Would a chin implant help me achieve a more defined side profile or should I consider other options?

Based on these photos and short of in person evaluation and discussion about your goals, I do not think that chin augmentation would create more balance in your face/profile. Althought you do not mention your nose, I do believe that it is dominating your face and profile; small reduction would bring more harmony in your profile without chin surgery. Hope this helps.

The side profile photographs demonstrate an overly projecting nose, and a mild recessive chin. Placement of a small chin implant can accomplish augmenting your chin forward for better facial balance and proportions. A closed rhinoplasty approach can accomplish decreasing the overall projection of your nose, and shaving down the dorsal hump with all of the incisions placed on the inside of the nose. It would be helpful to undergo Digital computer imaging to understand what can be accomplished with your facial features with either one or both procedures

Ideally, one would consider alteration of the dental/teeth positions. The upper teeth are 'tilted' back and the lower teeth are not forward enough to support the lower lip. The lower jaw is 'retrognathic'. The orthodontist/oral maxillofacial surgeon can guide you. A chin procedure is not a good plan since it will 'dish in' the area between the nose and chin