F1000ResearchF1000Research2046-1402F1000 Research LimitedLondon, UK10.12688/f1000research.179345.1Research ArticleArticlesOral Health–Related Quality of Life and Patient-Reported Outcomes After Implant Rehabilitation Using CAS Kit–Assisted Indirect Maxillary Sinus Augmentation: A Cross-Sectional Study
[version 1; peer review: 1 approved, 1 approved with reservations]
Kumar ShettySanathMethodologySupervisionValidationVisualization1RagherMallikarjunaConceptualizationInvestigationMethodologyProject Administrationhttps://orcid.org/0009-0001-3233-975Xa2ShettyRajeshData CurationInvestigationResourcesValidationhttps://orcid.org/0000-0002-2538-20123DandekeriSavithaVisualizationWriting – Original Draft Preparation4MSunainaWriting – Original Draft PreparationWriting – Review & Editing5Abdul AzizNafiyaWriting – Original Draft PreparationWriting – Review & Editing6
PROSTHODONTICS, Yenepoya (Deemed to be University) Dental College, Mangaluru, Karnataka, India
PROSTHODONTICS, Yenepoya (Deemed to be University) Dental College, Mangalore, Karnataka, 575018, India
PROSTHODONTICS, Yenepoya (Deemed to be University) Dental College, Mangalore, Karnataka, 575018, India
PROSTHODONTICS, Yenepoya (Deemed to be University) Dental College, Mangalore, Karnataka, 575018, India
PROSTHODONTICS, Yenepoya (Deemed to be University) Dental College, Mangalore, Karnataka, 575018, India
PROSTHODONTICS, Yenepoya (Deemed to be University) Dental College, Mangalore, Karnataka, 575018, Indiaragher@yenepoya.edu.in
Partial edentulism in the posterior maxilla is frequently complicated by alveolar bone resorption and maxillary sinus pneumatization, limiting implant placement and negatively affecting oral health–related quality of life (OHRQoL). Minimally invasive sinus augmentation techniques, such as CAS KIT–assisted indirect sinus elevation, aim to reduce surgical morbidity; however, evidence regarding patient-reported outcomes and quality of life following such interventions remains limited.
Objective
To evaluate oral health–related quality of life and patient-reported outcomes following implant rehabilitation using CAS KIT–assisted indirect maxillary sinus augmentation.
Materials and Methods
This observational cross-sectional study included 34 patients who underwent CAS KIT–assisted transcrestal sinus augmentation with implant placement in the posterior maxilla. Postoperative recovery and satisfaction were assessed using the HRQOLquestionnaire over seven postoperative days. OHRQoL was evaluated using the OHIP-14 questionnaire at baseline and one month after prosthetic rehabilitation. Data were analyzed using repeated measures ANOVA with a significance level set at p < 0.05.
Results
HRQOLscores showed a statistically significant improvement over the seven-day postoperative period (p < 0.001), with stabilization observed from Day 5 onward. OHIP-14 scores demonstrated a highly significant reduction from baseline to post-intervention assessment (p < 0.001), indicating marked improvement in OHRQoL across all participants.
Conclusion
CAS KIT–assisted indirect sinus augmentation followed by implant rehabilitation results in rapid postoperative recovery and significant improvement in patient-reported outcomes, supporting its role as a predictable and patient-centered treatment modality for posterior maxillary rehabilitation.
Maxillary Sinus Augmentation; Dental Implants; Quality of Life; Patient-Reported Outcome Measures; Posterior Maxilla; Minimally Invasive Surgical ProceduresThe author(s) declared that no grants were involved in supporting this work.Introduction
Partial edentulism in the posterior maxilla remains a prevalent clinical condition with significant implications for oral health–related quality of life (OHRQoL).
1 Individuals with fewer than 20 natural teeth consistently report poorer OHRQoL compared with those retaining functional dentitions, as tooth loss compromises masticatory efficiency, speech, facial esthetics, and self-esteem, thereby influencing nutritional intake, social interaction, and overall wellbeing.
2 Following tooth extraction, the posterior maxilla undergoes progressive alveolar bone resorption accompanied by maxillary sinus pneumatization, frequently resulting in reduced vertical bone height that limits conventional implant placement. Epidemiological studies indicate that posterior maxillary bone deficiency is among the most common anatomical constraints encountered in implant dentistry, necessitating adjunctive bone augmentation procedures that may prolong functional disability and restrict treatment options.
3–
5
The evolution of maxillary sinus augmentation techniques reflects a progressive shift from invasive surgical procedures toward more conservative and predictable approaches. Traditionally, sinus floor elevation has been performed using either the lateral (direct) window technique or the crestal (indirect) approach. The lateral window technique permits substantial vertical bone augmentation and is indicated in cases of severe alveolar bone deficiency; however, it is associated with increased surgical trauma, longer operative time, higher postoperative morbidity, and delayed recovery. Conversely, the transcrestal approach was introduced as a less invasive alternative, offering reduced patient discomfort and faster healing, though earlier techniques were limited by restricted control over sinus membrane elevation. Advances in surgical philosophy have driven a paradigm shift toward minimally invasive sinus augmentation, emphasizing reduced tissue trauma, shorter procedure duration, lower complication rates, and enhanced patient comfort. This shift has been facilitated by innovations such as hydraulic pressure systems, balloon-assisted membrane elevation, and piezoelectric instruments, which improve the safety and predictability of Schneiderian membrane elevation. Among these developments, the Crestal Approach Sinus (CAS) Kit represents a significant advancement by enabling controlled, atraumatic, and minimally invasive transcrestal sinus elevation. Its calibrated instrumentation allows precise membrane elevation while minimizing the risk of perforation, aligning with contemporary trends in patient-centered implant therapy.
