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

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.

Study Overview

• Status: Completed
• Conditions: Patients With Anterior Open Bite Malocclusion and Who Benefited of an Orthognathic Surgery; Infantile Swallowing and Tongue Malposition Necessitating Tongue Rehabilitation
• Intervention / Treatment: Other: type of post-operative rehabilitation : with physiotherapy or speech therapy

• Study Type: Observational
• Enrollment (Actual): 50

Contacts and Locations

Study Locations

• France
  • France
    • Lyon, France, France, 69004
      • Service de chirurgie en maxillo-faciale Hôpital de la Croix Rousse -Lyon

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

patients undergoing orthognathic surgery with a gap prior to surgery (50 patients)

Description

Inclusion Criteria:

• Major patients
• Having undergone ortho gnathic surgery in the Maxillofacial Surgery Department of the Croix Rousse Hospital
• Patients with an anterior gap of more than 3 mm
• Abnormal tongue position at diagnosis

Exclusion Criteria:

• Syndromic patients (cleft lip and palate, craniostenosis)
• Patient refusal

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Relapse of anterior open bite; All patients who presented relapse of anterior open bite after 6 months post operative.	Other: type of post-operative rehabilitation : with physiotherapy or speech therapy; mean duration of rehabilitation; assess the tongue position at rest, and during speech; assess the surgical movements associated with relapse : advancement, rotation, expansion, genioplasty
No relapse of anterior open bite; All patients who did not present a relapse of anterior open bite after 6 months post operative.	Other: type of post-operative rehabilitation : with physiotherapy or speech therapy; mean duration of rehabilitation; assess the tongue position at rest, and during speech; assess the surgical movements associated with relapse : advancement, rotation, expansion, genioplasty

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measurement of the association between anterior open bite recurrence, defined as the absence of contact between the upper and lower incisors at 6 months postoperatively, and the rehabilitation factors.	Duration of rehabilitation in months	6 months

Collaborators and Investigators

• Sponsor: Hospices Civils de Lyon

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2022
• Primary Completion (Actual): January 1, 2025
• Study Completion (Actual): August 1, 2025

Study Registration Dates

• First Submitted: July 28, 2025
• First Submitted That Met QC Criteria: April 2, 2026
• First Posted (Actual): April 9, 2026

Study Record Updates

• Last Update Posted (Actual): April 9, 2026
• Last Update Submitted That Met QC Criteria: April 2, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Orthognathic surgery; Anterior open bite; Tongue rehabilitation
• Additional Relevant MeSH Terms: Therapeutics; Patient Care; Rehabilitation; Aftercare; Continuity of Patient Care; Rehabilitation of Speech and Language Disorders; Speech Therapy; Physical Therapy Modalities
• Other Study ID Numbers: 25-5191