Velopharyngeal changes after maxillary distraction in cleft patients using a rigid external distraction device: A retrospective study.

OBJECTIVE: To evaluate early and late velopharyngeal changes in cleft lip and palate (CLP) patients after use of the Rigid External Distractor (RED) device and to correlate these changes to the amount of maxillary advancement. MATERIALS AND METHODS: Thirty Class III CLP patients were included in the study. Maxillary advancement was performed using the RED device in combination with titanium miniplates and screws for anchorage. Lateral cephalograms, nasometer, and nasopharyngoscope records were taken before distraction, immediately after distraction, and 1 year after distraction. A paired t-test was used to detect differences at P < .05. RESULTS: SNA angle and A point and ANS to Y axis were significantly increased after maxillary distraction (P  =  .0001). Statistically significant increases in nasopharyngeal and oropharyngeal depths, velar angle, and need ratio were also found (P  =  .0001). Nasalance scores showed a significant increase (P  =  .008 for nasal text and .044 for oral text). A significant positive correlation was observed between the amount of maxillary advancement and the increase in nasopharyngeal depth and hypernasality (P  =  .012 and .026, respectively). CONCLUSIONS: Nasopharyngeal function was deteriorated after maxillary advancement in CLP patients. There was a significant positive correlation between the amount of maxillary advancement and the increase in nasopharyngeal depth and hypernasality.

Velopharyngeal changes after maxillary distraction in cleft patients using a rigid external distraction device: A retrospective study.

OBJECTIVE: To evaluate early and late velopharyngeal changes in cleft lip and palate (CLP) patients after use of the Rigid External Distractor (RED) device and to correlate these changes to the amount of maxillary advancement. MATERIALS AND METHODS: Thirty Class III CLP patients were included in the study. Maxillary advancement was performed using the RED device in combination with titanium miniplates and screws for anchorage. Lateral cephalograms, nasometer, and nasopharyngoscope records were taken before distraction, immediately after distraction, and 1 year after distraction. A paired t-test was used to detect differences at P < .05. RESULTS: SNA angle and A point and ANS to Y axis were significantly increased after maxillary distraction (P  =  .0001). Statistically significant increases in nasopharyngeal and oropharyngeal depths, velar angle, and need ratio were also found (P  =  .0001). Nasalance scores showed a significant increase (P  =  .008 for nasal text and .044 for oral text). A significant positive correlation was observed between the amount of maxillary advancement and the increase in nasopharyngeal depth and hypernasality (P  =  .012 and .026, respectively). CONCLUSIONS: Nasopharyngeal function was deteriorated after maxillary advancement in CLP patients. There was a significant positive correlation between the amount of maxillary advancement and the increase in nasopharyngeal depth and hypernasality.

In vitro and in vivo biofilm adhesion to esthetic coated arch wires and its correlation with surface roughness.

OBJECTIVE: To evaluate the in vitro ability of esthetic coated rectangular arch wires to retain oral biofilms and in vivo biofilm formation on these wires after 4 and 8 weeks of clinical use and to correlate the findings with the surface roughness of these wires. MATERIALS AND METHODS: Three brands of esthetic coated nickel-titanium (NiTi) arch wires were selected. Arch wires retrieved after 4 and 8 weeks of intraoral use were obtained from 30 orthodontic patients. Surface roughness (SR) was assessed with an atomic force microscope. In vitro adhesion assays were performed using Streptococcus mutans (MS), Staphylococcus aureus, and Candida albicans. The amount of bacterial adhesion was quantified using the colony-count method. Paired t-test, analysis of variance, post hoc Tukey's test, and Pearson's correlation coefficient test were used for statistical analysis at the .05 level of significance. RESULTS: In vitro bacterial adhesion showed significant differences between wires in terms of MS adhesion (P  =  .01). All wires showed significant increases in SR (P  =  .001 after 4 weeks and .007 after 8 weeks) and biofilm adhesion (P  =  .0001 after 4 weeks and .045 after 8 weeks) after intraoral exposure. A significant positive correlation (P  =  .001 after 4 weeks and .05 after 8 weeks) was observed between these two variables in vivo, but the correlation was not significant for in vitro bacterial adhesion. CONCLUSIONS: SR and biofilm adhesion increased after intraoral use at all time intervals. There was a positive correlation between SR and biofilm adhesion in vivo only.

