Dental nurse Lynne Ryan had been working at the Paediatric Dentistry of Northbrook for more than 21 years before she recruited JoJo to help out around the surgery.
However JoJo isn't just any old colleague, she is a golden retriever who has been trained as a 'comfort dog' to calm nervous or anxious people.
JoJo is owned by a Lutheran church charity and during her time as a 'comfort dog' has been dispatched to situations including tornados in Missouri and even the Sandy Hook elementary school massacre in 2012.
The six-year-old canine now helps calm nervous children as they undergo dental procedures, sitting on their lap and encouraging people to stroke her.
Nurse Veronica Renteria explained how one young girl was having her teeth extracted but remained calm throughout as she stroked JoJo's ears.
The dog has become so popular that people even 'call up to specifically request JoJo' for their operation.
In fact JoJo has settled in so well that she even has her own headshot and biography on the team website.
Lynne told Buzzfeed news; 'She's a very loving and sweet dog... I sometimes call her the "queen of the lean" because she'll just come up to someone and if she likes them she'll just lean on them as if to say – here I am and you can pet me now.'
JoJo has weekly shifts while continuing her other charity work at residential homes and centres for the disabled.
Her co-worker Veronica Renteria said; 'In the past three months she has become a big hit... she's just there waiting for you. If you sit down, she'll put her head on your lap.'
Veronica added; 'Parents will say – is this really happening? They can't believe that JoJo just sits there.'