Anterior open bite (AOB) is a complex malocclusion characterized by the absence of vertical overlap between the maxillary and mandibular anterior teeth when the posterior teeth are in occlusion.
It presents significant clinical challenges due to its multifactorial etiology, high relapse potential, and the need for interdisciplinary treatment planning.
AOB affects both function and aesthetics, compromising speech, mastication, and facial harmony.
This condition is prevalent in both pediatric and adult populations, with studies reporting varying incidence rates depending on age, ethnicity, and environmental influences.
Accurate diagnosis and identification of etiologic factors are critical to formulating a successful and stable treatment plan.
Etiology of Anterior Open Bite
Anterior open bite has a multifactorial origin, including both skeletal and dentoalveolar components:
✔ Habits: Prolonged thumb sucking, tongue thrusting, or pacifier use can interfere with normal eruption patterns.
✔ Skeletal discrepancies: Vertical maxillary excess or mandibular hypodivergence may contribute to AOB.
✔ Genetic predisposition: A strong hereditary component is often observed.
✔ Neuromuscular factors: Abnormal muscle function, such as macroglossia or hypotonia, can lead to anterior open bite.
✔ Airway obstruction: Chronic mouth breathing due to nasal obstruction is a frequently associated factor.
► Read also: Enhancing Orthodontic Outcomes: The Role of Facial Harmony in Diagnosis and Treatment Planning
Clinical Diagnosis
A comprehensive diagnostic approach includes:
✔ Clinical examination: Identifying lack of incisal contact, overjet/overbite relationship, and assessing functional habits.
✔ Cephalometric analysis: Lateral radiographs can reveal skeletal patterns like increased lower anterior facial height, mandibular plane angle, and vertical maxillary growth.
✔ Dental casts and intraoral scans: For evaluating arch form and tooth position.
✔ Photographic analysis: To assess facial aesthetics and smile line.
Treatment Approaches
Treatment varies depending on the age of the patient, severity of the AOB, and whether the etiology is skeletal or dental:
1. Interceptive Treatment (Children and Adolescents)
✔ Habit-breaking appliances (e.g., tongue crib).
✔ Myofunctional therapy.
✔ Early orthodontic intervention to guide eruption.
2. Orthodontic Treatment (Adolescents and Adults)
✔ Fixed appliances with vertical elastics.
✔ Temporary Anchorage Devices (TADs) to intrude posterior teeth and reduce anterior open bite.
✔ Clear aligner therapy with bite-block mechanics (e.g., Invisalign with SmartForce features).
3. Surgical-Orthodontic Approach (Severe Skeletal Cases)
✔ Le Fort I osteotomy for maxillary impaction.
✔ Bilateral sagittal split osteotomy (BSSO) of the mandible.
✔ Genioplasty in cases of significant soft tissue imbalance.
Long-Term Stability and Retention
Relapse is a major concern in AOB cases. Post-treatment strategies should include:
✔ Myofunctional re-education.
✔ Long-term use of retainers (particularly bonded retainers).
✔ Monitoring and control of habits and tongue posture.
Conclusion
Anterior open bite remains one of the most challenging malocclusions in orthodontics.
A multidisciplinary approach integrating accurate diagnosis, habit control, and biomechanical precision is essential for stable correction.
The integration of digital orthodontics, skeletal anchorage systems, and orthognathic surgery has significantly expanded the treatment possibilities for managing this condition effectively.
References
- Orthodontic Waves Volume 76, Issue 1, March 2017, Pages 40-45. Non-surgical treatment of anterior open bite using miniscrew implants with posterior bite plate.
