Hypoxia Differentially Affects Chondrogenic Differentiation of Progenitor Cells from Different Origins

Background and Objectives

Ear cartilage malformations are commonly encountered problems in reconstructive surgery, since cartilage has low self-regenerating capacity. Malformations that impose psychological and social burden on one's life are currently treated using ear prosthesis, synthetic implants or autologous flaps from rib cartilage. These approaches are challenging because not only they request high surgical expertise, but also they lack flexibility and induce severe donor-site morbidity. Through the last decade, tissue engineering gained attention where it aims at regenerating human tissues or organs in order to restore normal functions. This technique consists of three main elements, cells, growth factors, and above all, a scaffold that supports cells and guides their behavior. Several studies have investigated different scaffolds prepared from both synthetic or natural materials and their effects on cellular differentiation and behavior.

Methods and Results

In this study, we investigated a natural scaffold (alginate) as tridimensional hydrogel seeded with progenitors from different origins such as bone marrow, perichondrium and dental pulp. In contact with the scaffold, these cells remained viable and were able to differentiate into chondrocytes when cultured in vitro. Quantitative and qualitative results show the presence of different chondrogenic markers as well as elastic ones for the purpose of ear cartilage, upon different culture conditions.

Conclusions

We confirmed that auricular perichondrial cells outperform other cells to produce chondrogenic tissue in normal oxygen levels and we report for the first time the effect of hypoxia on these cells. Our results provide updates for cartilage engineering for future clinical applications.

[Improving the accuracy of the preoperative planning of mandibular osteogenic distraction by an external custom-made device]

PURPOSE

The aim of this study was to analyze the predictability of virtual surgical planning of mandibular reconstruction by osteogenic distraction (OD) with a custom-made osteogenic distraction device (DEOS) after ballistic trauma and to make recommendations to mitigate potential sources of discrepancy.

METHODS

This retrospective study involved 12 patients who were victims of facial mandibular ballistic trauma and were reconstructed with osteogenic distraction with a DEOS device. Postoperative images were compared to the planned situation by means of several measures made in two plans : distraction plane and frontal plane.

RESULTS

The mean bone loss was 54.2mm. The anteroposterior difference was systematically inferior or equal postoperatively (10.8mm). The interrami angle difference in the frontal plane was positive, with an average of 4.8°. There was a significant negative correlation in univariate analysis between the antero-posterior difference measurement and the difference of the interrami angle in distraction.

CONCLUSION

A significant difference between the planning and postoperative results was shown, explained by the device being too adjustable leading to the loosening of the locking screws of the device. A static analysis showed that there are significant rotational forces at the carriages, which can lead to the loosening of the locking elements. It is then proposed that the device be optimized by customization of some elements.

Towards an evolution in ambulatory surgery for orbital floor repair? Our experience over a period of 11 years

INTRODUCTION

Orbital floor fracture repair is a complex surgery with intra-orbital hematoma being the most feared complication as it can lead to visual loss if not treated in good time. This is why currently patients are monitored for almost 48 hours as inpatients. The purpose of this study was to find out if orbital floor repair surgery could be safely undertaken as a day case by reviewing the experience of the last 11 years at the Caen University Hospital.

MATERIALS AND METHODS

A retrospective, monocentric study was conducted at the Caen University Hospital. All patients undergoing orbital floor reconstruction in a trauma setting from January 2008 to December 2019 were included.

RESULTS

Of the 130 included patients, none presented a post-operative complication such as intra-orbital hematoma. 3 patients had their surgery performed as a day case.

DISCUSSION

In the literature, more and more surgeons are proposing orbital floor fracture repair to be undertaken as day case. Indeed, the theoretical risk of intra-orbital hematoma is greater within the first 6 hours after surgery and can persist up to 10 days postoperatively. Provided patients meet the classic criteria for outpatient surgery, and are provided with a precise post-operative care protocol. Under these conditions, orbital floor fractures may be repair in ambulatory surgery.

