Three-dimensional Measurement of the Zygomatic-maxillary Complex in the Class III Malocclusion Patients with Maxillary Retrusion.

This study investigated the anatomic features of the zygomatic-maxillary complex in patients with maxillary retrusion without clefts. Individuals were grouped, and craniofacial measurements were performed for 21 individuals with skeletal Class III malocclusion with maxillary retrusion (CIII) and 48 individuals from the control group (CG). We evaluated the predetermined hard-tissue and soft-tissue points of the facial profile in each group. Independent sample t -tests were performed to determine the differences between groups (significance set at P <0.05). Multiple points on the midface, including the most posterior point on the contour of the maxillary alveolar process, lowest point of the zygomaticomaxillary suture, furthest point to the zygomatic self-base plane, superior point in the infraorbital foramen, and lowest point of the inferior margin of the orbit to the coronal plane were smaller in CIII than in CG (all P <0.05). The soft tissue thickness in these regions was significantly increased compared with that in the normal group. In summary, for class III malocclusion patients with maxillary retrusion, the deficiency in the midface gradually decreased going upward, with the deficiency at the maxillary alveolar level being the most serious. To some extent, soft tissues compensate for the deficiencies in the facial skeleton, and standard Le Fort I osteotomy advancement was sufficient to achieve a harmonious appearance.

Effect of Bone-Borne Trans -Sutural Distraction Osteogenesis Therapy on the Cranial Base of Children With Midfacial Hypoplasia Due to Cleft Lip and Palate.

Bone-borne trans -sutural distraction osteogenesis (TSDO) is widely used to treat midfacial hypoplasia in children with cleft lip and palate; however, its effects on the cranial base are still poorly understood. The authors aimed to study morphological changes in the cranial base after TSDO. Pre and postoperative computed tomography (CT) images of cleft lip and palate children with midfacial skeleton dysplasia who underwent TSDO were collected retrospectively, and their corresponding 3-dimensional models were measured. Results showed no significant change in the length of the anterior or posterior cranial fossa, but the length of the middle cranial fossa increased significantly. The anterior cranial base rotated upward with the sella turcica at the center, whereas the cranial base angle increased. The sphenoid bone exhibited morphological changes. Post-TSDO, the lateral plate of the pterygoid process increased in length. The angle of the 2 lateral plates of the pterygoid process, the greater wings of the sphenoid bone, and the smaller wings of the sphenoid bone decreased. Posterior inclination of the pterygoid process increased. Mean volume of the sphenoidal sinus increased postoperatively compared with the preoperative volume. Apparent changes in the cranial base after TSDO are primarily in the middle cranial fossa, manifesting as an increase in the sphenoid bone body length, expansion of the sphenoidal sinus volume, growth of the pterygoid process forward and downward, a decrease in the angle of both the greater and smaller wings of the sphenoid bone, and an increase in the posterior inclination of the pterygoid process.

A 3-Dimensional Measurements of Bone and Airway Variables After Le Fort I Distraction Osteogenesis in Patients With Cleft Lip and/or Palate-Induced Midface Hypoplasia: A Retrospective Study.

The authors retrospectively analyzed the effects of Le Fort I advancement with distraction osteogenesis on skeletal and airway variables in patients with midfacial hypoplasia induced by cleft lip and/or palate using 3-dimensional computed tomography reconstructions. The authors enrolled 23 subjects with moderate-to-severe midface hypoplasia induced by cleft lip and palate who were treated with Le Fort I distraction osteogenesis (mean age, 19.22±3.48 y; male/female ratio, 20/3); computed tomography images (1 before distraction and another at completion of distraction) were acquired. A 3-dimensional craniometric findings and airway volumes for the nasal cavity, nasopharynx, velopharynx, and upper and lower oropharynx were compared before and after distraction. The relationships between craniofacial morphology and changes in airway volume were also assessed ( P <0.05 was considered significant). Significant increases were observed in airway volumes for the nasal cavity (13.85%), nasopharynx (50.82%), velopharynx (29.57%), and upper oropharynx (36.92%) ( P =0.007, P <0.001, P =0.023, and P <0.001, respectively), whereas no significant changes were observed for the lower oropharynx ( P =0.117). Maxillary horizontal advancement was positively correlated with the airway volumes of the nasopharynx and upper oropharynx after distraction osteogenesis ( rs =+0.451, P =0.031; rs =+0.548, P =0.007); however, no significant correlations were observed for the nasal cavity and velopharynx. The authors' finding indicate that despite rotation of the mandible along with the maxilla, this change does not impact airway volume at the mandibular level. Le Fort I distraction osteogenesis can be feasible for patients with cleft lip and palate-induced midface hypoplasia, with satisfactory appearance and occlusion. Long-term detailed follow-up of the patients postdistraction osteogenesis is warranted.