While clinical and radiographic outcomes of sinus augmentation—including implant survival rates, bone gain, and complication rates—are well documented, these parameters fail to capture patients’ subjective experiences.
6–
8 Contemporary dental research increasingly emphasizes patient-reported outcome measures (PROs) as essential indicators of treatment success, with OHRQoL representing a multidimensional construct encompassing functional limitation, physical pain, psychological discomfort, and social disability. Previous systematic reviews demonstrate that implant-supported prostheses improve oral health–related quality of life (OHRQoL) in edentulous and partially edentulous patients; however, evidence comparing different surgical modalities—particularly CAS-KIT assisted technique remains limited. It is unclear whether the improved surgical control and predictability associated with CAS-guided indirect sinus augmentation translate into superior patient-centered outcomes, including chewing efficiency, dietary habits, psychosocial wellbeing, and overall satisfaction.
Therefore, a significant knowledge gap exists regarding the impact of CAS KIT–assisted indirect maxillary sinus augmentation followed by implant rehabilitation on OHRQoL and PROs. The objective of this cross-sectional study was to evaluate oral health–related quality of life and patient-reported outcomes in individuals who underwent implant rehabilitation following CAS KIT–assisted indirect maxillary sinus augmentation. The null hypothesis was that CAS KIT–assisted indirect sinus augmentation followed by implant rehabilitation would not result in significant improvements in OHRQoL, while the alternative hypothesis proposed that this minimally invasive approach would significantly enhance OHRQoL, yield high patient satisfaction, and exert minimal negative impact on daily functioning.
Materials and methodsStudy design and ethical considerations
This observational cross-sectional study was conducted to evaluate oral health–related quality of life (OHRQoL) and patient-reported outcomes following implant rehabilitation using CAS KIT–assisted indirect maxillary sinus augmentation. The cross-sectional design was chosen to assess patient-centered outcomes after completion of surgical and prosthetic treatment without modifying standard clinical care. Ethical approval was obtained from the Yenepoya Ethics Committee-2(Ref. YEC2/2024/342), Yenepoya (Deemed To Be University) prior to study initiation, and the study was conducted in accordance with the Declaration of Helsinki (2013 revision). Written informed consent was obtained from all participants after providing detailed information in their native language. The study adhered to the STROBE guidelines for reporting cross-sectional studies.
Study population and setting
The study was carried out at the Centre for Oral Implantology a university-based tertiary care center, between June 2024 and September 2025. Thirty-four patients aged 18–60 years (
Table 1) requiring implant-supported rehabilitation in the deficient posterior maxilla with CAS KIT–assisted indirect sinus augmentation were recruited using simple random sampling. All participants completed implant placement followed by prosthetic rehabilitation and consented to participate in questionnaire-based evaluation.
Demographic characteristics of participants.
Characteristic
N (%) or Mean ± SD
Number of patients
34
Age (years)
42.3 ± 11.5
Sex
– Male
18 (52.9%)
– Female
16 (47.1%)
Implant site
– Right posterior maxilla
20 (58.8%)
– Left posterior maxilla
14 (41.2%)
Sample size calculation
Sample size estimation was performed using G*Power software based on data from a previous study by Hadar et al. Power analysis for an independent t-test was conducted with a conventional effect size of 0.5, a type I error rate (α) of 5%, and a type II error rate (β) of 20%, corresponding to a power of 80%. The calculated minimum sample size required for the study was 34 participants.
Surgical protocol
All participants underwent preoperative clinical evaluation and cone-beam computed tomography (CBCT) imaging to assess residual alveolar bone height and maxillary sinus anatomy. Digital planning was performed to guide implant positioning and depth control using the CAS KIT system. Indirect maxillary sinus augmentation was carried out via a transcrestal approach following the CAS KIT drilling protocol, with controlled elevation of the Schneiderian membrane and implant placement performed as per standard clinical indications. Postoperative care included routine medications, oral hygiene instructions, and scheduled follow-up visits.
Prosthetic rehabilitation
Prosthetic rehabilitation was completed following an adequate healing period and confirmation of implant stability. Implant-supported restorations were fabricated and delivered based on clinical requirements, with the type of prosthesis and loading protocol determined according to patient-specific factors and standard implant prosthetic principles.
Patient-reported outcome measures
Patient-reported outcomes were assessed using two validated questionnaires. Postoperative recovery and satisfaction were evaluated using the HRQOL questionnaire consisting of 19 items assessing oral function, general activity, other symptoms, and pain, recorded daily for seven postoperative days using a five-point Likert scale through structured telephonic interviews. Oral health–related quality of life was assessed using the OHIP-14 questionnaire at baseline and one month following prosthetic rehabilitation, with responses recorded on a five-point frequency scale and analyzed both as overall scores and across seven standardized subdomains.
