Comprehensive Guide to Orthodontic Diagnostic Aids and Examinations

Posted on Aug 24, 2024 in Biology

Essential Diagnostic Aids

These clinical aids are crucial for all orthodontic cases, as they are simple and don’t require expensive equipment:

  • Case history
  • Clinical examination
  • Study models
  • Certain radiographs:
    1. Periapical radiographs
    2. Bitewing radiographs
    3. Panoramic radiographs
  • Facial photographs

Supplemental Diagnostic Aids

These aids are not essential in all cases and may require specialized equipment:

  • Specialized radiographs
  • Electromyographic examination of muscle activity
  • Hand-wrist radiographs (to assess bone age or maturation age)
  • Endocrine tests
  • Estimation of basal metabolic rate

Case History

This involves gathering and documenting relevant information from the patient and parent to assist in diagnosis.

Personal Details

  • Name: Recorded for communication and identification.
  • Age: Chronological age aids in diagnosis and treatment planning.
  • Sex: Important for planning, as growth spurts differ between males and females.
  • Address and Occupation: Helps evaluate the socio-economic status of the patient and parents.

Chief Complaint

Record the patient’s primary concern in their own words.

Medical History

  • Delay orthodontic treatment if the patient has uncontrolled epilepsy.
  • Diabetic patients can undergo treatment if their condition is managed.

Dental History

Gather information on:

  • Eruption age of deciduous and permanent teeth
  • History of extractions, decay, restorations, and trauma
  • Past dental history helps evaluate patient and parent’s attitude towards treatment

Prenatal History

Record information on:

  • Mother’s condition during pregnancy
  • Type of delivery
  • Drug use (e.g., thalidomide) or infections (e.g., German measles) during pregnancy, which can cause congenital deformities

Postnatal History

Gather information on:

  • Type of feeding
  • Presence of habits
  • Milestones of normal development

Family History

Record details of malocclusions in family members, as many conditions are inherited (e.g., skeletal Class II and III malocclusions, clefts of lip and palate).

General Examination

Height and Weight

Provide clues to physical growth and maturation, which may correlate with dentofacial development.

Gait

Observe the way a person walks, as abnormalities often relate to neuromuscular disorders with potential dental correlations.

Posture

Abnormal posture can contribute to malocclusion due to altered maxillomandibular relationships.

Body Build (Physique)

  • Aesthetic: Thin physique, often with narrow dental arches.
  • Plethoric: Obese individuals, generally with large, square dental arches.

Sheldon’s Classification of Body Build

  • Ectomorphic: Tall and thin physique.
  • Mesomorphic: Average physique.
  • Endomorphic: Short and obese physique.

Extraoral Examination

A. Shape of the Head

  • Mesocephalic: Average head shape with normal dental arches.
  • Dolicocephalic: Long and narrow head with narrow dental arches.
  • Brachycephalic: Broad and short head with broad dental arches.

B. Facial Form

  • Mesoprosopic: Average or normal face form.
  • Euryprosopic: Broad and short face.
  • Leptoprosopic: Long and narrow face.

C. Assessment of Facial Symmetry

  • Slight asymmetry is considered normal.
  • Gross facial asymmetry can result from:
    • Congenital defects
    • Hemi-facial atrophy/hypertrophy
    • Unilateral condylar ankylosis and hyperplasia

D. Facial Profile

View the patient from the side to diagnose gross deviations in maxillomandibular relationships.

E. Facial Divergence

Defined as the anterior or posterior inclination of the lower face relative to the forehead.

F. Assessment of Anteroposterior Jaw Relationship

Ideally, the maxillary skeletal base is 2-3mm forward of the mandibular skeletal base in occlusion.

G. Assessment of Vertical Skeletal Relationship

The distance between the eyebrows to the nose-lip junction should equal the distance from that point to the underside of the chin.

H. Evaluation of Facial Proportions

A well-proportioned face divides into three equal thirds using four horizontal planes at the hairline, eyebrows, nose base, and chin.

I. Examination of Lips

  • The upper lip should cover the entire labial surface of the upper anteriors, except for 2-3mm of the incisal edges.
  • The lower lip should cover the entire labial surface of the lower anteriors and 2-3mm of the incisal edges of the upper anteriors.

J. Examination of the Nose

The nose significantly contributes to the aesthetic appearance of the face.

K. Examination of the Chin

  • Mentolabial Sulcus: The concavity below the lower lip. A deep sulcus is seen in Class II, division 1 malocclusion, while it is shallow in bimaxillary protrusion.

Intraoral Examination

Examination of Tongue

  • Tongue abnormalities can disrupt muscle balance, leading to malocclusion.
  • An excessively large tongue can cause teeth indentations on its lateral margins, giving it a scalloped appearance.

Examination of Palate

  • Check for variations in palatal depth, which can occur with variations in facial form.

Examination of Gingiva

Examine for inflammation, recession, and other mucogingival lesions.

Examination of Frenum Attachments

An abnormally high mandibular labial frenum attachment can cause gingival recession.

Examination of Tonsils and Adenoids

Inflamed tonsils can alter tongue and jaw posture, disrupting orofacial balance and potentially leading to malocclusion.

Assessment of Dentition

Record the following:

  1. Teeth present
  2. Unerupted teeth
  3. Missing teeth
  4. Status of dentition (e.g., caries, restorations)
  5. Molar relationship in centric occlusion

Functional Examination

This includes:

  1. Assessment of postural rest position and interocclusal space
  2. Path of closure
  3. Assessment of respiration
  4. Examination of TMJ
  5. Examination of swallowing
  6. Examination of speech

Assessment of Postural Rest Position and Interocclusal Clearance

The postural rest position is the mandibular position where the muscles of jaw opening and closing are at minimal contraction.

Phonetic Method

  • The patient repeats consonants like ‘M’ or ‘C’ or a word like ‘Mississippi’.
  • The mandible returns to postural rest position 1-2 seconds later.
  • Observe the interocclusal space without the patient changing their jaw, lip, or tongue position.

Command Method

The patient performs functions like swallowing, which tends to return the mandible to rest position.

Non-Command Method

Observe the patient’s jaw position during natural speaking or swallowing without their knowledge.

Evaluation of the Path of Closure

This refers to the mandibular movement from rest position to habitual occlusion.

Assessment of Respiration

Mirror Test

  • Hold a double-sided mirror between the nose and mouth.
  • Fogging on the oral side indicates oral breathing.

Cotton Test

  • Place a butterfly-shaped cotton piece on the upper lip below the nostrils.
  • Downward fluttering indicates nasal breathing.
  • This test can also detect unilateral nasal blockage.