In vitro study of the potential protection of sound enamel against demineralization.

BACKGROUND: The objective of this study was to study the potential protection effect of different treatments against sound enamel demineralization around orthodontic brackets. METHODS: This is an in vitro randomized controlled study; artificial enamel demineralization of human premolars was created and compared with reference to control. The three materials used for enamel treatment were resin infiltrate (ICON), fluoridated varnish (Clinpro), and the self-etch primer system (Transbond Plus Self-Etch Primer). Fifty premolars divided equally into five groups were included in the study for quantitative surface micro-hardness assessment using a micro-hardness tester (MHT). Qualitative assessment of the enamel demineralization with a polarized light microscope (PLM) was also used. Enamel was demineralized by subjecting the specimens to cycling between artificial saliva solution and a demineralizing solution for 21 days. RESULTS: The mean Vickers hardness in kgf/mm(2) was as follows: intact enamel = 352.5 ± 13.8, demineralized enamel = 301.6 ± 34.0, enamel treated with Clinpro = 333.6 ± 18.0, enamel treated with SEP = 370.7 ± 38.8, and enamel treated with ICON = 380.5 ± 53.8. CONCLUSIONS: ICON, Clinpro, and Transbond Plus Self-Etch Primer (TPSEP) increased enamel resistance to demineralization. Attempting to protect the enamel around the orthodontic brackets could be done by applying a preventive material before bonding, if not compromising the bond strength, the orthodontic brackets.

Effect of different sterilization modes on the surface morphology, ion release, and bone reaction of retrieved micro-implants.

OBJECTIVE: To compare as-received and sterilized micro-implants in order to assess the prospects of reusing them. MATERIALS AND METHODS: Forty micro-implants from a single manufacturing lot were used in the study. Thirty were retrieved from patients after successful service in their mouth and with no signs of failure. The retrieved micro-implants were divided into three groups, according to method of sterilization: autoclave, gamma radiation, or ultraviolet radiation. All groups were subjected to scanning electron microscope analysis for surface morphology assessment. The specimens were immersed in a standard simulated body-fluid solution kept at 37°C in an incubator; the solution was then withdrawn at 24 hours and 30 days to evaluate aluminum and vanadium ion release by atomic absorption spectrophotometer in parts per billion. The micro-implants were then surgically implanted into the tibia of rabbits for a 1-month healing period, and the bone-implant blocks were processed for routine histologic examination. RESULTS: This study revealed that sterilized micro-implants had altered surface topography, different ion release values, and different histologic cell reactions than the as-received micro-implants. CONCLUSIONS: Within the limitations of this study, it can be concluded that retrieved self-drilling micro-implants have tip sharpness variations that require correction before insertion by bone drilling. The autoclave-sterilized micro-implants showed better histologic results than micro-implants sterilized by gamma or ultraviolet rays.

Effect of enamel protective agents on shear bond strength of orthodontic brackets.