Focus on the use of maxillomandibular fixation in mandibular fracture oseosynthesis

OBJECTIVES

The objective of this study was to evaluate the efficiency of three methods of isolated mandibular fracture intraoperative reduction.

MATERIALS AND METHODS

This 6-year retrospective study included patients with isolated extra-articular mandibular fractures who would benefit from osteosynthesis. The endpoint was postoperative occlusion according to the type of intraoperative immobilization: screws, arch, or manual reduction.

RESULTS

A total of 145 patients were included, with 233 fractures. Forty-five patients underwent manual reduction without maxillo-mandibular fixation (MMF), 51 MMF with screws, and 49 MMF with arch, with 11.1%, 5.9% and 4.1% of patients in these groups experiencing postoperative malocclusion, respectively. The overall malocclusion rate was 6.9%. There was no significant difference among the 3 methods according to univariate statistical analysis (p = 0.42) or after comparing MMF (grouping screws and arches) to manual reduction without MMF (p = 0.29).

CONCLUSION

This study did not show a significant difference between the different methods of intraoperative reduction of isolated extra-articular mandibular fractures, even though intraoperative MMF was much more commonly used for complex fractures. However, there is a non-significant tendency to get a better post-operative occlusal result with MMF, which remains the reference traitement. Intraoperative manual reduction without MMF may be used within trained teams in some instances.

Risk factors for lower border notching after bilateral mandibular sagittal ramus advancement: three-dimensional evaluation

Bilateral sagittal split osteotomy (BSSO) mandibular advancement can cause mandibular lower border notching (MLBN). The objective of this study was to calculate the incidence of MLBN and identify risk factors. This single-centre, retrospective study was performed between January 2018 and November 2020, in the Maxillofacial Surgery Department, Centre Hospitalier Universitaire, Caen. Patients who underwent BSSO advancement and had cone beam computed tomography (CBCT) scans obtained preoperatively, immediately postoperative (within 1 week), and late postoperative (≥1 year) were included. Measurements were made on the CBCT images. A total of 113 patients (226 operated sides) were enrolled. Mean age at the time of surgery was 17 years; 66.4% of patients were female and 33.6% were male. MLBN was observed on 35 operated sides (15.5% of sides). Advanced age (P = 0.002) and the degree of mandibular advancement (P = 0.008) were determined to be risk factors for developing MLBN. Sex, the operated side, third molar removal, and genioplasty were not associated with an increased occurrence of MLBN. Older patient age at the time of surgery and the requirement for a large advancement should be taken into consideration by the surgeon in order to reduce the risk of MLBN by using a modified BSSO procedure or bone grafting.

Hallermann Streiff syndrome: Cranio-facial manifestations systematic review and report of two cases

Hallermann Streiff syndrome (HSS) is a rare congenital abnormality with about 200 case reports in the literature. Its etiology is unknown although it may be due to a sporadic mutation. Diagnosis is based on the association of craniofacial malformation, dental abnormalities, hypotrichosis, atrophy of the skin, proportionate nanism, congenital cataract and bilateral microphtalmos. Cranio-facial deformities are the main signs detected and the most easily recognizable. We report cranio-facial and oral signs from a systemic literature review, and illustrate our findings with two of our patients diagnosed with HSS. Common cranio-facial manifestations are craniofacial malformation with a « parrot beak » nose, micrognathia, aprominent skull, sutures closing anomaly, malocclusion, dental anomalies, eyebrows and eyelash lack and atrophy of the nose skin. Knowledge of these signs should allow for early diagnosis and adequate treatment and follow up.

Embryological approach to philtral hair sparsity in bilateral cleft lip deformities

OBJECTIVE

In bilateral cleft lip cases, surgeons have long known that the medial nasal prominence or prolabium is devoid of muscle. Despite cheiloplasty restoring orbicular muscle continuity, moustache hair growth is less developed on the philtral skin. We sought to understand this hair disparity.

BASIC PROCEDURES

The authors conducted a comprehensive literature search using reference materials on the physiological and pathological development of the face in utero and the PubMed database using the keywords 'embryology', 'bilateral cleft lip' and 'hair'.

