21. RELATED PARTY TRANSACTIONS

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As a result of the acquisition of EnvisionTEC, the Company entered into certain agreements with entities affiliated with Mr. El Siblani, who served as a director and executive officer of the Company until his resignation November 5, 2021. As of December 31, 2021, the Company recorded $0.5 million of right of use asset and $0.6 million of lease liability related to leases with Mr. El Siblani. During the year ended December 31, 2021, the Company paid $0.4 million of lease expense related to these leases. Additionally, during the year ended December 31, 2021, the Company paid $0.3 million of service expense to entities owned by Mr. El Siblani.

As a result of other acquisitions, the Company assumed lease agreements with related parties for facilities located across the United States which extend through 2029. As of December 31, 2022, the Company recorded $4.9 million of right of use asset and lease liabilities associated with these leases. As of December 31, 2021, the Company recorded $3.6 million of right of use asset and lease liabilities. During the years ended December 31, 2022, and 2021, the Company paid lease expense of $0.8 million and $0.6 million to the related parties, respectively. As of December 31, 2022, the Company’s annual commitment related to these lease agreements is $0.8 million.

The Company sells products to Lightforce Orthodontics which is affiliated with a member of the Company’s Board of Directors. Management believes the sales were conducted on terms equivalent to those prevailing in an arm’s-length transaction. During the year ended December 31, 2022 the Company recognized $1.5 million of revenue. As of December 31, 2022, the Company has an immaterial account receivable balance with Lightforce Orthodontics.