concurring in part and dissenting in part.
I would affirm the district court’s judgment of unenforceability of the ’540 patent. The evidence of record supports its conclusion that Therma-Tru committed inequitable conduct.
This court “reviews judgments not opinions, as we have previously stated on numerous occasions.” Milliken Research Corp. v. Dan River, Inc., 739 F.2d 587, 593 (Fed.Cir.1984). A judgment should be upheld if any grounds to sustain the judgment find support in the record. Consolidated Aluminum Corp. v. Foseco Int’l Ltd., 910 F.2d 804, 814 (Fed.Cir.1990) (“An appellate court need not close its eyes to the record where ... there is a way clearly open to affirm the district court’s action.”).
A party attempting to prove inequitable conduct must show that material information was withheld from the PTO with the intent to deceive or mislead the examiner. LaBounty Mfg., Inc. v. United States International Trade Comm’n, 958 F.2d 1066, 1070 (Fed.Cir.1992). Here, the trial court, to whom the inequitable conduct issue was reserved by consent of the parties, found that “clear & convincing evidence” established that “material information was withheld” intentionally from the examiner during prosecution of the patent applications. The question is whether these findings of materiality and intent have a sufficient basis in the record, keeping in mind that we should not disturb them unless we have a definite and firm conviction that a mistake has been committed. Verdegaal Bros., Inc. v. Union Oil Co., 750 F.2d 947, 952 (Fed.Cir.1984). We review the district court’s determination of inequitable conduct for abuse of discretion, and its factual findings for clear error. Kingsdown Medical Consultants, Ltd. v. Hollister Inc., 863 F.2d 867, 876 (Fed.Cir.1988) (en banc).
The record demonstrates that the finding of materiality is not clearly erroneous. Materiality is established by a showing that a reasonable examiner is substantially likely to consider the information “important in deciding whether to allow the application to issue as a patent.” LaBounty, 958 F.2d at 1074 (quoting 37 C.F.R. § 1.56(a) (1991)). Here, Therma-Tru failed to disclose material prior art and misrepresented material information about the prior art to the PTO. For example, Thorn and Therma-Tru did not advise the examiner that compression molded skins had been used by Owens-Corning Fiberglass in doors that were sold and described in printed publications in the early 1970s, while arguing that the prior art skins were not compression molded. They also did not advise the examiner that General Tire & Rubber Company had proposed the use of compression molded skins in making a plastic *998entry door in October 1980. This information obviously would have been important in deciding whether the patent should issue.
Nor is the finding of intent clearly erroneous. The district court recognized that intent is a required element of inequitable conduct, and that more than negligence or gross negligence is required. There is evidence in the record that Therma-Tru knowingly withheld highly material information about prior art from the PTO, as discussed above. The elements of materiality and intent “must be balanced against each other, and if one is particularly strong, a lesser degree of the other may suffice to show inequitable conduct.” Under Sea Indus., Inc. v. Dacor Corp., 833 F.2d 1551, 1559 (Fed.Cir.1987). It is often necessary to prove intent, direct evidence being unavailable, by “a showing of acts the natural consequences of which are presumably intended by the actor.” Merck & Co. v. Danbury Pharmacal, Inc., 873 F.2d 1418, 1422 (Fed. Cir.1989) (quoting Kansas Jack, Inc. v. Kuhn, 719 F.2d 1144, 1151 (Fed.Cir.1983)). Even when there is conflicting evidence about intent, “[w]here there are two permissible views of the evidence, the factfinder’s choice between them cannot be clearly erroneous.” Anderson v. City of Bessemer City, 470 U.S. 564, 574, 105 S.Ct. 1504, 1511, 84 L.Ed.2d 518 (1985).
That the district court may not have fully articulated its findings does not warrant reversal. See Paragon Podiatry Lab., Inc. v. KLM Lab., Inc., 984 F.2d 1182, 1189 (Fed.Cir.1993) (“To reach the conclusion of inequitable conduct under the law, ... the district court necessarily had to have found an intent to deceive the PTO.”); cf. Stratoflex, Inc. v. Aeroquip Corp., 713 F.2d 1530, 1540 (Fed. Cir.1983). The court made factual findings that the omissions were material and that petitioner intentionally withheld them from the PTO. The court’s failure to reference the record in its opinion does not render the decision defective or permit the inference that it ignored relevant evidence. See Medtronic, Inc. v. Daig Corp., 789 F.2d 903, 906 (Fed.Cir.1986) (“We presume that a fact finder reviews all the evidence presented unless he explicitly expresses otherwise.”). Furthermore, because there is sufficient evidence in the record to sustain the judgment based on intentional withholding of material prior art, the judgment does not conflict with the jury’s factual findings, and thus the jury’s verdict on validity does not impinge on the enforceability issue. See Gardco Mfg., Inc. v. Herst Lighting Co., 820 F.2d 1209, 1213 (Fed.Cir.1987) (“The simple fact is that a patent may be valid and yet be rendered unenforceable for misuse or inequitable conduct.”). There was no reversible error in the district court’s findings and no abuse of discretion in its judgment.