Observation of Nasal Morphology in Unilateral Microform Cleft Lip Repaired by a Hidden Skin Incision.

BACKGROUND: Microform cleft lip is the mildest type of cleft lip without obvious defects of the upper lip. The nose deformities of microform cleft lip include flattened nostril rim, alar base asymmetry, and septal deviation. A hidden skin incision with nasal base muscle reconstruction was introduced in nose deformities of microform cleft lip. METHOD: To investigate the operative effect, we reviewed 21 patients with microform cleft lip treated with a hidden skin incision with nasal base muscle reconstruction from May 2020 to October 2022. Photogrammetric nasal morphometric measurements were compared preoperatively and six months postoperatively. The proportional value was obtained from the cleft and the noncleft sides, and paired t-test analysis was used to evaluate the surgical outcome. RESULT: Significant differences were found in all nasal morphologic measurements at 6 months postoperatively compared to preoperatively (p < 0.05). After surgery, the alar base and nostril were narrowed, while the lateral lip height was increased on the affected side. The height of the nostrils on the affected side was increased, and the nasal columella deviation was released. In addition, the ratio of the cleft-to-noncleft nostril area was closer to 1.0 after surgery. CONCLUSION: The unilateral microform cleft lip nasal deformity can be repaired through a small hidden incision. 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 .

An Auxiliary Cranioparietal Anchorage System to Improve the Stability of the Rigid External Distraction Device in Children With Crouzon Syndrome.

ABSTRACT: Rigid external distraction (RED) device instability because of thin skulls in syndromic craniosynostosis patients remains challenging. The authors propose the use of an auxiliary cranioparietal anchorage system to improve RED device stability in patients with Crouzon syndrome. Five consecutive patients with Crouzon syndrome underwent Le Fort III osteotomy with midface advancement using a modified external device. Cephalometric analysis and three-dimensional computed tomography images were evaluated preoperatively and after device removal. Mechanical analyses of the RED device with and without the auxiliary cranioparietal anchorage system were performed. Both postoperative photographs and follow-up computed tomographs showed obvious midfacial advancement with no intracranial pin perforation or external frame migration. Mechanical analysis showed that the new system reduced the possibility of postoperative external frame migration. The auxiliary cranioparietal anchorage system might be considered an adjunct to the RED device in patients with Crouzon syndrome to avoid postoperative complications.

Three-Dimensional Measurement of the Zygomatic-Maxillary Complex in Unilateral Cleft Lip and Palate Patients With Maxillary Retrusion.

ABSTRACT: The purpose of this study was to investigate the anatomical features of the zygomatic-maxillary complex in unilateral cleft lip and palate (UCLP) patients with maxillary retrusion. Individuals were grouped and craniofacial measurements were carried out for 34 individuals in the UCLP with maxillary retrusion group (UMRG) and 50 from a control group (CG). The authors measured the length, width, and height of the maxilla and zygoma and also measured predetermined regions on the midface in each group. Independent sample group t tests were performed to determine differences between groups (with significance set at P < 0.05). Multiple points on the midface (the most posterior point on the contour of the maxillary alveolar process, lowest point of the zygomaticomaxillary suture, furthest point to the zygomatic self-base plane, superior point in the infraorbital foramen, and lowest point of the inferior margin of the orbit) to the coronal plane were smaller in the UMRG than in the CG (all results P < 0.05). In addition, the maxillary length was significantly reduced in the UMRG than in the CG (P < 0.05). In summary, for the UCLP patients with maxillary retrusion, the deficiency in the midface gradually reduced going upward, with the deficiency in the maxillary alveolar level the most serious. The zygoma was influenced to a lesser extent.