Data collection and quality assurance
All questionnaires were administered in the participants’ native language using validated translations. Measures were taken to ensure completeness and consistency of responses, and participants with incomplete or inconsistent data were excluded according to predefined withdrawal criteria. Collected data were anonymized, securely stored, and prepared for statistical analysis.
Statistical analysis
Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) software, version 26.0 (IBM Corp., Armonk, NY, USA). Descriptive statistics, including mean, standard deviation (SD), standard error (SE), and coefficient of variation, were calculated for HRQOL and OHIP scores at different time points. Changes in HRQOL scores over the seven-day observation period were analyzed using repeated measures analysis of variance (ANOVA) to assess the effect of time. Following a significant ANOVA result, post hoc pairwise comparisons were performed to identify specific differences between individual days. Changes in OHIP scores between pre- and post-intervention assessments were also evaluated using repeated measures ANOVA. A p value <0.05 was considered statistically significant for all analyses.
Results
The HRQOL scores demonstrated a significant improvement over the seven-day observation period. Repeated measures ANOVA revealed a statistically highly significant effect of time on HRQOL scores (F = 261.1, p < 0.001). The mean HRQOL score decreased progressively from Day 1 (1.429 ± 0.109) to Day 4 (1.053 ± 0.090), indicating an improvement in health-related quality of life over time. Post hoc pairwise comparisons showed significant differences between Day 1 and all subsequent days, as well as between Day 2 and Days 3–7 (p < 0.001). No significant difference was observed between Day 3 and Day 4 (p = 0.325). From Day 5 onwards, HRQOL scores stabilized at 1.000 with no inter-individual variability, and no significant differences were observed among Days 5, 6, and 7, indicating sustained improvement [
Tables 2-
4;
Graph 1].
Descriptive statistics of HRQOL scores across the 7-day follow-up period.
Descriptive statistics
Day
Mean
SD
SE
Coefficient of variation
1
1.429
0.109
0.019
0.076
2
1.247
0.071
0.012
0.057
3
1.059
0.092
0.016
0.087
4
1.053
0.090
0.015
0.085
5
1.000
0.000
0.000
0.000
6
1.000
0.000
0.000
0.000
7
1.000
0.000
0.000
0.000
Repeated measures ANOVA showing changes in HRQOL scores over time.
Repeated measure ANOVA
Cases
Sum of squares
df
Mean square
F
p
HRQOL
5.540
6
0.923
261.1
< .001
Post hoc pairwise comparisons of HRQOL scores between different time points.
Post hoc comparisons – HRQOL
Day vs day
Mean difference
SE
df
t
p value
1
2
0.182
0.017
33
10.642
< .001
1
3
0.371
0.020
33
18.095
< .001
1
4
0.376
0.022
33
16.834
< .001
1
5
0.429
0.019
33
23.015
< .001
1
6
0.429
0.019
33
23.015
< .001
1
7
0.429
0.019
33
23.015
< .001
2
3
0.188
0.008
33
22.978
< .001
2
4
0.194
0.010
33
18.863
< .001
2
5
0.247
0.012
33
20.391
< .001
2
6
0.247
0.012
33
20.391
< .001
2
7
0.247
0.012
33
20.391
< .001
3
4
0.006
0.006
33
1.000
0.325
3
5
0.059
0.016
33
3.708
0.005
3
6
0.059
0.016
33
3.708
0.005
3
7
0.059
0.016
33
3.708
0.005
4
5
0.053
0.015
33
3.447
0.006
4
6
0.053
0.015
33
3.447
0.006
4
7
0.053
0.015
33
3.447
0.006
5
6
0.000
0.000
33
NaN
NaN
5
7
0.000
0.000
33
NaN
NaN
6
7
0.000
0.000
33
NaN
NaN
Graph depicting trend of Mean HRQOL Scores Over the 7-Day Observation Period.
A statistically highly significant reduction in OHIP scores was observed from pre- to post-intervention assessment. Repeated measures ANOVA demonstrated a significant effect of time on OHIP scores (F = 1706, p < 0.001). The mean OHIP score decreased from 2.050 ± 0.148 at baseline to 1.000 ± 0.000 following the intervention, indicating a marked improvement in oral health–related quality of life. The absence of variability in post-intervention scores reflects uniform improvement across all participants [
Tables 5,
6;
Graph 2].
Descriptive statistics of OHIP scores at pre- and post-intervention assessments.
Descriptive statistics
OHIP
Mean
SD
SE
Coefficient of variation
Pre
2.050
0.148
0.025
0.072
Post
1.000
0.000
0.000
0.000
Repeated measures ANOVA comparing pre- and post-intervention OHIP scores.
Repeated measures ANOVA
Cases
Sum of squares
df
Mean square
F
p
OHIP
18.743
1
18.743
1,706
< .001
Graph depicting comparison of Mean OHIP Scores Before and After Intervention.
