1lapgskullxr
A cephalometric X-ray measurement that assesses facial profile and dental alignment for orthodontic and surgical planning.
{"Measures the relationship between lower teeth and facial profile","Used for orthodontic treatment and jaw surgery planning","Performed on a lateral skull X-ray (cephalogram)","Helps assess facial balance and proportions","Normal values vary by age, sex, and ethnic background"}
Key facts at a glance
- LOINC
- 60601-2
- Short code
- LI-APg
- Synonyms
- 1L-APg Skull XR
- Category
- chemistry
- Sample
- serum
- Container
- N/A - Imaging study, not a specimen collection
- Units
- N/A
- Ref low
- 62
- Ref high
- 70
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 8–99 years
- Method
- xr-measured
- CPT
- 70350 (Cephalometric X-ray, skull, 2 views)
- SNOMED
- 363679005
- Specimen volume
- N/A - Radiographic measurement
- Stability
- N/A - Radiographic image stability depends on digital storage conditions
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–48 hours
- Order
- routine
What is this test?
This test measures the distance from the tip of your lower front tooth (lower incisor) to a line connecting two facial reference points: A-point (where the upper jaw meets the nose) and Pogonion (the most forward point on your chin). This measurement is taken from a special X-ray called a cephalometric radiograph or lateral skull film.
How is the test performed?
You will be positioned next to an X-ray machine with your head carefully placed in a standardized position using ear rods and a forehead rest. The machine will capture a side view of your skull and face. The dentist or orthodontist then uses special software or manual tracing to identify the anatomical landmarks and measure the distance between them.
Why is it important?
This measurement helps healthcare providers understand how your teeth and jaws relate to your facial structure. It is commonly used to plan orthodontic treatment (braces), determine if jaw surgery is needed, and assess treatment outcomes. The measurement helps determine if your lower teeth are too far forward or backward relative to your facial profile.
Reference range
Reference range varies by age, sex, and ethnic population; typically 62-70mm for adults (ANB angle 2-4 degrees normal)N/A
Patient should remove all metallic objects including earrings, necklaces, and dental appliances. Patient positioned in natural head position with lips at rest. Teeth in centric occlusion. X-ray beam centered on external auditory meatus.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Does this test involve any pain?
How long does the test take?
Are there any risks?
Do I need to prepare anything before the test?
When will I get my results?
Sources
- 1
- 2
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy