Assessment and Identification of Improvement Areas for Facial Symmetry in Hemifacial Microsomia (Type IIB) Using Three-dimensional Measurements.

Background: Surgical planning for hemifacial microsomia (HFM) patients often involves planning the amount of maxillary movement and mandibular bone distraction from three-dimensional (3D) volumetric images constructed from computed tomography scans. By representing anatomical indicators for facial symmetry in X, Y, and Z coordinates, we identified the more challenging areas in correcting facial asymmetry. Methods: The study included five HFM patients with a mean age of 22.2 years, all diagnosed with HFM (type IIB). We established measurement points with high reproducible 3D coordinates on the 3D volumetric images obtained from computed tomography scans for before surgery, treatment objectives, and after surgery. We assessed the symmetry of measurement points between the affected side and nonaffected side at each time point. Results: In the before-surgery group, significant differences were observed between the affected side and nonaffected side in X,Y (excluding Palatine foramen, upper molar, canine) and Z coordinates for measurement items. In the treatment objectives group, no differences were observed between the affected side and nonaffected side in X, Y, and Z coordinates, resulting in facial symmetry. In the after-surgery group, significant differences were observed in Y coordinates in the mental foramen area, and significant differences were observed in z axis measurement items in the canine and mental foramen areas. Conclusions: It is evident that relying solely on a front view assessment is insufficient to achieve facial symmetry. Particularly, both anterior-posterior and vertical improvements in the area near the mental foramen on the affected side are necessary.

Mechanical stress-induced FGF-2 promotes proliferation and consequently induces osteoblast differentiation in mesenchymal stem cells.

Mechanical stimuli serve as crucial regulators of bone mass, promoting bone formation. However, the molecular mechanisms governing how mesenchymal stem cells (MSCs) respond to mechanical cues during their differentiation into osteogenic cells remain elusive. In this study, we found that cyclic stretching enhances MSC proliferation but does not increase the expression of osteoblast-related genes. We further revealed that this proliferative effect is mediated by fibroblast growth factor 2 (FGF-2), synthesized by MSCs in response to mechanical stress. Cell proliferation induced by cyclic stretching was inhibited upon the addition of either U0126, an inhibitor of mitogen-activated protein kinase kinase (MEK), or early growth response 1 (EGR1)-targeting small-hairpin RNA (shRNA), indicating the involvement of the extracellular signal-regulated kinase (ERK)/EGR1 signaling pathway. Osteoblast differentiation, evaluated through ALP activity, osteoblast-related gene expression, and mineralization, was stimulated by recombinant human FGF-2 (rhFGF-2) when applied during the proliferation phase, but not when applied during the differentiation stage alone. Our results suggest that FGF-2 indirectly promotes osteoblast differentiation as a downstream effect of stimulating cell proliferation. For the first time, we demonstrate that cyclic stretching induces MSCs to produce FGF-2, which in turn encourages cell proliferation through an autocrine/paracrine mechanism, consequently leading to osteoblast differentiation.

Incidence of Otalgia After Orthognathic Surgery.

BACKGROUND: In orthognathic surgery, it is well known that maxillary osteotomies and displacements sometimes affect auditory function. Thus, this study examined the relationship between the direction of maxillary displacement and postoperative otalgia. METHODS: Twenty consecutive patients underwent Le Fort I maxillary osteotomy using advancement, impaction, setback, or a combination of these procedures. The direction of movement and incidence of otalgia were investigated. Patients provided informed consent preoperatively, and postoperative reassurance was prudent. RESULTS: Pure-tone average evaluation based on horizontal or vertical movements did not show significant differences, although vertical movements resulted in fewer changes in the hearing threshold. Specifically, no significant changes were observed in the hearing thresholds of patients after surgery. No significant difference was also observed between horizontal and vertical movements in the tympanometry results. Negative changes were found in the results of the Eustachian tube dysfunction test in vertical movements, which returned to preoperative values in the final test. CONCLUSIONS: The risk of minor changes in hearing function is probable during the first week after orthognathic surgery; however, these negative changes either completely disappear or remain negligible.