Discussion
This study demonstrated a statistically significant improvement in oral health–related quality of life following the intervention, thereby rejecting the null hypothesis and fulfilling the primary research objectives. Both HRQOL and OHIP-14 scores showed substantial reductions over the observation period, reflecting marked improvement in patient-reported outcomes. This study evaluates patient-centered outcomes following CAS KIT–assisted indirect sinus augmentation, offering novel evidence that this minimally invasive approach translates directly into measurable patient-reported benefits. The most pronounced improvement occurred during the early follow-up phase, with HRQOL scores demonstrating rapid and sustained normalization from Day 5 onwards, indicating high levels of patient satisfaction and consistent clinical success across the study population. The uniform post-intervention OHIP-14 scores further underscore the effectiveness of the intervention in minimizing the perceived impact of oral health on daily functioning. Collectively, these findings highlight favorable clinical outcomes, the presence of strong time-dependent effects as key predictors of improvement, and the significant value of incorporating patient-reported outcome measures into evaluations of minimally invasive sinus augmentation techniques.
The postoperative recovery pattern observed in the present study demonstrates a rapid improvement during the early healing phase (Days 1–4), followed by stabilization between Days 5 and 7, which is consistent with patient-reported outcome data from sinus augmentation literature. Rengo et al. reported moderate pain limited to the first two postoperative days with a progressive decline thereafter, alongside low discomfort scores and high willingness to repeat the procedure, indicating favorable short-term morbidity.
9 Similarly, Schiegnitz et al. showed that procedure-related complaints peak immediately postoperatively and significantly diminish over time. Compared with lateral window approaches, which are commonly associated with prolonged swelling, discomfort, and delayed recovery, transcrestal techniques have been shown to result in reduced morbidity and faster functional recovery.
10 These findings may be attributed to reduced surgical trauma, preservation of Schneiderian membrane integrity, and minimal bone manipulation inherent to indirect sinus elevation techniques. The accelerated recovery timeline observed in the present study appears comparable or superior to conventional crestal approaches reported in the literature, supporting the clinical advantage of minimally invasive sinus augmentation strategies.
Beyond early recovery, the complete restoration of oral health–related quality of life observed post-intervention, reflected by a uniform OHRQoL score of 1.000, aligns with previous studies demonstrating significant improvements following implant rehabilitation in the posterior maxilla. Schiegnitz et al. reported marked enhancement across functional, physical, and psychological OHIP domains following sinus augmentation, particularly in edentulous patients.
10 The multidimensional improvement observed—including functional limitation, psychosocial disability, and patient satisfaction—can be attributed to restored masticatory efficiency, improved esthetics, and enhanced psychosocial wellbeing, reinforcing the patient-centered benefits of successful sinus augmentation and implant-supported rehabilitation as outlined in the introduction.
At present, there is a clear absence of literature specifically evaluating CAS Kit–guided sinus augmentation; however, meaningful inferences can be drawn by comparing its principles with established transcrestal techniques described in the literature. Comprehensive reviews, including that by Lafzi et al., consistently demonstrate that transcrestal approaches—particularly those employing drill-based, hydraulic, balloon-assisted, and piezoelectric modalities—are associated with lower postoperative morbidity, reduced membrane perforation rates, and faster patient recovery when compared with the lateral window technique. These advantages underpin the broader paradigm shift toward minimally invasive sinus augmentation. The CAS approach conceptually aligns with this evolution by emphasizing controlled sinus membrane elevation, elimination of malleting forces, and gradual, predictable manipulation of the sinus floor. Such controlled elevation mechanisms parallel those reported in hydraulic and balloon-assisted techniques, which distribute pressure evenly across the Schneiderian membrane and reduce focal stress concentrations, thereby minimizing perforation risk.
11 Furthermore, the ability to achieve predictable bone graft placement and simultaneous implant insertion with minimal bone manipulation supports improved surgical precision and patient tolerance. Collectively, these characteristics suggest that CAS-KIT assisted sinus elevation represents a logical refinement of existing transcrestal methodologies and may account for the superior clinical and patient-reported outcomes observed, even in the absence of technique-specific comparative trials.
The uniform post-intervention scores with zero variability observed in this study indicate a high level of procedural reliability and reproducibility of the crestal approach technique. This consistency suggests predictable membrane elevation and graft stabilization with minimal technique-related variability. Although the use of specialized crestal systems involves an initial equipment cost and learning curve, these factors are balanced by improved patient comfort, reduced morbidity, shorter operative time, and fewer postoperative complications. Careful patient selection remains essential, with favorable outcomes primarily seen in cases with adequate residual bone height, favorable sinus anatomy, and absence of sinus pathology. When appropriately indicated, the crestal approach can be effectively integrated into treatment planning for posterior maxillary rehabilitation, facilitating minimally invasive sinus augmentation with simultaneous implant placement and enhanced patient-centered outcomes.
The present study has several limitations that warrant consideration. Its cross-sectional design, with a single post-treatment assessment and absence of a control or comparison group, restricts causal inference and direct comparison with alternative sinus augmentation techniques. Although the sample size provided adequate statistical power, the single-center setting limits the generalizability of the findings. Additionally, the lack of long-term follow-up beyond the immediate post-prosthetic period precludes evaluation of the durability of patient-reported benefits. The reliance on subjective outcome measures without objective functional assessments, such as masticatory performance or nutritional evaluation, further limits comprehensive outcome interpretation, while retrospective baseline OHIP-14 assessment may be subject to recall bias. Future research should focus on well-designed comparative studies evaluating CAS KIT against conventional transcrestal and lateral window techniques, with extended follow-up. Incorporation of radiographic parameters, implant stability measures, economic evaluations, multicenter validation, and objective functional outcomes would strengthen the evidence base and better define the clinical value of minimally invasive sinus augmentation techniques.
