From the Code of Ethics and Professionalism:
The following dress code guidelines for faculty, students, residents, and staff have been established...
General Attire
Men must wear a dress shirt with necktie, trousers, socks, and dress shoes or dress boots.
Women must wear either a skirt or slacks and blouse or a dress. Hosiery must be worn with skirts and dresses, and socks or hosiery must be worn with slacks. Dress shoes/dress boots must be worn. Trousers/slacks must reach the ankle. Skirts and dresses must approximate the knees in length or fall below them. Culottes which conform to the skirt/dress length standard are acceptable.
The following items apply to the general attire guidelines above:
A visible official school identification badge must be worn above the waistline at all times.
Jeans, stirrup pants, tights alone, leggings, and shorts are
unacceptable.
Denim or denim-like fabrics are unacceptable.
When working in the clinic or laboratories, shoes must be worn to provide protection against accidental puncture injury. Open- toe shoes, sling-backs, moccasins or sandals are not allowed.
Clinical staff may wear sport shoes, but only clean white or black leather sport shoes. No designs or patterns are permitted.
No caps or any other type of head gear will be worn.
Exceptions:
For male faculty members, students, residents, or staff, a necktie is optional if:
1) the majority of the days activities will require wearing a clinical gown.
2) it is during a quarter break period and no public contact is anticipated. This exception does not apply to personnel in the Administrative Area, Business Office, Human Resources, Clinical Sciences/Basic Sciences clerical support staff, Postgraduate Studies, Advanced Education in General Dentistry, International Dental Studies, Department of Dental Practice, Student Services, Student Store, and all Patient Care Areas.
3) Work is limited to the 6th floor Research Laboratories and
no public contact is anticipated.
However, only shirts which are designed to be worn with a necktie or polo shirts with collars are acceptable attire.
For second and third year student, the requirement of a tie is waived due to the unpredictability of their day in relation to patient contact. However, only shirts which are designed to be worn with a necktie or polo shirts with collar are acceptable.
For first year students and Professional Services Laboratory staff, a more casual attire is permissible with the following limitations:
1) Shorts, cut-offs, tee-shirts, halter-type tops, gym or sweat clothes are not permitted.
2) Jeans that are clean and are in good repair are permitted but not encouraged.
3) Clean shoes and socks must be worn.
4) No caps or any other types of head gear will be worn."
In other words...yes, you'll be wearing a necktie during 1st year. You may become one of those people who becomes lax and stops wearing one after a while...but it isn't recommended and you can be called out on it.
2nd and 3rd year you get to drop the tie because of the clinical gown exception rule.