The effects of cortical bone thickness and miniscrew implant root proximity on the success rate of miniscrew implant: A retrospective study.

OBJECTIVE: To investigate the effects of cortical bone thickness (CBT), miniscrew implant root proximity (MRP) and other related factors on the success rate of miniscrew implant (MSI). MATERIALS AND METHODS: Four hundred and five MSIs placed in 171 patients were analysed in this retrospective study. The primary predictor variables were CBT and MRP at MSI insertion sites. The predictor variables also included patient, location, MSI design and procedure related factors. The outcome variable was the survival of MSI. The differences in measurement data between success group and failed group were evaluated by the analysis of variance and independent samples t tests. Patient, location, MSI design and procedure related factors associated with the MSI prognosis were analysed by survival analysis with Cox proportional hazard regression model. The P value was set at .05. And the survival curves of independent factors were plotted. RESULTS: The overall success rate of MSI was 82.7%. The age of MSI host, CBT, interdental root distance (IRD) and MRP at MSI sites showed no significant differences between failed group and success group. CBT and insertion jaws were independent prognosis factors screened out by Cox proportional hazard regression model. Failure risk (hazard ratio) of MSI with CBT <1 mm was 4.72. The failure risk in the mandible was 3.80 times as high as that in the maxilla. CONCLUSION: Inadequate CBT (<1 mm) contributed to the failure of MSI. MSI placed in the maxilla showed better prognosis compared to the mandible. MRP had no significant effect on the prognosis.

SQUAT: a Sequencing Quality Assessment Tool for data quality assessments of genome assemblies.

BACKGROUND: With the rapid increase in genome sequencing projects for non-model organisms, numerous genome assemblies are currently in progress or available as drafts, but not made available as satisfactory, usable genomes. Data quality assessment of genome assemblies is gaining importance not only for people who perform the assembly/re-assembly processes, but also for those who attempt to use assemblies as maps in downstream analyses. Recent studies of the quality control, quality evaluation/ assessment of genome assemblies have focused on either quality control of reads before assemblies or evaluation of the assemblies with respect to their contiguity and correctness. However, correctness assessment depends on a reference and is not applicable for de novo assembly projects. Hence, development of methods providing both post-assembly and pre-assembly quality assessment reports for examining the quality/correctness of de novo assemblies and the input reads is worth studying. RESULTS: We present SQUAT, an efficient tool for both pre-assembly and post-assembly quality assessment of de novo genome assemblies. The pre-assembly module of SQUAT computes quality statistics of reads and presents the analysis in a well-designed interface to visualize the distribution of high- and poor-quality reads in a portable HTML report. The post-assembly module of SQUAT provides read mapping analytics in an HTML format. We categorized reads into several groups including uniquely mapped reads, multiply mapped, unmapped reads; for uniquely mapped reads, we further categorized them into perfectly matched, with substitutions, containing clips, and the others. We carefully defined the poorly mapped (PM) reads into several groups to prevent the underestimation of unmapped reads; indeed, a high PM% would be a sign of a poor assembly that requires researchers' attention for further examination or improvements before using the assembly. Finally, we evaluate SQUAT with six datasets, including the genome assemblies for eel, worm, mushroom, and three bacteria. The results show that SQUAT reports provide useful information with details for assessing the quality of assemblies and reads. AVAILABILITY: The SQUAT software with links to both its docker image and the on-line manual is freely available at https://github.com/luke831215/SQUAT .

Evaluation of three-dimensional superimposition technique on parietal bone of the puberty beagle dogs.