BACKGROUND: This paper aimed to study the effect of two enamel protective agents on the shear bond strength (SBS) of orthodontic brackets bonded with conventional and self-etching primer (SEP) adhesive systems. METHODS: The two protective agents used were resin infiltrate (ICON) and Clinpro; the two adhesive systems used were self-etching primer system (Transbond Plus Self Etching Primer + Transbond XT adhesive) and a conventional adhesive system (37% phosphoric acid etch + Transbond XT primer + Transbond XT adhesive ). Sixty premolars divided into three major groups and six subgroups were included. The shear bond strength was tested 72 h after bracket bonding. Adhesive remnant index scores (ARI) were assessed. Statistical analysis consisted of a one-way ANOVA for the SBS and Kruskal-Wallis test followed by Mann-Whitney test for the ARI scores. RESULTS: In the control group, the mean SBS when using the conventional adhesive was 21.1 ± 7.5 MPa while when using SEP was 20.2 ± 4.0 MPa. When ICON was used with the conventional adhesive system, the SBS was 20.2 ± 5.6 MPa while with SEP was 17.6 ± 4.1 MPa. When Clinpro was used with the conventional adhesive system, the SBS was 24.3 ± 7.6 MPa while with SEP was 11.2 ± 3.5 MPa. Significant differences in the shear bond strength of the different groups (P = .000) was found as well as in the ARI scores distribution (P = .000). CONCLUSION: The type of the adhesive system used to bond the orthodontic brackets, either conventional or self-etching primer, influenced the SBS, while the enamel protective material influenced the adhesive remnant on the enamel surface after debonding.

Relationship between dental crowding, skeletal base lengths, and dentofacial measurements.

OBJECTIVES: The objectives of this study were to study the correlation between dental crowding, skeletal base lengths, and dentofacial measurements. MATERIALS AND METHODS: Pretreatment dental casts and lateral cephalograms of randomly selected 45 Class I orthodontic cases divided into two groups according to the severity of mandibular crowding were evaluated. Group 1 comprised 15 patients with mandibular crowding less than 3mm while group 2 comprised 30 patients with mandibular crowding of 3mm or more. Maxillary and mandibular dental crowding and dentofacial measurements were compared between the two groups. For correlations the whole sample was combined to a single group where crowding was used as a continuous variable. RESULTS: The only significant difference (p=0.000) between the two groups was in the amount of dental crowding in the lower arch. Direct moderate correlation (r=0.45; p=0.002) between maxillary crowding and mandibular crowding, direct high correlation (r=0.68; p=0.000) between maxillary base length (Co-A) and mandibular base length (Co-Gn) and also direct high correlation (r=0.74; p=0.000) between maxillary base position (SNA angle) and mandibular base position (SNB angle) were detected. Correlation between maxillary incisor position and facial vertical dimension measured by the MP to SN angle showed inverse moderate correlation. Correlation between mandibular incisor position and the anteroposterior jaw relationship measured by the ANB angle showed direct moderate correlation. CONCLUSIONS: Results showed the presence of correlation between the skeletal dimensions and the absence of correlation between dental crowding and the same measurements. Results suggest that dental crowding is independent of the skeletal measurements.

Prevalence and distribution of dental anomalies in orthodontic patients.

AIM: To study the prevalence and distribution of dental anomalies in a sample of orthodontic patients. METHODS: The dental casts, intraoral photographs, and lateral panoramic and cephalometric radiographs of 509 Egyptian orthodontic patients were studied. Patients were examined for dental anomalies in number, size, shape, position, and structure. The prevalence of each dental anomaly was calculated and compared between sexes. RESULTS: Of the total study sample, 32.6% of the patients had at least one dental anomaly other than agenesis of third molars; 32.1% of females and 33.5% of males had at least one dental anomaly other than agenesis of third molars. The most commonly detected dental anomalies were impaction (12.8%) and ectopic eruption (10.8%). The total prevalence of hypodontia (excluding third molars) and hyperdontia was 2.4% and 2.8%, respectively, with similiar distributions in females and males. Gemination and accessory roots were reported in this study; each of these anomalies was detected in 0.2% of patients. CONCLUSION: In addition to genetic and racial factors, environmental factors could have more important influence on the prevalence of dental anomalies in every population. Impaction, ectopic eruption, hyperdontia, hypodontia, and microdontia were the most common dental anomalies, while fusion and dentinogenesis imperfecta were absent.