MAIN RESULTS

In bilateral cleft lip, the normal fusion between the maxillary and intermaxillary process does not occur, and the migration of cranial neural crest cells (CNCC) is disturbed. CNCCs from different locations and with different myoblastic differentiation potential are arrested on each side of the cleft. Therefore, a reduced concentration of myoblasts and myocytes as well as hormone receptors in the medial process could hinders the normal physiological development of the different layers of the philtral skin and especially the skin appendages.

CONCLUSION

Philtral hair sparsity in patients with bilateral cleft lip can be explain by a defect in the migration of CNCCs to the prolabium, whose cells are not able to develop hair follicles, due to a disruption of the exchange of Wnt/β-catenin, EDA, and or Noggin signals and due to the absence of androgen receptor.

EZH2 inhibition reduces cartilage loss and functional impairment related to osteoarthritis

Histone methyltransferase EZH2 is upregulated during osteoarthritis (OA), which is the most widespread rheumatic disease worldwide, and a leading cause of disability. This study aimed to assess the impact of EZH2 inhibition on cartilage degradation, inflammation and functional disability. In vitro, gain and loss of EZH2 function were performed in human articular OA chondrocytes stimulated with IL-1β. In vivo, the effects of EZH2 inhibition were investigated on medial meniscectomy (MMX) OA mouse model. The tissue alterations were assayed by histology and the functional disabilities of the mice by actimetry and running wheel. In vitro, EZH2 overexpression exacerbated the action of IL-1β in chondrocytes increasing the expression of genes involved in inflammation, pain (NO, PGE2, IL6, NGF) and catabolism (MMPs), whereas EZH2 inhibition by a pharmacological inhibitor, EPZ-6438, reduced IL-1β effects. Ex vivo, EZH2 inhibition decreased IL-1β-induced degradation of cartilage. In vivo, intra-articular injections of the EZH2 inhibitor reduced cartilage degradation and improved motor functions of OA mice. This study demonstrates that the pharmacological inhibition of the histone methyl-transferase EZH2 slows the progression of osteoarthritis and improves motor functions in an experimental OA model, suggesting that EZH2 could be an effective target for the treatment of OA by reducing catabolism, inflammation and pain.

Impact of the COVID-19 lockdown on the epidemiology of maxillofacial trauma activity: a French multicentre comparative study

The coronavirus disease 2019 (COVID-19) outbreak has had a major impact on medical and surgical activities. A decline in facial trauma incidence was noticed during the lockdown period. The aim of this study was to evaluate the decline in maxillofacial trauma in France during this particular period. A retrospective multicentre comparative study was initiated in 13 major French public hospital centres. The incidence of facial trauma requiring surgery during the first month of lockdown was compared to that during equivalent periods in 2018 and 2019. Differences in the types of trauma were also analysed. Thirteen maxillofacial departments participated in the study. A significant decline in maxillofacial trauma volumes was observed when compared to equivalent periods in 2018 and 2019 (106 patients compared to 318 and 296 patients, respectively), with an average reduction of 65.5% (P = 0.00087). The proportion of trauma due to sports and leisure was reduced when compared to reports in the literature. As a consequence, in the context of a pandemic, the material and human resources related to this activity could be reallocated to the management of other pathologies that cannot be postponed.

Repair of gauge earlobe medium defect

Defects due to earlobe gauging are becoming more and more frequent. Many techniques have been described to repair major defects but very few papers exist about medium defects. The aim of this article is to describe a simple surgical technique to repair medium deformations, based on two opposite crescents on the anterior and posterior sides of the earlobe. It gives a harmonious result to the overall shape of the earlobes with a natural curve along the inferior border which is the most difficult part of this surgery.