Surgical Planning for Cleft Lip and/or Palate-Induced Moderate-to-Severe Midfacial Hypoplasia.

BACKGROUND: Distraction osteogenesis and conventional bimaxillary orthognathic surgery have been performed for the treatment of midfacial hypoplasia for a long time. However, the effect of these 2 techniques on the maxilla, mandible, and whole-facial profile is significantly different. In this study, we aimed to measure the pre- to post-treatment changes in maxillary prominence, mandible size, and facial length and compare them between these 2 techniques to inform selection of the best technique. METHODS: This single-center, retrospective study included 35 patients with a cleft lip and/or palate-induced midfacial hypoplasia; 25 were treated using rigid external distraction osteogenesis and 10 using bimaxillary orthognathic surgery. Three-dimensional measures of changes in facial structure were obtained from reconstructed computed tomography images and used to compare the effects of the 2 techniques. RESULTS: Satisfactory appearance and occlusion were achieved in all patients. Three-dimensional reconstruction of the craniofacial skeleton revealed significant maxillary advancement (P < 0.001), mandibular (clockwise) rotation (P < 0.001), and increased facial length (P < 0.001) after rigid external distraction osteogenesis and obvious shortening of the mandibular body (P < 0.001) after bimaxillary orthognathic surgery. CONCLUSION: Distraction osteogenesis can be selected as the first choice of treatment for cleft lip and/or palate-induced midfacial hypoplasia. A mandibular setback procedure can be performed as a second-stage surgery when severe temporomandibular joint complications develop with distraction osteogenesis. Bimaxillary orthognathic surgery results in an obvious shortening of the mandibular body, which is not a natural change in facial morphology. LEVEL OF EVIDENCE: Therapeutic III.

Silk Ligation Delay for the Random Pattern Flap.

OBJECTIVE: The purpose of this study is to explore a silk ligation delay for the expanded and unexpanded random flaps to improve the vascularization and survival length of the flap. METHODS: Marked incision points 2 to 3 cm at every interval along the design line with methylene blue, each incision was about 3 mm long. A subepidermal tunnel was formed on the superfacial layer of dermis between every adjacent incision; another gap was done on the surface of the expander. One end of a No 7 silk thread was inserted into the incision and traversed the surface of the expander until the adjacent incision point, then returned back to the original site through subepidermal tunnel. The both ends of the thread were ligated together to a single knot. All the designed points were performed as above. Then, the ligation procedure was performed along the long axis of the flap from proximal to distal. Both ends of each silk thread were tightly ligated together to a square knot to clamp the soft tissues including the vessels entering the flap. The progress of ligation should depend on blood supply changes of the flap. Remainders would finish under local anesthesia with 0.5% lidocaine or surface anesthetic cream in dressing room at 5 to 7 days after operation as schedule. After that the authors tested the blood supply of the flap and decided the opportunity of final transfer. RESULTS: There were no complications such as infection, wound dehiscence, expander exposure, significant effusion, and necrosis of the flap in all patients. All the flaps survived completely. Only 1 expander rupture happened during delay operation. CONCLUSIONS: The technique is a safe and reliable method, it is simple and easy for application, it may provide another choice for the surgical delay.

Midface Distraction Osteogenesis Using a Modified External Device With Elastic Distraction for Crouzon Syndrome.

