Alveolar Microperforation for Inflammation-Enhanced Tooth Movement During Orthodontic Treatment: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Alveolar Microperforation for Inflammation-Enhanced Tooth Movement During Orthodontic Treatment (NCT01720797), a randomized na study. The primary outcome is Tooth Movement Between the Groups.

2. Clinical Question

3. Trial Design

The registry describes a randomized, parallel-group study of micro-osteoperforation during orthodontic treatment. It lists the study as completed, with a start date of 2013-02 and primary completion in 2015-04. The listed enrollment is 21. The record identifies the University of Florida as sponsor and malocclusion as the condition. The phase is listed as NA.

The intervention arm received micro-osteoperforation, described as a minimally invasive procedure intended to achieve rapid orthodontic tooth movement. Topical or local anesthetic was to be delivered in the treated area according to standard practice. The comparator arm is named Non Micro-osteoperforation. Both arm descriptions include chlorhexidine, with the comparator description specifying a rinse before the intervention and rinses twice a day for a week. These differences in the arm descriptions are relevant context when interpreting the contrast: the registry describes the assigned groups as more than simply a device versus no device, although the primary comparison is named for micro-osteoperforation.

Masking is listed as none. The registry record does not describe who knew treatment assignment during care, measurement, or analysis beyond the no-masking entry. It does not report the randomization procedure, allocation concealment, site count, eligibility criteria, or a detailed protocol. These design details should not be inferred from the randomized label alone.

The primary outcome is tooth movement at 6 months, measured using dental impressions. The registry lists reported outcome values for 9 participants in each arm. This is distinct from the total enrollment listed for the study; the record does not explain the relationship between enrollment and the reported outcome counts. It also does not report whether the outcome population was defined by assignment, treatment received, or another analysis rule.

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

Reasons for not completing this period:

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 Tooth Movement Between the Groups, measured over 6 months.

The primary endpoint is titled Tooth Movement Between the Groups and is assessed at 6 months. The registry describes dental impressions taken at follow-up and says Ortholnsight software was used to measure millimeters of tooth movement from the impressions. It also describes the endpoint unit as percentage of movement and says the measured values were converted into a mean and standard deviation. The record does not give a formula for that conversion or define the reference used to express movement as a percentage, so the exact scale should be interpreted according to the registry’s description rather than reconstructed.

Tooth movement is used because the stated research purpose is to assess whether micro-osteoperforation is associated with accelerated movement during orthodontic treatment. Dental impressions provide a way to compare tooth positions over time. A continuous measure can retain variation across participants rather than reducing the result to a yes-or-no outcome. The posted summaries report a mean and standard deviation for each arm, which describe the central value and spread of the recorded measurements.

The endpoint is a measure of movement over the stated follow-up, not a direct measure of total treatment duration or completion of orthodontic care. The registry does not report a measure of time to treatment completion, a prespecified threshold for clinically meaningful movement, or other details that would translate the endpoint values into those outcomes.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What do the arm means describe?

For a continuous outcome, the mean is the arithmetic average of the recorded measurements in an arm. In general, it gives a measure of the central location of the observed values. Here, the registry reports arm means for tooth movement measured from dental impressions at 6 months. The standard deviation describes how spread out the recorded values are around their arm’s mean. A larger standard deviation indicates more variation among the observations, while a smaller one indicates that observations are more closely grouped. These are descriptive statistics, not a direct test of whether the arms differ.

The registry describes the outcome unit as percentage of movement, while the measurement description says that software measured millimeters of movement from dental impressions and that the measurements were converted into mean and standard deviation measurements. The calculation that connects those descriptions is not reported in the registry record. That limits what can be said about the precise scale and interpretation of the values. It would not be appropriate to infer a conversion rule or apply one.

Why is a between-arm estimate needed?

