Australasian Dentist Magazine March April 2021

Category 54 Australasian Dentist I n the first article “Management of the Orthodontic Class 2 Patient (Part 1) “ I discussed growth and development of the dentition and jaws and how this may affect the development of a Class 2 malocclusion and the possible management of the young child (age 6 to 10 years) who may present with this type of orthodontic problem. In Part 2 I discussed the management of the adolescent Class 2 patient who presents in the late mixed dentition or in the permanent dentition but still has sufficient growth remaining. Finally, in this article (Part 3) of this series, I will address the management of the Class 2 Division 1 and Class 2 Division 2 adult patient who has ceased growing. What is the clinical difference between a growing patient and an adult patient who has ceased growing? does not have the advantage of growth and hence in the non-growing adult patient we have three options: 1 To correct the underlying skeletal discrepancy which would require orthognathic surgery 2 To dentally compensate the dentition for the underlying skeletal discrepancy 3 To improve the alignment of the teeth and ignore the underlying skeletal discrepancy which would ultimately leave the patient with overjet. How do we decide which is the best treatment approach? The decision as to which approach is best for an individual patient will depend on the following factors: A. The severity of the skeletal discrepancy B. The amount of crowding or spacing present in each arch C. The existing dental compensations present D. The patient’s goal of treatment 1. To correct the underlying skeletal discrepancy which would require orthognathic surgery A non-growing patient who has a Class 2 skeletal discrepancy usually has a mandibular retrognathia. However, the correct diagnosis of the aetiology and knowledge of the extent of the skeletal discrepancy is essential to formulate the ideal treatment plan for an individual patient. Firstly, we utilise our clinical judgement to assess the position of the upper and lower jaw in the lateral view . We can also obtain a clinical idea of the position of the upper jaw and also the position of the upper anterior teeth from the assessment of the nasolabial angle. However, Cephalometric’s have been utilised since the 1950s and is still the most efficient method of accurately determining the skeletal sagittal relationship and the extent of any skeletal discrepancy. Some of the Cephalometric measure- ments utilised to assess the skeletal sagit- tal discrepancy are as follows. Management of the Orthodontic Class 2 Patient (Part 3) By Dr Geoffrey Hall, Specialist Orthodontist, B.D.Sc (Melb) Cert.Orth( Uni Of Penn) MRACDS (ORTH) Director OrthoED Institute Geoffrey Hall clinical Figure 1 Normal growth of maxilla and mandible Figure 2 a and b Clinical assessment of sagittal skeletal discrepancy. Figure 3 Lateral Cephalometric radiograph of a patient with Class 2 Skeletal pattern associated with a retrognathic mandible. Figure 4 Cephalometric measurements utilised in assessing the sagittal skeletal discrepancy As we discussed in part two of this series both the maxilla and mandible grow downward and forward with mandibular growth continuing for a couple of years after the cessation of maxillary growth when the parameters of growth are normal. Hence, this normal mandibular growth may even contribute to 2 or 3 mm of Class 2 correction over a couple of years. In addition, using different types of growth modification appliances(whilst growth remains) such as a headgear or functional appliance could provide some enhancement to mandibular growth in addition to reducing the forward growth of the maxilla – hence the possibility of successfully correcting the Class 2 by 6 to 8mm. Obviously, the non-growing patient