PURPOSE: Midface distraction osteogenesis has been popularized for the correction of midface hypoplasia associated with exophthalmos and obstructive sleep apnea in patients with Crouzon syndrome. The purpose of this study was to present the method of utilizing the modified external device with elastic distraction for the midface advancement in Crouzon syndrome, and the clinical outcomes and skeletal changes were analyzed. METHODS: Five consecutive patients with Crouzon syndrome underwent Le Fort III osteotomy with midface advancement using a modified external device with elastic distraction. The distraction system consists of a rigid external distractor, nickel-titanium shape memory alloy spring, and bone-borne traction hooks. The midface advancement was initiated with the bony anchorage around the nasomaxillary buttress at the level between occlusal plane and infraorbital margin. The device was activated at a rate of 1 to 1.5 mm per day by the length of spring. The skeletal changes were analyzed by cephalometric and computed tomographic measurement. RESULTS: All the patients achieved improvements in midface appearance, obstructive sleep apnea, exophthalmos, and occlusion. No complications occurred during this procedure. After the distraction, 1 patient developed an open bite that was corrected by a definitive orthognathic surgery. Cephalometric and computed tomographic measurement analysis showed a differential advancement of midface with more at the occlusal level than the orbital level. In addition, midface suture and bone remodeling was also observed in growing patient. CONCLUSIONS: Our modified external device with elastic distraction offers an alternative method to achieve midface advancement in patients with Crouzon syndrome.

Changes in the Zygomaticomaxillary Suture During Aging.

Trans-sutural distraction osteogenesis (TSDO) has been successfully used to correct midfacial hypoplasia in growing patients for years. The effects of TSDO, however, remain difficult to predict in adult patients. The aim of this study was to determine the biologic basis for the age-related increase in difficulty of performing TSDO. A total of 45 male Sprague Dawley (SD) rats were obtained in 3 age groups: 4 weeks old (4W, N = 15), 3 months old (3M, N = 15), and 13 months old (13M, N = 15). The zygomaticomaxillary sutures (ZMS) were dissected, and their morphology was evaluated by histology and micro-computed tomography (micro-CT). Quantitative real-time polymerase chain reaction of the ZMS and blood samples taken from the abdominal aorta were also used to assess the effects of age at the molecular level. Compared with the 4W rats, the number of fibroblasts in the ZMS was decreased, the bone plate adjacent to the ZMS was thicker, and the texture was denser in the 13M rats. Micro-computed tomography analysis showed the density of the ZMS was significantly increased in the 13M group (P < 0.05). The density ratio of the ZMS to the adjacent bone was increased from 0.14:1 in the 4M group to 0.54:1 in the 13M group. The gene expression of osteocalcin (OC) was significantly lower at 13M than at 3M (P < 0.05). The OC and alkaline phosphatase (ALP) serum levels were significantly lower at 13M than at 4W (P < 0.05). During aging, the decreased osteogenesis activity both systemically and locally may be the biologic effect that limits the application of TSDO in older patients.

Transsutural distraction osteogenesis applied to maxillary complex with new internalized distraction device: analysis of the feasibility and long-term osteogenesis outcome.

BACKGROUND: The purposes of this study were to evaluate the effects of transsutural distraction osteogenesis applied to the maxillary complex with a new internalized distraction device and to analyze the long-term osteogenesis outcome. MATERIALS AND METHODS: Three-month-old beagle dogs were treated with a self-designed internalized distractor. The feasibility was evaluated, and the effects of the maxillary growth were measured using radiography and computed tomography (CT). The regenerated bone was examined with micro-CT, biomechanical testing, and histology 1 year after the distraction. RESULTS: The experimental group showed significantly larger forward displacement of maxillary during the distraction. One year after the distraction, the micro-CT showed more incompact structure and bone volume/total volume was significantly less in the experimental group. Biomechanical testing also showed a significantly lower yield but with no difference in stiffness. Histologic staining found osteoclasts deposited in the region of the suture and osteoblasts on the bone surface. The immunohistochemical staining of osteoprotegrin and receptor activator of nuclear factor-κ B ligand showed evidence of expression in suture area components and osteocytes with no difference between the groups. CONCLUSIONS: Transsutural distraction osteogenesis using an internalized distractor with skull anchorage demonstrated feasibility. It is expected that this device may provide new thoughts in developing an appropriate appliance for clinical use in young patients with midfacial hypoplasia. Moreover, the long-term osteogenesis analysis findings suggest that the metabolism of sutural area still remained active, which enhanced our understanding of bone remodeling in the sutural area to manage maxillary relapse after transsutural distraction osteogenesis.

Autologous fat grafting in lip reconstruction following hemangioma treatment.