Conclusion
Within the limitations of this cross-sectional study, CAS KIT–assisted indirect maxillary sinus augmentation followed by implant-supported rehabilitation resulted in significant improvement in oral health–related quality of life and patient-reported outcomes. The rapid postoperative recovery, minimal functional impairment, and uniform improvement in OHIP-14 scores reflect high patient satisfaction and favorable psychosocial impact associated with this minimally invasive approach. These findings suggest that the enhanced surgical control and reduced morbidity of CAS-KIT assisted sinus augmentation translate into meaningful patient-centered benefits. Incorporation of patient-reported outcome measures alongside clinical and radiographic parameters is essential for comprehensive evaluation of treatment success in posterior maxillary implant rehabilitation. Further longitudinal and comparative studies are warranted to validate these findings and assess long-term outcomes.
Data availability and extended data
Oral Health–Related Quality of Life and Patient-Reported Outcomes After Implant Rehabilitation Using CAS Kit–Assisted Indirect Maxillary Sinus Augmentation: A Cross-Sectional Study [Data set]. Zenodo.
https://doi.org/10.5281/zenodo.19274689.
12
Data are available under the terms of the
Creative Commons Attribution 4.0 International license (CC-BY 4.0).
ReferencesMorinagaDNagaiSKakuT:
Effects of various prosthetic methods for patients with Kennedy Class I partial edentulism on oral hypofunction, subjective symptoms, and oral health-related quality of life.Int. J. Implant. Dent.2024 Jun 27;10(1):33.
3893533510.1186/s40729-024-00555-wPMC11211286BerniyantiTPalupiRAlkadasiBA:
Oral health-related quality of life (OHRQoL) analysis in partially edentulous patients with and without denture therapy.Clin. Cosmet. Investig. Dent.2023 May 16;15:89–98.OhWSSaglikBBakSY:
Bone loss in the posterior edentulous mandible with implant-supported overdentures vs complete dentures: A systematic review and meta-analysis.Int. J. Prosthodont.2020;33(2):184–191.
10.11607/ijp.6636AlrabiahMAl DeebMAlsahhafA:
Clinical and radiographic assessment of narrow-diameter and regular-diameter implants in the anterior and posterior jaw: 2 to 6 years of follow-up.J. Periodontal Implant Sci.2020;50(2):97–105.
10.5051/jpis.2020.50.2.97LombardiTRapaniAEzeddineF:
Clinical Outcomes of Bone-Level and Tissue-Level Short Implants Placed in Posterior Maxilla: A Case-Control Study.Clin. Implant. Dent. Relat. Res.2025 Feb;27.
10.1111/cid.13428ComuzziLTumedeiMPetriniM:
Clinical and radiological evaluation of a self-condensing bone implant in one-stage sinus augmentation: A 3-year follow-up retrospective study.Int. J. Environ. Res. Public Health.2023 Jan 31;20(3):2583.MamidiARGottumukkalaSNVSMantenaSR:
Comparison of clinical and radiological outcomes using crestal approach sinus kit and piezoelectric surgery for sinus membrane elevation: A prospective clinical trial.Dent. Res. J (Isfahan).2022 Oct 20;19:88.Toledano-SerrabonaJRomeu-I-FontanetAGay-EscodaC:
Clinical and histological outcomes of maxillary sinus floor augmentation with synthetic bone substitutes for dental implant treatment: A meta-analysis.J. Oral Implantol.2022 Apr 1;48(2):158–167.
10.1563/aaid-joi-D-20-00202RengoCFiorinoACucchiA:
Patient-reported outcomes and complication rates after lateral maxillary sinus floor elevation: a prospective study.Clin. Oral Investig.2021 Jul;25(7):4431–4444.
10.1007/s00784-020-03755-xSchiegnitzEKämmererPWSaghebK:
Impact of maxillary sinus augmentation on oral health-related quality of life.Int. J. Implant. Dent.2017 Dec;3(1):10.LafziAAtarbashi-MoghadamFAmidR:
Different techniques in transalveolar maxillary sinus elevation: A literature review.J. Adv. Periodontol. Implant. Dent.2021 Apr 6;13(1):35–42.
3591991610.34172/japid.2021.004PMC9327482ShettySKRagherMShettyR:
Oral Health–Related Quality of Life and Patient-Reported Outcomes After Implant Rehabilitation Using CAS Kit–Assisted Indirect Maxillary Sinus Augmentation: A Cross-Sectional Study.[Data set].
Zenodo.2026.
10.5281/zenodo.1927468910.5256/f1000research.197850.r477155Reviewer response for version 1AradyaAnupama1Referee
JSS Dental College and Hospital, JSS Academy of Higher Education and Research, Mysuru, Karnataka, India
Competing interests: No competing interests were disclosed.
