James Pennell launched the attack on Eva Smith after she was unable to push the car out of the field.
Jon Straw, prosecuting, said “The two of them had been out in the car. They had been drinking.
“It seems that on the way back Eva, who had been asleep, became aware he had left the road and crashed the car into a field.
“He couldn’t get the car out. He told her to get out and try and push. She did her best to assist but in the event couldn’t.
“He told her she was useless. It finished with him punching her to the side of the jaw. That caused her extreme pain and the loss of teeth.
“She has had considerable dental work at a cost of £1,800. She had to have a complete set of dentures across the upper jaw. All the teeth had to be extracted.”
Mr Straw said that on another occasion Pennell grabbed Ms Smith and squeezed her neck in an attempt to strangle her.
The prosecutor said the couple were in a relationship that deteriorated to the point where it became toxic.
Mr Straw said “It is clear that the defendant would initially be loving but then became abusive, demeaning, threatening and altogether unpleasant. All this had a devastating effect on Eva Smith.”
Pennell, 29, of Willows Court, Tattershall, admitted a charge of controlling or coercive behaviour towards Eva Smith between November 2018 and January this year.
He also admitted a charge of breach of a non-molestation order.
That involved a previous partner who Pennell spotted as she was driving to work with her current boyfriend.
Pennell followed their car through Louth. The couple drove to the town’s police station to get away from him and reported the incident to officers.
Pennell was jailed for a total of 17 months and given a five year restraining order banning him from contact with Eva Smith.
Nick Bleaney, in mitigation, said that Pennell acknowledged that his behaviour was unacceptable.
He said Pennell has spent time in custody awaiting his court hearing and has completed a number of educational courses.