Assessment of Palatal Mucosal Wound Healing Following Connective-Tissue Harvesting by Laser Speckle Contrast Imaging: An Observational Case Series Study

Ultrasonographic analysis of palatal donor site healing accelerated with platelet-rich fibrin following subepithelial connective tissue harvesting

OBJECTIVE

Platelet-rich fibrin (PRF) contains a variety of growth factors and bioactive molecules that play crucial roles in wound healing and angiogenesis. We aimed to evaluate the effects of PRF on tissue thickness and vascularization of the palatal donor site by ultrasound (USG) following subepithelial connective tissue harvesting.

METHODOLOGY

A subepithelial connective tissue graft was harvested from the palatal region with a single incision for root coverage in 20 systemically healthy patients. In the test group (n = 10), the PRF membrane was placed at the donor site, whereas no material was applied in the control group (n=10). Palatal tissue thickness (PTT) and pulsatility index (PI) were evaluated by USG at baseline and on the 3rd, 7th, 14th, 30th, and 90th days after surgery. The early healing index (EHI) was used to evaluate donor site healing for 30 days.

RESULTS

PTT was significantly higher in the PRF group on the 3rd and 14th days after surgery when compared to the controls. In the PRF-treated group, PI levels were significantly higher than in the controls, especially on the 14th day. PTT increased significantly 90 days after surgery compared to the test group baseline, but controls showed a significant decrease. The PRF group showed statistically significant improvements in EHI scores compared to controls on days 3, 7, and 14. This study found a negative correlation between PI values and EHI scores on postoperative days three and seven in the test group.

CONCLUSION

USG is a non-invasive, objective method to radiographically evaluate the regenerative effects of PRF on palatal wound healing after soft tissue harvesting. To overcome graft inadequacy in reharvesting procedures, PRF application may enhance clinical success and reduce possible complications by increasing tissue thickness and revascularization in the donor area.

Oral Wound Healing: A Scoping Review and Proposal of a New Index for Palatal Mucosa

Purpose

The aim of this scoping review was to evaluate the wound healing indices available in literature and propose a new intra-oral wound healing index to assess the healing of palatal mucosa.

Materials and Methods

A PubMed database search was conducted to identify relevant studies using the search strategy: ('Oral Wound healing') OR ('Palatal tissue healing') OR ('Healing indices in Oral and Maxillofacial Surgery') OR ('Palatal wound healing') OR ('Complications in wound healing'). A qualitative and quantitative synthesis of the results was done and data was presented following the PRISMA-ScR guidelines.

Results

The search resulted in 9 articles published between 2019 and 2022, which were eligible for inclusion in the study. The data revealed that the indices currently available for the assessment of intra-oral healing were limited and primarily concerned with the assessment of gingival and periodontal tissues.

Conclusion

The healing indices devised for gingival and periodontal tissues cannot be applied to palatal healing due to the differences in clinical and histological aspects. Therefore, a new index to monitor the healing response specifically for the soft tissues in the palate has been proposed. This maybe particularly useful in cleft palate repair and other procedures performed over the palatal tissues.

Acute effects of traditional and electronic cigarettes on palatal blood flow in smokers: A cross-over pilot study

Background

Smoking is a significant health hazard and contributes to cardiovascular and pulmonary diseases. It can increase postoperative complications during oral and maxillofacial surgery due to its topical effect on the oral mucosa. New alternatives to traditional tobacco products are gaining popularity, in particular, electronic cigarettes.

Objectives

This pilot study investigated the acute effects of nicotine-containing and nicotine-free electronic cigarettes on palatal blood flow (PBF), and compared their effects to traditional cigarettes.

Materials and methods

14 medically healthy volunteers (8 males, 6 females, age: 34.7 ± 7.0) were recruited for the study. All patients (N = 14) were requested to smoke nicotine-containing (ECN) and nicotine-free electronic cigarettes (EC0) and a mouthpiece (end of a traditional cigarette) as a control sham smoking blind test (BT). EC users did not smoke a traditional cigarette (TC), resulting in 10 people in the TC group. Palatal blood flow was measured by Laser Speckle Contrast Imager before, immediately after, and 15 min after the exposures. Exhaled carbon monoxide (eCO) and carboxyhemoglobin (COHb) were measured before and immediately after smoking with a piCO+ Smokerlyzer machine.

Results

In all groups, no significant differences were observed in the changes of palatal blood flow between time points. Exhaled carbon monoxide and carboxyhemoglobin were significantly higher in the traditional cigarette (TC) group compared to the nicotine-containing electronic cigarette (ECN) and nicotine-free electronic cigarette (EC0) groups, both before and after the exposure (p < 0.05).

Conclusion

Acute use of either traditional or electronic cigarettes may have minimal impact on palatal blood flow, but additional studies are required to clarify their impact on the mucosa.

Revisiting the vascularity of the keratinized gingiva in the maxillary esthetic zone

Background

The active arterial-to-arterial collaterals are a significant factor in the prevention of ischemia and extensive tissue necrosis in the case of arterial blockage of various tissues. The present study investigates the mucogingival vasculature in the maxillary esthetic zone mucosa in human cadavers and functionally evaluates the area, which is supplied by the terminal arterioles, on the individual level.