The manuscript addresses a clinically relevant topic by evaluating patient-reported outcomes following CAS KIT–assisted indirect sinus augmentation and implant rehabilitation. The emphasis on oral health–related quality of life adds value to the existing literature
The introduction is comprehensive; however, the rationale for selecting a cross-sectional design should be explained more clearly, particularly considering that baseline and postoperative assessments were performed over time.
The methodology section requires clarification regarding the timing of OHIP-14 administration. Please specify whether the baseline questionnaire was administered before surgery or retrospectively after treatment completion.
The discussion section is well supported with relevant literature, but additional comparison with recent studies evaluating minimally invasive sinus augmentation techniques would strengthen the manuscript further.
Minor grammatical and formatting inconsistencies are present throughout the manuscript (e.g., spacing, punctuation, and author affiliation superscripts) and should be carefully revised during proofreading.
Overall, the manuscript is informative and clinically relevant. After addressing the above comments and improving methodological clarity, the article may be considered suitable for indexing.
Is the work clearly and accurately presented and does it cite the current literature?
Yes
If applicable, is the statistical analysis and its interpretation appropriate?
Yes
Are all the source data underlying the results available to ensure full reproducibility?
Yes
Is the study design appropriate and is the work technically sound?
Yes
Are the conclusions drawn adequately supported by the results?
Yes
Are sufficient details of methods and analysis provided to allow replication by others?
Yes
Reviewer Expertise:
implant dentistry, gerodontology, prosthodontics
I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.
RAGHERMALLIKARJUNAPROSTHODONTICS, Yenepoya (Deemed to be University) Dental College, Mangaluru, Karnataka, India
Competing interests: No competing interests were disclosed.
1152026
Reviewer Comment 1
Comment:
The manuscript addresses a clinically relevant topic by evaluating patient-reported outcomes following CAS KIT–assisted indirect sinus augmentation and implant rehabilitation. The emphasis on oral health–related quality of life adds value to the existing literature.
Response:
We thank the reviewer for the positive appreciation of our work and for recognizing the clinical relevance of evaluating patient-reported oral health–related quality-of-life outcomes following CAS KIT–assisted indirect sinus augmentation and implant rehabilitation.
Reviewer Comment 2
Comment:
The introduction is comprehensive; however, the rationale for selecting a cross-sectional design should be explained more clearly, particularly considering that baseline and postoperative assessments were performed over time.
Response:
We agree that the study design was incorrectly described as cross-sectional in the original manuscript. Since the same participants were evaluated prospectively across multiple postoperative time intervals, the study is more appropriately classified as a prospective longitudinal observational study. The terminology has been revised throughout the manuscript to accurately reflect the study design.
Revised manuscript text:
This study was designed as a prospective longitudinal observational study
Reviewer Comment 3
Comment:
The methodology section requires clarification regarding the timing of OHIP-14 administration. Please specify whether the baseline questionnaire was administered before surgery or retrospectively after treatment completion.
Response:
The methodology section has been clarified to specify the timing of OHIP-14 administration. The baseline OHIP-14 questionnaire was administered preoperatively before the surgical procedure, and subsequent assessments were recorded during the postoperative follow-up period.
Revised manuscript text:
The baseline OHIP-14 questionnaire was administered preoperatively before the surgical procedure, and postoperative assessments were recorded during follow-up visits.
Reviewer Comment 4
Comment:
The discussion section is well supported with relevant literature, but additional comparison with recent studies evaluating minimally invasive sinus augmentation techniques would strengthen the manuscript further.
Response:
Additional recent studies related to minimally invasive transcrestal sinus augmentation techniques and CAS KIT-assisted procedures have now been incorporated into the Discussion section to better contextualize the present findings with the existing literature.
Reviewer Comment 5
Comment:
Minor grammatical and formatting inconsistencies are present throughout the manuscript (e.g., spacing, punctuation, and author affiliation superscripts) and should be carefully revised during proofreading.
Response:
The manuscript has been carefully revised for grammatical accuracy, formatting consistency, spacing, punctuation, and author affiliation formatting throughout the text.
10.5256/f1000research.197850.r477157Reviewer response for version 1DhawanPankaj1Refereehttps://orcid.org/0000-0002-5458-9506
Manav Rachna International Institute Of Research And Studies, Faridabad, Haryana, India
Competing interests: No competing interests were disclosed.
1. The study evaluates the CAS KIT, an established system for minimally invasive transcrestal sinus elevation. Because the study does not introduce a new protocol and completely lacks a comparison group (e.g., conventional crestal approaches vs. lateral window techniques), it adds very little novel data to the existing literature.
2. The authors explicitly describe their research as an "observational cross-sectional study". However, they track patient outcomes over a 7-day postoperative period and compare baseline OHIP-14 data with 1-month follow-up. Tracking the same subjects across multiple time points defines a longitudinal or cohort study, which means the paper's core methodological classification is incorrect.
3. There is a massive statistical anomaly in the reported results. From Day 5 onward, the HRQOL scores stabilized at exactly 1.000 with a standard deviation of 0.000. Furthermore, the post-intervention OHIP scores were also reported as 1.000 with a standard deviation of 0.000. In subjective, questionnaire-based human research involving 34 distinct individuals, achieving absolute zero variability is biologically and psychologically implausible. This suggests a severe data entry error, a misunderstanding of the questionnaire, or data manipulation.