Impact of early intravelar veloplasty at six months on mandibular growth in patients with Pierre Robin Sequence

Pierre Robin Sequence (PRS) combines mandible microretrognathia, asynchronism of the pharynx and tongue, glossoptosis and, in some cases, cleft palate. Its principal functional consequences are respiratory and feeding problems during the neonatal period. In this study, we focused on the impact of early closure of the cleft at six months on mandibular growth in patients with PRS. We performed a retrospective study of 15 patients followed for PRS and undergoing surgery performed by the same senior surgeon (HB) at our cleft center between 2005 and 2012. These patients underwent early closure of the cleft (at a mean age of 5.87 months) by intravelar veloplasty, as described by Sommerlad. Only one article with exploitable data analyzing facial and mandibular growth in a cephalometric study of children with PRS has been published. The children in this series, constituting the control group for our study, underwent veloplasty between the ages of 12 and 18 months, often accompanied by labioglossoplasty, and the cephalometric study was carried out between the ages of four and seven years. We compared this control group in which surgery was performed at 12-18 months with our series of children undergoing surgery at six months, in a cephalometric study based on teleradiographic profile measurements performed between the ages of four and seven years. We found that early closure of the cleft soft palate yielded results identical to those for the control group in terms of mandibular growth, without the need for labioglossopexy. Finally, early intravelar veloplasty led to early functional improvement in terms of speech and phonation.

[Microcystic adnexal carcinoma: A case report]

We report a case of microcystic adnexal carcinoma in a 80-year-old woman. This is a rare malignant adnexal cutaneous tumor with glandular and follicular differentiation, rare, often asymptomatic, with late diagnosis and slow growth, locally aggressive and rarely metastatic. The distinction with other benign and malignant skin tumors is difficult.

Cholesterol granuloma of the maxilla

Intra-osseous cholesterol granuloma (CG) is a rare and benign lesion. Very few cases of CG of the jaws have been described in the literature. CG of the jaws seems to be due to the accumulation of cholesterol of hematogenous origin in odontogenic cysts. We report on one case of CG of the maxilla treated by surgical enucleation in a 46-year-old man who presented an asymptomatic swelling of the maxilla.

Tessier number 4 bilateral craniofacial cleft associated with amniotic band syndrome: 22 years of follow-up

Tessier clefts are a very rare entity. Number 4 Tessier cleft is describe like an orbito-facial cleft with trajectory between the lower eyelid and the lip. We report management of a bilateral number 4 Tessier cleft with amniotic band syndrome with 22 years of follow-up. After reviewing literature, we talk about difficulty to manage these kinds of rare Tessier clefts.

Study of the mechanical reliability of an S-shaped adjustable osteosynthesis plate for bilateral sagittal split osteotomies. Study on 15 consecutive cases

INTRODUCTION

The main challenge during the osteosynthesis of a bilateral sagittal split osteotomy (BSSO) is to take into account the correct position of the condyle. Adjustable plates can be used to fine-tune the final occlusion without changing the osteosynthesis. A new type of adjustable plate is presented in this article. The aim is to assess the mechanical reliability of this system during the surgery and during the healing period, thanks to a preliminary prospective on 15 consecutive cases.

MATERIAL AND METHODS

The bridge of the plate studied here has an "S"-shape and can be bent in two different planes. Fifteen patients presenting a maxilla-mandibular disharmony have been operated on with this device. Clinical results were evaluated three months postoperatively and the mechanical reliability of the device was studied prospectively from teleradiographies of 15 patients operated on in our department.

RESULTS

This study shows good results, with respect to the mechanical reliability of this S-shaped adjustable plate, three months postoperatively corresponding to the bone-healing period. Radiographic observations did not show any significant displacement at the osteosynthesis site.

DISCUSSION

This preliminary study shows the mechanical reliability of this new S-shaped adjustable plate. Its semi-rigid character may allow for certain condyle position adaptability. No plate fracture was reported for this 15 patient series. These encouraging results have to be confirmed on a larger series.

Cheiloplasty associated to a palatal obturator in a preterm infant with a cleft lip and palate

INTRODUCTION

Preterm infants are commonly treated by non-invasive ventilation (NIV) and nasal continuous positive airway pressure (CPAP), which are associated with fewer complications than nasotracheal intubation. In preterm infants with a cleft lip and palate, this method of respiratory management is difficult or impossible to perform because of air leakage through the cleft defect.