Soluble Sema4D cleaved from osteoclast precursors by TACE suppresses osteoblastogenesis.

Bone remodelling is mediated by orchestrated communication between osteoclasts and osteoblasts which, in part, is regulated by coupling and anti-coupling factors. Amongst formally known anti-coupling factors, Semaphorin 4D (Sema4D), produced by osteoclasts, plays a key role in downmodulating osteoblastogenesis. Sema4D is produced in both membrane-bound and soluble forms; however, the mechanism responsible for producing sSema4D from osteoclasts is unknown. Sema4D, TACE and MT1-MMP are all expressed on the surface of RANKL-primed osteoclast precursors. However, only Sema4D and TACE were colocalized, not Sema4D and MT1-MMP. When TACE and MT1-MMP were either chemically inhibited or suppressed by siRNA, TACE was found to be more engaged in shedding Sema4D. Anti-TACE-mAb inhibited sSema4D release from osteoclast precursors by ~90%. Supernatant collected from osteoclast precursors (OC-sup) suppressed osteoblastogenesis from MC3T3-E1 cells, as measured by alkaline phosphatase activity, but OC-sup harvested from the osteoclast precursors treated with anti-TACE-mAb restored osteoblastogenesis activity in a manner that compensates for diminished sSema4D. Finally, systemic administration of anti-TACE-mAb downregulated the generation of sSema4D in the mouse model of critical-sized bone defect, whereas local injection of recombinant sSema4D to anti-TACE-mAb-treated defect upregulated local osteoblastogenesis. Therefore, a novel pathway is proposed whereby TACE-mediated shedding of Sema4D expressed on the osteoclast precursors generates functionally active sSema4D to suppress osteoblastogenesis.

Vertical Vibration of Mouse Osteoblasts Promotes Cellular Differentiation and Cell Cycle Progression and Induces Aging In Vitro.

BACKGROUND: This study aimed to investigate the effect of the vibration of osteoblasts on the cell cycle, cell differentiation, and aging. MATERIALS AND METHODS: Primary maxilla osteoblasts harvested from eight-week-old mice were subjected to vibration at 3, 30, and 300 Hz once daily for 30 min; control group, 0 Hz. A cell proliferation assay and Cell-Clock Cell Cycle Assay were performed 24 h after vibration. Osteoblast differentiation assay, aging marker genes, SA-ß-Gal activity, and telomere length (qPCR) were assayed two weeks post- vibration once every two days. RESULTS: Cell proliferation increased significantly at 30 and 300 Hz rather than 0 Hz. Several cells were in the late G2/M stage of the cell cycle at 30 Hz. The osteoblast differentiation assay was significantly higher at 30 Hz than at 0 Hz. Runx2 mRNA was downregulated at 30 Hz compared to that at 0 Hz, while osteopontin, osteocalcin, and sclerostin mRNA were upregulated. p53/p21, p16, and c-fos were activated at 30 Hz. SA-ß-Gal activity increased significantly at 30 or 300 Hz. Telomere length was significantly lower at 30 or 300 Hz. CONCLUSIONS: The results suggest that providing optimal vibration to osteoblasts promotes cell cycle progression and differentiation and induces cell aging.

Influence of Lip Revision Surgery on Facial Growth in Patients With A Cleft Lip.

