They are said to have what is known as Hyperdivergent Growth Pattern which includes characteristics such as:
Increased Lower Anterior Facial Height
Occlusal plane diverges after the 1st molar contact
May accompany dental open bite
Narrow nostrils with upturned nose
Dolicofacial or Leptoprosopic face pattern
Constricted maxillary arch
Bilateral Posterior Crossbite
High and narrow palatal vault
Presence of crowding in teeth
Mentalis muscle strain upon forcibly closing of lips
Possible gummy smile with increased interlabial gapCephalometric analysis features of skeletal open bite may include:
Increased Frankfurt-Mandibular Plane angle
Steep Occlusal Plane Angle
Increased SN-MP Angle
Short Mandibular ramus
Increased mandibular body length
Downward and backward position of mandible
Increased gonial angle
Proclined upper incisors, retroclined or upright lower incisors
Posterior part of maxilla is tipped downwards
Posterior facial height equals 1/2 of anterior facial height
Increased hard tissue Lower Anterior Facial Height
Increased total anterior facial height
Short mandibular ramusViken Sassouni developed Sassouni analysis which indicates that patients with long face syndrome have 4 of their bony planes (mandibular plane, occlusal plane, palatal plane, SN plane) steep to each other. Dental open bite
Dental open bite occurs in patients where the anterior teeth fail to touch. However, this is not accompanied by the skeletal tendency of having an open bite. Thus this type of open bite may happen in patients who have horizontal or hypodivergent growth pattern. These patients have normal jaw growth and do not have the long face syndrome. The anterior open bite in these patients may be caused by Macroglossia, Tongue thrusting habit or digit sucking habits.
Some of the characteristics of a dental open bite include:
Normal lower anterior facial height
Horizontal/Hypodivergent growth pattern
Occlusal plane diverges after the premolar contact
Under-eruption of the anterior incisors
Over-eruption of the posterior molars
Proclined upper and lower incisors
No vertical maxillary excess or gummy smile
Presence of habits such as thumb sucking, tongue thrusting
Spacing between anterior incisors due to their proclination

Open bite correction
Primary/mixed dentition
Behavior modification
Behavior therapy is important especially when children are in their primary dentition in the pre-adolescent age. Improving habits at this time may lead to self-correction of open bite in many cases. Sometimes presence of infantile swallowing into early childhood may lead to an anterior open bite. Habit control through appliances such as Tongue crib or Tongue spurs may be used in adolescents if behavior modification fails to stop the habit. Tongue crib therapy
A tongue crib is a removable appliance placed in the maxillary arch to stop the tongue thrusting habit. This appliance may be used in patients with mixed dentition or permanent dentition. The tongue crib is attached through a bar to two bands placed on the upper 1st molars. The crib is shaped like a horseshoe with metal bars that prevent thrusting. The tongue crib eliminates the habit in approximately 90% of patients. . Huang et al. published a study in 1990 which stated that patients who achieved a positive overbite during their tongue crib therapy had a good chance of maintaining that overbite after their orthodontic treatment.