Would hyaluronic acid-induced mental bone resorption be a concern? A prospective controlled cohort study and an updated retrospective cohort study.

BACKGROUND: Hyaluronic acid (HA) is a widely used filler for face contouring and is generally believed to be safe and effective. However, there have been reports of HA-related bone erosion in the chin area without clear scientific data regarding its existence, incidence, and severity. This exploratory study was to evaluate HA-related mental bone resorption through a prospective, controlled, observer-blind, nonrandomized clinical trial and a retrospective cohort study. METHODS: On the one hand, a prospective, controlled, nonrandomized, single-shot HA-injection clinical trial was conducted. Computed tomographic scans were collected at baseline and at 6-12 months of follow-up for both HA-injection and control groups. On the other hand, an updated retrospective cohort study compared the HA-injection with a blank control group. The primary outcomes composed of three quantitative parameters [bone resorption index (BRI M and BRI N ), bone resorption thickness ratio] and one subjective evaluation index (severity ranking). Information about demographics, complications, and injection volume were also recorded. RESULTS: From June 2021 to March 2023, 78 patients were prospectively recruited for the study. There was a significant association between HA-injection and bone resorption [BRI M : pre (84.24±8.10%) vs post (79.21±8.70%), P <0.001; BRI N : pre 92.50% (73, 144%) vs 87.99% (63, 132%), P <0.001; bone thickness ratio: HA 24.08% (0, 48%) vs control 0 (0, 17%), P <0.001]. However, there was no difference in large-volume (>1 ml) and small-volume (≦1 ml) injection subgroups [bone resorption thickness ratio: (21.50±10.91%) vs (24.51±11.92%), P =0.350]. The imaging manifestation revealed discernible bone resorption in 35.90% of the patients, with an median bone resorption thickness ratio of 24.08%. Between October of 2019 and March 2023, 95 HA-injection patients (190 semimandibular cases), 95 normal controls were enrolled. The BRI M was significantly lower in the HA-injection group compared to the controls ( P <0.001). CONCLUSIONS: HA may induce bone resorption in the mentum. Large-scale randomized controlled clinical trial is warranted for further confirmation. Patients should be informed of this potential complication.

The Influence of Extracellular Vesicles Secreted by Dural Cells on Osteoblasts.

To explore the influence of extracellular vesicles secreted by dural cells (Dura-EVs) on osteoblasts. Our methodology involves assessing the effects of these EVs at concentrations of 50ug/ml, 100ug/ml, and 200ug/ml on osteoblasts proliferation, differentiation, migration, osteogenesis, and inhibition of apoptosis. We also treated a cranial defect model with injections of these Dura-EVs and monitored the healing rate of cranial defects. Tissue sections were analyzed using Hematoxylin and Eosin (H & E), Masson's trichrome, and immunofluorescence (IF) staining. Our results suggest that Dura-EVs can enhance osteoblasts proliferation, migration, differentiation, and osteogenesis in a dose-dependent manner in vitro. In vivo, Dura-EVs may promote the repair of skull defects. Dura-EVs have an important influence on osteoblasts, our findings shed light on a novel aspect of the dura mater's contribution to cranial osteogenesis.

Successful Treatment and Long-term Follow-up of Parry-Romberg Syndrome with Anterolateral Thigh Adipofascial Flap.

BACKGROUND: Anterolateral thigh (ALT) adipofascial free flap transfer is a frequently used method to reconstruct the facial symmetry and restore facial soft-tissue contour in PRS patients. While its long-term prognosis and patient outcomes assessment are still lack of understanding. METHOD: The authors report their treatment experience in 42 patients between 2001 and 2017 using microsurgical free anterolateral thigh adipofascial flap transfer. The long-term follow-up results and final reconstructive outcomes were evaluated. RESULTS: A total of 42 patients were included. The follow-up ranged from 5 to 21 years. All patients were satisfied with the surgery. Photographic evaluation revealed significant enhancement of postoperative appearance. Numbness or hypesthesia of the local area was the most common symptom in the long-term follow up. CONCLUSION: This study has evaluated the long-term treatment results of Parry-Romberg disease with microsurgery using ALT free flap in our department. Over 20 years' experience and the significant enhancement of the overall appearance indicate a long-lasting, excellent outcome.

