Q: where can I find a healthcare lawyer who handles general negligence, medical negligence, & unprofessional conduct?
A minor was falsely accused of sexual abuse and questioned without parental consent by her dentist.
This is an extraordinarily unusual situation and there is no clear 'area of law' that governs it.
Complaints about unprofessional conduct of a dentist can be made to the Texas State Board of Dental Examiners (https://tsbde.texas.gov/complaint-investigations-process/). This may not be satisfactory in your particular situation because false accusations of sexual abuse aren't really encompassed by the professional ethics rules for dentists.
Medical malpractice attorneys deal with the conduct of health care professionals in providing healthcare within the standard of care of a particular field of medicine. Sexual abuse most likely falls completely outside the field of dentistry.
Libel and slander might apply, but it depends to whom the dentist published the false accusations. If the dentist only accused the minor--and did not publish such accusations to third parties--the minor hasn't really been defamed because the minor presumably knows the accusations against them are false ("loss of reputation for defamation is concerned with a recipient believing the statement. If every recipient discredits the statement, no loss of reputation has occurred.")
Arguably, the minor might have a claim for intentional infliction of emotional distress depending upon the facts and circumstances, but proving any damages of consequence may be very difficult. Were there any economic damages at all, or only non-economic damages like mental anguish? If so, does it meet the standard to be compensable ("a substantial disruption in the minor's daily routine" or "a high degree of mental pain and distress that is more than mere worry, anxiety, vexation, embarrassment or anger")?
You may need an attorney with a broad-base of experience in several areas. But you may also find that the cost of such an attorney is likely to be more than any potential recovery the minor may be receive from the dentist, depending again upon the specific facts of your situation.
A: I believe you would do best with an experienced Medical Malpractice Attorney in the State where this occurred.