A comparative question is usually expressed with an estimate of the difference between treatment arms, accompanied by a measure of uncertainty. The estimate describes the magnitude and direction of the observed contrast under the chosen analysis. A confidence interval, in general, shows the range of values compatible with the data and statistical assumptions. A hypothesis test can summarize how well the data align with a specified null hypothesis, but a p-value does not describe the size of an effect or its clinical importance. These general concepts do not substitute for a trial-specific estimate.

The registry provides the arm-level means and standard deviations but lists no analysis for the continuous endpoint. The reason given is that values were missing or not estimable for a two-arm comparison. Consequently, no trial-specific contrast, confidence interval, or p-value is available to interpret. It would be misleading to treat the difference someone might calculate from the arm means as the registry’s analyzed result. A simple recalculation from summary statistics would still rely on assumptions and would not resolve the registry’s stated issue about estimability or account for unavailable participant-level information.

Why can spread and precision differ?

Standard deviation concerns the spread of individual observations. Precision concerns uncertainty in an estimate, such as an arm mean or between-arm contrast. These ideas are related, but they are not interchangeable: precision also depends on the amount of information in the analysis and on the statistical method. A standard deviation alone is not a confidence interval. The record does not report confidence limits, standard errors, or a model-based estimate for the comparison, so precision of the comparative result cannot be evaluated from the posted results.

In general, a model may be needed when observations have a structure that makes a simple comparison unsuitable, or when the analysis adjusts for prespecified variables. A model can also address features such as repeated measurements or clustering when those features are part of the design. The registry does not report a statistical model, adjustment variables, or repeated-measure analysis for this outcome. It is therefore not possible to state whether any such method was planned or used.

What do randomization and masking contribute?

Random allocation is intended, in general, to make treatment assignment independent of participant characteristics at the point of assignment. It can support a fair comparison when the assignment process is implemented and the analysis follows an appropriate plan. The randomized label alone does not establish that the groups were balanced on all characteristics, that allocation was concealed, or that all randomized participants were included in the analysis. Those details are not reported in the registry record.

Masking can reduce the influence of knowledge of assigned treatment on care, measurement, or reporting, depending on who is masked. Masking is listed as none. Because the endpoint is measured from dental impressions using software, the record does not say whether the person collecting or assessing the impressions knew assignment. It also does not report any steps taken to standardize or blind measurement. These are uncertainties about possible sources of measurement bias, not proof that such bias occurred.

What do the planning assumptions mean?

In general, sample-size calculations are planning tools that estimate how many participants per arm may be needed under stated assumptions about the effect to detect, variability, significance level, allocation, and statistical method. The registry’s stated planning assumptions use a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. Such values, when reported, are illustrations of planning under those assumptions; they are not observed power and do not show the probability that the result of this completed trial is correct.

The record does not give a trial-specific sample-size justification or state that the trial was designed around those planning assumptions. It also does not report an inferential result to which a planning calculation could be compared. A planning illustration cannot repair the lack of an estimable posted comparison, and it should not be read as a post hoc measure of the strength of the evidence.

What is not available?

The registry lists 0 analyses for the primary outcome and does not report an inferential method, a statistical analysis plan, handling of missing measurements, or a definition of the analysis population. The posted summaries do not include a confidence interval or test result. Without those details, readers can describe the reported values and their within-arm spread, but cannot evaluate the comparative estimate using a trial-specific inferential analysis. General statistical principles explain what these elements would mean; they do not fill in information that the registry does not report.

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("Micro-osteoperforation", "Non Micro-osteoperforation")
n   <- c(9, 9)
m   <- c(4.345, 4.04)
sp  <- c(1.257, 0.991)
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  Micro-osteoperforation  9  4.345  1.257  3.379  5.311
CARM  Non Micro-osteoperforation  9  4.040  0.991  3.278  4.802

11. Multiplicity, Missing Data and Analysis Populations

The registry identifies 1 outcome measure and reports 0 secondary outcomes. It lists the tooth-movement measure as primary and provides arm-level descriptive values. No multiplicity adjustment or strategy for interpreting multiple statistical tests is reported in the registry record. Since no inferential analyses are listed, the record does not show a set of outcome tests for which adjustment can be evaluated. This absence does not establish what analyses may have been planned outside the posted record.

