Cavity Defects Research Articles

Forehead Flap - A Salvage Option for Failed Anterolateral Thigh Flap in Buccal Mucosa Carcinoma Reconstruction

Introduction: Pedicled lateral forehead flap could be a valuable option for reconstruction in the floor of the orbit and floor of the mouth in the absence of other resources available. Case presentation: A-57-year-old male with multiple comorbidities, underwent partial maxillectomy, hemi mandibulectomy and hemiglossectomy with infratemporal fossa clearance due to a rapidly spreading buccal mucosa carcinoma on the left side. The last resort was the pedicled lateral forehead flap after unsuccessful reconstructive attempts with an anterolateral thigh flap. Discussion: The pedicled forehead flap which has rich vascularity, decreased donor site morbidity and reliable anatomy made it a favorable locoregional flap for oral reconstruction. Conclusion: Flaps should be chosen considering the patient’s condition and resources available. Forehead flap due to its proximity is an ideal option for reconstruction of oral cavity defects.

Feasibility of Super-thin Anterolateral Thigh Free Flap for Oral and Pharyngeal Reconstruction.

To highlight the feasibility of employing super-thin ALT free flaps for reconstruction of complex oral cavity and oropharyngeal defects. Retrospective chart review. Sixteen super-thin ALT free flaps were performed in 15 patients between 2020 and 2023 for reconstruction of oral cavity defects (seven oral tongue, three floor of mouth, three buccal, two oropharynx, one lower lip). Flap success rate was 100% with only minor complications reported, with no patient requiring return to the operating room within 30 days and no patient requiring radial forearm free flap reconstruction. One patient experienced partial flap failure, one patient experienced superficial necrosis of the distal skin paddle measuring 1 cm, and one patient was converted intraoperatively to a contralateral traditional ALT free flap due to insufficient perforator size. Average operative time was 509 min, average length of hospitalization was nine days, and two patients required gastrostomy placement prior to discharge for dysphagia. Super-thin ALT free flap harvest technique represents a feasible option for oral cavity and oropharyngeal reconstruction in select patients and does not require additional surgical training, invasive testing, or technology. It can be readily adopted by reconstructive surgeons with a simple adaptation in existing ALT harvest technique. Level 4 Laryngoscope, 2024.

Study on the Influence of Injection Velocity on the Evolution of Hole Defects in Die-Cast Aluminum Alloy

Aluminum alloy die casting has achieved rapid development in recent years and has been widely used in all walks of life. However, due to its high pressure and high-speed technological characteristics, avoiding hole defects has become a problem of great significance in aluminum alloy die casting production. In this paper, the filling visualization dynamic characterization experiment was innovatively developed, which can directly study and analyze the influence of different injection rates on the formation and evolution of alloy flow patterns and gas-induced defects. As the injection speed increased from 1.0 m/s to 1.5 m/s, the average porosity increased from 7.49% to 9.57%, marking an increase in the number and size of the pores. According to the comparison with Anycasting, simulation results show that a liquid metal injection speed of 1.5 m/s when filling the flow front vs. the previous injection rate of 1.0 m/s caused fractures when filling at the same filling distance. Therefore, the degree of the broken splash at the flow front is more serious. Combined with the analysis of transport mechanics, the fracturing is due to the wall-attached jet effect of the liquid metal in the filling process. It is difficult for the liquid metal to adhere to the type wall in order to fuse with subsequent liquid metal to form cavity defects. With an increase in injection velocity, the microgroup volume formed via liquid breakage decreases; thus the volume of air entrapment increases, finally leading to an increase in cavity defects.

