Open bite malocclusion
Open bite is a type of orthodontic malocclusion which has been estimated to occur in 0.6% of the people in the United States.
Lastly, some researchers have stated that a lack of incisal contact must be present to diagnose an open bite.
On the contrary, the intrinsic forces of the lips and tongue while at rest create a necessary equilibrium to place the teeth in their correct position.
Balance is when a body remains at rest, even when various forces are pushing it in different directions, and it doesn't accelerate or (in the case of teeth) move.
In the earlier age, open bite may occur due to a transitional change from primary to the permanent dentition.
[14] Some authors suggest that the muscular forces generated during swallowing and speaking could potentially warp the shape of the dental arches.
[1] The effect of airway obstruction on the occlusion was demonstrated by Harvold et al.[18] who, after placing acrylic blocks in the posterior region of the palate of rhesus monkeys, found that AOB had developed.
Anterior open can be caused by functional habits such as digit sucking, tongue thrust or long-term pacifier use.
[2] In a study of an adult Caucasian American population, it was reported that the prevalence of AOB (acute apical abscess) was approximately 3%, though this can vary from 1.5-11% depending on the ethnicity and age of the participant's teeth.
[21] A complex AOB malocclusion is typically caused by a combination of habit, skeletal, dental, and functional factors.
It is shown that as long as the sucking habit stops before the eruption of permanent teeth, the open bite self-corrects.
[30] Hakan Iscan and others used vertical pull chin cup in 17 patients for 9 months where they applied 400g of force on each side.
They stated that vertical chin cup maybe effective in treating skeletal open bite patients.
They found that no positive skeletal influence on the vertical facial pattern of patients treated for open bite in the mixed dentition by their stated protocol.
Extrusion of anterior teeth in these patients will lead to excessive gummy smile which in some cases is not desirable.
They concluded that this effect resulted due to counter-clockwise rotation of mandible which was caused by intrusion of posterior teeth and increased eruption of incisors.
[35][36][37] Macroglossia has been reported to cause open bite and bimaxillary protrusion and is also known to be make orthodontic treatment unstable after its completion.
[36] An orthognathic surgical approach can be taken to correct an open bite once vertical growth has finished in male and female patients.
A two jaw surgery can also be performed where Bilateral Sagittal Split Osteotomy can be done to correct any Antero-Posterior changes of the mandible.
However, with two jaw surgery a relapse leading to bite opening may happen due to condylar remodeling and resorption.
[40] Man-Suk Baek and others evaluated long-term stability of anterior open bite by intrusion of maxillary posterior teeth.
