N. PATRICK CROOKS, J.
¶ 1. The question we consider in this case is whether Ramon Gonzalez's constitutional right not to be a witness against himself was violated when the court, over defense objection, asked in front of the jury that Gonzalez "display his teeth," and Gonzalez complied. Gonzalez argues that he was compelled to be a witness against himself at trial because the teeth, which were platinum, were more than physical evidence — they conveyed a message to the jury because they give him a "fierce" appearance. A witness had testified that the victim had identified one of his attackers as a fellow inmate with platinum teeth. [4]*4The circuit court1 ruling came after the prosecutor asked "for the jury's sake, that we show Mr. Gonzalez's dental work ... so the witness can describe whether or not he has particular dental work." Gonzalez was convicted of battery by a prisoner, as a party to a crime.
¶ 2. The question requires us to decide whether, in this case, teeth are the kind of evidence that implicates the Self-Incrimination Clause.2 Gonzalez acknowledges that it is well settled that the right against [5]*5self-incrimination applies only to testimonial evidence, but he argues that in this case the physical evidence "had a 'testimonial' aspect because it revealed content —the 'fierce-looking' appearance of his teeth,"3 and he says this fits within the category of cases where physical evidence has been held to have a testimonial aspect and, as a result, to fall under constitutional protection. He argues in the alternative that even if it has no testimonial aspect, it was improperly admitted because it was not material, given that other evidence served the purpose of identification. The State argues that his platinum teeth were physical evidence that did not have a testimonial aspect, and were material to the identification of Gonzalez, which was central to the trial.
¶ 3. We hold that the evidence of his platinum teeth was physical evidence that did not have a testimonial aspect sufficient to implicate constitutional protections. The relevant question under the case law is whether the evidence in question expresses, makes use of, reveals, or discloses the contents of the defendant's mind.4 Teeth do not do so. We also hold that Gonzalez's teeth are material to identification because they are [6]*6probative of Gonzalez's identity, which was a matter at issue.5 This case therefore fits squarely into the long-recognized category of cases involving the body as evidence and does not offend constitutional principles against self-incrimination. We affirm the court of appeals.
I. BACKGROUND
¶ 4. This case arises from an attack by multiple people on an inmate in the Milwaukee County Jail. Gonzalez was among the inmates who were accused of attacking the victim. He was charged with battery by a prisoner, as a party to a crime, and went to trial. Challenging the identification of the accused as one of the attackers was the focus of the defense. The victim was clearly reluctant to testify and repeatedly said so while under oath; he claimed he was unable to identify his attackers. While video of the attack was shown to jurors, the defense disputed that the grainy video was sufficient to make an identification, and the State offered further evidence on that issue. The jury heard the following during testimony about the identification of Gonzalez and his involvement in the beating:
- An eyewitness, a deputy on duty at the jail, saw Gonzalez stomp on the victim during the fight.
- Minutes after the attack, the victim of the assault told an investigating officer that one of the persons involved was from Cell 10.
- While in the jail infirmary, the victim told a second investigating officer that the inmate in Cell 10 who had platinum teeth had hit and kicked him.
[7]*7- The victim also testified that he knew Gonzalez by the nickname "Platinum" because of his teeth.
- Gonzalez was housed in Cell 10 and had platinum teeth.
No evidence was introduced that any other inmate besides Gonzalez fit this description.
¶ 5. During the trial, Gonzalez objected to the prosecutor's request, during a witness's testimony, that Gonzalez reveal his teeth to the jury. The circuit court overruled the objection. Gonzalez complied, and the record reflects that he smiled at the jurors to show his platinum teeth. Gonzalez's post-conviction motion for a new trial was denied, and the court of appeals affirmed the conviction on the grounds that the teeth were physical evidence, and thus Gonzalez's showing of his platinum teeth did not constitute the kind of compelled testimonial evidence the United States and Wisconsin Constitutions prohibit. Gonzalez petitioned for review, which we granted.
II. STANDARD OF REVIEW
¶ 6. The question we address is whether Gonzalez was compelled to provide the kind of evidence that is protected by the Fifth Amendment of the United States Constitution6 and its corollary in the Wisconsin Consti[8]*8tution, which prohibit the State from compelling a defendant to be a witness against himself or herself. Although this case does not arise from a suppression motion or motion in limine, it similarly presents a question of a constitutionally-based objection to the admission of certain evidence. "Whether evidence should be suppressed is a question of constitutional fact. In reviewing questions of constitutional fact, we uphold a circuit court's factual findings unless clearly erroneous, but we independently determine whether those facts meet the constitutional standard." State v. Samuel, 2002 WI 34, ¶ 15, 252 Wis. 2d 26, 643 N.W.2d 423 (citations omitted) (evaluating a constitutionally-based challenge to the admission of certain evidence).
