PARENTING : Building on a Pivotal Relationship : Although the modern family structure has changed over the years, the need for grandparents is a constant.

As a teen-ager, Joan Koss was convinced her parents could do nothing right. Now that she’s a parent herself, Koss is absolutely certain they can do nothing wrong.

“We fought every single day,” Koss says of her parents, Sandy and Alice Miller of Sherman Oaks. “Now, they’re my best friends.”

Maturity and marriage had a lot to do with the turnaround, Koss admits. But dealing with her parents as grandparents to her two children--Daniela, 3, and Jason, almost 2--has been pivotal.

“My parents have a little more patience with my children,” says Koss, 35, who lives in Thousand Oaks with her husband, Ron. “My mom loves to read to them. My dad loves to play and joke around. It’s unconditional love.”

Nothing changes a relationship between parents and children more than the arrival of a grandchild. Children suddenly become responsible adults caring for a new generation, while parents become respected elders who already have succeeded at the monumental task of raising children.

And nothing can be more satisfying to all three generations than a strong bond between grandparents and their grandchildren.

“The relationship between grandparents and grandchildren is really wonderful to watch,” says John Anderson, a Northridge psychologist. “It gives children a sense of heritage, not just of their immediate family, but it lets them know they are part of a lineage.

“With single-parent families and dual-career families, the relationship is increasingly important,” Anderson adds.

The bond between grandparents and grandchildren is considered so critical that on Jan. 1, 1994, the state of California enacted a law that allows grandparents to petition for visitation rights with their grandchildren when the youngsters’ parents divorce.

“One of the things that’s difficult for children in a divorce is the loss of a sense of a permanent relationship with somebody,” says Cynthia Davis, a Sherman Oaks psychologist. “What is helpful for children is knowing that they don’t have to lose all their relationships. That can sustain them.”

Though the modern family structure certainly has changed in the past few generations, the need for grandparents is a constant.

“Grandparents are an important part of a network of relationships,” Davis says. “The idea of knowing that there is somebody who cared for your parents over time is an important concept for children to have. It contributes to the idea of permanency.”

As important as the relationship is, fostering bonds between grandparents and grandchildren can be a challenge--especially if there is geographical distance between families or if relations are strained between grandparents and their own children.

Anderson, who is trying to encourage his 8-year-old daughter’s long-distance relationship with her grandparents, believes that telephone calls, letters, pictures and photo albums can go a long way toward building bonds.

“When they’re very young, I don’t think there’s any substitute for visits,” Anderson says. “Once they’re a little older, a handwritten letter can be very special.”

Of course, family relationships are complex. Sometimes, particularly if grandparents don’t get along with their own children, grandchildren may be reluctant to bond with them. But there are ways to mend fences.

“The smartest thing grandparents can do if they want a relationship with their grandchildren is to make contact and keep their relations separate from their relations with their children,” Davis says. “They should not talk to the children about difficulties with the parents.

“Most important, they should keep the boundaries of the relationship clear,” Davis says. “That’s always a good rule in any family. Each generation’s problems with each other should stay within the boundary of that system of relationships.”

For grandchildren, the rewards of a close relationship with their parent’s parents are invaluable.

“My grandparents are a big part of my life,” says Susan Farrar, 30, of her grandparents, Frank and Dorothy Jacobson of Northridge. “My grandparents were supportive of things in my life that sometimes my parents weren’t.

“They were very instrumental in getting me to the college I wanted to go to,” says Farrar, who lives in Turlock with her husband and two children. “They were very helpful emotionally and financially.”

For grandparents, grandchildren are a delightful gift. “I think you can see yourself in your grandchildren,” Dorothy Jacobson says. “You don’t have full responsibility for them, and they don’t keep you awake nights.”

Adds Alice Miller, in true grandparent fashion: “I wouldn’t have missed being a grandmother for the world.”