OBJECTIVE: Autologous fat grafting has been successfully used in lip cosmetic surgery. However, little supportive evidence exists for its use in lip reconstruction following hemangioma treatment. METHODS: Patients with lip deformity following hemangioma treatment at the Plastic Surgery Hospital in Beijing between September 2010 and July 2012 were retrospectively investigated. Twelve patients underwent autologous fat grafting. Aesthetic appearance and texture and volume persistence of the graft were measured preoperatively and postoperatively, and the presence of infection and hematoma was recorded. RESULTS: After a series of 3 to 4 injections and a mean 24 months of follow-up, all 12 patients were satisfied with their aesthetic appearance and the texture and volume persistence of the graft. There were no complications such as infection or hematoma. CONCLUSIONS: The current study demonstrates that autologous fat transplantation is a viable option for correction of lip deformities. It is beneficial not only for correction of the tissue defect themselves, but also in terms of its effect on surrounding tissues and its long-lasting results without major complications in the management of this difficult problem.

Temporomandibular joint dislocation in patients with cleft lip and palate after maxillary distraction osteogenesis: Three case reports.

INTRODUCTION: Distraction osteogenesis (DO) is a widely used for cleft and palate related maxillary hypoplasia. There has been little research on temporomandibular joint (TMJ) dislocation after maxillary DO. We present these 3 cases and analyze the possible causes for reference by other clinicians. PATIENT CONCERNS: In the late stages of maxillary DO, the patients gradually felt a decrease in mandibular mobility and suffered from limited mouth opening. Case 2 and 3 could open their mouth up to 1 and 2 fingers and Case 1 barely able to open her mouth at the completion of distraction. DIAGNOSIS: Case 1 and Case 3 were diagnosed as right TMJ dislocation and Case 2 had a TMJ dislocation on her left side. INTERVENTIONS: Patients with TMJ dislocation were repositioned with manipulation as soon as detected. OUTCOMES: There was no recurrence in all three cases during the postoperative follow-up period. CONCLUSIONS: Maxillary DO can sufficiently advance the maxilla in cleft lip and palate patients. Clinicians should be mindful of the TMJ dislocations that maxillary DO can exert on patients.

Imaging study of midface growth with bone-borne trans-sutural distraction osteogenesis therapy in growing cleft lip and palate patients.

Trans-sutural distraction osteogenesis (TSDO) promotes midface growth in growing cleft lip and palate (CLP) patients with midfacial hypoplasia. The superficial skeletal changes after therapy revealed rotation advancement of the midfacial skeleton associated with differential displacement in each segment, but reports rarely focus on the changes of internal structures, including circummaxillary sutures, the maxillary tuberosity and the maxillary sinus, which may play a crucial role during this process. This study evaluated the computed tomographic (CT) images of 26 growing CLP patients who received bone-borne TSDO therapy. The results revealed that the most prominent new bone formation occurred in the pterygomaxillary suture and pushed the P-point forward. The maxillary first molar exhibited significantly greater advancement compared with the P-point due to the growth of the maxillary tuberosity. The contribution ratio values of the advancement of the maxillary tuberosity and P-point to the maxillary first molar were 26% and 74%, respectively, in UCLP and 25% and 75%, respectively, in BCLP. Furthermore, the maxillary sinus volume was also significantly increased. In conclusion, midface growth with bone-borne TSDO therapy depends on both secondary displacement promoted by sutural bone formation mainly in the pterygomaxillary suture and primary displacement by growth of the maxillary tuberosity and maxillary sinus volume.

Rigid External Distraction with Intranasal Bone-borne Traction Hooks for Midfacial Hypoplasia.