Although patients with cleft lip and palate often present with poor maxillary growth because of intrinsic and iatrogenic factors, the surgical influence of lip revision surgery, palatal fistula repair, and pharyngeal flap procedures remains uncertain in contrast to that of primary cleft lip repair and palatoplasty. Therefore, this study aimed to reveal factors inhibiting maxillary growth and inducing later orthognathic surgery. A retrospective analysis was conducted on the data of patients with cleft lip and palate who underwent a series of treatments at Keio University Hospital from 1990 to 2000. We collected data on patient sex, cleft type, number and timing of lip revision surgery, the incidence of palatal fistulae, history of pharyngeal flap procedures, and timing of a repeat bone graft, and reviewed whether these patients underwent orthognathic surgery later in life. Multivariate analysis was conducted using binary logistic regression to extract factors affecting later orthognathic surgery. A total of 52 patients were included in this study. Results showed that revision surgery conducted more than twice was the highest statistically significant predictor of later orthognathic surgery in patients with a cleft lip and palate ( P <0.05, odds ratio=43.3), followed by palatal fistula occurrence after cleft palate repair ( P <0.05, odds ratio=22.3). Therefore, primary surgical procedure is most important for these patients.

An Elderly Patient With Crouzon Syndrome Treated With Monobloc Distraction.

Monobloc advancement by distraction osteogenesis is the treatment of choice in patients with syndromic craniosynostosis. This procedure is usually performed at 18 to 24 months/5 to 10 years of age. Herein, we present the case of a male patient with Crouzon syndrome who underwent monobloc advancement at the age of 62 years. Although the patient lived a normal life (employed, married, and being a father of a daughter), he visited our hospital for surgical improvement in facial esthetics. The patient underwent monobloc advancement by distraction osteogenesis. He was satisfied with the postoperative esthetic improvement and did not experience any major complications. This case highlights the fact that patients with syndromic craniosynostosis desire esthetic improvement and suggests that multidisciplinary treatment involving both the neuro and plastic surgeons is important in such cases.

Semaphorin 3A regulates alveolar bone remodeling on orthodontic tooth movement.

Semaphorin 3A (Sema3A) promotes osteoblast differentiation and inhibits osteoclast differentiation. In the present study, we observed the regulation of alveolar bone remodeling by Sema3A during orthodontic tooth movement (OTM). Four inflammatory cytokines (IL-1ß, IL-6, TNFα, and INF-γ) involved in OTM were applied to osteoblasts in vitro, and Sema3A expression was determined by reverse-transcription quantitative polymerase chain reaction (RT-qPCR). In vivo, springs were attached to the maxillary first molars of C56BL/6J mice (OTM model) and the localization of Sema3A was confirmed by immunofluorescent. Recombinant Sema3A (rSema3A) was locally injected into the OTM model. Inflammatory cytokine localization in the OTM model was confirmed by immunohistochemistry. In vivo, more Sema3A was observed on the tension side in the OTM group. Injection of rSema3A into the OTM model increased mineralization on the tension side and decreased the number of osteoclasts on the compression side. In vitro, IL-1ß significantly increased Sema3A mRNA levels. Immunohistochemistry for IL-1ß in vivo showed more concentrated staining in the periodontal ligament on the tension side than on the compression side. In summary, our findings revealed the distribution of Sema3A in the periodontal ligament and demonstrated that rSema3A administration promotes bone formation and inhibits bone resorption during OTM.

Quercetin Reduces the Development of 2,3,7,8-Tetrachlorodibenzo-p-dioxin-Induced Cleft Palate in Mice by Suppressing CYP1A1 via the Aryl Hydrocarbon Receptor.

Quercetin is a flavonoid with a wide range of pharmacological activities, including anticancer, antioxidant, and anti-inflammatory effects. Since it is a nutrient that can be consumed with a regular diet, quercetin has recently garnered interest. Quercetin acts as a phytochemical ligand for the aryl hydrocarbon receptor (AhR). Cleft lip and palate are among the most frequently diagnosed congenital diseases, and exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during pregnancy induces cleft palate via AhR. In this study, we investigated the preventive effect of quercetin intake on the TCDD-induced cleft palate and its mechanism of action. The in vivo results suggest that quercetin intake by pregnant mice can prevent cleft palate in fetal mice. In vitro, the addition of TCDD induced a reduction in cell migration and the proliferation of mouse embryonic palatal mesenchymal cells, which was mitigated by the addition of quercetin. The addition of quercetin did not alter the mRNA expression levels of the AhR repressor but significantly suppressed mRNA expression of CYP1A1. In addition, the binding of AhR to a xenobiotic responsive element was inhibited by quercetin, based on a chemically activated luciferase expression assay. In conclusion, our results suggest that quercetin reduces the development of TCDD-induced cleft palate by inhibiting CYP1A1 through AhR.

