Gianmarco O'Brien, DDS
- Industry payments
- $292
- Affiliated sites
- 1
- Medical group
- 1
- State license
- 1
- Year NPI issued
- 2007
- Practice address
- 1140 W La Veta Ave Ste 530 Suite 530, Orange, CA 92868-4227
- Practice phone
- Call (714) 953-1000
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Mark A. George
Dental practice · Orange, California
Find Gianmarco O'Brien's professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Gianmarco O'Brien is a prosthodontist in Orange, California
Gianmarco O'Brien practices at Mark A. George in Orange, California.
Gianmarco O'Brien's NPI, 1336338847, was assigned on October 20, 2007. Gianmarco O'Brien holds California license 51630.
- NPI
- 1336338847NPI Registry (opens in a new tab)
- NPI enumeration date
- October 20, 2007
- NPI status
- Active
- Practice phone
- (714) 953-1000
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Gianmarco O'Brien practices at Mark A. George in Orange, California
Gianmarco O'Brien's primary practice is Mark A. George, at 1140 W La Veta Ave Ste 530 Suite 530, Orange, CA 92868-4227. The practice phone is (714) 953-1000.
- Mark A. George1140 W La Veta Ave Ste 530 Suite 530, Orange, CA 92868-4227Phone(714) 953-1000
Sources: Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Gianmarco O'Brien is affiliated with 1 site of care and 1 medical group
Gianmarco O'Brien's primary practice is Mark A. George in Orange, California. Dmand AI also links Gianmarco O'Brien to 1 medical group, named with a free account.
Sources: Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dmand AI tracks the EHR system at Gianmarco O'Brien's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Gianmarco O'Brien practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Mark A. George | Available with a free account |
| +1 medical group | Available with a free account |
Source: Dmand AI Technology Install Data
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Gianmarco O'Brien is one of 159 prosthodontists in California
Prosthodontics is Gianmarco O'Brien's primary specialty in the NPI Registry, under taxonomy code 1223P0700X. Gianmarco O'Brien is licensed in California.
Specialties and state licenses
- Prosthodontist, CaliforniaPrimary
Prosthodontists near Gianmarco O'Brien
Counts of prosthodontists with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Gianmarco O'Brien received $292 in industry payments in 2025
CMS Open Payments shows 7 general payments to Gianmarco O'Brien from 2 drug and device companies in 2025. Food and beverage make up the largest share, 60% of the total. Straumann USA LLC paid the most, $274.
General payments to Gianmarco O'Brien by kind, 2025 to 2025
- Food and beverage$17460%
- Education$10034%
- Honoraria$176%
Companies that paid Gianmarco O'Brien the most, 2025 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Sources for Gianmarco O'Brien's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | Dmand AI Affiliation DataDoctors and Clinicians National Downloadable File (CMS) (opens in a new tab) |
| Primary practice, affiliations and health system | Dmand AI Affiliation DataDoctors and Clinicians National Downloadable File (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Gianmarco O'Brien
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Gianmarco O'Brien's NPI number?
Gianmarco O'Brien's NPI number is 1336338847. It was assigned on October 20, 2007, and it is active in the NPI Registry.
What does Gianmarco O'Brien specialize in?
Gianmarco O'Brien is a prosthodontist in Orange, California. The primary specialty in the NPI Registry is Prosthodontist (taxonomy code 1223P0700X).
Where does Gianmarco O'Brien practice?
Gianmarco O'Brien practices at 1140 W La Veta Ave Ste 530 Suite 530, Orange, CA 92868-4227. Gianmarco O'Brien's primary practice is Mark A. George in Orange, California. Dmand AI also links Gianmarco O'Brien to 1 medical group.
What is Gianmarco O'Brien's office phone number?
The practice phone on file for Gianmarco O'Brien is (714) 953-1000.
What is Gianmarco O'Brien's medical license number?
Gianmarco O'Brien holds California license 51630.
Has Gianmarco O'Brien received payments from drug or device companies?
CMS Open Payments shows $292 in general payments to Gianmarco O'Brien from 2 companies from 2025 to 2025. The largest total came from Straumann USA LLC.
How long has Gianmarco O'Brien been practicing?
Gianmarco O'Brien's NPI was assigned in 2007.
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