Class II malocclusion includes those anomalies with the mesiobuccal cusp of maxillary first permanent molar occludes mesial to the mesiobuccal grove of the mandibular first permanent molar.

Class II malocclusion is divided into:

  • Class II, division I – if the incisors are proclined
  • Class II, division II – if the incisors are retroclined
Aetiology Of Class 2 MalocclusionsTreatment Of Class 2 Division 1Treatment Of Class 2 Division 2References

1) Skeletal factors

Anterior posterior aspect:

  • Often associated with a Class II skeletal pattern:
    • Most likely due to a retrognathic mandible
    • Less likely due to a protrusive midface.
    • You can often find an increased overjet on Class I or even Class III base due to habits of soft tissue factors.

Vertical skeletal aspect:

  • Class II Div I can be found on a range of vertical skeletal patterns
    • Management can vary
    • Often have a deep overbite
    • Class II div II almost always have a deep overbite.

2) Soft tissue factors

If lips are incompetent, patient achieves an oral seal by the lower lip being drawn up behind the upper incisors, which seals off the mouth and allows the patient to swallow.

  •  This further proclines the upper incisors and retroclines the lower incisors causing the overjet to worsen.

An oral seal may be achieved by circumoral muscular activity to achieve a normal lip seal, with evidence of mentalis strain
Reduced facial height causes lower lip to sit higher relative to upper incisors. Tend to have a high lower lip line – exerting more force on upper central incisors contributing to retroclined upper incisors.

  • Shorter upper laterals often escape the lip and have normal angulation.

3) Dental factors

  • Malocclusions may occur in the presence of crowding or spacing
  • If crowded, lack of space may cause upper incisors to become crowded out of the arch labially, exacerbating the overjet.
  • However large overjets means the teeth sit in a wider arch causing spaced malocclusions.

4) Habits

Persistent digit sucking acts as a force on the teeth

  • If >6 hrs/day:
    • Upper incisors may become proclined
    • Lower incisors retroclined
    • Incomplete OB or AOB
    • Narrowing of the upper arch and possible posterior cross bites

1) No Treatment:

  • If the patient has poor oral hygiene, a low IOTN, medical history contraindications, or if the patient declines treatment.

2) Upper Removable Appliances (URA):

  • URA can be given to patients that are compliant and have good oral hygiene to tip teeth mesio-distally. Proclined upper incisors can be tipped backed to a class I position.

3) Functional Appliances (Twin block):

  • If arches are well aligned at the start of treatment and there is only anteroposterior discrepancy between the arches, functional appliance alone may be sufficient. Tell the patient to wear at night every day until growth has completed. Wear for longer to account for any relapse.
  • This is called growth modification or dentofacial orthopaedics 
  • By correcting anteroposterior problems with functional appliances reduces amount of anchorage needed with fixed appliance stage 
  • Following the functional stage, patient is reassessed for need of extractions/ fixed appliances.  

4) Fixed Appliance:

  • Often the treatment of choice and allow 3D bodily movement of the tooth.
  • Patients require excellent oral hygiene

5) Extractions:

  • Extraction are usually combined with fixed appliances
    • Upper premolars usually used to create space

Moderate/Severe Cases:

  • If there is a large trauma risk provide a mouthguard and wait until the late mixed dentition
    • Following the functional stage, patient is reassessed for need of extractions/ fixed appliances– consider orthognathic surgery

Difficult to treat due to increased overbite 

1) No Treatment:

  • If the patient has poor oral hygiene, a low IOTN, medical history contraindications, or if the patient declines treatment.

2) Upper Removable Appliances (URA):

  • URA can be given to patients that are compliant and have good oral hygiene to tip teeth mesio-distally. Proclined lateral incisors can be tipped backed to a class I position.

3) Functional Appliances (Twin block):

Using functional appliances followed by fixed is better than trying to treat this malocclusion with fixed alone. 

  • Class 2 div 2 incisor relationship converted to class 2 div 1 then a functional appliance is used. 
  • Retroclined upper incisors can be proclined using pre-functional removable appliance/ sectional fixed appliance on upper labial segment 
  • Some functional appliances can be modified to procline the upper incisors as part of the functional appliance phase of treatment 

4) Fixed Appliance:

  • Often the treatment of choice and allow 3D bodily movement of the tooth.
  • Patients require excellent oral hygiene

5) Extractions:

  • Extraction are usually combined with fixed appliances
    • Upper premolars usually used to create space
  1. Thiruvenkatachari B, Harrison JE, Worthington HV et al. Orthodontic treatment for prominent upper front teeth (Class II malocclusion) in children. Cochrane systematic review. Cochrane Oral Health Group. First published: 13 November 2013.
  2. Selwyn-Barnett, B.J., 1996. Class II/division 2 malocclusion: a method of planning and treatment. British Journal of Orthodontics, 23(1), pp.29-36.
  3. Uribe, F. and Nanda, R., 2003. Treatment of Class II, Division 2 malocclusion in adults: biomechanical considerations. Journal of Clinical Orthodontics, 37(11), pp.599-606.

See also Class III Malocclusions