[Oral mesenchymal cells, a specific niche, from development to regeneration]. / Les cellules mésenchymateuses orales, une niche spécifique, du développement à la régénération.

Oral buccal tissues, including bone and mucosa, have unique properties. Oral mucosal fibroblasts and jaw osteoblasts, both derived from Cranial Neural Crest cells, play a key role in healing and repair. These cells express a specific repertoire of genes with their regenerative properties, but also craniofacial diseases. Understanding these tissues holds clinical promise for tissue regeneration and repair of bone and mucosal defects. These multidisciplinary advances also offer potential for better management of periodontal-related conditions and improved oral health.

Title: Les cellules mésenchymateuses orales, une niche spécifique, du développement à la régénération. Abstract: Les tissus muqueux et osseux oraux présentent des propriétés uniques. Les fibroblastes de la muqueuse orale et les ostéoblastes des mâchoires, issus des crêtes neurales crâniennes, jouent un rôle clé dans la cicatrisation/réparation. Ces cellules expriment un répertoire spécifique de gènes associés à leurs propriétés régénératives, mais aussi liés aux maladies rares crâniofaciales. La connaissance de ces tissus ouvre des perspectives cliniques pour la régénération tissulaire et la réparation des défauts osseux et muqueux. Ces avancées multidisciplinaires ont aussi un impact prometteur sur la prise en charge des maladies liées au parodonte et sur l'amélioration de la santé bucco-dentaire.

Replacement of missing lateral incisors for patients with cleft lip and palate: A decision-making tree based on a systematic review of the literature.

STATEMENT OF PROBLEM: Cleft lip and palate are the most frequent congenital anomalies of the face and are often linked with lateral incisor agenesis. The therapeutic decision on whether and how to replace the lateral incisors is not straightforward, and a decision-making tree is needed. PURPOSE: The purpose of this systematic review was to evaluate the available literature reporting on treatments for the replacement of missing lateral incisors in cleft areas. By analyzing the success and survival rates of these treatments, a decision-making tree was developed. MATERIAL AND METHODS: The literature search was performed on the PubMed (MEDLINE), Web of Science, Cochrane, EMBASE, Dentistry of Oral and Science Source, and Google Scholar databases and was based on the question: Which treatment for patients with lateral incisor agenesis and cleft lip and palate has a good success rate? RESULTS: Twenty-six articles were included in this systematic review. A meta-analysis was performed on 14 articles (20 case series, 6 case controls). The estimated overall 5-year survival rates were 96.4% for implant-supported prostheses. CONCLUSIONS: Different treatment options are available, depending on the clinical situation. If the patient meets the conditions for implant placement, this treatment remains a preferred solution. If the prosthetic space is reduced, orthodontic space closure and composite resin restorations are possible. When these options are not possible, a resin-bonded fixed partial denture is the preferred option. If the teeth adjacent to the edentulous area require extensive restorations, a fixed partial denture may be a suitable alternative.

Role of periosteum during healing of alveolar critical size bone defects in the mandible: a pilot study.

OBJECTIVES: Minipigs present advantages for studying oral bone regeneration; however, standardized critical size defects (CSD) for alveolar bone have not been validated yet. The objectives of this study are to develop a CSD in the mandibular alveolar bone in Aachen minipigs and to further investigate the specific role of periosteum. MATERIALS AND METHODS: Three female Aachen minipigs aged 17, 24, and 84 months were used. For each minipig, a split-mouth design was performed: an osteotomy (2 cm height × 2.5 cm length) was performed; the periosteum was preserved on the left side and removed on the right side. Macroscopic, cone beam computed tomography (CBCT), microcomputed tomography (µCT), and histological analyses were performed to evaluate the bone defects and bone healing. RESULTS: In both groups, spontaneous healing was insufficient to restore initial bone volume. The macroscopic pictures and the CBCT results showed a larger bone defect without periosteum. µCT results revealed that BMD, BV/TV, and Tb.Th were significantly lower without periosteum. The histological analyses showed (i) an increased osteoid apposition in the crestal area when periosteum was removed and (ii) an ossification process in the mandibular canal area in response to the surgical that seemed to increase when periosteum was removed. CONCLUSIONS: A robust model of CSD model was developed in the alveolar bone of minipigs that mimics human mandibular bone defects. This model allows to further investigate the bone healing process and potential factors impacting healing such as periosteum. CLINICAL RELEVANCE: This model may be relevant for testing different bone reconstruction strategies for preclinical investigations.