Locally Secreted Semaphorin 4D Is Engaged in Both Pathogenic Bone Resorption and Retarded Bone Regeneration in a Ligature-Induced Mouse Model of Periodontitis.

It is well known that Semaphorin 4D (Sema4D) inhibits IGF-1-mediated osteogenesis by binding with PlexinB1 expressed on osteoblasts. However, its elevated level in the gingival crevice fluid of periodontitis patients and the broader scope of its activities in the context of potential upregulation of osteoclast-mediated periodontal bone-resorption suggest the need for further investigation of this multifaceted molecule. In short, the pathophysiological role of Sema4D in periodontitis requires further study. Accordingly, attachment of the ligature to the maxillary molar of mice for 7 days induced alveolar bone-resorption accompanied by locally elevated, soluble Sema4D (sSema4D), TNF-α and RANKL. Removal of the ligature induced spontaneous bone regeneration during the following 14 days, which was significantly promoted by anti-Sema4D-mAb administration. Anti-Sema4D-mAb was also suppressed in vitro osteoclastogenesis and pit formation by RANKL-stimulated BMMCs. While anti-Sema4D-mAb downmodulated the bone-resorption induced in mouse periodontitis, it neither affected local production of TNF-α and RANKL nor systemic skeletal bone remodeling. RANKL-induced osteoclastogenesis and resorptive activity were also suppressed by blocking of CD72, but not Plexin B2, suggesting that sSema4D released by osteoclasts promotes osteoclastogenesis via ligation to CD72 receptor. Overall, our data indicated that ssSema4D released by osteoclasts may play a dual function by decreasing bone formation, while upregulating bone-resorption.

Dual-Function Semaphorin 4D Released by Platelets: Suppression of Osteoblastogenesis and Promotion of Osteoclastogenesis.

Effects of the antiosteoblastogenesis factor Semaphorin 4D (Sema4D), expressed by thrombin-activated platelets (TPs), on osteoblastogenesis, as well as osteoclastogenesis, were investigated in vitro. Intact platelets released both Sema4D and IGF-1. However, in response to stimulation with thrombin, platelets upregulated the release of Sema4D, but not IGF-1. Anti-Sema4D-neutralizing monoclonal antibody (mAb) upregulated TP-mediated osteoblastogenesis in MC3T3-E1 osteoblast precursors. MC3T3-E1 cells exposed to TPs induced phosphorylation of Akt and ERK further upregulated by the addition of anti-sema4D-mAb, suggesting the suppressive effects of TP-expressing Sema4D on osteoblastogenesis. On the other hand, TPs promoted RANKL-mediated osteoclastogenesis in the primary culture of bone-marrow-derived mononuclear cells (BMMCs). Among the known three receptors of Sema4D, including Plexin B1, Plexin B2 and CD72, little Plexin B2 was detected, and no Plexin B1 was detected, but a high level of CD72 mRNA was detected in RANKL-stimulated BMMCs by qPCR. Both anti-Sema4D-mAb and anti-CD72-mAb suppressed RANKL-induced osteoclast formation and bone resorptive activity, suggesting that Sema4D released by TPs promotes osteoclastogenesis via ligation to a CD72 receptor. This study demonstrated that Sema4D released by TPs suppresses osteogenic activity and promotes osteoclastogenesis, suggesting the novel property of platelets in bone-remodeling processes.

A Case of Orthodontic Treatment for Generalized Aggressive Periodontitis.