Infrahyoid myocutaneous flap for reconstruction in head and neck cancer patients

Background: Reconstruction of head and neck defects following tumor excision is one of the most challenging surgeries due to multiple reasons, such as associated cosmetic and functional impairments. The three-dimensional aspect of the defect makes it more difficult. Although in modern settings, microvascular surgery is preferred in many conditions, it requires the presence of resources and expertise. Locoregional flaps are workhorse flaps in head and neck reconstruction. In this article, we present an uncommonly used flap with high acceptability and success rate in head and neck reconstruction. Aim: To find outcomes of using infrahyoid flap reconstruction in head and neck defects following cancer excision. Materials and Methods: The retrospective study was conducted in the surgical oncology department of our institute. Patients with squamous cell carcinoma of the oral cavity, clinically T1–T3 and N0–N1 stage, with anticipated defects of small to medium defects were included in the study. The study was conducted from July 2020 to June 2022, including a follow-up of 1 year. A total of 14 patients were included in the study. All patients had squamous cell carcinoma of the oral cavity involving different subsites. Patients were operated on by a single surgeon, using the same technique. Result: A total of 14 patients were included with a male-to-female ratio of 11:3 and age between 45 and 60 years. None of the patients underwent revision surgery, and none of the patients had total flap loss. Four patients had minor flap complications, of which three patients had partial, superficial skin necrosis of the flap which was managed conservatively and epithelized later. None of the patients developed major complications, oro-cutaneous fistula, or radiation necrosis. None of the patients developed recurrence after 1 year of surgery. Conclusion: The infrahyoid myocutaneous flap (IHF) is a fairly reliable and easy-to-perform flap for small- and medium-sized defects of the oral cavity, without requiring additional incisions and donor site reconstruction.

Study on the Plastic Deformation Mechanism of Void‐Containing Twin‐Crystal Magnesium with Symmetric Tilt Grain Boundary Angles

AbstractA twin‐crystal magnesium (Mg) model with 9 different symmetric tilt grain boundary (STGB) angles (20°–80°) with preset nanohole defects is established by atomsk and lammps software. The mechanical behavior of grain boundary (GB) angles on twin‐crystal Mg with cavity defects and its cavity evolution are simulated by the molecular dynamics method with embedded atomic potential, and the plastic deformation mechanism is revealed. The results show that the yield stress decreases with the increase of the STGB Angle during the stretching process. When the GB Angle increases from 20° to 80°, the yield stress decreases from 2.28 to 1.42 Gpa. This is because the larger the STGB Angle is, the larger the Schmidt factor is, and the easier it is to start dislocation slip during the stretching process. On the other hand, the larger the Angle of STGB, the more the number of atomic voids at the interface, and the more the number of dislocation nucleation points. The larger the Angle of STGB, the lower the strength of twinning Mg but the better the plasticity to avoid fracture. The plastic deformation mechanism mainly includes the nucleation of Shockley incomplete dislocation at STGBs, dislocation slip generates stacking faults (SFs), GB migration, and base plane dislocations.

Initial experience with ovine forestomach matrix graft for glossectomy defect reconstruction: A case series

Soft tissue reconstruction of oral cavity defects, such as glossectomy defects secondary to malignancy, pose a challenge for head and neck, oral, and maxillofacial surgeons. Reconstruction options for mucosal defects include primary closure, healing by secondary intention, full mucosal and split-thickness skin grafts, pedicled flaps, and microvascular free flaps. Biological grafts have become an integral part of the modern reconstructive ladder and are widely used for the regeneration of various soft tissue defects, including oral defects. This case series describes our initial experience using ovine forestomach matrix grafts in tongue and oral cavity reconstruction. Oral reconstruction using ovine forestomach matrix grafts was undertaken on three patients post wide excision and resulted in good functional and cosmetic outcomes. The rate of tissue formation provided by the graft and the grafts’ relative resistance to the hostile environment of the oral cavity support further clinical research to validate the use of these devices in oral reconstruction.

Local Flap Reconstructions in Oral Cavity Defects: An Insight from 104 Cases.

Resection of oral cavity carcinoma often leads to complex defects causing functional and aesthetic morbidity. Providing optimum reconstruction with free flaps becomes challenging in a high-volume center setting with constrained resources. Hence, understanding the local flap technique for reconstructing oral cancer defects is prudent. This study is a retrospective analysis of prospectively operated cases of oral cavity resections which were subsequently reconstructed using local flaps from 2019 to 2022. Patients who underwent reconstruction with either melolabial flap, islanded facial artery myomucosal (FAMM) flap, submental flap, supraclavicular artery island flap, infrahyoid flap, or platysma myocutaneous flap (PMF) were included in this analysis. Eligible patients were followed up to evaluate functional outcomes like oral feeding and to analyze the Performance Status Scale for Head and Neck Cancer. The study included 104 patients. The tongue was the most common subsite, resulting in most hemiglossectomy defects, which were reconstructed using the melolabial flap procedure. Buccal mucosa defects in our series were reconstructed using the supraclavicular flap, whereas the submental flap procedure was the choice for lower lip-commissure defects. Complications such as partial and total flap loss, deep neck infection, and donor site complications like infection and gaping, oral cutaneous fistula, parotid fistula, and seroma were analyzed; the supraclavicular flap presented with a majority of complications. Local flaps are an alternative to free flap reconstruction in select cases with optimum functional outcomes and minimal donor site morbidity. This article comprehensively reviews the surgical steps for various local flap procedures in oral cancer defects.