Redefining Mandibular Sub-units: The "ABC" Classification and Surgical Strategies for Lower Face Contouring.

BACKGROUND: In east Asia, lower face contouring surgeries including reduction mandibuloplasty and genioplasty are the most popular aesthetic craniofacial surgeries. Conventional selection of surgical strategies mainly relied on the visual judgment of the mandibular angle, without overall assessment of the mandibular sub-units. Furthermore, only a few studies offered quantitative assessment of the mandibular shape. METHODS: From 2010 to 2021, 1241 patients diagnosed with square faces and received customized lower face contouring surgeries by the senior author were reviewed and analyzed to propose an "ABC" classification system for facilitating surgical planning. RESULTS: Among them, 998 (80.42%) received bilateral mandible reshaping, 155 (12.49%) underwent bilateral mandible reshaping combined with genioplasty, and 88 (7.09%) received asymmetric mandible reshaping. A modified classification system composed of three critical parameters (height, morphology/thickness, divergence) in three aesthetic zones (mandibular angle, mandibular body, chin) was proposed based on quantitative summarization of the CT database and the senior author's 12-year experience. The way to facilitate surgical planning with this classification was demonstrated. CONCLUSIONS: This modified classification system ushered a decision-making process that prioritized several critical measurements and proposed an operative planning form. Meanwhile, it can also be cooperated into the three-dimensional virtual surgical plan. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Study on the difference of osteogenesis and Notch signaling pathway expression in biphasic calcium-phosphorus ceramic granule materials with different microstructure.

Different microstructures including micropore diameter, micropore volume, and micropore area of biphasic calcium phosphate (BCP, hydroxyapatite: ß-tricalcium phosphate = 8:2) ceramics granules were obtained by varying their sintering temperatures. Sprague-Dawley rat bone marrow-derived stem cells (BMSCs) were co-cultured with BCPs in vitro study and the BMSCs showed different degrees of proliferative activity under the influence of three materials. Cell proliferation and vitality were assessed. Three kinds of BCPs were implanted in the dorsal muscle of beagle dogs. At 1, 2, and 3 months, histological analyses were conducted to estimate the rate of osteogenesis. Expression of Notch pathway genes and osteogenic-related genes were detected by quantitative real-time polymerase chain reaction (q-rtPCR). The proportion of osteogenesis area increased to:48.75 ± 4.20%, 29.48 ± 1.55%, and 26.58 ± 3.86% at 3 months after the implantation (1050, 1150, 1250). Significant differences were observed in the upregulation of Notch pathway genes among different BCPs. BCPs with different micropore diameters have different ectopic osteogenesis effects and led to up-regulation of the Notch signaling pathway genes to different extents.

Surgical Result and Identification of FGFR2 Variants Using Whole-Exome Sequencing in a Chinese Family With Crouzon Syndrome.

ABSTRACT: Crouzon syndrome is considered as one of the most common craniosynostosis syndromes with a prevalence of 1 in 65,000 individuals, and has a close relationship with variants in fibroblast growth factor receptor 2. Here the authors described a Crouzon syndrome case, which was asked for surgery treatment for the symptom of multisuture craniosynostosis. Mild midfacial retrusion, larger head circumference, proptosis, pseudo-prognathism, and dental malposition could also be found obviously. Then fronto-orbital advancement and cranial cavity expansion were performed to the child. After whole-exome sequencing (WES) and Sanger sequencing, gene variants in the exons 2 and 3 of FGFR2 were detected. And protein tyrosine 105 replaced by cysteine in the extracellular region of FGFR2 was also detected. After operation, she presented a satisfactory anterior plagiocephaly and scaphocephaly correction, and the result was satisfied by surgeons and her parents. Variants detected using WES have further research prospect.

Dura cells in the etiopathogenesis of Crouzon syndrome: the effects of FGFR2 mutations in the dura cells on the proliferation of osteoblasts through the hippo/YAP mediated transcriptional regulation pathway.