III. DISCUSSION AND ANALYSIS
¶ 7. The facts relevant to our discussion are not in dispute. It is not disputed that the evidence in question was compelled by the circuit court; Gonzalez was ordered by the court in open court to display his teeth to the jury. The dispute we address is solely one of law: whether this is the kind of evidence that cannot be compelled without violating constitutional guarantees. Gonzalez gives two reasons the evidence should not have been admitted. After setting out briefly the relevant law, we will address the parties' arguments on those two points.
[9]*9A. The Self-Incrimination Clause And Body-As-Evidence Cases
¶ 8. The United States Supreme Court has, in cases in which the self-incrimination clause has been invoked, repeatedly recognized that certain distinguishing characteristics of a defendant may be used against him or her even if they are incriminating. It summarized its interpretation of the self-incrimination clause concisely in United States v. Hubbell prior to starting its analysis in that case:
It is useful to preface our analysis of the constitutional issue with a restatement of certain propositions that are not in dispute.
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N. PATRICK CROOKS, J.
¶ 1. The question we consider in this case is whether Ramon Gonzalez's constitutional right not to be a witness against himself was violated when the court, over defense objection, asked in front of the jury that Gonzalez "display his teeth," and Gonzalez complied. Gonzalez argues that he was compelled to be a witness against himself at trial because the teeth, which were platinum, were more than physical evidence — they conveyed a message to the jury because they give him a "fierce" appearance. A witness had testified that the victim had identified one of his attackers as a fellow inmate with platinum teeth. [4]*4The circuit court1 ruling came after the prosecutor asked "for the jury's sake, that we show Mr. Gonzalez's dental work ... so the witness can describe whether or not he has particular dental work." Gonzalez was convicted of battery by a prisoner, as a party to a crime.
¶ 2. The question requires us to decide whether, in this case, teeth are the kind of evidence that implicates the Self-Incrimination Clause.2 Gonzalez acknowledges that it is well settled that the right against [5]*5self-incrimination applies only to testimonial evidence, but he argues that in this case the physical evidence "had a 'testimonial' aspect because it revealed content —the 'fierce-looking' appearance of his teeth,"3 and he says this fits within the category of cases where physical evidence has been held to have a testimonial aspect and, as a result, to fall under constitutional protection. He argues in the alternative that even if it has no testimonial aspect, it was improperly admitted because it was not material, given that other evidence served the purpose of identification. The State argues that his platinum teeth were physical evidence that did not have a testimonial aspect, and were material to the identification of Gonzalez, which was central to the trial.
¶ 3. We hold that the evidence of his platinum teeth was physical evidence that did not have a testimonial aspect sufficient to implicate constitutional protections. The relevant question under the case law is whether the evidence in question expresses, makes use of, reveals, or discloses the contents of the defendant's mind.4 Teeth do not do so. We also hold that Gonzalez's teeth are material to identification because they are [6]*6probative of Gonzalez's identity, which was a matter at issue.5 This case therefore fits squarely into the long-recognized category of cases involving the body as evidence and does not offend constitutional principles against self-incrimination. We affirm the court of appeals.
I. BACKGROUND
¶ 4. This case arises from an attack by multiple people on an inmate in the Milwaukee County Jail. Gonzalez was among the inmates who were accused of attacking the victim. He was charged with battery by a prisoner, as a party to a crime, and went to trial. Challenging the identification of the accused as one of the attackers was the focus of the defense. The victim was clearly reluctant to testify and repeatedly said so while under oath; he claimed he was unable to identify his attackers. While video of the attack was shown to jurors, the defense disputed that the grainy video was sufficient to make an identification, and the State offered further evidence on that issue. The jury heard the following during testimony about the identification of Gonzalez and his involvement in the beating:
- An eyewitness, a deputy on duty at the jail, saw Gonzalez stomp on the victim during the fight.
- Minutes after the attack, the victim of the assault told an investigating officer that one of the persons involved was from Cell 10.
- While in the jail infirmary, the victim told a second investigating officer that the inmate in Cell 10 who had platinum teeth had hit and kicked him.