4. The study was conducted at a single university-based tertiary care center (Center for Oral Implantology). This single-center approach severely restricts the external validity and generalizability of the findings to broader clinical populations.
5. In the discussion, the authors claim that their findings suggest "superior clinical and patient-reported outcomes observed". Because the study lacks a control group or an active comparator, any claims of "superiority" over other surgical methods are unscientific and unjustified, and must be scaled back to reflect the actual data.
6. While the bibliography does include recent papers up to 2025 regarding the general quality of life and sinus augmentation, it lacks depth regarding the specific intervention. Out of 12 references, only one (Mamidi et al., 2022) directly evaluates the CAS kit. By ignoring the established body of foundational literature on this exact transcrestal system, the authors fail to properly contextualize their findings or justify the necessity of their research.
7. The authors used repeated measures ANOVA to show a "statistically highly significant effect of time" (p < 0.001). However, performing an ANOVA on data with zero variance at later time points is mathematically questionable, as it violates the assumptions of normality and homogeneity of variance required for parametric testing.
8. The post hoc pairwise comparisons in Table 4 report "NaN" (Not a Number) for comparisons between Days 5, 6, and 7. This occurs because the software cannot calculate a t-value when there is zero difference and zero variance between groups, further highlighting that the data distribution is unsuitable for this type of statistical analysis.
9. Claims of superiority and predictability require comparative and longitudinal data, which this study lacks.
Major Revision.
Is the work clearly and accurately presented and does it cite the current literature?
Partly
If applicable, is the statistical analysis and its interpretation appropriate?
Partly
Are all the source data underlying the results available to ensure full reproducibility?
Yes
Is the study design appropriate and is the work technically sound?
Partly
Are the conclusions drawn adequately supported by the results?
Partly
Are sufficient details of methods and analysis provided to allow replication by others?
Partly
Reviewer Expertise:
IMPLANTOLOGY
I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.
RAGHERMALLIKARJUNAPROSTHODONTICS, Yenepoya (Deemed to be University) Dental College, Mangaluru, Karnataka, India
Competing interests: No competing interests were disclosed.
1152026
Reviewer Comment 1
Comment:
The study evaluates the CAS KIT, an established system for minimally invasive transcrestal sinus elevation. Because the study does not introduce a new protocol and completely lacks a comparison group (e.g., conventional crestal approaches vs. lateral window techniques), it adds very little novel data to the existing literature.
Response:
We acknowledge that the CAS KIT is an established technique and that the present study does not introduce a novel surgical protocol or include a comparative group. However, the primary aim of the present study was to evaluate patient-reported oral health–related quality of life (OHRQoL) outcomes following CAS KIT–assisted indirect sinus augmentation and implant rehabilitation. Although several studies have evaluated the surgical and radiographic outcomes of transcrestal sinus elevation procedures, limited literature is available regarding patient-centered postoperative outcomes associated specifically with the CAS KIT technique. Therefore, the present study adds clinical evidence regarding postoperative recovery, patient comfort, and OHRQoL following this minimally invasive approach. The manuscript has been revised to better clarify the observational scope and clinical relevance of the study.
Addition in manuscript :
Although the CAS KIT technique is well established for transcrestal sinus elevation, limited evidence is available regarding patient-reported postoperative quality-of-life outcomes following this minimally invasive approach.
Reviewer Comment 2
Comment:
The authors explicitly describe their research as an "observational cross-sectional study". However, they track patient outcomes over a 7-day postoperative period and compare baseline OHIP-14 data with 1-month follow-up. Tracking the same subjects across multiple time points defines a longitudinal or cohort study, which means the paper's core methodological classification is incorrect.
Response:
We agree that the study design was incorrectly described as cross-sectional in the original manuscript. Since the same participants were evaluated prospectively across multiple postoperative time intervals, the study is more appropriately classified as a prospective longitudinal observational study. The terminology has been revised throughout the manuscript to accurately reflect the study design.
Revised manuscript text:
This study was designed as a prospective longitudinal observational study.
Reviewer Comment 3
Comment:
There is a massive statistical anomaly in the reported results. From Day 5 onward, the HRQOL scores stabilized at exactly 1.000 with a standard deviation of 0.000. Furthermore, the post-intervention OHIP scores were also reported as 1.000 with a standard deviation of 0.000. In subjective, questionnaire-based human research involving 34 distinct individuals, achieving absolute zero variability is biologically and psychologically implausible. This suggests a severe data entry error, a misunderstanding of the questionnaire, or data manipulation.
Response:
The uniform HRQOL values observed during the later postoperative periods reflect the consistent absence or minimal presence of discomfort reported by the study participants following recovery. As the assessed parameters were based on categorical patient-reported outcomes with limited response variability at later healing stages, identical scores were obtained across several participants. Nevertheless, we acknowledge that reporting values with zero standard deviation may create concerns regarding interpretability. Therefore, the presentation of the data and its explanation in the Results section have been clarified to improve transparency and avoid misinterpretation.
Revised manuscript text:
The stabilization of HRQOL scores during the later postoperative period reflects minimal postoperative discomfort and functional limitation reported by the majority of participants following healing.
