Morphological Pattern of the Atrophic Posterior Maxillae: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Morphological Pattern of the Atrophic Posterior Maxillae (NCT02833337), a registered phase not stated study. The primary outcome is Lateral Wall Thickness.

2. Clinical Question

This framing is important because the record does not describe a randomized treatment comparison. The study summary explains that vertical and horizontal bone deficiency in the posterior maxillae creates challenges for implant-supported oral rehabilitation, and that understanding the anatomy may help avoid complications. Those statements give the anatomical motivation for the investigation; they do not establish that CBCT changes anatomy or improves a clinical outcome. The registered outcome is a measurement of sinus lateral wall thickness, not a patient outcome or a comparison of treatment strategies.

3. Trial Design

The registry record describes a completed study titled “Morphological Pattern of the Atrophic Posterior Maxillae.” It lists the condition as bone deficiency in the posterior maxillae and identifies CBCT as the intervention. The listed enrollment is 180. The recorded start is 2016-07 and primary completion is 2016-09. The sponsor is the Center of Implantology, Oral and Maxillofacial Surgery, Badajoz, Spain.

The study summary motivates the use of CBCT by describing its possible advantages relative to conventional CT, including lower-dose radiation, high isotropic spatial resolution, and cost. It presents the imaging method as a tool for studying anatomical structures such as the atrophic posterior maxillae. These are statements of rationale in the summary, not comparative findings from the study. No measured comparison of imaging methods is reported in the registry record.

The record specifically indicates that this is not a randomized comparison and that allocation was not stated. It also cautions that any arms are not a like-for-like control comparison. Details of the study design beyond those statements are not reported in the registry record. In particular, the record does not define participant groups, explain how any groups were formed, or describe whether the same participants contributed multiple observations.

The primary outcome is lateral wall thickness, expressed as a mean with standard deviation, measured in mm at one month. The record lists one outcome measure and zero analyses. Although the study is marked completed, completion status alone does not establish that outcome results or a statistical analysis are available. The registry record does not report a numerical result for the primary outcome, a participant flow, or the number included in an analysis. Thus, the study can be characterized from the record as an anatomical imaging investigation, but its reported statistical findings cannot be summarized as an observed result.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Lateral Wall Thickness, measured over One month.

The primary endpoint is the thickness, in mm, of the lateral aspect of the maxillary sinus. It is specified as a continuous measurement summarized by a mean and standard deviation, with a timeframe of one month. This endpoint describes an anatomical feature of the posterior maxillae rather than a clinical event, treatment response, or patient-reported outcome.

The study summary explains why anatomical assessment is relevant: vertical and horizontal bone deficiency in the posterior maxillae is described as a challenging setting for implant-supported oral rehabilitation, and detailed anatomical understanding is presented as important to avoiding potential complications. In that context, lateral wall thickness provides a measurable description of one aspect of the maxillary sinus. It can characterize the anatomy examined, but by itself it does not measure the success of rehabilitation or show whether complications were avoided.

General: a continuous endpoint can be summarized by its mean to describe the central value of measurements and by its standard deviation to describe their spread around that mean. The standard deviation is not the same as the uncertainty in the mean. A confidence interval, if reported, would communicate uncertainty in an estimate under the assumptions of the analysis. No confidence interval or numerical mean and standard deviation for this endpoint are reported in the registry record.

The one-month timeframe is listed for the outcome, but the record does not explain the timing in relation to imaging, enrollment, or any other study procedures. The measurement protocol, anatomical landmarks, reader procedures, and handling of repeated or unreadable images are not reported in the registry record. These details matter for interpreting how consistently the endpoint could be measured and what anatomical quantity the reported mean would represent.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

General: statistical methods connect a scientific question to a summary of the observed data. The choice of method depends on the design, endpoint, measurement structure, and analysis population. In this study, the listed outcome is continuous and is intended to be summarized as a mean and standard deviation. The registry record does not provide an outcome value or analysis, so no trial-specific estimate can be interpreted.

What does a mean describe?

General: the mean is the arithmetic average of observations in a defined analysis set. It is a measure of the central location of a continuous variable. Its meaning depends on what was measured and who contributed observations. For this endpoint, that would require a clear definition of the participants and images included, the anatomical landmark used for thickness, and the procedure for producing each measurement. Those details are not reported in the registry record.

General: the standard deviation describes how spread out individual observations are around the mean. It is a description of variation in the measured values, not a measure of the precision of the mean. Precision is often communicated with a confidence interval, which reflects uncertainty in an estimate under specified assumptions. A standard deviation and a confidence interval therefore serve different purposes. Neither is numerically available for the primary endpoint in the registry record.

What would a comparison require?

General: a comparison between groups requires clearly described groups and a defined contrast. In randomized studies, random allocation can help balance measured and unmeasured factors on average, subject to the conduct of the study. This registry record states that the study is not a randomized comparison and that allocation was not stated. It also cautions that arms are not a like-for-like control comparison. The record does not report enough information to define a group contrast or explain how potential differences between groups would be handled.