CASE

We report a male infant who was born at 29 weeks of gestation with a left complete unilateral cleft lip and palate. Birth weight was 900 grammes. Because of the cleft, we have any problems to ventile this infant. We decide to close the cleft prematurely on day 17 after multidisciplinary discussion.

DISCUSSION

NIV cannot be performed with the usual equipment in very premature infants with a cleft lip and palate because of air leakage through the cleft defect. Very few studies report pre term infant with cleft lip and palate and his difficulties of ventilation. This is the first case reported to perform cheiloplasty on a 900g preterm infant.

[Diagnosis and management of ankyloglossia in young children]

Ankyloglossia is a common condition. Its prevalence is between 3.2% and 4.8% depending on the series and is largely underestimated given the fact of non-diagnosis when the symptoms are limited. It is defined as a short lingual frenulum resulting in a limitation of the lingual mobility. It is due to a defect in cellular apoptosis embryogenesis between the floor of the mouth and tongue. The result is a fibrous and short lingual frenulum. Several classifications were used to make the diagnosis. However, these are the clinical implications, particularly on food and primarily breastfeeding in the baby and phonation in older children that will motivate the management. This is surgical and different techniques are available: infants before the age of 6 months and when the lingual frenulum is still a fine cellular membrane, frenotomy is recommended. Frenectomy with or without frenoplasty is indicated for the older child. The surgery is simple, the results are good and rapidly improving grievances. Complications are rare. Finally, speech therapy is important when there are implications for phonation.

Treatment of the nasal abnormalities of Hallermann-Streiff syndrome by lipofilling

Hallermann-Streiff syndrome (HSS) is a rare congenital abnormality affecting mostly the head and face area. Craniofacial deformities, which are present in 98-99% of cases, are the principal abnormalities detected. We focus here on a particular subset of these deformities: atrophy of the skin of the centre of the face and nose. Two patients diagnosed with HSS were treated in our department. Both patients underwent nasal lipofilling to treat the atrophy of the nasal skin, as described by Nguyen et al. In both cases, a satisfactory improvement in nasal skin colour and texture was observed. A functional gain was also reported by the parents and observed during follow-up consultations. Lipofilling thus appears to be an excellent option for treating craniofacial deformities in children.

[Split temporalis muscle flap vascularized by the superficial temporal pedicle]

INTRODUCTION

The temporalis muscle has been used for more than a century for facial reconstruction. But this flap cannot fill defects beyond the midline. Splitting the temporalis muscle in the plane of the tendon insertion allows lengthening the flap and crossing the midline.

TECHNICAL NOTE

The scalp incision is followed by a subcutaneous dissection, taking care to spare hair follicles and superficial temporal vessels. Then the temporalis muscle is detached by a strictly subperiosteal dissection and deep temporal pedicles are dissected and ligated. The flap is split in the plane of the insertion tendon up to its distal end.

DISCUSSION

This technique allows reconstructing cranio-facial defect beyond the midline with well-vascularized tissue.

Split temporalis muscle flap anatomy, vascularization and clinical applications

INTRODUCTION

For more than a century, the temporalis muscle has been used for facial reconstructions. More recently, a split temporalis muscle flap elevated on the superficial temporal pedicle has been described, for which the resulting gain of length makes crossing of the midline possible, as well as reconstruction of substance losses exceeding the midline.

MATERIALS AND METHODS

Fourteen fresh cadaveric dissections were performed to study the different techniques for splitting the temporalis muscle. Dissections with catheterization and injection of radio-opaque contrasting agent in the external carotid artery were then performed to specify the vascularization of the flap split on the superficial temporal pedicle.

RESULTS

The duplication of the superficial temporal pedicle grants greater length compared to that of the deep pedicles, 57 mm versus 40 (p = 0.036). The middle temporal artery is capable of ensuring the vascularization, and therefore the viability, of the split flap. From these results, we spoke about the limitations of this study and we have inferred the main indications.