BACKGROUND: FGFR2 (fibroblast growth factor receptor 2) mutations are implicated in the etiopathogenesis of syndromic craniosynostosis, and C278F- or C342Y-FGFR2 mutations can lead to Crouzon syndrome. The dura mater exerts crucial effects in the regulation of cranial suture development. However, the underlying mechanisms of these biological processes are rarely studied. This research explored and analyzed the biological function of FGFR2 overexpressed by dura cells on cranial osteoblasts. METHODS: Dura cells and cranial osteoblasts from C57BL/6 mice aged 6 days were obtained and cultured respectively. Lentivirus-FGFR2 constructs were engineered with C278F- and C342Y-FGFR2 mutations. The dura cells were infected with the constructs and co-cultured with osteoblasts in a trans-well system. Four experimental groups were established, namely the Oste group, the Oste+Dura-vector group, the Oste+Dura-C278F group, and the Oste+Dura-C342Y group. FACS, CCK8, and EdU assays were used to evaluate the osteoblast proliferation levels. Western blot and RT-qPCR were used to measure the expressions of the factors related to proliferation, differentiation, and apoptosis. Furthermore, the expression levels of the key factors in the Hippo/YAP-PI3K-AKT proliferation pathway were measured and analyzed. Finally, rescue experiments were performed with an RNA interfering assay. RESULTS: The proliferation and differentiation levels of the osteoblasts in the Oste+Dura-C278F and Oste+Dura-C342Y groups were significantly up-regulated, but the apoptosis levels in the four groups were not significantly different. The YAP, TEADs1-4, p-PI3K, and p-AKT1 expressions in the mutant FGFR2 groups were higher than the corresponding expressions in the control groups, and the results of the rescue experiments showed a reverse expression tendency, which further confirmed the effects of the FGFR2 mutations in the dura cells on the proliferation of the osteoblasts and the underlying possible mechanisms. CONCLUSION: Our studies suggest that the Crouzon mutations (C278F- and C342Y-) of FGFR2 in dura cells can enhance osteoblast proliferation and differentiation and might influence the pathogenesis of craniosynostosis by affecting the Hippo/YAP-PI3K-AKT proliferation signaling pathway.

Effect of hydroxyethyl cellulose soluble hemostatic gauze on hemostasis in facial contouring surgery.

BACKGROUND: In facial contour surgery, due to the narrow field of vision in the oral approach and the abundant blood supply to the maxillofacial area, hemostasis is not easy. The purpose of this study was to evaluate the hemostatic effect of soluble hemostatic gauze. METHODS: We organized a prospective randomized study of 282 patients receiving facial contouring surgery (4 types of procedures in total) during 2016.1.1 to 2018.12.30. For each type of procedure, patients were randomly divided into study group (received hemostatic gauze) and control group (received sterile gauze). Two groups were compared for each type of procedure regarding 5 major perioperative variables: intraoperative blood loss, operation time, 24-hour postoperative drainage volume, total postoperative drainage volume, and postoperative drainage time. Correlation between variables was analyzed. RESULTS: Compared with control group, the study group had higher amount of intraoperative blood loss in mandibular angle ostectomy (MAO) (P < .01) and mandibular angle-body-chin curved ostectomy procedures (P < .05), less total postoperative drainage volume in MAO (P < .01) but not in malarplasty with MAO and partial masseter muscle resection along with MAO procedures. No significant difference was observed between respective study and control groups regarding operation time, 24-hour postoperative drainage volume, and postoperative drainage time in any of the 4 types of surgery. In all 4 types of procedures, a strongly positive correlation was observed between total drainage volume and 24-hour drainage volume in both the study and control groups (r: 0.88-0.97, P < .01). CONCLUSION: The effect of hydroxyethyl cellulose soluble hemostatic gauze on hemostasis in facial contouring surgery is associated with the type of surgery, which can reduce the risk of postoperative bleeding in MAO. However, for surgery with relatively large amount of intraoperative and postoperative bleeding, the hemostatic gauze had a limited postoperative hemostasis efficacy, which needs further evaluation.

A Modified Procedure for Single-eyelid Asian Females with Lacrimal Gland Prolapse: Lacrimal Gland Reposition combined with Fat Transposition in Double-eyelid Operation.