A mean difference or other comparative estimate is not reported in the registry record. No inferential test, confidence interval, or adjustment model is listed. General: statistical significance, when assessed, concerns compatibility of data with a specified statistical model and null hypothesis; it does not by itself describe the size or clinical relevance of a difference. Since no test result or comparison is reported, there is no statistical significance finding to interpret for this endpoint.

How should planning calculations be read?

The sample-size planning description states that its illustrations use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It also states that the effect to detect is a stated fraction of the observed effect. These are planning assumptions, not a report of the study's original design or an observed finding. The registry record does not report a sample-size justification for the trial, and the planning description does not establish that the study was designed or conducted according to those assumptions.

General: sample-size calculations estimate the number of participants needed under specified assumptions about the outcome, variability, effect, error rates, and design. Planning illustrations can show how required sample size changes when assumptions change. They do not show the probability that a completed study found a true effect, and they are not observed power. The planning figures should not be interpreted as enrollment targets actually used by the investigators or as evidence that a particular level of precision was achieved.

The registry describes the endpoint as continuous, so the time-to-event convention in the planning description does not apply to the listed primary outcome. No trial-specific variability estimate or numerical effect estimate is reported alongside the outcome, and no completed analysis is listed. Thus, no trial-specific calculation can be reconstructed from the record. Any recalculated results are not reported in the registry record.

Why can measurement procedures matter?

General: imaging measurements may vary because of anatomical variation, image quality, reader judgment, and landmark definition. Consistent procedures can reduce avoidable measurement variability, while blinded or repeated readings can help assess aspects of reliability when those procedures are part of a study. The registry record does not report reader blinding, repeat readings, calibration, reliability assessment, or image-quality criteria. These omissions prevent assessment of how measurement error might affect a future estimate, but they do not establish that measurement error occurred.

General: if observations are clustered, such as multiple measurements from the same participant, they may not be statistically independent. Analyses that treat correlated observations as independent can misstate uncertainty. The record does not report whether repeated measurements or multiple images per participant were analyzed, so the dependence structure cannot be evaluated. No model, variance adjustment, or other handling of such structure is reported.

Overall, the methods information supports a limited account: a continuous anatomical endpoint is specified, while the statistical analysis and numerical findings are absent. Explanations of means, variation, comparisons, and planning assumptions describe general statistical concepts and should not be mistaken for methods confirmed to have been used in the completed study.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Consecutive Individuals")
n   <- c(180)
m   <- c(161)
sp  <- c(11)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Consecutive Individuals  180  161.000  11.000  159.382  162.618

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists one outcome measure and zero analyses. Lateral wall thickness is identified as the primary outcome. The record does not report additional outcome analyses or statistical tests. It also does not describe a multiplicity strategy, such as adjustment for multiple outcomes or comparisons, so such a strategy is not reported in the registry record.

General: multiplicity arises when several hypotheses or outcomes are examined. With repeated testing, the chance of obtaining at least one apparently notable result can increase, depending on the tests and their dependence. Prespecifying a primary outcome and analysis can help clarify which result addresses the main question. Here, one primary outcome is listed, but the analysis plan and any prespecified testing strategy are not reported. The record does not allow assessment of whether additional analyses were conducted outside the registry.

Missing-data methods are also not reported in the registry record. There is no count of participants with missing CBCT measurements, no description of reasons for missingness, and no account of how incomplete observations were handled. The listed enrollment of 180 cannot be assumed to equal the number with an observed primary endpoint. No imputation method, complete-case approach, or sensitivity analysis is reported.

The analysis population is not defined. The record does not state whether analysis was intended for all enrolled participants, only those with interpretable images, or another group. It also does not give the number included in an analysis. General: specifying an analysis population helps establish the denominator and the population to which an estimate pertains. Without that information, the scope and potential selection of any endpoint estimate cannot be assessed.

The adverse-event entry states that no adverse events were monitored. This is distinct from missing-data handling for the primary anatomical outcome and does not provide a safety analysis. No additional details on analysis populations, multiplicity, or missing outcome data are reported in the registry record.

12. What the Result Does, and Does Not, Mean

The record establishes that an investigation of atrophic posterior maxillary anatomy was registered, that CBCT was the listed intervention, and that lateral wall thickness was the primary outcome. The endpoint was intended to be reported as a mean and standard deviation in mm, at one month. These details identify what the study set out to measure, but they do not give the measured value.

No numerical outcome, uncertainty estimate, or analysis result is reported in the registry record. Therefore, the record does not show how thick the lateral wall was in the study population, how much measurements varied, or how precisely a population mean was estimated. It also does not support a comparison between groups, because the comparison structure is not established and the record explicitly says the arms are not a like-for-like control comparison.

