NCT07520682: COBA 50

Orthognathic Surgery in Anterior Open Bite: a Retrospective Study of 50 Patients With Initial Tongue Malposition

Completed Last updated 9 April 2026

What this trial tests

trial testing type of post-operative rehabilitation : with physiotherapy or speech therapy in Patients With Anterior Open Bite Malocclusion and Who Benefited of an Orthognathic Surgery in 50 participants. Completed in 1 August 2025.

Timeline

1 January 2022

Primary endpoint
1 January 2025

1 August 2025

Quick facts

Lead sponsor	Hospices Civils de Lyon
Status	Completed
Study type	OBSERVATIONAL
Enrollment	50
Start date	1 January 2022
Primary completion	1 January 2025
Estimated completion	1 August 2025
Sites	1 location across France

Drugs / interventions tested

• type of post-operative rehabilitation : with physiotherapy or speech therapy

Conditions studied

• Patients With Anterior Open Bite Malocclusion and Who Benefited of an Orthognathic Surgery — all drugs for Patients With Anterior Open Bite Malocclusion and Who Benefited of an Orthognathic Surgery →
• Infantile Swallowing and Tongue Malposition Necessitating Tongue Rehabilitation — all drugs for Infantile Swallowing and Tongue Malposition Necessitating Tongue Rehabilitation →

Sponsor

Hospices Civils de Lyon — full company profile →

Who can join

18 and older, any sex, with Patients With Anterior Open Bite Malocclusion and Who Benefited of an Orthognathic Surgery or Infantile Swallowing and Tongue Malposition Necessitating Tongue Rehabilitation. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

The anterior gap is defined by a lack of contact between the upper and lower dental arches.

It is mainly due to the persistence of infantile swallowing during and after childhood, i.e. interposition of the tongue between the two dental arches.

Patients presenting with an anterior gap in adulthood are likely to develop functional sequelae (masticatory difficulties, dental loosening, periodontal disease, etc.) and aesthetic sequelae (edentulous smile, excess height of the lower third of the face compared to the upper and middle third).

Patients who are diagnosed with this condition very often benefit from orthodontic-surgical treatment, comprising a period of orthodontics followed by orthognathic surgery to close the anterior gap. This is combined with lingual re-education to treat infantile swallowing. This lingual re-education is not always carried out, either because infantile swallowing has not been diagnosed, or because of a lack of cooperation on the part of the patient, or because of difficulties in finding a suitable specialist. When rehabilitation is introduced, it is sometimes only after surgery, and for a short time.

For example, it has been observed that among all patients undergoing orthognathic surgery, those with an anterior gap were particularly at risk of surgical treatment failure, or recurrence in the short to medium term.

The main reason cited was the persistence of infantile swallowing and consequent malpositioning of the tongue between the dental arches, creating permanent pressure on the lingual surface of the teeth and eventually leading to recurrence of the gap.

Identifying patient management factors associated with postoperative recurrence of anterior hollowness in patients with infantile swallowing would enable us to adapt the management of these patients.

Publications & conference data

No peer-reviewed publications indexed yet for this trial. Completed trials usually publish results within 12-18 months.