CLASSIFICATION OF SKELETAL AND DENTAL MALOCCLUSION: REVISITED
Class III. The mesio-buccal groove of the mandibular 1 st permanent molar lies anterior to the mesio-buccal cusp of the Maxillary 1 st permanent molar. Relationship between right and left buccal occlusion is further grouped to resolve the notion of subdivisions: Class IV. Class I on one side and Class II( either ½ unit or full unit) on the other side. Class V: Class I on one side and Class III on the other side. Class VI: Class III on one side and Class II( either ½ unit or full unit) on the other side. Analyzing profile photographs to evaluate sagittal
jaw relationships is a practical tool in determining soft tissue harmony. Soft tissue measurements provide a sagittal differential diagnosis in relation to Angle’ s classification of malocclusion 21. A suggested treatment protocol is easily derived from the present classification skeletal( Table 1) and dental( Table 2).
This varies from mechanics to mechanics, but the idea is to help the undergraduate to understand orthodontic diagnosis and treatment planning and for postgraduate residents and orthodontists to formulate accurate stable orthodontic treatment results.
Figure 4. Molar’ s classification
Table 1. Suggested treatment protocol for skeletal bases Suggested Treatment Protocol
Skeletal I
There is a harmonious relationship antero-posteriorly; the problem is either in the vertical or transverse plane. Advice surgical correction if needed.
Type 1
Functional appliance( growing children) or mandibular surgery( adult or syndromic patients e. g. Pierre Robin).
Type 2 Headgear( children and adolescents) or maxillary surgery for adults.
Skeletal II
Type 3
Type 1
Here the treatment could of combination, functional [ removable e. g. twin block or fixed e. g. Forsus ], Headgear, camouflage with the extraction of upper 1 st premolars alone or in combination with lower 2 nd premolars or Bi-maxillary orthognathic surgery.
Functional appliances e. g. Yanagisawa Class III shield( YC3) 19. Palatal expansion ± facemask( Delaire, reverse pull headgear by Nakamura) advised before the age of 10 years. 20
Type 2 Mandibular excess is treated with surgery e. g. Bilateral sagittal split osteotomy( BSSO).
Skeletal III Type 3
Here the treatment could of combination: functional( Yanagisawa, YC3), palatal expansion ± facemask, camouflage with the extraction of lower 1 st premolar and upper 2 nd premolars, or extraction of a single lower central incisor, Bi-maxillary orthognathic surgery( Le Fort I ± BSSO) or genioplasty in some cases.
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