Three-Dimensional Facial Soft Tissue Changes After Orthognathic Surgery in Cleft Patients Using Artificial Intelligence-Assisted Landmark Autodigitization.

ABSTRACT: The purpose of this study was to investigate three-dimensional facial soft tissue changes after bimaxillary orthognathic surgery (BOGS) in patients with cleft lip and palate. The samples consisted of 34 Korean young adult patients with skeletal class III malocclusion who underwent BOGS for maxillary advancement/posterior impaction and mandibular setback. They were divided into cleft-class III (C-CIII) group (n = 18) and noncleft-class III (NC-CIII) group (n = 16). Three-dimensional computed tomography images were taken 1 month before (T1) and 3 months after (T2) surgery. After 34 hard/soft tissue landmarks were automatically identified using software, the amount and direction of change in landmarks and the amount of change in 16 soft tissue variables during T1-T2 were calculated. Then, statistical analysis was performed. Compared to NC-CIII group, C-CIII group showed more posteriorly-positioned hard/soft tissue landmarks, larger alar width, alar base width and philtrum width, and more obtuse nasal tip angle at both T1 and T2 stages. C-CIII group exhibited higher soft-to-hard tissue movement ratios at the bottom of the nose (ΔSn/ΔANS, 1.08 versus 0.81) and the upper part of the upper lip (ΔPoint A'/ΔPoint A, 1.08 versus 0.91), but a lower ratio at the lower part of the upper lip (ΔLs'/ΔIs, 0.72 versus 1.01) than NC-CIII group. The number of hard-soft tissue landmarks with high correlation (>0.90) was smaller in C-CIII group than in NC-CIII group (2 versus 6). Scar tissues and abnormal muscles in the nose and upper lip might elicit different responses in the nasolabial soft tissues to BOGS between C-CIII and NC-CIII patients.

What Are the Contributing Factors for Postsurgical Relapse After Two-Jaw Surgery in Patients With Cleft Lip and Palate.

The purpose of this study was to investigate the amount and pattern of postsurgical relapse after 2-jaw surgery in cleft lip and palate patients in terms of the sagittal and vertical aspects. The samples consisted of 21 adult patients who had the similar initial skeletodental pattern before surgery and underwent 2-jaw surgery. They were divided into high relapse (n = 11) and low relapse groups (n = 10) (criteria, 30% forward relapse of the B point). After the cephalometric variables of cephalograms taken at 1 month before surgery (T0), immediately after surgery (T1), and at least 1 year after surgery (T2) were measured, the Wilcoxon test, Mann-Whitney U test, and Pearson correlation test were performed for statistical analysis. When compared with the low relapse group, the high relapse group exhibited significant counterclockwise rotation of the distal segment of the mandible resulting in more forward movement of the mandible and significant labioversion of the maxillary incisors during T1-T2. The amount of postsurgical relapse of the mandible had a positive relationship with the amounts of setback and clockwise rotation of the mandible with surgery. In addition, the more decrease in overbite through surgery occurred, the more relapse (forward movement of the mandible) produced. Therefore, for the prevention of significant postsurgical relapse of the mandible in cleft patients, it is necessary to reduce unnecessary clockwise rotation of the mandible and to increase the vertical stability of maxilla during orthognathic surgery.

Three-dimensional virtual-surgery simulation-assisted asymmetric bilateral mandibular distraction osteogenesis for a patient with bilateral condylar fractures.

INTRODUCTION: Our objective was to report a patient treated with 3-dimensional virtual-surgery simulation-assisted asymmetric bilateral mandibular distraction osteogenesis. METHODS: A boy (age, 9.5 years) had mandibular hypoplasia and facial asymmetry, induced by bilateral condylar fractures at 4 years of age. The asymmetric bilateral mandibular distraction osteogenesis was planned to correct facial asymmetry and mandibular hypoplasia. The 3-dimensional virtual-surgery simulation results were 11 mm of horizontal distraction on the right side and 4.5 mm of horizontal and 18 mm of vertical distraction on the left side of the mandible. Bilateral ramus osteotomies were performed, and intraoral unidirectional distraction devices were inserted. After a 6-day latency period, distraction was performed at 1 mm per day, followed by a 5-month consolidation period. Transarch and interarch elastics and an acrylic plate were used during distraction and consolidation. Total treatment time was 30 months. RESULTS: Satisfactory outcomes were obtained (achievement ratios between postconsolidation results and simulated results: gonial angle, 106% and 103.9%; mandibular body length, 94.2% and 89.9%; ramus height, 104.1% and 94.5% [values of the right and left sides, respectively]). The chin-point deviation and the transverse cant of the maxillary occlusal plane were significantly improved (10.1 mm to 3.3 mm; -6.8° to -4.4°). At 53 months of follow-up, the Class I molar relationship was well maintained. The transverse cant of the maxillary occlusal plane was slightly improved to -3.7° during pubertal growth. CONCLUSIONS: Three-dimensional virtual-surgery simulation can help clinicians to determine the optimal vector and amount of distraction with high accuracy in complex cases requiring simultaneous correction of a hypoplastic mandible and facial asymmetry.