BACKGROUND: The awareness and treatment of lacrimal gland prolapse (LGP) have been primarily improved with a further understanding of lateral eyelid bulging over the decades. However, for Asian single-eyelid females with LGP, a tailor-made procedure applicable to their comparatively young puffy eyes is needed. METHODS: This is a retrospective study. From Jan. 2009 to Jan. 2019, two hundred and three Asian single-eyelid females with LGP, who met the inclusion criteria, underwent double-eyelid surgeries and adjunctive lacrimal gland repositions with preaponeurotic fat transposition. Pertinent demographics, complications, pre-and post-operative photography were collected. RESULTS: A total of 167 patients completed the 4-24 months' follow-up (average: 16.3 months). One hundred and thirty-two cases (79.0%) were diagnosed as LGP preoperatively, and the rest (35/167, 21.0%) were diagnosed intraoperatively. All patients (average: 28.4 years old) received modified blepharoplasty. Postoperative symptoms involving local mild pain (2.9%, 5/167), upper eyelid tightness (3.6%, 6/167), and moderate epiphora (9.0%, 15/167) were all recovered spontaneously within one month. Prolapse recurrence and severe complications such as dry eye syndrome were not observed. CONCLUSIONS: We proposed a modified procedure to enhance the diagnosis and treatment of LGP during Asian blepharoplasty. The lacrimal gland suspension and fat transposition assured the cosmetic outcome for selected young, puffy Asian eyes. The supratarsal creases were satisfactory, and the complication rate was low. Furthermore, the rearrangement of preaponeurotic fat smoothed the contour transition and preserved the orbital volume. Therefore, this is a safe and effective technique worth recommending.

Facial Contour Refining after Surgery-First SSRO with Computer-Assisted Design in East Asians.

BACKGROUND: Surgery-first sagittal split ramus osteotomies (SF-SSRO) are an effective treatment for patients with dental malocclusion. However, some patients with mandibular prognathism usually have facial deficiencies which cannot be corrected completely after orthognathic surgery. These are not accepted because the remaining facial contours are in disharmony. METHODS: Twenty-five patients, who were unsatisfied with their appearances after SF-SSRO and orthodontics, were included. The preoperative CTs were used to investigate patients for facial deformity. To achieve a harmonious facial contour, mandible long-curve osteotomy/mandible U-shaped osteotomy, genioplasty or facial autologous fat grafting was selected depending on patients' contour deformities with the assistance of CAD. RESULTS: Among the patients who underwent osteotomy, the gonial angle was improved from 111.16° ± 9 to 111.58° ± 9.06 after SF-SSRO because of distal fragment setback and rotation. After facial refine surgery, the gonial angle was significantly increased to 121.69°±2.41 (p < 0.05). And the mandibular width was decreased from 11.29 cm ± 0.44 to 10.45 cm ± 0.39 (p < 0.05) after mandibular outer plate griding. All patients were shown no signs of infection, massive bleeding, and osteonecrosis in the early stage. After follow-up time, they were all satisfied with their results and most of them recovered from lip numbness. CONCLUSIONS: This study indicated the clinical feasibility of two-stage orthognathic and facial bone contouring surgery for the treatment of dentofacial deformities. Two-stage facial contouring surgery can provide esthetic improvement for more accuracy in refining the facial contour. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Rapamycin and 3-Methyladenine Influence the Apoptosis, Senescence, and Adipogenesis of Human Adipose-Derived Stem Cells by Promoting and Inhibiting Autophagy: An In Vitro and In Vivo Study.

