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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