Aggressive periodontitis mostly affects young people, causing rapid destruction of periodontal tissue and loss of supporting alveolar bone. The destruction of periodontal tissue induces pathological tooth movement, resulting in various types of malocclusion such as crowding or spacing in the dentition. This report describes orthodontic treatment for malocclusion due to generalized aggressive periodontitis. The patient was a 31-year-old woman who presented with the chief complaint of displacement in the anterior teeth. An oral examination revealed pathological tooth mobility throughout the entire oral cavity due to severe loss of periodontal support. Many gaps in the displaced maxillary anterior teeth and crowding in the mandibular anterior teeth were also observed. The goal of subsequent treatment was to achieve ideal overjet and overbite by aligning the teeth and closing the spaces via non-extraction orthodontic treatment with stripping. The periodontal disease was managed by a periodontist who provided guidance on oral hygiene and periodontal disease control throughout the course of orthodontic treatment. Appropriate occlusion and a good oral environment were achieved. The condition of the periodontal tissue stabilized during and after orthodontic treatment, and favourable occlusal stability was observed at the 2-year follow-up examination.

A Case of Mandibular Prognathism with Generalized Aggressive Periodontitis and Crowding.

Aggressive periodontitis during adolescence has a poor prognosis due to rapid alveolar bone resorption. Few studies have investigated long-term follow-up after surgical orthodontic treatment performed in conjunction with that for invasive periodontitis. Here, we report a case of mandibular prognathism accompanied by generalized aggressive periodontitis and crowding. A 31-year-old woman was referred to our department for treatment of masticatory dysfunction due to reverse overjet. The patient exhibited a class III molar relationship, protrusion of the ANB of －6.0°, and severe maxillary crowding. Initial periodontal examination revealed deep periodontal pockets and extensive inflammation. Mandibular prognathism accompanied by generalized aggressive periodontitis and crowding was diagnosed. Therefore, it was necessary to adopt an interdisciplinary approach involving surgical, orthodontic, and periodontal treatment. Prior to commencement of orthodontic treatment, plaque control, scaling, and root planing of all teeth were performed by a periodontist to suppress inflammation and reduce probing depth. During pre-surgical orthodontic treatment, the maxillary first premolars were extracted to reduce crowding of the maxillary incisors. To correct the mandibular prognathism, the mandible was repositioned by sagittal split ramus osteotomy. Proper occlusion of the incisors and maximum intercuspation were achieved by post-surgical orthodontic treatment. After completion of active orthodontic treatment, acceleration of inflammation was observed together with aggravated resorption of the alveolar bone surrounding the molars. However, reduction of probing depth and inflammation were observed after scaling and root planing. The surgical-orthodontic treatment time was 1 year and 11 months, which was followed by a 2-year retention period. There was no tooth loss due to periodontitis, and an overall satisfactory outcome was achieved.

The Effects of Fluvastatin on Indian Hedgehog Pathway in Endochondral Ossification.

Statins have demonstrated to be effective for treating chondrodysplasia and its effects were believed to be associated with the fibroblast growth factor receptor 3 (FGFR3). Statins promoted the degradation of FGFR3 in studies using disease-specific induced pluripotent stem cells and model mice, however, recent studies using normal chondrocytes reported that statins did not degrade FGFR3. In order to further investigate the effects of statins in endochondral ossification, this study examined the influence of statins on Indian hedgehog (Ihh), another important component of endochondral ossification, and its related pathways. The chondrocyte cell line ATDC5 was used to investigate changes in cell proliferation, mRNA, and protein expression levels. In addition, an organ culture of a mouse metatarsal bone was performed followed by hematoxylin-eosin staining and fluorescent immunostaining. Results indicated that expression level of Ihh increased with the addition of statins, which activated the Ihh pathway and altered the localization of Ihh. Changes in cholesterol modification may have affected Ihh diffusibility; however, further experiments are necessary. A reactive increase in parathyroid hormone-related protein (PTHrP) was observed in addition to changes in the Wnt pathway through secreted-related protein 2/3 and low-density lipoprotein 5/6. This led to the promotion of cell proliferation, increase of the hypertrophic chondrocyte layer, inhibition of apoptosis, and decrease in mineralization. This study demonstrated that statins had an influence on Ihh, and that the hyperfunction of Ihh may prevent premature cell death caused by FGFR3-related chondrodysplasia through an indirect increase in the expression of PTHrP.