Rigid external distraction is currently performed to correct cases of severe maxillary hypoplasia. As an improvement of this technique, we propose the use of an intranasal bone-borne traction hook. This study is a retrospective chart review of the intranasal bone-borne traction hooks used in the treatment of severe maxillary hypoplasia. There were 110 patients treated with the hooks from 2005 to 2017. The maximum traction force was 7.75 kg, and there were few complications encountered during distraction. There were 76 patients who had the hooks removed under local anaesthesia. A cephalometric analysis was conducted in 56 patients. The average advancement of A-point was 9.9 ± 4.2 mm, 8.4 ± 2.5 mm, 11.0 ± 3.7 mm, 17.9 ± 4.4 mm for the trans-sutural distraction osteogenesis (DO), maxillary anterior segment DO, Le Fort I osteotomy DO and Le Fort III/II osteotomy DO, respectively. The average changes of sella-nasion-point A (SNA) were 8.89 ± 4.30 degrees, 8.21 ± 3.17 degrees, 10.49 ± 3.26 degrees, and 15.10 ± 4.00 degrees, respectively. The A point-nasion-B point (ANB) also showed increases in all procedures with P < 0.001. In conclusion, this technique sufficiently advances the midface and ensures the scars are concealed in the nasal base. The traction hook can bear a large traction force, causes minimal complications and is easily removed.

Therapeutic potential of human minor salivary gland epithelial progenitor cells in liver regeneration.

Liver disease is a serious problem affecting millions of people with continually increasing prevalence. Stem cell therapy has become a promising treatment for liver dysfunction. We previously reported on human minor salivary gland mesenchymal stem cells (hMSGMSCs), which are highly self-renewable with multi-potent differentiation capability. In this study, keratinocyte-like cells with self-regeneration and hepatic differentiation potential were isolated and characterized, and named human minor salivary gland epithelial progenitor cells (hMSG-EpiPCs). hMSG-EpiPCs were easily obtained via minor intraoral incision; they expressed epithelial progenitor/stem cell and other tissue stem cell markers such as CD29, CD49f, cytokeratins, ABCG2, PLET-1, salivary epithelial cell markers CD44 and CD166, and the Wnt target related gene LGR5 and LGR6. The cells were induced into functional hepatocytes in vitro which expressed liver-associated markers ALB, CYP3A4, AAT, and CK18. Upon transplantation in vivo, they ameliorated severe acute liver damage in SCID mice caused by carbon tetrachloride (CCl4) injection. In a two-thirds partial hepatectomy mouse model, the transplanted cells survived at least 4 weeks and exhibited hepatic potential. These findings demonstrate that hMSG-EpiPCs have potential as a cellular therapy basis for hepatic diseases, physiological and toxicology studies and regenerative medicine.

[Classification and operation in the treatment of maxillary retrusion of adult patients with cleft lip and palate].

OBJECTIVE: To classify the patients with cleft lip and palate who need orthognathic surgery and to propose the corresponding operations. METHODS: From January 2005 to May 2015, 121 patients with cleft lip and palate diagnosed as maxillary retrusion were treated by orthognathic surgery. Inclusion criteriar: (1) male aged over 16, female aged over 14; (2) diagnosed as non-syndromic cleft lip and palate without systemic disease and other genetic diseases; (3) without previous orthodontic and orthognathic treatment; (4) having no other craniofacial malformation. Maxillary features and repaired types were recorded. RESULTS: 93 patients were included and divided into two categories depended on the dental crowding. Class I: the teeth quantity and bone quantity is coordinated, space analysis ≤ 4 mm (mild dental crowding). The forward distance of maxillary less than 6 mm was defined as Class I a (36 cases) more than 6 mm as Class I b (28 cases). Class II: the teeth quantity and bone quantity is not coordinated, space analysis > 4 mm ( moderate or severe dental crowding). After the simulation of distraction osteogenesis, the anterior crossbite was corrected defined as Class II a (23 cases), not corrected defined as Class II b (6 cases). Class I a were corrected by conventional orthognathic surgery. While Class I b were corrected by Le Fort I maxillary advancement using distraction osteogenesis. Class II a were repaired just by anterior maxillary distraction. While Class II b need to combine conventional orthognathic surgery with anterior maxillary distraction. All the patients were satisfied with the treatment effect. CONCLUSIONS: The patients of cleft lip and palate with maxillary retrusion who need orthognathic surgery can be classified as the method mentioned above, and then choose the appropriate operations.

Three-dimensional quantitative evaluation of midfacial skeletal changes after trans-sutural distraction osteogenesis for midfacial hypoplasia in growing patients with cleft lip and palate.