Reviewer Comment 4
Comment:
The study was conducted at a single university-based tertiary care center (Center for Oral Implantology). This single-center approach severely restricts the external validity and generalizability of the findings to broader clinical populations.
Response:
We agree that the single-center nature of the study may limit the external validity and generalizability of the findings to broader clinical populations. However, standardized treatment protocols and follow-up procedures were followed to maintain consistency in patient management and outcome assessment. This limitation has now been acknowledged in the revised manuscript. Further multicenter studies with larger and more diverse populations are required to validate and generalize the present findings.
Revised in manuscript:
One limitation of the present study is its single-center design with a relatively limited sample size, which may restrict the generalizability of the findings. Further multicenter studies with larger and more diverse populations are necessary to validate the present results.
Reviewer Comment 5
Comment:
In the discussion, the authors claim that their findings suggest "superior clinical and patient-reported outcomes observed". Because the study lacks a control group or an active comparator, any claims of "superiority" over other surgical methods are unscientific and unjustified, and must be scaled back to reflect the actual data.
Response:
We agree that the term “superior” may overstate the findings in the absence of a control or comparative group. As the present study was observational in nature and did not include direct comparison with other sinus augmentation techniques, definitive comparative conclusions cannot be established. Accordingly, the wording has been revised throughout the manuscript to avoid implications of superiority and to more accurately reflect the findings of the present study.
Revised manuscript text:
The findings of the present study demonstrated favorable clinical healing and improvement in patient-reported oral health–related quality-of-life outcomes following CAS KIT–assisted indirect sinus augmentation and implant rehabilitation.
Reviewer Comment 6
Comment:
While the bibliography does include recent papers up to 2025 regarding the general quality of life and sinus augmentation, it lacks depth regarding the specific intervention. Out of 12 references, only one (Mamidi et al., 2022) directly evaluates the CAS kit. By ignoring the established body of foundational literature on this exact transcrestal system, the authors fail to properly contextualize their findings or justify the necessity of their research.
Response:
We agree that inclusion of additional foundational literature related to the CAS KIT and transcrestal sinus elevation techniques would further strengthen the scientific context of the study. Accordingly, additional relevant studies evaluating CAS KIT-assisted sinus elevation and minimally invasive transcrestal augmentation procedures have now been incorporated into the Introduction and Discussion sections. However, literature specifically assessing patient-reported oral health–related quality-of-life outcomes following CAS KIT-assisted sinus augmentation remains limited. Therefore, the present study was intended to further evaluate postoperative patient-reported outcomes associated with this minimally invasive approach.
The favorable postoperative healing and clinical outcomes observed in the present study are consistent with previous reports by Ceruso et al., who demonstrated satisfactory clinical and radiographic outcomes following minimally invasive transcrestal sinus augmentation with simultaneous implant placement
Reviewer Comment 7
Comment:
The authors used repeated measures ANOVA to show a "statistically highly significant effect of time" (p < 0.001). However, performing an ANOVA on data with zero variance at later time points is mathematically questionable, as it violates the assumptions of normality and homogeneity of variance required for parametric testing.
Response:
The minimal variability observed during the later postoperative intervals reflects the consistent improvement and reduced postoperative discomfort reported by participants following healing. As the patient-reported outcomes demonstrated highly similar responses during the later stages of recovery, closely clustered values were observed across these time points. The repeated measures ANOVA was performed to evaluate changes in outcomes over time within the study population. We acknowledge that the reduced variability during later intervals should be interpreted in the context of the clinical recovery pattern observed among participants, and this clarification has been incorporated into the revised manuscript.
The minimal variability observed during later postoperative intervals may reflect consistent patient recovery and reduced postoperative discomfort following healing and implant rehabilitation.
Reviewer Comment 8
Comment:
The post hoc pairwise comparisons in Table 4 report "NaN" (Not a Number) for comparisons between Days 5, 6, and 7. This occurs because the software cannot calculate a t-value when there is zero difference and zero variance between groups, further highlighting that the data distribution is unsuitable for this type of statistical analysis.
Response:
The “NaN” values observed in the post hoc pairwise comparisons between Days 5, 6, and 7 reflect the absence of measurable differences in patient-reported outcomes during the later postoperative healing period. As participants demonstrated highly similar responses during these intervals, the statistical software generated non-computable values for certain pairwise comparisons. These findings may indicate stabilization of postoperative recovery and minimal variation in patient-reported discomfort during the later stages of healing. The interpretation of these results has been clarified in the revised manuscript to improve transparency and readability.
Reviewer Comment 9
Comment:
Claims of superiority and predictability require comparative and longitudinal data, which this study lacks.
Response:
We agree that claims regarding superiority or predictability should be interpreted cautiously in the absence of a comparative group. The present study was primarily intended to evaluate patient-reported postoperative outcomes following CAS KIT–assisted indirect sinus augmentation within the study population. Accordingly, statements implying superiority or predictability have been revised throughout the manuscript to ensure that the conclusions remain consistent with the observational nature and scope of the study.
Revised manuscript text:
The present study demonstrated favorable postoperative clinical healing and improvement in patient-reported oral health–related quality-of-life outcomes following CAS KIT–assisted indirect sinus augmentation and implant rehabilitation.