In a normal smile, the gingival margins of central incisors and canines should be:

Central incisors 5 mm more gingival

The lateral incisor gingival margins should lie approximately:

1 mm more gingivally than central incisors

At the same level as central incisors and canines

1 mm more incisally than canines and central incisors

3 mm more incisally than canines

The buccal corridor is the space between:

The central incisors and canines

The angle of the mouth and the buccal surface of the most distal visible tooth

The upper dental midline should ideally coincide with:

The distal surface of a lateral incisor

A competent lip is defined as lips that:

Remain apart at rest and need excessive activity to close

Are apart because of obstruction but close comfortably

Potentially competent lips are characterized by:

No ability to close during function

Lips apart at rest due to physical obstruction, but can be held together if required

Lips apart at rest and considerable muscular activity needed for closure

Incompetent lips are characterized by:

Lips apart only due to an obstruction with comfortable closure

A normal nasolabial angle in every patient

Lips together at rest without effort

Lips apart at rest and considerable muscular activity needed for lip seal

Lip incompetence tends to increase with age due to:

Vertical growth of the soft tissues

Achieving lip competence at the end of treatment improves stability particularly when reducing overjet in:

Class II division 1 malocclusion

Why is the tongue assessed during extraoral soft-tissue examination?

To diagnose all skeletal Class II cases

To identify anterior seal during swallowing and tongue position at rest

An adaptive tongue thrust in a patient with incompetent lips may:

Always persist after successful treatment

Prevent the need for oral examination

Bring the tongue forward to contact the lips and form an anterior seal

Cause all Class III malocclusions

An endogenous tongue thrust is clinically important because it may:

Always disappear after fixed appliances

Re-establish after treatment and contribute to relapse

Only affect posterior molar eruption

Which combination is associated with endogenous tongue thrust in the lecture?

Retroclined upper incisors, deep bite, no lisp

Proclination of upper and lower incisors, anterior open bite, lisp, and tongue between incisors at rest

Posterior crossbite and competent lips

Class I molars and normal overjet

Which is NOT one of the listed aims of intraoral examination?

Oral hygiene and overall dental health

Soft tissues and periodontium for pathology

Orthodontic treatment should not begin until the patient demonstrates:

A preference for fixed appliances

Completion of all facial growth in every case

Consistently high levels of oral hygiene

Which statement about informed consent is correct according to the lecture?

Only the proposed appliance needs explanation

The option of no treatment must always be included among alternatives

Retention requirements do not need to be discussed

A parent's preference always overrides a competent child's decision

Normal overjet is approximately:

One-third of the lower incisor crown

A normal overbite is described in the lecture as approximately:

One-third coverage of the crown of the lower incisor

Orthodontics — History & Clinical Examination — Part 4 (Questions 76–100)

University of Baghdad, College of Dentistry, Fifth Year, Lecture 1 & 2. Part 4 of 4. 25 single-best-answer MCQs, 1 point each. Based on the attached lecture.