[7]*7- The victim also testified that he knew Gonzalez by the nickname "Platinum" because of his teeth.
- Gonzalez was housed in Cell 10 and had platinum teeth.
No evidence was introduced that any other inmate besides Gonzalez fit this description.
¶ 5. During the trial, Gonzalez objected to the prosecutor's request, during a witness's testimony, that Gonzalez reveal his teeth to the jury. The circuit court overruled the objection. Gonzalez complied, and the record reflects that he smiled at the jurors to show his platinum teeth. Gonzalez's post-conviction motion for a new trial was denied, and the court of appeals affirmed the conviction on the grounds that the teeth were physical evidence, and thus Gonzalez's showing of his platinum teeth did not constitute the kind of compelled testimonial evidence the United States and Wisconsin Constitutions prohibit. Gonzalez petitioned for review, which we granted.
II. STANDARD OF REVIEW
¶ 6. The question we address is whether Gonzalez was compelled to provide the kind of evidence that is protected by the Fifth Amendment of the United States Constitution6 and its corollary in the Wisconsin Consti[8]*8tution, which prohibit the State from compelling a defendant to be a witness against himself or herself. Although this case does not arise from a suppression motion or motion in limine, it similarly presents a question of a constitutionally-based objection to the admission of certain evidence. "Whether evidence should be suppressed is a question of constitutional fact. In reviewing questions of constitutional fact, we uphold a circuit court's factual findings unless clearly erroneous, but we independently determine whether those facts meet the constitutional standard." State v. Samuel, 2002 WI 34, ¶ 15, 252 Wis. 2d 26, 643 N.W.2d 423 (citations omitted) (evaluating a constitutionally-based challenge to the admission of certain evidence).
III. DISCUSSION AND ANALYSIS
¶ 7. The facts relevant to our discussion are not in dispute. It is not disputed that the evidence in question was compelled by the circuit court; Gonzalez was ordered by the court in open court to display his teeth to the jury. The dispute we address is solely one of law: whether this is the kind of evidence that cannot be compelled without violating constitutional guarantees. Gonzalez gives two reasons the evidence should not have been admitted. After setting out briefly the relevant law, we will address the parties' arguments on those two points.
[9]*9A. The Self-Incrimination Clause And Body-As-Evidence Cases
¶ 8. The United States Supreme Court has, in cases in which the self-incrimination clause has been invoked, repeatedly recognized that certain distinguishing characteristics of a defendant may be used against him or her even if they are incriminating. It summarized its interpretation of the self-incrimination clause concisely in United States v. Hubbell prior to starting its analysis in that case:
It is useful to preface our analysis of the constitutional issue with a restatement of certain propositions that are not in dispute. The term "privilege against self-incrimination" is not an entirely accurate description of a person's constitutional protection against being "compelled in any criminal case to he a witness against himself."
The word "witness" in the constitutional text limits the relevant category of compelled incriminating communications to those that are "testimonial" in character. As Justice Holmes observed, there is a significant difference between the use of compulsion to extort communications from a defendant and compelling a person to engage in conduct that may be incriminating. Thus, even though the act may provide incriminating evidence, a criminal suspect may be compelled to put on a shirt, to provide a blood sample or handwriting exemplar, or to make a recording of his voice. The act of exhibiting such physical characteristics is not the same as a sworn communication by a witness that relates either express or implied assertions of fact or belief.
United States v. Hubbell, 530 U.S. 27, 34-35 (2000) (footnotes omitted).
¶ 9. In clarifying what constituted testimonial evidence, the United States Supreme Court has differ[10]*10entiated between "communications" from the defendant and "his body as evidence": "The prohibition of compelling a man in a criminal court to be witness against himself is a prohibition of the use of physical or moral compulsion to extort communications from him, not an exclusion of his body as evidence when it may be material." Schmerber v. California, 384 U.S, 757, 763 (1966) (quoting Holt v. United States, 218 U.S. 245 (1910) (emphasis added)). "The distinction which has emerged, often expressed in different ways, is that the privilege is a bar against compelling 'communications' or 'testimony,' but that compulsion which makes a suspect or accused the source of 'real or physical evidence' does not violate it." Id. at 764. The Court has also described testimonial evidence as "knowledge of facts [compelled from the defendant] relating him to the offense," "his thoughts and beliefs" and "evidence of a testimonial or communicative nature." Doe v. United States, 487 U.S. 201, 210, 213 (1988). In keeping with this distinction, courts have held that there is no violation of the Self-Incrimination Clause where a defendant is compelled to show his or her body, or to display tattoos, scars, physique, or limbs.7
¶ 10. However, the United States Supreme Court has recognized that some physical evidence has a sufficiently testimonial aspect to warrant Fifth Amendment protection.8 As we will explain, those cases arise when a [11]*11particular piece of compelled physical evidence reveals the thoughts of the defendant and those thoughts are incriminating. There are, then, two types of physical evidence: 1) physical evidence (including the body) that does not have a sufficiently testimonial aspect to warrant Fifth Amendment protection, and 2) physical evidence (including the body) that does have a sufficiently testimonial aspect to warrant such protection.