Methods

In the human cadaver study, macroscopic arterial analyses of the anterior maxillary vestibule in 7 specimens were scrutinized by latex milk injection. The tracks of the mucosal branches in relation to the mucogingival junction were investigated. In the functional study, individual gingival blood flow (GBF) changes were measured by laser speckle contrast imaging (LSCI) in 31 young subjects with healthy gingiva before and during 30-s compressions. This was conducted with a ball-shaped condenser. The data was analyzed by the linear mixed model.

Results

The vertically aligned branches of the superior labial artery (SLA) divided into small, slightly deviating sub-branches near the mucogingival junction. These arteries created collateral plexuses and supplied the attached gingiva. The compression of these branches resulted in ischemia coronally with significant individual variation. The ischemia was either apico-mesial, apico-distal, or straight apical to the compression. A significant correlation was found between the ischemic area and the magnitude of the decrease in GBF (r = 0.81, p < 0.001). In males, 77% of the subjects, and 50% of the female subjects had an ischemic response in either region. The horizontal extension of the ischemic area ranged between 0.26 mm and 8.76 mm. Males had significantly higher baseline GBF and larger ischemia than females. At the base of the papilla, significant restoration of GBF was observed during compression in males, but not in females.

Conclusion

The arcade anastomoses formed by the small arteries in the keratinized gingiva of the upper esthetic zone explain the consequences of vertical incisions. The considerable individual variations in ischemic responses might be the reason for unexpected surgical outcomes in some cases. Furthermore, there is increasing evidence that men have different vascular reactivity and/or regulation of collateral circulation than women, which may affect wound healing.

Ultrasonographic tissue perfusion analysis at implant and palatal donor sites following soft tissue augmentation: A clinical pilot study

AIM

To describe the application of power Doppler Ultrasonography (US) for evaluating blood flow at implant and palatal donor sites following soft tissue augmentation with the connective tissue graft (CTG).

MATERIALS AND METHODS

Five patients exhibiting a peri-implant soft tissue dehiscence received treatment with a coronally advanced flap and corresponding CTG. Power Doppler US was used for assessing blood volume at baseline, 1 week, 1 month, 6 months and 12 months post-surgery for assessing blood-flow dynamics at the implant and palatal donor sites. The speed-weighted and power-weighted colour pixel density (CPPD) were computed from colour velocity (CV) and colour power (CP), respectively.

RESULTS

A mean increase in CV of 199.25% was observed at the midfacial region of the implant sites after 1 week compared to baseline. CV and CP were increased in all sites at 1 week and 1 month. At 6 and 12 months, the mean CV appeared lower than baseline at the implant sites. CCPD was increased at the palatal donor sites and at the great palatine foramen areas at the 1-week and 1-month post-operative evaluations.

CONCLUSIONS

Power Doppler US is a non-invasive and valuable tool for estimating tissue perfusion and CPPD variation during different phases of intra-oral soft tissue graft healing.

Epinephrine penetrates through gingival sulcus unlike keratinized gingiva and evokes remote vasoconstriction in human

Background

It has been demonstrated in non-oral tissues that the locally evoked vasoconstriction could elicit remote vasoconstriction. This study aimed to investigate the spreading vasoconstrictor effects of epinephrine in the gingiva.

Methods

Gingival blood flow (GBF) was measured by laser speckle contrast imager in 21 healthy volunteers. In group A, two wells were fabricated from orthodontic elastic ligature and placed 2 mm apically to the free gingival margin at the mid buccal line of 12 (test side) and 21 (control side) teeth. The GBF was measured in the wells and tightly apical, coronal, distal and mesial to the wells. In group B, the wells were made on the buccal surface of the same teeth, including the gingival sulcus. Four regions were selected for measurement from the gingival margin reaching the mucogingival line (coronal, midway1, midway2 and apical). After the baseline recording, 3 µg epinephrine was applied into the test, and physiological saline into the control well. The GBF was recorded for 14 min. The gingival thickness was measured with a PIROP Ultrasonic Biometer.

Results

In group A, the GBF did not increase or decrease after the application of epinephrine. In group B, the GBF significantly decreased in all regions of the test side and remained low for the observation period. The vasoconstriction appeared with delays in more apical regions (at min 1 in the coronal and the midway1, at min 2 in the midway2, at min 4 in the apical region). Similarly, the amount of the decrease at 14 min was the largest close to sulcus (− 53 ± 2.9%), followed by the midway1 (− 51 ± 2.8%) and midway2 (− 42 ± 4.2%) and was the lowest in the apical region (− 32 ± 5.8%). No correlation was found between GBF and gingival thickness.

Conclusion

Epinephrine could evoke intense vasoconstriction propagating to the mucogingival junction, indicating the presence of spreading vasoconstriction in the human gingiva. The attached gingiva is impermeable to epinephrine, unlike the gingival sulcus.

This trial was registered in ClinicalTrials.gov titled as Evidence of Spreading Vasoconstriction in Human Gingiva with the reference number of NCT04131283 on 16 October 2019. https://clinicaltrials.gov/show/NCT04131283