Biomimetic Periodontal Ligament Transplantation Activated by Gold Nanoparticles Protects Alveolar Bone.

Stem cell therapy might be a promising method to stimulate alveolar bone regeneration, which is currently a major clinical challenge. However, its therapeutic features largely depend on pretreatment and transplantation preparation. Herein, a novel biomimetic periodontal ligament transplantation composed of human periodontal ligament stem cells (hPDLSCs) pretreated with gold nanocomplexes (AuNCs) and embedded in a type-I collagen hydrogel scaffold is developed to protect alveolar bone from resorption. AuNCs are readily absorbed by primary hPDLSCs, with limited cytotoxicity, and promote osteogenic differentiation of hPDLSCs effectively in vitro. In addition, the AuNCs-induced hPDLSCs are encapsulated with type-I collagen hydrogel scaffold to mimic their native physiological niche, and then are transplanted into a rat model of alveolar bone resorption. Both micro-computed tomography (micro-CT) and immunohistochemical assays demonstrate that alveolar bone loss is significantly prevented. Furthermore, the underlying therapeutic mechanism is elucidated, in which transplantation-activated osteogenesis is associated with autophagy, which enables bone remodeling and regeneration. This study provides critical insight into the role of PDLSCs in bone homeostasis and proposes an innovative AuNCs-based strategy for stem cell therapy in bone regeneration.

In Vivo Micro-Computerized Tomography Tracking of Human Periodontal Ligament Stem Cells Labeled with Gold Nanocomplexes.

Gold nanocomplexes have been proposed as contrast agents for computerized tomography (CT) and cell tracking, which is especially useful in stem cell therapy. However, their potential for long-term in vivo cell detection is still unknown. This study proposes an optimized approach to labeling human periodontal ligament stem cells (hPDLSCs) with gold nanocomplexes to evaluate their detection with micro-CT after transplantation at four different rat tissues. The gold nanocomplexes of 0.05 mg mL-1 do not affect cell viability nor osteogenic differentiation capacity, but render fluorescent and radiopaque hPDLSCs. Excellent linear correlation with the number of labeled cells is shown over a wide range (r = 0.99, P < 0.01), with a detection limit of ≈1.2 × 103 cells/µL. In vivo, strong, and durable detection of transplanted labeled cells within 5 days at all investigated areas is seen by micro-CT and immunohistochemical assay. This approach confirms the potential of gold nanocomplexes in longitudinal in vivo cell tracking, which may facilitate their application in CT image-guided interventions commonly used in oromaxillofacial or systemic applications of stem cell therapy.

Surgical and Orthodontic Approach to Temporomandibular Joint Ankylosis After Ear Infection: A Case Series.

Ankylosis of the temporomandibular joint (TMJ) is defined as the emergence of a bony or fibrous compound between the condyle and the cranial base. It can result in divergent craniofacial characteristics. The aim of this study was to present an orthodontic-surgical approach in a case series of 4 patients with a diagnosis of TMJ ankylosis as a complication of otomastoiditis. The patient characteristics of 4 patients in whom TMJ ankylosis was diagnosed as a complication of otomastoiditis were described. All patients were treated with gap arthroplasty with costochondral graft, physiotherapy, and orthodontic therapy to achieve acceptable mouth opening and function. All reacted differently to this therapy, and additional interventions were required during childhood. In early-onset ankylosis, however, guiding the mandibular growth orthodontically can prevent increasing facial asymmetry and canting of the occlusal plane. After the pubertal growth spurt is finished, orthodontic treatment combined with surgical intervention may be considered to correct facial asymmetry and provide good dental occlusion. Orthodontic and surgical treatments showed themselves to be fundamental for patients with TMJ ankylosis as a complication of otomastoiditis, although continual monitoring until the end of growth is necessary to achieve the most functional recovery possible.

Dental development in cleft lip and palate patients: A systematic review.

OBJECTIVE: To investigate a potential delay in dental development in cleft patients compared with non-cleft patients. SEARCH METHODS: An unlimited electronic search was performed in four databases (PubMed, Embase, Lilacs and OpenGrey), from inception until October 2018. Full text articles concerning dental development or tooth eruption of non-syndromic children with cleft lip and/or palate (CL(P)) were included and reviewed. Case reports/series, review articles, articles in languages other than English, Dutch, French or Spanish and studies considering the eruption of deciduous teeth were excluded. Data extraction followed the PRISMA guidelines and study quality was assessed using MINORS. RESULTS: The primary search resulted in 991 citations, of which 36 studies were finally analyzed. Most articles were retrospective studies based on panoramic radiographs. A delay in tooth development or -eruption in CL(P) patients was found in 32 out of the 36 included articles. The amount of delay varied from 0.20 to 0.90 years, with a mean delay of 0.56 years for all types of clefts. In UCLP patients, a mean delay of 0.53 years was found. The lateral incisor at the cleft side was generally the most delayed. Conflicting results were found regarding the influence of sex and age. The amount of delay was reported to be independent of the cleft severity or type. The teeth near the cleft generally showed a greater delay than the teeth further away from it. Finally, an increased risk of asymmetrical tooth development in CL(P) patients was observed in all publications studying this aspect. 31 articles were comparative, 5 were non-comparative; with a median MINORS score of 16/24 (range 10-18) and 10/16 (range 8-10) for both groups respectively. CONCLUSIONS: The majority of the included articles reports a delay in dental development or tooth eruption in CL(P) patients compared to non-CL(P) patients. The obtained results could be important for forensic age estimation outcomes and for orthodontic and surgical treatment planning in CL(P) patients. The delay in tooth development implies a delay in start of orthodontic treatment. Moreover, CL(P) patients could falsely be considered to be a minor when applying the existing reference tables for dental age estimation. SYSTEMATIC REVIEW REGISTRATION: International prospective register of systematic reviews (PROSPERO: CRD42018082106).

Regenerative Endodontic Procedures Posttrauma: Immunohistologic Analysis of a Retrospective Series of Failed Cases.

INTRODUCTION: Regenerative endodontic procedures (REP) are a novel treatment modality to restore the function of necrotic pulp tissue via stimulation or transplantation of stem cells into the root canal. This study aimed to investigate the immunohistologic outcome of 3 extracted teeth because of sequelae of trauma and unsatisfactory REP outcomes. METHODS: Three immature permanent maxillary central incisors of 3 female patients (6-9 years) were extracted 5.5-22 months after REP. Additionally, 1 sound permanent immature central maxillary incisor of 1 of the included patients was extracted for orthodontic reasons. The teeth were immunohistologically stained with Masson's trichrome, neurofilament (NF), pan cytokeratin, dentin sialophosphoprotein, and Gram+/-. RESULTS: The REP-teeth presented intracanalar vascularized connective/mineralized reparative tissue (RT), which was less organized than the pulp tissue of the sound tooth. Moderate to considerable calcification was observed below the Portland cement used during REP. In 1 case, the RT was NF+; in the 2 other cases, the periodontal ligament and apical granuloma/papilla were NF+. All teeth were Gram+/- negative; nevertheless, inflammatory cells were present in 2 cases. The pan cytokeratin and dentin sialophosphoprotein stainings were not specific enough for 2 cases. CONCLUSIONS: This immunohistologic study of failed REP cases resulted in bacteria-free intracanalar RT and biomaterial-induced calcification. Nevertheless, the presence of inflammatory cells revealed a persistent inflammation. Hence, the clinical and radiographic signs were decisive for tooth survival and multidisciplinary outcome determination.