OBJECTIVE: We aimed to clarify the changes in apoptosis, proliferation, senescence, and adipogenesis after promoting and inhibiting autophagy in adipose-derived stem cells (ADSCs) by rapamycin and 3-methyladenine in vitro and in vivo. METHODS: After rapamycin and 3-methyladenine pretreatment, ADSC autophagy was detected by immunofluorescence for LC3, RT-PCR for ATG genes, and western blotting (WB) for the LC3 II/I and p62 proteins. TUNEL staining, PCR of BAX, and WB of Caspase-3 were preformed to assess ADSC apoptosis. The adipogenesis of ADSCs was evaluated by Oil red O staining and PCR of PPAR-γ. CCK8 assays were conducted to detect proliferation. Senescence was tested by Sa-ß-gal staining and PCR of the P16/ 19/21 genes. Moreover, the mass and volume retention rate were determined, and perilipin and CD31 staining were performed in vivo. RESULTS: Rapamycin and 3-methyladenine pretreatment increased and decreased autophagy of ADSCs, respectively, under normal and oxygen-glucose deprivation conditions. Apoptosis and senescence of ADSCs were decreased, and adipogenesis was increased along with the upregulation of autophagy. However, the proliferation of ADSCs was inhibited after either rapamycin or 3-methyladenine pretreatment. In vivo, the volume and mass retention rate and the angiogenesis of the grafts were also improved after rapamycin pretreatment. CONCLUSIONS: Rapamycin pretreatment reduced apoptosis, delayed senescence, and promoted adipogenesis of ADSCs. These effects were inhibited by 3-methyladenine, indicating that the changes may be mediated by autophagy. Moreover, the survival rate and angiogenesis of the grafts were increased after upregulation of ADSC autophagy in vivo, which may help improve the efficiency of clinical fat transplantation. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

[Influence of different sintering temperatures on mesoporous structure and ectopic osteogenesis of biphasic calcium phosphate ceramic granule materials].

OBJECTIVE: To detect the difference in the osteogenesis ability of biphasic calcium phosphate (BCP) ceramic granular materials with different mesoporous diameters prepared at different sintering temperatures through in vivo and in vitro experiments, so as to provide evidence for screening BCP materials with better clinical application parameters. METHODS: Three kinds of BCP (materials 1, 2, 3) were prepared by mixing hydroxyapatite (HA) and ß-tricalcium phosphate (ß-TCP) at a ratio of 8∶2 and sintered at 1 050, 1 150, and 1 250℃ for 3 hours, respectively. The internal porosity and the diameter, volume, and area of the mesopore were measured by Brunauer-Emmett-Teller test (BET); the composition of the material was evaluated by X-ray diffraction (XRD); the microscopic surface morphology of the material was observed by scanning electron microscopy (SEM). The 3rd generation bone marrow mesenchymal stem cells (BMSCs) from Sprague-Dawley rats were co-cultured with the materials 1, 2, and 3 for 7 days in vitro respectively (groups A, B, and C), and the cells adhesion on the materials was observed by SEM and phalloidine staining, respectively. Cell proliferation activity was measured by cell counting kit 8 method. In vivo, 9 muscle bags were made in dorsal muscles of 9 beagles, respectively. The muscle bags were randomly divided into 3 groups (3 per beagle in each group) and materials 1, 2, and 3 were placed into the muscle bags of groups A, B, and C, respectively. After 1, 2, and 3 months of operation, 3 beagles were anesthetized and the samples were stained with HE, Masson, and Safranin, and the bone formation area ratio in the BCP gap was calculated. Real-time fluorescence quantitative PCR (qRT-PCR) was performed to detect the expressions of bone-related genes [including alkaline phosphatase (ALP), osteopontin (OPN), and osteocalcin (OC)]. RESULTS: The BET test showed that with the increase of sintering temperature, the internal porosity of the particles did not change significantly, but the diameter, volume, and area of the mesopores gradually decreased. The XRD detection showed that the XRD waves of HA and ß-TCP could be seen in all 3 kinds of materials; SEM showed that there were widely distributed macropores on the surface of 3 kinds of BCPs, and the interpores connected with the others. In vitro, BMSCs adhered and proliferated on the surfaces of 3 kinds of BCPs, and the cell biocompatibility of the materials in groups B and C was better than that in group A. In vivo, obvious osteoid tissue deposition could be observed in the intergranular space of 3 kinds of BCPs from 2 months after implantation. The bone formation area ratio of each group increased with time. The bone formation area ratio in group A was significantly higher than that in groups B and C at 2 and 3 months after implantation, and in group A than in group B at 1 month ( P<0.05). qRT-PCR showed that the expressions of osteogenic related genes peaked at 2 months in group A, and gradually increased with time in groups B and C. The relative expressions of ALP and OPN mRNAs in group A were significantly higher than those in groups B and C at 1 month after implantation, the relative expression of OC mRNA in group A was significantly higher than that in groups B and C at 2 months after operation, the relative expression of ALP mRNA in groups B and C and the relative expression of OPN mRNA in group B were significantly higher than those in group A, all showing significant differences ( P<0.05); there was no significant difference in the relative expression of each gene among the other groups at each time point ( P>0.05). CONCLUSION: The mesoporous diameter of BCP decreases with the increase of sintering temperature. Different mesoporous diameters lead to different ectopic osteogenesis of BCP materials. BCP material with mesoporous diameter of 12.57 nm has better osteogenic ability which can activate the osteogenic gene earlier. The mesoporous diameter is expected to be an adjustable index for optimizing the osteogenic capacity of BCP materials.