Effect of Secondary Alveolar Bone Grafting on the Maxillary Growth: Unilateral Versus Bilateral Cleft Lip and Palate Patients.

The purpose of this study was to investigate the effect of secondary alveolar bone grafting (SABG) on the maxillary growth in patients with unilateral (UCLP) and bilateral cleft lip and palate (BCLP). The samples consisted of 40 Korean boy cleft patients who had the similar initial skeletal characteristics and were treated with the identical treatment protocol. They were divided into UCLP group (N = 25; mean SABG age, 9.9 years; mean follow-up duration, 42.3 months) and BCLP group (N = 15; mean SABG age, 10.2 years; mean follow-up duration, 40.6 months). In the lateral cephalograms taken 1 month before (T1) and at least 2 years after SABG (T2), cephalometric variables were measured. At T1 stage, the 2 groups did not exhibit significant differences in the cephalometric variables except posterior maxillary height (P-HRP) (P < 0.05). At T2 stage, both groups exhibited the reduced sagittal growth (UCLP, ANB, P < 0.001; AB to facial plane angle (AB-FPA), P < 0.01; BCLP, A to N perpendicular, P < 0.05; ANB and AB-FPA, P < 0.001) and the undisturbed vertical growth (A-HRP and P-HRP, all P < 0.001) of the maxilla. During T1 to T2, BCLP group experienced more aggravation of Class III skeletal pattern than UCLP group (ΔAB-FPA, P < 0.05). There, however, were no differences in the amounts of changes in the maxillary vertical position and mandibular plane angulation between the 2 groups. Two-stage SABG procedure subgroup in patients with BCLP demonstrated a more retrusive maxilla compared with 1-stage SABG procedure subgroup (ΔSNA, P < 0.05). Patients with BCLP, especially who underwent 2-stage SABG procedure, might have a possibility of poor sagittal growth of the maxilla compared with patients having UCLP.

Repression of TNF-alpha-induced IL-8 expression by the glucocorticoid receptor-beta involves inhibition of histone H4 acetylation.

Increased expression of a number of proinflammatory genes, including IL-8, is associated with inflammatory conditions such as asthma. Glucocorticoid receptor (GR)beta, one of the GR isoforms, has been suggested to be upregulated in asthma associated with glucocorticoid insensitivity and to work as a dominant negative inhibitor of wild type GRalpha. However, recent data suggest that GRbeta is not a dominant negative inhibitor of GRalpha in the transrepressive process and has its own functional role. We investigated the functional role of GRbeta expression in the suppressive effect of glucocorticoids on tumor necrosis factor (TNF)-alpha-induced IL-8 release in an airway epithelial cell line. GRbeta expression was induced by treatment of epithelial cells with either dexamethasone or TNF-alpha. GRbeta was able to inhibit glucocorticoid-induced transcriptional activation mediated by binding to glucocorticoid response elements (GREs). The suppressive effect of dexamethasone on TNF-alpha-induced IL-8 transcription was not affected by GRbeta overexpression, rather GRbeta had its own weak suppressive activity on TNF-alpha-induced IL-8 expression. Overall histone deacetylase activity and histone acetyltransferase activity were not changed by GRbeta overexpression, but TNF-alpha-induced histone H4 acetylation at the IL-8 promoter was decreased with GRbeta overexpression. This study suggests that GRbeta overexpression does not affect glucocorticoid-induced suppression of IL-8 expression in airway epithelial cells and GRbeta induces its own histone deacetylase activity around IL-8 promoter site.