Evaluation of Pain, Discomfort and Acceptance During the Orthodontic Treatment of Class III Malocclusion

The aim of this study is to evaluate the levels of pain, discomfort and acceptance between two treatment modalities of Class III correction of growing patients in the late mixed dentition period.

The acceptance of orthodontic appliance is measured by the amount of discomfort occurring during orthodontic treatment. Different feelings can be encountered during the course of orthodontic treatment such as pressure, tension and pain. Pain is defined as an unpleasant feeling and a bad subjective experience combined with internal or external reason and it is considered as the most annoying factor during orthodontic treatment with fixed appliance. In a study by Oliver and Knappman, patients stated that the worse thing related to the orthodontic treatment was pain and 70% of the subjects suffered from pain during orthodontic treatment regardless the appliance' type. The fear from the pain is considered as the most important factor that not encourage patient to ask orthodontic treatment.Many studies demonstrated that there were no differences in the amount of the pain resulted from the orthodontic treatment between males and females \[2, 5\]. In a study of the reasons which make patient stopped the orthodontic treatment, Haynes found that the pain was the first reason, whereas the second one was the effect of the orthodontic appliance on the patient's daily social life.

When reviewing the medical literature, few studies have been found to identify the patient acceptance degree to the orthodontic appliance used for treating Class III cases in general and Class III functional appliances in particular.Removable appliances were evaluated by a series of publications by Sergl et al in Germany.Additionally, when rigorous study designs are considered utilizing randomized controlled trials (RCTs), there are only few RCTs in the dental literature that evaluated patients' responses towards orthodontic treatment. Idris et al., evaluated Class II growing patients undergoing functional orthopedic corrections, whereas Khattab et al., compared labial brackets versus lingual brackets in terms of speech and functional impairments. Recently, Saleh et al., evaluated the levels of acceptance towards the removable mandibular retractor (RMR) when treating young children with Class III malocclusion in the late primary dentition and early mixed dentition (i.e. between 5 and 9 years) and found high levels of acceptance recommending the need for further analysis of patients' responses to this appliance in older age groups.

Bone-anchored intermaxillary elastics have been proposed as a method of correcting Class III deformities. Although this method was compared to the removable mandibular retractor in terms of skeletal and dentoalveolar changes, but the published paper did not report any information about the associated levels of pain and discomfort as well the general acceptability to this treatment modality.

Eligibility Criteria:
Inclusion Criteria:

1. Class III malocclusion according to Angle
2. Presence of anterior cross bite on two teeth or more
3. Class III Skeletal relationship confirmed radiographically (-4\<ANB\<+1)
4. The lower incisors have normal inclination (Incisor-Mandibular-Plane angle not exceeding 100° and not less than 85°)
5. Late mixed dentition or the beginning of the permanent dentition
6. Eruption of The lower canines and first premolars on both sides
7. Absence of craniofacial syndromes or cleft lip and/or palate abnormalities
8. no supernumerary teeth or missing teeth except for the third molars
9. no previous orthodontic treatment

Exclusion Criteria:

1. Pure maxillary deficiency
2. Pure mandibular prognathism
3. Diseases that prevent the application of mini-implants (e.g. Osteoporosis- cortisone and its derivatives treatment - radiation)
4. The roots of the canine are so close to the first premolar
5. Long face (Maxillary-mandibular plane angle greater than 30° or Mandibular-Cranial-Base angle greater than 36°).