A Simple Dressing Fixation Method Following Harvest of the Ear Cartilage Graft.

ABSTRACT: Auricular cartilage is a common autologous graft material for rhinoplasty. Even though surgical techniques for the harvest of cartilage graft are well established, the management of the postoperative dressing fixation is still limited. Therefore, the authors propose a simple dressing fixation method in which gauze strips instead of gauze block or wet cotton, the suture of tie-over dressing fixed just through the cartilage rather than the full thickness of the auricle, a vaseline gauze interposed between the stitch knot and the skin and no additional pressure dressings postauricularly. No case of hematoma, infection and skin necrosis of the donor site was observed. This simple and reproducible technique provides perfect and homogeneous adhesion of the dressing all over the conchal cartilage while decreasing the risk of postoperative hematoma and discomfort.

What happens to an acellular scar matrix after implantation in vivo? A histological and related molecular biology study.

It has been established that scar acellular matrices (AMs), which allow cell proliferation, have similar characteristics. The aim of this study was to investigate the repair effect of scar AMs on animals, thus providing a reference for clinical application. Selected mature and immature scar AMs were implanted into animals, and then a negative control group was set for comparison. The effect of scar AMs on wound healing was observed through tissue staining, RT-qPCR, and immunohistochemistry. The materials showed milder inflammation and faster extracellular matrix (ECM) deposition than the negative control group. The ECM deposition and new vessels increased over time. However, the arrangement of ECM in mature scar AM was more regular than in immature scar AM and the negative control group, and more new vessels grew in the mature scar AM group than in the immature scar AM group and negative control group over the same period. The transforming growth factor-ß level was elevated at one month, two months, and six months. COLA1 and vimentin levels all peaked at six months. Matrix metalloproteinase and TIMP1 were also elevated at different months. Collectively, scar AMs can effectively promote wound healing and vascularization. Mature scar AMs have a better regeneration effect.

Unexpected Bone Resorption in Mentum Induced by the Soft-Tissue Filler Hyaluronic Acid: A Preliminary Retrospective Cohort Study of Asian Patients.

BACKGROUND: As one of the most commonly used soft-tissue fillers, hyaluronic acid is generally considered safe and efficacious. However, evident bone resorption in mentum was observed. In this study, the authors analyzed the impact of hyaluronic acid on bone resorption in mentum and the influencing factors. METHODS: The authors retrospectively compared the computed tomographic scans of patients with or without mentum augmentation using hyaluronic acid. The body mass index- and sex-matched control group was selected randomly. Semimandibular bone resorption index was calculated as the ratio of bone thickness in the incisive fossa to that in the mandibular symphysis. Injection volume, injection interval, the number of injections, product, complication were also recorded. RESULTS: From January of 2014 to June of 2019, 80 patients (160 cases) and 80 controls were recruited. The bone resorption index in the hyaluronic acid injection cohort was significantly lower than in the controls (75.25 ± 10.02 versus 82.86 ± 6.38; p = 0.000). Patients injected with greater than or equal to 1 ml per time were more susceptible to bone erosion compared with patients injected with less (68.89 ± 10.84 versus 76.49 ± 9.42; p = 0.000). There was no significant difference between one- versus multiple-injection groups and short-injection-interval versus long-injection-interval (≥6 months) groups. Furthermore, no reduced aesthetics were realized. CONCLUSIONS: Hyaluronic acid injection could induce bone resorption in the mentum; nevertheless, the aesthetics were not impaired. The severity of the bone loss was positively correlated with the injection volume per time; therefore, large-volume injection of hyaluronic acid should be performed with caution. The patients should be fully informed about this complication preoperatively. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Simultaneous surgery of mandibular reduction and impacted mandibular third molar extraction: A retrospective study of 65 cases.