Research on wavelet packet energy entropy extraction method for acoustic signal of tunnel lining cavity

Abstract Tunnel lining cavity is a common disease in high-speed railway tunnels, which seriously affects the safe operation of the line.At present, the commonly used method is manual knocking inspection, but it relies on manual judgment, subjective factors have great influence, and there are errors. This paper proposes a feature extraction method of acoustic vibration signal of tunnel lining cavity based on wavelet packet energy entropy and uses wavelet packet energy entropy to realize the identification of cavity defects.The full-scale simulation model of tunnel with a radius of 6m was constructed by COMSOL and different cavity conditions were set up. The wavelet packet energy entropy characteristics of acoustic signals were extracted and analyzed. The mapping relationship between cavity depth and cavity size and wavelet packet energy entropy was explored. The wavelet packet energy entropy and frequency band distribution characteristics were extracted to realize the identification of cavity defects.The local model which can characterize the whole tunnel is designed and the embedded defects are verified by experiments. The results show that the wavelet packet energy entropy can be used as the identification feature of tunnel lining cavity defects. When the wavelet packet energy entropy is less than 2.53, the existence of tunnel lining cavity defects is characterized.When the wavelet packet energy entropy is in the range of 2.53-2.94, it characterizes the existence of the transition boundary between tunnel lining cavity defect and no disease.This index can be used to realize the rapid and effective identification of cavity defects.

Impact of Flap Size and Comorbidities on Supraclavicular Artery Island Flap Outcomes.

Use of the supraclavicular artery island flap (SCAIF) in head and neck reconstruction has increased in recent years. Limited but improving experience among reconstructive surgeons with the procedure have exposed numerous issues associated with flap success. The objective of this study is to examine the role of flap size on viability. Retrospective case series. Tertiary Academic Medical Center. Review of patients undergoing SCAIF reconstruction between January 2014 and March 2022 was performed. Flap failure was defined as >50% skin paddle loss. The total flap surface area was examined. Multivariable analysis was performed to evaluate the association of other variables associated with flap failure. Eighty-nine supraclavicular island flaps were reviewed. Mean patient age was 63.2 ± 11.4 years. Fifty-five (61.2%) were male. Forty-five flaps (50.6%) were used for the reconstruction of defects of the skin of the neck/face. Twenty-nine flaps (32.6%) were utilized for defects of the pharynx/oropharynx, and 15 (16.9%) were utilized for oral cavity defects. Flap success rate was 94% (73/89). Flap site was not associated with flap failure (P = .46). Flaps >25 cm2 were 75% more likely to be successful. Multivariable logistic regression to assess the association of flap size in the context of other co-morbidities indicated flaps >25 cm2 were 3.6 times more likely to succeed regardless of co-morbidities, and patients with chronic obstructive pulmonary disease (COPD) have a 7-fold risk of flap failure (odds ratio: 7.3, 1.72-30.98, P = .007). An association with improved flap outcomes and larger skin paddles was observed in this series. The applicability of these observations to smaller flaps and larger series with more surgeons requires further study. Co-morbidities, particularly, COPD, continue to impact flap outcomes.

Solder Defect Assessment Method for Power Electronic Devices Based on Mechanical Stress Wave Signals

The health of a power electronic device is closely related to the mechanical stress waves released at the moment when the device is turned on and off. Research has shown the potential of mechanical stress waves in power electronic device health monitoring. However, the correlation between power device defect severity and mechanical stress wave signal characteristics has not been fully established and an effective evaluation method is currently lacking. This article uses finite element simulation methods to explore the impact of void defects in the chip solder and base plate solder of insulated gate bipolar transistor (IGBT) devices on mechanical stress wave signals. By analyzing the mechanical stress wave curves of cavity defects of multiple sizes, a method for assessing the health status of power devices based on principal component analysis (PCA) is proposed. By calculating the projection of the mechanical stress wave signal on the principal component, the characteristic quantity representing the severity of the defect is obtained. Simulation results indicate that for chip soldering defects, as the severity of defects increases, the feature values gradually decrease. Therefore, this method exhibits good evaluation performance for defects throughout the entire lifecycle. In the case of plate solder defects, this approach can effectively identify mid-to-late-stage defects in devices and can also be utilized for reliability prediction before device failure.