Overload of the Temporomandibular Joints Accumulates γδ T Cells in a Mouse Model of Rheumatoid Arthritis: A Morphological and Histological Evaluation.

Recently, it has been reported that γδ T cells are associated with the pathology of rheumatoid arthritis (RA). However, there are many uncertainties about their relationship. In this study, we investigated the morphological and histological properties of peripheral as well as temporomandibular joints (TMJ) in a mouse model of rheumatoid arthritis with and without exposure to mechanical strain on the TMJ. Collagen antibody-induced arthritis (CAIA) was induced by administering collagen type II antibody and lipopolysaccharide to male DBA/1JNCrlj mice at 9-12 weeks of age, and mechanical stress (MS) was applied to the mandibular condyle. After 14 days, 3D morphological evaluation by micro-CT, histological staining (Hematoxylin Eosin, Safranin O, and Tartrate-Resistant Acid Phosphatase staining), and immunohistochemical staining (ADAMTS-5 antibody, CD3 antibody, CD45 antibody, RORγt antibody, γδ T cell receptor antibody) were performed. The lower jawbone was collected. The mandibular condyle showed a rough change in the surface of the mandibular condyle based on three-dimensional analysis by micro-CT imaging. Histological examination revealed bone and cartilage destruction, such as a decrease in chondrocyte layer width and an increase in the number of osteoclasts in the mandibular condyle. Then, immune-histological staining revealed accumulation of T and γδ T cells in the subchondral bone. The temporomandibular joint is less sensitive to the onset of RA, but it has been suggested that it is exacerbated by mechanical stimulation. Additionally, the involvement of γδ T cells was suggested as the etiology of rheumatoid arthritis.

Three-Dimensional Measurements of Pharyngeal Airway in Patients with Unilateral Cleft Lip and Palate.

The aim of this study was to investigate 3-dimensional (3D) airway volume in patients with unilateral cleft lip and palate (UCLP) using computed tomography (CT). The study population comprised 15 UCLP patients (UCLP group) scheduled to receive alveolar bone grafts and 15 with impacted teeth (control group). The clinical requirements for a CT scan were met in both groups. Measurements were recorded from 3D reconstructions of Digital Imaging and Communications in Medicine data obtained from the CT images. Airway volume, cross-sectional area, and linear and angular measurements were recorded. Airway volume and cross-sectional area showed no significant difference between the two groups. The narrowest section of the airway in the UCLP group was tighter than that in the control group, however (p=0.017). The results of this study suggest that this difference in the measurements of the narrowest section of the airway is involved in the particular maxillofacial morphology found in UCLP patients.

Interdental Distraction Osteogenesis in Unilateral Cleft Lip and Palate Patient with Wide Alveolar Cleft.

Alveolar bone grafting is routinely performed in repair of alveolar clefts. When the alveolar cleft is wider than 11 mm, however, the survival rate of the bone graft and prognosis are poor. Here, we describe successful orthodontic treatment using interdental distraction osteogenesis (IDO) with a tooth-tooth type distractor to reduce the width of the alveolar cleft in a patient with unilateral cleft lip and palate. The patient was a 12-year-old girl with unilateral cleft lip and palate, maxillary dentition midline deviation, congenitally missing maxillary lateral incisors, a palatally-displaced right upper first premolar, a wide alveolar cleft (20 mm), and mandibular prognathism due to maxillary hypoplasia. Treatment comprised a combination of orthodontic treatment and IDO. After treatment, appropriate occlusion, space closure in the maxillary arch, coincidence of the maxillary and facial midlines, and incorporation of the right maxillary first premolar into the arch were obtained. These results suggest that IDO is effective in treating cleft lip and palate patients with a wide alveolar cleft.