B. Whether Gonzalez's Platinum Teeth Were Physical Evidence With A "Testimonial Aspect"
¶ 11. Gonzalez's first argument is based on the proposition that physical evidence can nonetheless have a testimonial aspect that turns the evidence into the kind barred by the Fifth Amendment to the United States Constitution. Such cases turn on the fact that the evidence in question in some way disclosed the contents of the defendant's mind.
¶ 12. Gonzalez argues that his platinum teeth constitute the kind of physical evidence that has a "testimonial aspect" that conveys or communicates an additional message, and that evidence is therefore testimonial for purposes of Self-Incrimination Clause [12]*12analysis. He points to Pennsylvania v. Muniz, a case in which the United States Supreme Court considered whether the Self-Incrimination Clause barred use of several pieces of evidence obtained from the defendant following a drunk driving arrest. The booking officer asked Muniz his "name, address, height, weight, eye color, date of birth, current age, and the date of his sixth birthday." Pennsylvania v. Muniz, 496 U.S. 582, 590 (1990).
¶ 13. As the lower court had found, "[b]oth the delivery and content of Muniz's answers were incriminating," as both tended to support the inference that Muniz was intoxicated. Id. The responses to all questions were spoken in a slurred manner, and Muniz was unable to give the date of his sixth birthday. Id. But for purposes of Fifth Amendment analysis, the United States Supreme Court made a distinction between the manner in which Muniz answered questions, which it deemed a physical attribute, and the particular answer that revealed something about his thoughts — namely that he was so impaired that he was unable to perform the simple calculation of the date of his sixth birthday. Thus, it held,
Under Schmerber and its progeny ... any slurring of speech and other evidence of lack of muscular coordination revealed by Muniz's responses to Officer Hosterman's direct questions constitute nontestimonial components of those responses. Requiring a suspect to reveal the physical manner in which he articulates words, like requiring him to reveal the physical properties of the sound produced by his voice, does not, without more, compel him to provide a "testimonial" response for purposes of the privilege.
Muniz, 496 U.S. at 592 (citation omitted).
[13]*13¶ 14. In contrast, it held that Muniz's answer about his sixth birthday did constitute testimonial evidence, because in answering it, he was forced to disclose something about his mental faculties:
Muniz was left with the choice of incriminating himself by admitting that he did not then know the date of his sixth birthday, or answering untruthfully by reporting a date that he did not then believe to be accurate (an incorrect guess would be incriminating as well as untruthful). The content of his truthful answer supported an inference that his mental faculties were impaired ....
Id. at 599.
¶ 15. Another case where physical evidence took on a testimonial aspect involved a subpoena for some tax documents that were later used as the basis for criminal charges. What is significant for our purposes is the fact that the United States Supreme Court recognized that in some circumstances, compliance with a subpoena, which would ordinarily not implicate the Self-Incrimination Clause, could have a "compelled testimonial aspect." Hubbell, 530 U.S. at 45. In the context of a dispute over the terms of a grant of immunity, the Court noted that "[w]e have held that 'the act of production' itself may implicitly communicate 'statements of fact.' ... Moreover ... [the custodian] may be compelled to take the witness stand and answer questions designed to determine whether he has produced everything demanded by the subpoena." Id. at 36-37.
¶ 16. As these two cases illustrate, the factual scenarios in which physical evidence has a "testimonial aspect" sufficient to implicate constitutional protections are quite limited and unusual. Gonzalez cites only Muniz as an example of such a case; he argues that the platinum teeth evidence is like the sixth-birthday answer in Muniz in that both reveal too much — that both [14]*14allow jurors to make improper negative inferences about the defendant. In response, the State simply points to the similarities between the facts of this case and the extensive body-as-evidence case law.