For the primary outcome, the reported arm summaries each have n=9. The study enrollment is listed as 21, but the record does not explain why the outcome counts differ from the enrollment figure. It does not report the number of measurements unavailable, reasons for unavailable measurements, participant flow, or any imputation or other missing-data procedure. Therefore, the extent and consequences of missing outcome data cannot be assessed from the registry record.

The analysis population is not specified. The registry does not say whether the reported summaries include all randomized participants, participants who received assigned procedures, or a subset defined by availability of impressions. Randomization describes how assignment was made; it does not, by itself, establish which participants were included in outcome summaries. No intention-to-treat analysis or per-protocol analysis is reported.

These omissions matter because missing outcomes and analysis-population choices can affect the interpretation of a randomized comparison. In general, the direction and magnitude of any effect of missing data depend on why measurements are missing and how the analysis handles them. The posted record does not provide enough information to judge those issues. It is not appropriate to assume that the reported arm summaries represent all randomized participants or that missing measurements had no influence.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

The registry reports serious adverse events for the Micro-osteoperforation arm among 12 participants at risk, with 0 affected. For the Non Micro-osteoperforation arm, 9 participants were listed as at risk, with 0 affected. The record also reports 0 other adverse events among 12 participants at risk in the Micro-osteoperforation arm and among 9 at risk in the Non Micro-osteoperforation arm. These are counts as reported, not estimates of comparative risk.

The at-risk counts in the safety record differ from the n=9 listed for each arm in the primary outcome summaries. The registry does not explain that difference, so the safety counts should be read separately from the outcome counts. The record does not report death counts. It also does not list serious adverse event terms, consistent with the absence of reported serious events in the posted summary.

Zero reported events in these groups means that the registry lists no events of those categories for the stated at-risk counts. It does not establish that an event is impossible, nor does it quantify how frequently an event might occur in other settings. With no comparative safety analysis, no confidence interval, and no further detail on event collection or follow-up, the record supports only a descriptive account of the posted counts. It does not establish a safety advantage or disadvantage between the arms.

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

The registry record documents a randomized comparison of micro-osteoperforation with a non-micro-osteoperforation arm during orthodontic treatment. It reports arm-level means and standard deviations for tooth movement at 6 months, along with the measurement approach based on dental impressions. It also reports zero serious and zero other adverse events in the stated at-risk groups. These registry entries describe what is posted; they do not amount to a complete estimate of comparative effectiveness or safety.

The primary outcome summaries show the recorded mean and variation in each arm. They do not include an estimated between-arm contrast, confidence interval, or p-value. The registry lists no analysis and notes that values were missing or not estimable for a two-arm comparison of the continuous endpoint. Without an analyzed contrast and its uncertainty, the data cannot be read as demonstrating a difference, no difference, or equivalence.

The outcome is movement measured at a specific follow-up, not overall orthodontic treatment duration. The study summary explains that accelerated tooth movement was the research aim, but the posted endpoint does not directly report when braces treatment was completed. The registry also does not state a threshold for clinically meaningful movement. Thus, even a statistically precise contrast, if one were available, would need additional context to determine its practical importance.

The record does not explain the relationship between listed enrollment and the smaller outcome counts, define the analysis population, or describe how unavailable measurements were handled. Those gaps limit interpretation of both the representativeness and precision of the outcome summaries. Similarly, no masking is listed, but details about who measured impressions and whether the assessment was blinded are not reported.

Any sample-size values used for planning are planning illustrations under stated assumptions, not observed power and not evidence that the trial was adequately or inadequately powered. The registry does not report a trial-specific sample-size justification. The responsible reading is therefore narrow: the record provides descriptive outcome and adverse-event counts, but does not provide the inferential analysis needed to quantify the comparative effect or its uncertainty.