A considerable number of patients with prominent mandibular angle have mandibular third molar impaction that needs surgical removal. Mandibular reduction is a popular and effective surgery to correct prominent mandibular angle, but it has been rarely performed simultaneously with impacted third molar extraction. In order to decrease the number of operations and suffering of patients, safely performing these 2 operations together is necessary and important. From January 2016 to June 2018, patients received mandibular reduction and impacted mandibular third molar extraction together were retrospectively reviewed. Forty-seven patients receiving long-curve mandibular reduction (n = 12) or simple mandibular reduction (n = 35) were included in this study. A total of 65 impacted mandibular third molars were extracted during mandibular reduction. One patient had hematoma within facial soft tissue which reabsorbed spontaneously. Seven patients who underwent long-curve mandibular reduction reported transient inferior lip numbness for several weeks. No infection or poor wound healing was reported. No immediate or delayed mandibular fracture occurred. All the patients were satisfied with both the aesthetic result of mandibular reduction and the unnecessity of receiving a secondary surgery to extract the impacted third molar. Simultaneously performing mandibular reduction and impacted mandibular third molar extraction can effectively reduce the number of operations and patients' suffering. It is also safe with adequate pre-op assessment, professional surgical knowledge, proper use of surgical instruments, meticulous surgical procedures, and correct post-op care.

The Relationship Between the Facial Proportion Changes in Hard Tissue and the Satisfaction of Patients After Reduction Malarplasty: a Research Based on Three-Dimensional Cephalometry.

OBJECTIVE: We aim to measure the zygomatic width and protrusion changes in hard tissue after reduction malarplasty and then calculate facial proportion changes and analyze the relationship between facial proportion changes and patients' satisfaction. METHODS: We retrospectively reviewed our database and selected 36 eligible patients who underwent isolated reduction malarplasty in our department from March 2015 to July 2018. The preoperative and postoperative facial width and protrusion, as well as head height, in hard tissue were measured using ProPlan software. Patients' satisfaction was evaluated by questionnaire. The correlations between the facial proportion changes and patients' satisfaction were analyzed using Spearman correlation analysis. RESULTS: The preoperative and postoperative midface widths were 135.87 ± 4.09 mm and 129.06 ± 4.95 mm. The relative zygomatic protrusion was reduced by 3.29 ± 1.54 mm in the left and 2.88 ± 1.73 mm in the right after surgery. The ratio of the midface width to lower face width changed from 1.43 ± 0.05 to 1.36 ± 0.06 after surgery. And the ratio of the head height to midface width changed from 1.53 ± 0.05 to 1.61 ± 0.05 after surgery. The ratios were indeed close to the ideal ratios we presumed (4:3 and 1.618). Moreover, patients' total and morphology satisfaction were both significantly higher with the postoperative ratio of the midface width to lower face width closer to 4:3 (R = - 0.732, P < 0.001; R = - 0.906, P < 0.001, respectively). But only morphology satisfaction was higher with the ratio of the head height to midface width closer to 1.618 (R = - 0.404, P = 0.014) and the ratio of the postoperative midface to lower face width decreased (R = - 0.434, P = 0.008). CONCLUSIONS: We found patients' morphology satisfaction was higher with the proportion of the postoperative midface to lower face width decreased. What's more, the proximity degree between the postoperative facial proportion and the ideal facial proportions we presumed was significantly correlated with patients' high satisfaction. Therefore, 4:3 and 1.618 may be the ideal postoperative facial ratios for the patients who underwent reduction malarplasty. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors https://www.springer.com/00266.

Comparison of Bilateral Mandibular Angle Ostectomy Between East Asian Males and Females: A Study Based on Three-Dimensional Computed Tomography Reconstruction.

