Osteocyte numbers decrease only in postcranial but not in cranial bones in humans of advanced age

Nanocrystalline hydroxyapatite in regeneration of periodontal intrabony defects: A systematic review and meta-analysis

BACKGROUND

Alveolar bone loss and mobility of teeth is commonly observed in periodontitis patients. Regeneration of periodontal intrabony defects is indicated to restore the lost bone and periodontal tissues. The aim of the present study was to evaluate the clinical outcomes of periodontal intrabony lesions by using nanocrystalline hydroxyapatite (NHA) graft and comparing it with open flap debridement (OFD) alone.

MATERIALS AND METHODS

The eligibility criteria encompassed randomized (RCTs) and controlled clinical trials (CCTs). Weighted mean differences were calculated for clinical attachment level (CAL) gain, probing pocket depth (PPD) reduction and gingival recession (REC) change, demonstrated as forest plots. The revised Cochrane Risk of Bias tool for randomized trials (RoB2) and Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool were used for quality assessment of RCTs and non-randomized trials respectively.

RESULTS

From 22 full-text articles identified, three RCTs, one CCT and one retrospective follow-up of RCT were included. All the five papers comprised the quantitative evaluation. The use of NHA graft provided additional CAL gain of 0.96 mm (p = 0.0009) and PPD reduction of 0.97 mm (p < 0.00001) when compared to OFD alone. However, in terms of REC changes, no considerable benefits of NHA graft were demonstrated than OFD alone (p = 0.48).

CONCLUSIONS

The bioactive NHA graft showed promising results clinically in regenerative periodontology and can be considered for the management of periodontal intrabony defects. The use of NHA graft considerably provided better clinical outcomes in intrabony defects compared to using the OFD alone. Future research investigating NHA graft against other regenerative materials including specific BGs, at longer follow-up periods and bigger sample sizes and in furcation defects warranted.

The Cranial Bowl in the New Millennium and Sutherland's Legacy for Osteopathic Medicine: Part 2

Cranial osteopathic medicine is practiced all over the world, respecting the dictates of the creator, Dr Sutherland. Despite the current manual approach faithfully follows the theoretical and practical bases that make up the cranial model of the last century, there are many scientific evidences that highlight the criticalities of the same model. In the first part we reviewed the role of the meninges and cerebrospinal fluid (CSF), as well as we discussed some rhythms present in the central nervous system; these latter elements are the pillars to support the theoretical idea of the movement of the skull evaluated and palpated by the osteopath. In this second part we will review the mechanical characteristics of other structures that make up the cranial system, highlighting new perspectives for clinical practice, thanks to the most recent data derived from scientific research.

Muscle-Bone Crosstalk in the Masticatory System: From Biomechanical to Molecular Interactions

The masticatory system is a complex and highly organized group of structures, including craniofacial bones (maxillae and mandible), muscles, teeth, joints, and neurovascular elements. While the musculoskeletal structures of the head and neck are known to have a different embryonic origin, morphology, biomechanical demands, and biochemical characteristics than the trunk and limbs, their particular molecular basis and cell biology have been much less explored. In the last decade, the concept of muscle-bone crosstalk has emerged, comprising both the loads generated during muscle contraction and a biochemical component through soluble molecules. Bone cells embedded in the mineralized tissue respond to the biomechanical input by releasing molecular factors that impact the homeostasis of the attaching skeletal muscle. In the same way, muscle-derived factors act as soluble signals that modulate the remodeling process of the underlying bones. This concept of muscle-bone crosstalk at a molecular level is particularly interesting in the mandible, due to its tight anatomical relationship with one of the biggest and strongest masticatory muscles, the masseter. However, despite the close physical and physiological interaction of both tissues for proper functioning, this topic has been poorly addressed. Here we present one of the most detailed reviews of the literature to date regarding the biomechanical and biochemical interaction between muscles and bones of the masticatory system, both during development and in physiological or pathological remodeling processes. Evidence related to how masticatory function shapes the craniofacial bones is discussed, and a proposal presented that the masticatory muscles and craniofacial bones serve as secretory tissues. We furthermore discuss our current findings of myokines-release from masseter muscle in physiological conditions, during functional adaptation or pathology, and their putative role as bone-modulators in the craniofacial system. Finally, we address the physiological implications of the crosstalk between muscles and bones in the masticatory system, analyzing pathologies or clinical procedures in which the alteration of one of them affects the homeostasis of the other. Unveiling the mechanisms of muscle-bone crosstalk in the masticatory system opens broad possibilities for understanding and treating temporomandibular disorders, which severely impair the quality of life, with a high cost for diagnosis and management.