Thumb-up modification of the radial forearm free flap in oral cavity reconstruction: a description of a surgical technique

<b>Introduction:</b> Head and neck surgeons face the challenge of achieving maximum patient benefit that includes simultaneously curing the cancer and preserving the function of the affected organ. This is particularly challenging in patients with oral cancer.<b>Aim:</b> The aim of this study was to present the ‘thumb-up’ modification of the radial forearm free flap (RFFF) paddle in the reconstruction of postoperative oral cavity defects.<b>Material and methods:</b> The fasciocutaneous paddle of the RFFF flap in the ‘thumb-up’ modification was designed to form a rectangle with a narrow thumb-like extension. A three-dimensional canopy-like structure was then created after the sides forming the indentation in the flap paddle were properly sutured.<b>Results:</b> The three-dimensional roof-like structure fits perfectly into the resected tumour site of the soft palate, tongue root, and oral vestibule. Another advantage of this technique is that there is less risk of compression of the flap pedicle and better control of the pedicle during reconstruction.<b>Conclusions and significance:</b> the ‘thumb-up’ modification of the RFFF appears to provide a satisfactory functional outcome, with better control of the flap pedicle during surgery in oral cavity reconstruction compared with the two-dimensional shape of the RFFF paddle.

Data-Physics Fusion-Driven Defect Predictions for Titanium Alloy Casing Using Neural Network.

The quality of Ti alloy casing is crucial for the safe and stable operation of aero engines. However, the fluctuation of key process parameters during the investment casting process of titanium alloy casings has a significant influence on the volume and number of porosity defects, and this influence cannot be effectively suppressed at present. Therefore, this paper proposes a strategy to control the influence of process parameters on shrinkage volume and number. This study constructed multiple regression prediction models and neural network prediction models of porosity volume and number for a ZTC4 casing by simulating the gravity investment casting process. The results show that the multiple regression prediction model and neural network prediction model of shrinkage cavity total volume have an accuracy of over 99%. The accuracy of the neural network prediction model is higher than that of the multiple regression model, and the neural network model realizes the accurate prediction of shrinkage defect volume and defect number through pouring temperature, pouring time, and mold shell temperature. The sensitivity degree of casing defects to key process parameters, from high to low, is as follows: pouring temperature, pouring time, and mold temperature. Further optimizing the key process parameter window reduces the influence of process parameter fluctuation on the volume and number of porosity defects in casing castings. This study provides a reference for actual production control process parameters to reduce shrinkage cavity and loose defects.

Systematic review of minimally-invasive reconstructive options for oral cavity defects.

Systematic review of minimally-invasive reconstructive options for oral cavity defects.

Chimeric versus Multiple Flaps for Composite Oral Cavity Defects: A Systematic Review and Meta-Analysis.

Complex head and neck defects involving composite defects can be reconstructed using chimeric flaps or multiple flaps with separate anastomoses. Limited comparisons exist between chimeric and multiple flap reconstructions. We compare outcomes between chimeric and multiple flap reconstructions in oral cavity reconstruction. PubMed (NLM), Embase (Elsevier), Web of Science (Clarivate Analytics), and Cochrane CENTRAL (Wiley). A systematic review was conducted, including English articles reporting outcomes of oral cavity reconstruction with either chimeric flaps or multiple flaps. Data extraction included patient characteristics, flap type, and outcomes such as flap survival, partial flap loss, operating room time, hospital length of stay, and postoperative complications. Forty-seven articles comprising 1435 patients were included. Notably, 552 patients underwent multiple flaps, while 883 received chimeric flaps. Meta-analysis revealed no statistically significant difference in flap survival between chimeric and multiple flap patients (98% vs. 99%, p = 0.198). Multiple flap patients had higher rates of operating room take-backs for anastomotic issues and longer hospital stays compared with chimeric flap patients. There were no significant differences in partial flap failure, resumption of diet and speech, need for subsequent flaps, fistula formation, or general complications. This large-scale meta-analysis demonstrates equivalent flap survival between chimeric and multiple flaps in the reconstruction of composite oral cavity defects. Both approaches appear to be safe and acceptable, with comparable outcomes in terms of diet and speech resumption, rates of fistulization, and general postoperative complications. Multiple flap patients had higher rates of operating room take-backs and longer hospital stays. NA Laryngoscope, 134:4196-4202, 2024.