OBJECTIVES: This study aimed to (a) evaluate the stability of the parietal bone of 6-9 months old beagles and (b) examine whether parietal regional superimposition can provide an atraumatic and effective solution for further maxillary expansion study. MATERIALS AND METHODS: Six prepubertal 6-month-old male beagles were included. Six miniscrew markers were inserted into the left and right sides of the parietal bone, and two of them were placed bilaterally near the palatal suture. The subjects were scanned with cone beam computed tomography (CBCT) at three time points of T0 (6 months old), T1 (7.5 months old) and T2 (9 months old), respectively. All skull models were analyzed by both the miniscrew superimposition and the parietal regional superimposition. RESULTS: The two superimposition methods had no significant difference (p > 0.05) in displacements of miniscrew markers between left and right first premolars (PM1). The maxillary superimposition between T0 and T2 indicated that the length and width of the maxillary as well as the width of the zygoma root increased significantly (p < 0.05), while the height of maxillary had no significant difference (p > 0.05) over the 3 months. CONCLUSIONS: The parietal bone is relatively stable for beagles from 6 months old to 9 months old and thus can be used as a reference region for 3D skull model superimposition of the beagle dog.

Asymmetric Dental Development Investigated by Cone-Beam Computed Tomography in Patients With Unilateral Cleft Lip and Alveolus.

OBJECTIVE: To investigate a possible delay in dental development of cleft-side teeth compared with the contralateral teeth in patients with unilateral cleft lip and alveolus with or without cleft palate (UCLA ± CP) and to correlate this delay to developmental stages of the corresponding teeth. DESIGN: Cross-sectional study. SETTING: Cleft Lip and Palate Care Center of Shanghai Ninth People's Hospital, Shanghai, China. PATIENTS: Forty Chinese patients with UCLA ± CP. MAIN OUTCOME MEASURE: Crown height (CH), root length (RL), and full length (FL) of permanent incisors, canines, premolars, and first molars were measured using cone-beam computed tomography and compared between cleft and noncleft sides. Discrepancies in tooth length between sides during different developmental stages of delayed teeth were also compared. RESULTS: There were no statistically significant differences in tooth length between sides in the mandible, except for RL of lateral incisors and RL and FL of the second premolars. In the maxilla, CH, RL and FL of cleft-side incisors, as well as RL and FL of cleft-side canines and first premolars, were all significantly shorter than those on the noncleft side (P < .05). The lateral incisors showed the highest reductions in RL and FL (47% and 29%). Moreover, reduction of RL of cleft-side maxillary central incisors was most evident in the early developmental stage (23%) and decreased with dental maturation (5%). CONCLUSIONS: Asymmetric dental development was presented in both jaws but mainly in maxillary anterior region. The RL deficiency of cleft-side central incisors differed at different developmental stages.

Correction of Deep Overbite by Using a Modified Nance Appliance in an Adult Class II Division 2 Patient with Dehiscence Defect.

A modified Nance Appliance (MNA) is introduced as a treatment option for an adult class II division 2 malocclusion (CII/2) patient with deep overbite and dehiscence on the facial root surface of retroclined upper incisors through the cone-beam computed tomography (CBCT). Indications for this modified MNA as well as a brief description of fabrication procedure and biomechanical analysis of the treatment effects are shown in detail. Root control and absolute intrusion without enlarging the bony defect were achieved. The treatment results were satisfying and favorable.

A cone-beam computed tomography evaluation of facial asymmetry in unilateral cleft lip and palate individuals.

Our study aimed to examine facial asymmetry in patients with unilateral cleft lip and palates (UCLP) using cone-beam computed tomography (CBCT) and explore the factors responsible for lower facial asymmetry in these individuals. The experimental group included 21 adolescent patients with non-syndromic UCLP while the control group comprised 14 patients without any facial cleft defects. The maxillofacial regions of the patients in the two groups were scanned using CBCT, and the Mimics 10.01 software was used to analyze the images. Multiple linear stepwise regression analysis was used to explore the factors related to the deviation of the pogonion point (Pog). Comparison of the two groups showed that the position of the lateral point of the pyriform aperture and the length of the mandibular body exhibited significant asymmetry (P < 0.05). Pog in the UCLP group deviated to the cleft side (1.24 ± 2.28 mm), and was related to B6L(R) to Sagittal plane, CdL(R) to Sagittal plane, and U6L(R) to LS plane. We concluded that significant differences between the cleft and non-cleft sides existed only around the cleft, and not in the deeper regions of the maxillary complex. Functional adaption may be the main reason responsible for chin deviation in UCLP individuals. (J Oral Sci 58, 109-115, 2016).