14. Why This Trial Matters Statistically

This trial raises several statistical issues that are common in small randomized studies with continuous outcomes. Random allocation supports a comparative design, but the interpretability of that design depends on a clearly reported analysis linking assignment to the outcome. The registry describes a primary outcome and provides descriptive values, yet lists no analysis and says a two-arm continuous comparison was not estimable. That gap matters because the central research question is comparative, while the available primary results are arm-specific summaries.

The distinction between a mean, a standard deviation, and a treatment contrast is important. Means describe the observed central values in each arm; standard deviations describe the spread of observations within each arm. Neither is a direct measure of uncertainty in the difference between arms. Without a contrast and confidence interval, readers cannot judge the range of plausible comparative effects from the registry record. A p-value alone would not establish clinical importance, but the record does not report one either.

Outcome availability is another key issue. The listed enrollment and reported outcome counts are not the same, and the record does not explain why. This does not reveal whether values were unavailable, participants withdrew, or another process occurred. It does mean that readers cannot assess the analysis population or the possible influence of missing measurements. Transparent participant flow and missing-data methods are essential for understanding whether the randomized comparison is preserved in the analysis.

The endpoint also highlights the importance of defining measurement scales. The record refers to a percentage of movement and describes software measurement in millimeters, but does not explain the conversion. Clear scale definitions help readers understand the magnitude and clinical meaning of an outcome. Finally, the absence of masking and the lack of information about measurement procedures leave uncertainty about how impressions were assessed. These are not evidence that the measurement was biased; they are reporting gaps that make the result harder to evaluate.

15. 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.

Several limitations specific to this record constrain interpretation. The registry lists an enrollment of 21, but the primary outcome summaries report n=9 in each arm. The record does not explain the relationship between enrollment and those outcome counts, provide participant flow, or state why outcome values are not available for other enrolled participants. No missing-data approach is reported. Consequently, the completeness and representativeness of the primary outcome summaries cannot be evaluated.

The outcome measure is described as percentage of movement, while the measurement description says software measured millimeters of movement from impressions and that values were converted into mean and standard deviation measurements. The record does not specify the conversion formula or denominator. This makes it difficult to assess exactly what a unit of the reported mean represents. It also does not report a threshold for clinically meaningful movement or a direct measure of total treatment duration.

No inferential analysis is posted. The registry lists 0 analyses and states that values were missing or not estimable for a two-arm comparison of the continuous endpoint. There is no reported between-arm estimate, confidence interval, or test result. Therefore, comparative precision and statistical compatibility with different effect sizes cannot be evaluated from the record.

Masking is listed as none, and the record does not say whether impression assessment was blinded or how measurement was standardized. Randomization procedures and allocation concealment are also not described. The registry does not report a statistical analysis plan, a trial-specific sample-size justification, or the analysis population. These omissions should be treated as limitations of what is documented, not as proof that particular procedures were or were not used outside the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Alveolar Microperforation for Inflammation-Enhanced Tooth Movement During Orthodontic Treatment — NCT01720797.
• Registry record last updated 2015-06-19; status last verified 2015-06.
• Results first posted 2015-06-19.
• 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.

19. Record Summary

NCT01720797 is a completed randomized, parallel-group study sponsored by the University of Florida. The registry lists a start date of 2013-02, primary completion in 2015-04, and enrollment of 21. It compares micro-osteoperforation with a non-micro-osteoperforation arm in orthodontic treatment.

The primary outcome is tooth movement at 6 months, assessed from dental impressions. The registry reports a mean of 4.345 and standard deviation of 1.257 for the micro-osteoperforation arm, and a mean of 4.04 and standard deviation of 0.991 for the comparator arm. Each primary outcome summary has n=9. No inferential comparison is posted; the registry lists 0 analyses and says a two-arm continuous comparison was not estimable because values were missing.

Serious adverse events are reported as 0 in both arms, with 12 and 9 participants at risk, respectively. Other adverse events are also reported as 0 in both groups. The record does not report death counts, missing-data handling, an analysis population, or a trial-specific statistical plan.