Medial sural artery perforator free flap versus radial forearm free flap in oral cavity reconstruction and donor site morbidity.

Radial Forearm Free flap (RFFF) is widely used in head and neck reconstruction, yet its donor site defect remains a significant drawback. The Medial Sural Artery Perforator Free Flap (MSAPFF) is considered an alternative flap to RFFF. This study aims to comprehensively analyze their characteristics, outcomes, and their impact on patient quality of life. All patients who underwent oral cavity reconstruction using RFFF and MSAPFF between February 2017 and April 2023 were included in this study. Flap characteristics, outcomes and post-operative complications were recorded and compared. Subjective donor site morbidity, aesthetic and functional results, and quality of life were also analyzed. The study included 76 patients: 37 underwent reconstruction with RFFF, and 39 with MSAPFF. There was no significance difference between the RFFF and MSAPFF regarding the success rate (97.2% vs 97.4%), flap size (4.8 × 8.8 cm2 vs 5 × 9.8 cm2), hospital of stay (15.5 days vs 13.5 days) and recipient site complications (P > 0.05). However, MSAPFF showed larger flap thickness (P = 0.001), smaller arterial caliber (P = 0.008), shorter pedicle length (P = 0.001), and longer harvesting time (P < 0.001). No significant difference was observed between the pre-and postoperative ranges of wrist and ankle movements or in recipient site complications. MSAPFF showed a significant difference in donor site morbidity (P < 0.05). The MSAPFF is an excellent alternative to the RFFF for repairing oral cavity defects, with additional advantage of a well-hidden scar on the posterior calf, a larger flap thickness, accepted pedicle length and arterial caliber. However, one should consider the harvesting time and surgical skills required in comparison to the RFFF. The study highlights the importance of the MSAPFF as an alternative option for RFFF with less donor site morbidity and high success rate in oral cavity reconstruction and improved patient Quality of life after ablative surgery.

Defect Detection in Grouting Sleeve Grouting Material by Piezoelectric Wave Method

The construction defects in grouting sleeves can jeopardize the safety of precast reinforced concrete structures. Thus, efficient and accurate defect detection is critical in engineering construction. In this paper, a defect detection method based on piezoelectric wave theory was proposed. Two piezoelectric ceramics were arranged within the grouting sleeve. One piezoelectric ceramic was affixed on the top of the steel bar, while the other was embedded in the grouting material, serving as the driver and sensor, respectively. The compactness defects, air cavity defects, steel anchoring defects, and water–binder ratio defects were set in the grouting sleeves, and the trends in time domain signals and signal evaluation indicators based on the wavelet packet total energy value (WPTEV) of different specimens were investigated. Based on the WPTEV, the evaluation index (EI) was proposed. In addition, the effect of the grouting material’s age on the piezoelectric wave signal was verified. Furthermore, the influence of grouting material defects on signals was simulated in ABAQUS, and the time domain signals and wavelet packet energy of sensor signals for specimens with varying defect dimensions were evaluated. The results showed that: (1) The defects in the grouting materials reduced the stress waves propagated through the grouting materials, resulting in a decrease in attenuation and an increasing trend in the signal; (2) The peak-to-peak values of piezoelectric ceramic sensors and the WPTEV of the signal increased with the degree of defects, and the WPTEV was more pronounced. For specimen M68, the WPTEV was 3.3 times that of the healthy specimen, however, the peak-to-peak value was only 2.3 times that of the healthy specimen; (3) The degree of defects was accurately determined by the defect evaluation index (EI) based on the WPTEV; (4) The signal was significantly attenuated with the increase in the age of the grouting material, especially in the first three days, and finally the signal achieved a stable value; (5) The numerical simulation indicated that the defects in the length and thickness of the air cavity in the grouting material were efficiently detected by the proposed piezoelectric arrangement in this study.

Early feeding after free flap reconstruction of the oral cavity: A systematic review and meta-analysis.