Survey on Condition and Orthodontic Treatment of Maxillary Lateral Incisors in Patients with Cleft Lip and Palate.

The aim of this study was to investigate the condition of the maxillary lateral incisors and evaluate the methods used for cleft closure in patients with cleft lip and palate, including the treatment of the maxillary lateral incisors. A total of 214 patients (260 clefts) with alveolar clefts who had started Phase II treatment and entered the maintenance period at the Department of Orthodontics at Tokyo Dental College, Chiba Hospital, between 1975 and 2014 were included. Panoramic, intraoral, and occlusal radiographs, as well as intraoral photographs and medical records, were used to investigate cleft classification, the presence or absence and location of maxillary lateral incisors, and frequency and treatment method for peg lateral incisors in the cleft region. There were more unilateral cleft cases (78.5%) than bilateral cleft cases. The prevalence of congenital absence of the maxillary lateral incisors was similar between unilateral (53.0%) and bilateral cases (53.3%). Peg laterals occurred frequently, with 89.9% occurring in unilateral cases. The maxillary lateral incisors were more commonly found in the secondary than in the primary palate. The number of non-extraction cases was larger than that of extraction cases, regardless of cleft type or the location of the peg laterals. In many cases, the peg laterals were treated with non-extraction and space closure or crown modification. These results suggest that, depending on their condition, the peg laterals should be preserved as much as possible in devising a treatment plan.

Three-Dimensional Evaluation of Change in Maxillary Alveolar Arch after Expansion in Unilateral Cleft Lip and Palate Patients.

Narrowing of the maxillary dental arch is a major cause of occlusal abnormalities in cleft lip and palate patients. Although the dental arch may be expanded in such cases, relapse will often occur during the subsequent retention period. In this study, the stability of expansion of the maxillary arch was investigated by examining 3-dimensional change in the maxillary arch during the treatment and post-retention periods. Three-dimensional measurements was performed on maxillary plaster models obtained from 8 unilateral cleft lip and palate patients (mean age, 12.5 years) who had undergone maxillary arch expansion using an edgewise appliance and quad helix (CLP group). The controls consisted of 8 unilateral cleft lip and alveolus patients (mean age, 12.9 years). Measurements were made during the pretreatment, post-treatment, and post-retention periods. In the CLP group, horizontal relapse was observed in the alveolar and dental arches between the second premolars, together with vertical relapse on the cleft side of the central incisor, lateral incisor, and canine. The sites where relapse occurred demonstrated decreased growth before orthodontic treatment. A correlation was observed between the extents of expansion and relapse. These findings suggest that excessive horizontal or vertical tooth movement in areas showing developmental failure should be avoided in order to increase stability after orthodontic treatment.

Three-dimensional Coordinate System for Hemifacial Microsomia.

BACKGROUND: Hemifacial microsomia (HFM) is a congenital disorder characterized by facial asymmetry, but no midline reference has been established for evaluating facial morphology in patients with HFM. The purpose of this study was to develop a 3-dimensional coordinate system unaffected by the deformity of the external acoustic aperture or orbital circumference and to quantitatively evaluate craniofacial morphology in such patients. METHODS: We quantitatively evaluated craniofacial morphology using 3-dimensional measurements with the skull base as a reference. Using computed tomography data from 15 patients with HFM and 15 controls, a coordinate system was created for each patient, and left-right differences between measurement points were compared. RESULTS: When mandibular deformity was severe, the deformity of the posterior part of the palatine bone and lateral part of the orbit increased, but this trend was not evident for other measurement points. Thus, craniofacial deformity in HFM was not always related to mandibular deformity. Moreover, no difference was evident in the position of the hypoglossal canal between controls and patients with HFM. CONCLUSIONS: Quantitative assessments are possible using the coordinate system devised in this study, irrespective of the severity of HFM. The degree of mandibular deformity detailed in the Pruzansky classification was associated with the superoinferior deformity of the posterior part of the palatine bone and anteroposterior deformity of the lateral part of the orbit.