The study summary frames anatomical knowledge as relevant to challenging implant-supported oral rehabilitation and describes possible features of CBCT relative to conventional CT. This context helps explain why the anatomy may be of interest. It does not mean the registered study demonstrated better treatment outcomes, fewer complications, or advantages of CBCT in a comparative analysis. Such results are not reported in the registry record.

General: an anatomical measurement can describe a structure without showing that measuring it changes a clinical decision or patient outcome. Establishing a clinical consequence would require appropriate outcome data and a design capable of addressing that question. The registered primary endpoint is a structural measurement, not a direct measure of treatment success or harm.

The completed status should likewise be distinguished from completeness of reporting. The registry record lists enrollment of 180, but does not identify the number measured or analyzed. It also says that adverse events were not monitored, which cannot be interpreted as evidence that none occurred. In practical terms, the record offers a study rationale and an endpoint definition, but does not supply the outcome evidence needed to quantify the finding or its clinical implications.

13. Why This Trial Matters Statistically

This study is statistically relevant because it illustrates the distinction between registering a measurable question and reporting an analyzable result. The record specifies a continuous anatomical endpoint, its unit, its intended summary, and a timeframe. Those elements provide a starting point for interpreting a result, but they do not substitute for the estimate, variability, analysis population, and methods needed to evaluate it.

It also highlights why design labels matter. The record states that this was not a randomized comparison, that allocation was not stated, and that arms are not a like-for-like control comparison. Without well-defined groups and a credible comparison plan, group differences cannot automatically be interpreted as effects attributable to an intervention. A descriptive anatomical investigation and a causal treatment comparison answer different statistical questions.

General: a useful statistical report allows readers to understand both the observed data and the uncertainty around an estimate. It identifies who was analyzed, how outcomes were measured, how missing observations were handled, and what comparisons were prespecified. Those details help distinguish a stable estimate from one that may be affected by selection, measurement variability, or an unclear denominator. The registry record does not report these elements for the primary outcome.

The planning description further illustrates a common distinction: sample-size illustrations depend on assumptions and are not evidence of achieved precision or observed power. Their assumptions do not establish the investigators' original design, and no completed outcome analysis is available to connect planning with an observed result. The statistical lesson is to keep design rationale, planning calculations, and findings separate.

For clinical researchers, the record therefore matters as an example of how much interpretation depends on complete outcome reporting. A precise endpoint definition is useful, but a study's completion status and enrollment alone do not reveal the result. The record supports careful discussion of the question and reporting gaps, not conclusions about anatomical values or clinical benefit.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The main trial-specific limitation for statistical interpretation is that the registry record lists no analyses and reports no numerical primary outcome. The mean and standard deviation for lateral wall thickness are not reported in the registry record. Without these estimates, the magnitude and variability of the anatomical measurement cannot be assessed.

The record gives little detail about participant eligibility or characteristics. Although enrollment is listed as 180, the number with an interpretable CBCT measurement and the number included in an outcome analysis are not reported in the registry record. This prevents confirmation of the analysis denominator and assessment of whether the analyzed participants represent the enrolled population.

The measurement procedure is not described beyond the endpoint definition. The record does not report anatomical landmarks, image-acquisition parameters, reader training, blinding, repeated measurements, or reliability assessment. These details could help readers judge consistency and reproducibility; their absence from the record does not establish that the procedures were inadequate.

The study is explicitly not a randomized comparison, allocation is not stated, and the record cautions that arms are not a like-for-like control comparison. Group definitions and any adjustment approach are not reported. Consequently, the record does not establish a basis for attributing a difference to CBCT or comparing groups as if they were exchangeable.

The record also does not report missing-data methods, an analysis population, or a statistical analysis plan. No adverse events were monitored, so the entry cannot provide an assessment of event incidence or safety. These limitations concern what can be interpreted from the registry record; they should not be treated as proof that unreported procedures or analyses did not occur outside the record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Morphological Pattern of the Atrophic Posterior Maxillae — NCT02833337.
• Registry record last updated 2020-09-17; status last verified 2020-08.
• Results first posted 2020-09-17.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

The registry record describes a completed study of bone deficiency in the posterior maxillae, with CBCT listed as the intervention and an enrollment of 180. The recorded start is 2016-07 and primary completion is 2016-09. The sponsor is the Center of Implantology, Oral and Maxillofacial Surgery, Badajoz, Spain.

The primary outcome is lateral wall thickness of the maxillary sinus, measured in mm and intended to be summarized as a mean and standard deviation at one month. The study summary presents anatomical assessment as relevant to implant-supported oral rehabilitation and describes CBCT as a tool for examining posterior maxillary anatomy.

The registry record states that this is not a randomized comparison, allocation was not stated, and arms are not a like-for-like control comparison. It lists one outcome measure and zero analyses. A numerical primary outcome, analysis population, missing-data approach, and statistical analysis are not reported in the registry record. No adverse events were monitored. The record therefore describes the study question and context, but does not report findings that quantify the endpoint.