BACKGROUND: Mandibular angle ostectomy is a common plastic surgery for facial contouring in East Asians. However, rarely we could find reports on differences between East Asian males and females undergoing this surgery. OBJECTIVE: To describe the differences between East Asian males and females before and after mandibular angle ostectomy. METHODS: A total of 22 Asian males and 52 Asian females who underwent mandibular angle ostectomy from April 2015 to November 2018 were enrolled. Three-dimensional computed tomography was used to evaluate the preoperative and postoperative data of the mandible. Thirteen clinical data were measured on reconstructed mandibular models. The differences in data between males and females were analyzed to identify the causes of the differences before and after surgery. The follow-up was 6-12 months, and patient satisfaction was also evaluated. RESULTS: The ostectomy volume was positively correlated with the distance from the intersection of the occlusal plane and the anterior margin of the mandibular ramus to gonion (MR-Go; female, p < 0.01; male, p = 0.02). There was a positive correlation between the ostectomy volume and the postoperative drainage fluid (The drainage fluid is mainly blood) volume after surgery in females (p < 0.05), while there is no significant correlation between these two data in males (p = 0.19). Patients with a long distance from the second molar to the lower edge of the mandibular body (SM-MB) tended to have a higher risk of postoperative bleeding (female, r = 0.56, p < 0.01; male, r = 0.73, p = 0.01). CONCLUSION: Because of the difference in the anatomical size of the mandible and different aesthetic requirements for facial contouring between males and females, surgeons encounter different intraoperative conditions resulting in difficulties during surgery. Understanding differences in mandibular angles predicts differences in ostectomy volume and postoperative bleeding risk, thus aiding surgeons and leading to better operative outcomes. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

The implication of the notch signaling pathway in biphasic calcium phosphate ceramic-induced ectopic bone formation: A preliminary experiment.

Calcium phosphate (BCP) ceramic is a promising material in bone regeneration because it was proved biocompatible, osteoconductive, osteoinductive, and effective. Although it manifests favorable characteristics in critical-sized bone defects repair, the mechanism of its osteoinduction is still unclear. In the present study, we studied the mechanism of ectopic bone formation, with interest in the Notch signaling pathway. BCP ceramics with or without Notch signaling inhibitor RO4929097 were cocultured with bone marrow-derived stem cells in vitro. The expression of osteogenesis (OPN/Col/Runx2) and Notch signaling pathway-related genes (Hes1/Jagged/Notch1) were increased in the BCP group compared with the control group without BCP but significantly decreased after adding RO4929097. Furthermore, a higher level of alkaline phosphatase activity was observed in the BCP group compared with RO4929097 and control group separately. For further confirmation, the intramuscularly ectopic implantation models of Beagle dogs were used. Quantitative real-time polymerase chain reaction showed a similar trend with the in vitro experiment. Histological and histomorphometric analysis indicated that bone formation was delayed by RO4929097. These findings illustrated that the Notch signaling pathway plays a pivotal role in bone formation induced by BCP; Notch signaling pathway may positively influence ectopic bone formation by promoting BMSCs to differentiate toward osteoblasts.

En-Bloc U-Shaped Osteotomy of the Mandible and Chin for the Correction of a Prominent Mandibular Angle With Long Chin.

BACKGROUND: Lower face contouring surgery has become a popular aesthetic surgery in East Asian countries. Various surgical methods have been used to improve lower face aesthetics. When a patient has a wide as well as long lower face, procedures like chin polishing or T-type osteotomy are traditionally performed, but these surgical methods have several disadvantages. The authors devised a simple and reliable method to correct the wide and long lower face, without the complications associated with the traditional methods. METHODS: From July 2015 to January 2018, 30 patients with a prominent mandibular angle, long chin, and no malocclusion underwent en-bloc mandibular U-shaped osteotomy through an oral incision, in order to shorten the mandibular angle, body of the mandible, and the chin, and to improve the facial contour. The authors assessed the effectiveness of surgery through comparisons between pre- and postoperative radiographs, patient satisfaction, and surgical complications in the postoperative period. RESULTS: It was observed that all oral incisions healed by primary intention, and did not develop hematoma, infection, or osteonecrosis. Lower lip numbness occurred in 16 patients. After 6 to 12 months, all patients showed complete recovery from the numbness. All the patients were satisfied with their appearance after surgery. CONCLUSIONS: En-bloc mandibular U-shaped osteotomy is an improved form of mandibular surgery. The osteotomy line involves the whole mandible, which makes the length and width of the mandible considerably smaller. This surgery can effectively correct a prominent mandibular angle with long chin.