keratinocyte markers were detected in healed areas. NCDCs were extracted from normal palate mucosa and precultured with stem cell media for 14 days, then were differentiated into keratinocytes or osteoblasts to analyze pluripotency. The wound healing process started with marginal mucosal regeneration on day two and the entire wound area was lined by regenerated mucosa with EGFP-positive cells (NCDCs) on day 28. EGFP-positive cells comprised approximately 60% of cells in healed oral mucosa, and 65% of those expressed stem cell markers (Sca-1+, PDGFRα+) and 30% expressed a keratinocyte marker (CK13+). In tests of cultured palate mucosa cells, approximately 70% of EGFP-positive cells expressed stem cell markers (Sca-1+, PDGFRα+). Furthermore, under differentiation inducing conditions, cultured EGFP-positive cells were successfully induced to differentiate into keratinocytes and osteoblasts. We concluded that NCDCs exist in adult palate tissues as stem cells and have potential to differentiate into various cell types during the wound healing process.