An integrative approach for comparing microcirculation between normal and alveolar cleft gingiva in children scheduled for secondary bone grafting procedures

Evaluation of peri-implant perfusion in patients who underwent avascular augmentation or microvascular reconstruction using laser Doppler flowmetry and tissue spectrophotometry: a prospective comparative clinical study

OBJECTIVES

The aim of this study was to evaluate the peri-implant perfusion, such as oxygen saturation, the relative amount of hemoglobin, and blood flow, in implants placed in pristine bone and avascular and microvascular grafts using a non-invasive measurement method.

MATERIALS AND METHODS

A total of 58 patients with 241 implants were included. Among them, 106 implants were based in native bone (group I), 75 implants were inserted into avascular bone grafts (group II), and 60 implants were placed in microvascular bone grafts (group III). Gingival perfusion was measured using laser Doppler flowmetry and tissue spectrophotometry (LDF-TS). Implants with signs of gingival inflammation were excluded to analyze healthy implant perfusion in different bony envelopes.

RESULTS

The mean values for oxygen saturation, relative hemoglobin levels, and blood flow did not differ significantly between the groups (p = 0.404, p = 0.081, and p = 0.291, respectively). There was no significant difference in perfusion between implants that were surrounded by mucosa and implants based within cutaneous transplants (p = 0.456; p = 0.628, and p = 0.091, respectively).

CONCLUSION

No differences in perfusion were found between implants inserted into native bone and implants involving bone or soft tissue augmentation. However, implants based in avascular and microvascular transplants showed higher rates of peri-implant inflammation.

CLINICAL RELEVANCE

Peri-implant perfusion seems to be comparable for all implants after they heal, irrespective of their bony surroundings. Although perfusion does not differ significantly, other factors may make implants in avascular and microvascular transplants vulnerable to peri-implant inflammation.

Determination of baseline alveolar mucosa perfusion parameters using laser Doppler flowmetry and tissue spectrophotometry in healthy adults

Objectives: To determine the baseline perfusion parameters of the alveolar mucosa using laser Doppler flowmetry and tissue spectrophotometry (LDF-TS) in healthy adults.Material and methods: Forty-two healthy adult subjects of either sex were tested. The perfusion of the alveolar mucosa was evaluated using a laser Doppler flowmetry and tissue spectrophotometry using O2C 'oxygen to see' device. The measurements encompassed the maxillary and mandibular mucosa at 20 different points.Results: The O2C device is a reliable method for noninvasive measurement of different perfusion parameters of the oral mucosa. The hemoglobin saturation values (So2 in %), as well as relative amount of hemoglobin in arbitrary units (AU) of the maxillary mucosa demonstrated lower values of that in the mandible. The flow value (AU) exhibited a significant difference in the posterior molar region only, while the velocity value (AU) showed a significant difference across all points except for the anterior region.Conclusion: the present study provides a set of brand-new perfusion parameters of the microcirculation of the alveolar mucosa using LDF-TS. The study suggests a variation of the perfusion parameters between the maxilla and the mandible. Differences in the anatomy of the blood supply, the thickness of the mucosa and the cortical bone, may be attributed to this variation. Further studies using different probes and a combination of ultrasonic measurements and SDF imaging will aid in giving a better overview of the perfusion in the oral mucosa.

Rat Palatine Fissure: A Suitable Experimental Model for Evaluating Bone Regeneration

IMPACT STATEMENT

The rat palatine fissure is anatomically similar to human alveolar cleft. In this study, we examined potential bone repair by an autologous bone implant and beta-tricalcium phosphate (β-TCP) using rat palatine fissure as a model. Autologous bone chips or β-TCP granules were implanted into the rat palatine fissure. Our model demonstrated that higher bone volume and bone mineral density were achieved with autologous bone graft than with β-TCP. We have provided the first demonstration of the suitability of the rat palatine fissure as the implant site to simulate the transplantation of bone graft materials into human alveolar cleft.

A novel method for in vivo visualization of the microcirculation of the mandibular periosteum in rats

OBJECTIVE

The periosteum plays an important role in bone physiology, but observation of its microcirculation is greatly limited by methodological constraints at certain anatomical locations. This study was conducted to develop a microsurgical procedure which provides access to the mandibular periosteum in rats.

METHODS

Comparisons of the microcirculatory characteristics with those of the tibial periosteum were performed to confirm the functional integrity of the microvasculature. The mandibular periosteum was reached between the facial muscles and the anterior surface of the superficial masseter muscle at the external surface of the mandibular corpus; the tibial periosteum was prepared by dissecting the covering muscles at the anteromedial surface. Intravital fluorescence microscopy was used to assess the leukocyte-endothelial interactions and the RBCV in the tibial and mandibular periosteum. Both structures were also visualized through OPS and fluorescence CLSM.

RESULTS

The microcirculatory variables in the mandibular periosteum proved similar to those in the tibia, indicating that no microcirculatory failure resulted from the exposure technique.

CONCLUSION

This novel surgical approach provides simple access to the mandibular periosteum of the rat, offering an excellent opportunity for investigations of microcirculatory manifestations of dentoalveolar and maxillofacial diseases.

Vaginal microcirculation: Non-invasive anatomical examination of the micro-vessel architecture, tortuosity and capillary density

AIM

To describe the vaginal microcirculatory architecture and capillary density parameters using sidestream dark-field imaging (SDFI), and determine feasibility and reliability of this method.

METHODS

In nine healthy female volunteers SDFI measurements were performed at two different time points in the luteal phase of the menstrual cycle. Non-invasive tissue micro-angioarchitecture and vaginal capillary density measurements were assessed independently by two observers. Agreement was expressed with mean differences between the measurements of both observers and the limits of agreement. Inter- and intra-observer agreement was quantified with the intra-class correlation coefficient (ICC).

RESULTS

Vaginal microcirculatory assessment with the SDFI device was easy in use, painless and well accepted by the participants. Morphologically, the vaginal microcirculation revealed an array of single hairpin-shaped capillary loops distributed homogeneously across an imaged tissue segment. The intra-observer assessment of the capillary density measurements (comparing two measurement time points of one observer) showed good agreement with an ICC ranging from 0.62 to 0.85. The inter-observer assessments of the capillary density measurements (comparing assessments of two observers at one time point) revealed very good agreement, with small differences between observers and an ICC of more than 0.9.

CONCLUSIONS

This is the first report on both microcirculatory architecture and quantitative microcirculatory parameters of the vagina with the use of SDFI. Micro-vessels of the vagina show a recognizable pattern in our study population of young, healthy women. SDFI gives a reproducible assessment of the vaginal microcirculation offering the researcher a wide field of applications.