Traditionally, patients undergoing free flap reconstruction for oral cavity defects have been given nothing by mouth for 6-14 days post-operatively due to concern for orocutaneous fistula development. Multiple databases were screened for studies assessing the rate of orocutaneous fistula formation in early (≤5 days) versus late (>5 days) feeding groups following oral cavity free flap reconstruction. Fixed- and random-effects meta-analyses were used. One randomized controlled trial, one prospective cohort, and three retrospective cohort studies were included. The early feeding group displayed no significant increase in orocutaneous fistula formation (RD = -0.02, p = 0.06) or free flap failure (RD = -0.01, p = 0.39), with a significantly shorter hospital length of stay (mean difference [days] = -2.43, p < 0.01). While further prospective trials are necessary, initiation of oral intake before post-operative day 5 may be appropriate in properly selected patients following oral reconstruction.

Utility and influence mechanism of densification modulation on grain boundary diffusion in NdFeB magnets

Grain boundary diffusion technology is pivotal in the preparation of high-performance NdFeB magnets. This study investigates the factors that affect the efficiency of grain boundary diffusion, starting from the properties of the diffusion matrix. Through the adjustment of the sintering process, we effectively prepared magnets with varied densities that serve as the matrix for grain boundary diffusion with TbHx diffusion. The mobility characteristics of the Nd-rich phase during the densification stage are leveraged to ensure a more extensive distribution of heavy rare earth elements within the magnets. According to the experimental results, the increase in coercivity of low-density magnets after diffusion is significantly greater than that of relatively high-density magnets. The coercivity values measured are 805.32 kA/m for low-density magnets and 470.3 kA/m for high-density magnets. Additionally, grain boundary diffusion notably enhances the density of initial low-density magnets, addressing the issue of low density during the sintering stage. Before the diffusion treatment, the Nd-rich phases primarily concentrate at the triangular grain boundaries, resulting in an increased number of cavity defects in the magnets. These cavity defects contain atoms in a higher energy state, making them more prone to transition. Consequently, the diffusion activation energy at the void defects is lower than the intracrystalline diffusion activation energy, accelerating atom diffusion. The presence of larger cavities also provides more space for atom migration, thereby promoting the diffusion process. After the diffusion treatment, the proportion of bulk Nd-rich phases significantly decreases, and they infiltrate between the grains to fill the cavity defects, forming continuous fine grain boundaries. Based on these observations, the study aims to explore how to utilize this information to develop an efficient technique for grain boundary diffusion.

Infrahyoid Myocutaneous Flap for Reconstruction in Head and Neck Cancer Patients

Objective: Oral cancers are one of the most common cancers in India. Tongue and lower gingiva-buccal sulcus are the most common subsites in oral cancers. Good reconstruction after resection of primary is a demanding task and determines quality of life. This study reviews our experience with infrahyoid flap (IHF) in reconstruction of small and medium sized defects after oral cancer resection. Materials and Methods: This study retrospectively analyzes all patients of oral cavity squamous cell carcinoma who underwent IHF flap by a single surgeon from July 2018 till June 2022 with a median follow‑up of 12 months. Results were analyzed based on characteristics of the patients, site and size of defect, postoperative complications and clinical outcome. Results: Out of 14 patients, 4 patients had skin paddle necrosis (2 total and 2 partial). None of the patient suffered a total flap loss. All cases of partial flap loss resolved with conservative treatment and none of the patient required a revision surgery or developed orocutaneous fistula. The largest flap size was 9 × 4.5 cm. Conclusion: The infrahyoid myocutaneous flap is a fairly reliable and easy to perform flap for small and medium‑sized defects of the oral cavity.

Stability Analysis for High-Speed Boundary-Layer Flow with Cavities

This study uses direct numerical simulation and stability analysis methods to investigate the impact of wall cavity defects on the instability of boundary layers at Ma=5.92 and Ma=1.38. For flow at Ma=5.92, synchronization points with equal phase velocities in both fast and slow modes play a crucial role in controlling disturbance wave growth. When the inlet disturbance wave frequency (ω=0.98) approaches the synchronization point frequency, the impact of cavity size on the growth of the disturbance wave can be divided into three regions in the (L/δ99, D/δ99) plane, namely, region A, region B, and region C. Region A refers to small cavities with L/δ99<2, which have the weakest suppression effect. Region B includes large cavities with L/δ99>2 and D/δ99<1.5 and exhibits the best suppression effect. Finally, region C covers cavities with L/δ99>3 and D/δ99>1.5 and shows a non-monotonic control effect on the growth of disturbance wave as the cavity depth varies. For flow at Ma=1.38, cavities of different sizes always enhance the growth of disturbance waves. The widest and shallowest cavities (L/δ99>5, D/δ99<2) exhibit the most significant enhancement.