Protruding Mouth and Retruded Chin in Orthodontics: Dental vs. Skeletal, Limits of Braces, ASO vs. Double Jaw Surgery

Why does a protruding mouth happen?

A protruding mouth is a state in which the mouth area looks pushed forward, either because the front teeth tilt forward (dental) or because the alveolar bone and jawbone supporting the teeth sit forward (skeletal) [1]. It can come with lips that do not close easily or a lot of gum showing when smiling [1].

When DentStat analyzed 2,200 patient comments on protruding mouth, retruded chin and surgery, the most common question was whether “braces alone are enough,” and confusion over dental versus skeletal causes was widely observed [3].

Can orthodontics alone improve a protruding mouth?

A dental protruding mouth, where the cause lies in the teeth, can sometimes be improved with orthodontics [1]. The approach creates space, for example by extraction, and moves the front teeth back, and the amount of movement is limited by the extent of the alveolar bone [1]. On the other hand, orthodontics moves teeth and cannot change the position of the jawbone or alveolar bone itself, so a skeletal protruding mouth may improve only to a limited degree with orthodontics alone [1]. In that case, combining surgery is considered, which is decided through tests and consultation with orthodontics and oral and maxillofacial surgery [2].

What is the difference between ASO and double jaw surgery?

The two surgeries differ in the area moved and the purpose [2]. ASO (anterior segmental osteotomy) moves a segment of alveolar bone in the front tooth area, while double jaw surgery (orthognathic surgery) changes the position of the entire upper and lower jaws to improve the skeletal relationship and bite [2].

Category	ASO (anterior segmental osteotomy)	Double jaw surgery (orthognathic surgery)
Area moved	Alveolar bone segment in the front tooth area	Entire upper and lower jaws
Main purpose	Improving front protrusion	Improving the skeletal relationship and bite
Basis for decision	Joint diagnosis based on tests such as cephalometrics and CT	Same

Which one applies, and whether the case is one where surgery is considered at all, is a matter of test-based diagnosis. If orthodontics with extractions has already been completed, options can differ depending on the remaining space and root positions [2]. In the comment analysis, too, questions about re-evaluating remaining protrusion after extraction orthodontics appeared repeatedly [3].

Can orthodontics fix a retruded chin?

A skeletal retruded chin, where the lower jaw is small or set back, has limits with orthodontics alone [1]. When upper front tooth protrusion improves, the chin area can look relatively different, but the lower jaw skeleton itself does not move with orthodontics [1]. Ways to improve a skeletal retruded chin are discussed in oral and maxillofacial surgery consultation after a skeletal evaluation [2].

How can I tell whether it is dental or skeletal?

It is distinguished by lateral cephalometric X-ray (ceph) analysis, which measures the position and angle of the teeth and jawbone [1]. Even profiles that look similar from the outside call for different treatment directions depending on whether tooth inclination or jawbone position is the cause, so checking the explanation of the measurement results is the starting point for a decision [1]. In the comment analysis, many people shared that diagnoses and treatment plans differed between clinics, and some compared the diagnostic basis at multiple clinics [3].

Common misconceptions and facts

Common misconception	What the evidence shows
If you wear braces long enough, the jawbone will move back too	Orthodontics moves teeth, and in adults the position of the jawbone and alveolar bone does not change with orthodontics alone [1]
A protruding mouth always needs surgery	A dental protruding mouth can sometimes improve within the scope of orthodontics, and a diagnostic exam comes first [1]
The only purpose of double jaw surgery is appearance	Orthognathic surgery includes improving the skeletal relationship and bite function among its purposes [2]
A retruded chin can be fully solved with a simple procedure	When skeletal factors are large, soft tissue procedures alone have limits, so evaluating the cause comes first [1]

Surgery in the oral and maxillofacial surgery field in general is covered in the oral surgery guide, extraction, cost structure and retainers for orthodontics in general are in the orthodontics guide, and dental clinics by region can be found in Find a Dentist.