¶ 17. There is a crucial difference between the evidence in Muniz and the evidence here. In Muniz, the inference that concerned the United States Supreme Court was an inference about the working of Muniz's mind that went directly to the crime of which he was accused: driving while intoxicated. The evidence the Court found problematic in Muniz was problematic not because it supported a negative inference, but because the particular negative inference it supported was "that his mental state was confused," an inference about the contents of his mind that both parties acknowledged was incriminating in a drunk driving prosecution. Gonzalez's display of his teeth did not disclose anything to the jury about his mental state or the content or workings of his mind.
¶ 18. Likewise, in Hubbell, where physical evidence was found to have a testimonial aspect that brought it under the Fifth Amendment, the Court found it significant that "the prosecutor needed the [defendant's] assistance both to identify potential sources of information and to produce those sources" and this required the defendant to take "the mental and physical steps necessary to provide the prosecutor with an accurate inventory of the many sources of potentially incriminating evidence." Hubbell, 530 U.S. at 42 (emphasis added). It therefore concluded that the defendant's "act of production had a testimonial aspect" that made the Fifth Amendment applicable. Id. at 45.
¶ 19. The content or message he claims the teeth convey — that he is tough and fierce (and therefore more likely to assault someone) — is not the type of disclosure that was problematic in Muniz; his teeth are not [15]*15different from other non-testimonial physical evidence, such as tattoos,9 scars,10 muscular arms,11 teeth,12 and results of an in-court test of defendant's eyes,13 that courts have deemed physical evidence whose compelled display violates no constitutional right — even though some of those physical characteristics might likewise carry negative connotations or communicate an image of fierceness or toughness to some jurors.14 Nor is there use made by the prosecutors of Gonzalez that is com[16]*16parable to the use made by the prosecutors of Hubbell's mind that rendered the physical evidence testimonial in that case.
¶ 20. We therefore conclude that this is not a case in which physical evidence has a "testimonial aspect" that renders its use unconstitutional.15
C. Whether The Display Of Gonzalez's Platinum Teeth Was Material
¶ 21. Gonzalez's second argument is that the availability of other identification evidence renders the display of his teeth for such purpose immaterial, and therefore inadmissible. Gonzalez cites Schmerber for the proposition that the law permits "[defendant's] body as evidence" only "when it may be material." Schmerber, 384 U.S. at 763. He argues that because other identification evidence existed, the display of his teeth was not for the purpose of identification, and therefore it was not, as required, material.16 Specifically, he argues that "there was no need for the jury to determine whether [17]*17Mr. Gonzalez in fact had platinum teeth,"17 because the victim had identified Gonzalez in court as the inmate he knew as "Platinum."
¶ 22. Evidence is material if it is probative of a matter at issue. State v. Becker, 51 Wis. 2d 659, 677, 188 N.W.2d 449 (1971). Evidence that is probative of a matter at issue can be excluded on certain grounds, including that it is cumulative of already presented evidence,18 but that decision is one the circuit court has discretion to make and is subject to highly deferential review on appeal.19
¶ 23. Gonzalez's approach would appear to require us to hold that once any evidence serves the purpose of identification, any additional evidence offered to corroborate it would be immaterial. This case turned on identification, and the State, which is held to a high burden of proof, was entitled to corroborate the identification of the defendant by any permissible means within the ordinary constraints of evidence law [18]*18and subject to the discretion of the circuit court. It is simply untenable to assert that a central piece of identifying evidence is not material in a case like this. As the State notes, the relevance of the evidence was great in a case where "the identity of the assailant remained the central issue in dispute." Given the heavy burden the State bears in a criminal prosecution, it is inappropriate to limit otherwise admissible evidence on the grounds claimed here.
IV CONCLUSION
¶ 24. We hold that the evidence of Gonzalez's platinum teeth was physical evidence that does not have a testimonial aspect sufficient to implicate constitutional protections. The relevant question under the case law is whether the evidence in question expresses, makes use of, reveals, or discloses the contents of the defendant's mind. Teeth do not do so. We also hold that Gonzalez's teeth are material to identification because they are probative of Gonzalez's identity, which was a matter at issue. This case therefore fits squarely into the long-recognized category of cases involving the body as evidence, and does not offend constitutional principles against self-incrimination. We therefore affirm the court of appeals.
By the Court. — The decision of the court of appeals is affirmed.
¶ 25.