PURPOSE: Trans-sutural distraction osteogenesis (TSDO) is an alternative method for the early treatment of midfacial hypoplasia in growing patients with cleft lip and palate (CLP). The purpose of this study was to analyze three-dimensional (3D) midfacial skeletal changes after TSDO and to explore the mechanism in this process. MATERIAL AND METHODS: All patients with nonsyndromic CLP who underwent bone-borne TSDO for midfacial hypoplasia from 2005 to 2014 were reviewed in this retrospective study. 3D morphological and quantitative measurement analyses were performed to evaluate midfacial skeletal changes by superimposition of preoperative and postoperative computed tomographic images. RESULTS: Twenty-six patients with mean age of 11.5 years met the inclusion criteria. The 3D morphological findings exhibited the most significant suture stress changes at the pterygomaxillary suture area, with obvious bone generation in all patients. The whole midfacial skeleton had progressively increased advancement in a craniocaudal direction along the midface segment, associated with morphological changes in skeleton itself. The 3D quantitative measurement findings showed differential advancement of each landmark at the maxillary alveolar, zygomatic bone, orbital rim, and nasal bone, which was consistent with morphological findings. CONCLUSIONS: TSDO allows rotation advancement of the midfacial skeleton to achieve occlusal correction and facial harmony through the mechanism of both suture remodeling and bone remodeling.

Trans-Sutural Distraction Osteogenesis for Midfacial Hypoplasia in Growing Patients with Cleft Lip and Palate: Clinical Outcomes and Analysis of Skeletal Changes.

BACKGROUND: Although maxillary distraction osteogenesis has been used for early treatment of midfacial hypoplasia, the inevitable osteotomies are still a complicated and invasive procedure for growing patients. Based on the bone-borne trans-sutural distraction osteogenesis, novel improvements to the approach were made to treat midfacial hypoplasia, and the clinical outcomes and skeletal changes were analyzed. METHODS: Seventy consecutive growing cleft lip and palate patients with midfacial hypoplasia were treated with trans-sutural distraction osteogenesis. The distraction system consists of a rigid external distractor, nickel-titanium shape memory alloy spring, and bone-borne traction hooks. The whole distraction process was recorded in detail clinically. Lateral cephalographs and computed tomographic scans were taken and analyzed by cephalometric measurement and color-map analysis to assess the skeletal changes. RESULTS: All of the patients except one achieved satisfactory appearance and occlusal relationship. The unilateral maximum traction force presented an increased trend with age, but this relationship was not absolute. The whole trans-sutural distraction osteogenesis process was divided into three clinical stages: the startup period, the rapid movement period, and the consolidation period. Cephalometric analysis showed a great increase in SNA, ANB and horizontal movement of the maxillae after distraction, but with marginal relapse at 6 to 18 months postoperatively. Visualized changes of the midfacial skeleton were observed by three-dimensional color mapping. The results showed an unequal advancement in different regions. CONCLUSION: Trans-sutural distraction osteogenesis process with adaptations offers an alternative method for the early treatment of midfacial hypoplasia in growing patients with cleft lip and palate. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Characterization of a Self-renewing and Multi-potent Cell Population Isolated from Human Minor Salivary Glands.

Adult stem cells play an important role in maintaining tissue homeostasis. Although these cells are found in many tissues, the presence of stem cells in the human minor salivary glands is not well explored. Using the explant culture method, we isolated a population of cells with self-renewal and differentiation capacities harboring that reside in the human minor salivary glands, called human minor salivary gland mesenchymal stem cells (hMSGMSCs). These cells show embryonic stem cell and mesenchymal stem cell phenotypes. Our results demonstrate that hMSGMSCs have the potential to undergo mesodermal, ectodermal and endodermal differentiation in conditioned culture systems in vitro. Furthermore, in vivo transplantation of hMSGMSCs into SCID mice after partial hepatectomy shows that hMSGMSCs are able to survive and engraft, characterized by the survival of labeled cells and the expression of the hepatocyte markers AFP and KRT18. These data demonstrate the existence of hMSGMSCs and suggest their potential in cell therapy and regenerative medicine.