The authors have declared that no competing interests exist.
The treatment of class III malocclusion differs depending on the age of the patient. In adult patients, alternatives include either orthodontic dentoalveolar compensation treatment or a combined ortho-surgical approach. The aim of this paper is to present the orthodontic and surgical treatment of a 24 year old adult patient with increased anterior face height, a class III skeletal pattern and mandibular asymetry. Previous orthodontic treatment with removable appliances obtained a 1 mm overbite and overjet. Intraorally, class III molar relationship was observed, proclined upper incisors, retroclined lower incisors and a deviated lower midline. The main complaint was facial esthetics which required surgical intevention. After pre-surgical orthodontic preparation the maxilla was repositioned by a Le Fort I osteotomy and the mandible was set back using the Obwegeser-Dal Pont method. Final assesment revealed both functional and esthetic dentofacial results. A combination of orthodontic treatment and orthognathic surgery is often required in adult patients with dental malocclusion and skeletal discrepancies.
Class III malocclusion is a challenge to the orthodontic profession representing a complex skeletal imbalance between upper and lower jaw growth patterns accompanied by various dentoalveolar and soft tissue compensations.
Class III are mainly characterized by sagital skeletal discrepancies: mandibular prognathism, maxillary retrognathism or both.
The treatment of class III malocclusion differs depending on the age of the patient and on the severity of the skeletal and dental discrepancies.
In severe class III cases, with large skeletal and dental discrepancies, surgery is recommended in order to improve occlusion and facial esthetics. The surgical treatment plan is mainly based on the correction of the antro-posterior dicrepancy and includes repositioning of the jaws in the sagittal plane: either mandibular retrusion, maxillary protrusion, or both, depending on the case. Bimaxillary surgery is recommended in severe sagittal discrepancies, where the problem cannot be corrected by single-jaw surgery
Le Fort I osteotomy is a surgical procedure that involves repositioning of the maxilla and allows modifications in all three planes, being mostly recommended in maxillary hypoplasia
The aim of this paper is to present the orthodontic and surgical treatment of a 24 year old adult patient with increased anterior face height, a class III skeletal pattern and mandibular asymetry.
A 24-year old patient presented to a private clinic with the chief complaint of poor facial estheticsassociated with a protruded mandible and chin. Patient history revealed a class III pattern in the family on the side of the father and previous orthodontic intervention during childhood, with a removable appliance to correct the anterior crossbite.
Orthodontic examination digital photographs were taken before the patient underwent the initial cinical examination. Frontal esthetic analysis revealed a long face, an increased third floor of the face and an asymmetry due to mandibular deviation to the left. Lateral view analysis disclosed a concave profile, with a deficient nasomaxillary area and proeminent chin. The lower lip was protruded, the upper lip was retruded and the mentolabial anlge was reduced. (
Intraoral examination revealed bilateral Angle’s class III molar relationship, class III canine relationship on the right and class I on the left, a deviated lower dental midline to the left of the patient, a visible negative tip in the right upper lateral incisor and canine, crossbite between 1.2. and 4.3 and 4.4, retroclined lower incisors, proclined upper incisors, with a 1 mm overbite and overjet . (
The panoramic radiograph examination showed impacted bilateral mandibular third molars, and one maxillary third molar.Cephalometric analysis disclosed a skeletal class III (ANB -5 degrees), with a retruded maxilla and a protruded mandible (SNA 78 degrees and SNB 83 degrees). The patient is a hyperdivergent type, with FMA 30 degrees and IMPA 77 degrees, which suggests retruded lower incisors. Examination of soft tissue on the profile radiograph shows a concave profile and a protruded lower lip. (
Primary treatment objectives were to improve facial esthetics and correct the protruding chin and concave soft tissue profile. Other treatment objectives were to obtain a functional occlusion with class I molar and canine relationships, correct the lower midline deviation and retroclination of lower incisors.
Firststage of treatment began with third molar odontectomies. Afterwards the patient was bonded with conventional straight-wire metallic orthodontic braces with an0.22’’ Roth slot.For patient confort the upper arch was bonded first, bonding of the lower arch following a month later. The archwire sequence was as follows: 0.012”, 0.014”, 0.016” NiTi archwires progressing to 0.016 × 0.016”, 0.016 × 0.022” and 0.019x0.025 NiTi archwires, ending with a 0.019x0.025 SS archwires.
The pre-surgical orthodontic preparation successfully met the following objectives: levelling and aligning, flattening of curbe of Spee, proclination of the lower incisors and elimination of dental compensations. Before surgery, the patient had a normal position of the lower incisors, with IMPA 88 degrees. (
The surgical treatment included Le Fort I osteotomy for impactation and anterior traction of the maxilla. The Obwegeser-Dal Pont method for the set back of the mandible was used. The surgical and post-surgical phase had no complications.
Post-surgical orthodontic treatment was started 4 weeks after the surgery. Wearing of bilateral box elastics was recommended in order to improve interdigitation. (
Post-treatment extraoral examination revealed that all pretreatment objectives were met. The arches were leveled and aligned, obtaining a stable occlusion with both canine and molar class I relationships. Lower incisors mainteined a normal position at the moment of debonding.
Both the mandibular deviation and the dental midline were corrected improving facial esthetics and dental occlusion. The profile of the patient dramatically improved from concave to straight, the new skeletal ralation providing better support for the upper and lower lips with no lip strain..
The total duration of the treatment was 24 months. The patient was fitted with vacuum formed retainers for the upper and lower arches and a bonded retainer from cuspid to cuspid in the lower arch. The patient was satisfied with facial esthetics, chin projection, facial profile and smile. (
Class III malocclusions often imply a growth deficit in the maxilla and a more anterior growth in the mandible. According to Silva et al., prevalence of class III patients in European populations varies from 2% to 6%.
Treatment in such cases remains a challenge for the orthodontic specialists, especially in borderline cases when a decision between camouflage and surgical treatment should be made. Studies show that Wits appraisal is a decisive indicator determining either the orthodontic camouflage or orthognathic treatment of class III patients, together with the IMPA angle and the interincisal angle.
Early orthodontic treatment following a correct diagnosis can reduce the severity of a class III malocclusion in adulthood. Thus children with developing class III should be evaluated regarding family history of class III, functional mandibular shift, dental relationships and jaw discrepancies.
The use of digital patient records such as x-rays and digital photos, is particularly useful in cases where patients are treated in interdisciplinary teams.
In Class III cases orthodontic-surgical cases, the pre-surgical orthodontic stage is necessary to correct dental compensations that could cause interferences during the surgical repositioning of the maxilla and mandible
Interdisciplinary management of Class III malocclusions with orthodontic-surgical treatment can have excellent results, leading to a functional occlusion and improved facial esthetics.
The importance of a good diagnosis and treatment plan is as relevant and necessary as the communication between orthodontist and surgeon, in such complex cases.