Role of posterior transverse interarch discrepancy in Class II, Division 1 malocclusion during the mixed dentition phase.
Posterior transverse interarch discrepancy (PTID), measured as the difference between the maxillary and mandibular intermolar widths, was investigated in a sample of 60 Class II, Division 1 subjects during the mixed dentition phase. Two main groups were detected: Class II group 1 (30 subjects) with PTID and Class II group 2 (30 subjects) without PTID. A sample of 30 Class I subjects in the mixed dentition phase was used as a control group. In Class II group 1, PTID was found to be due to a significantly narrower maxillary arch. The craniofacial skeletal features of both Class II groups and of the Class I group were assessed. The Class II group with PTID showed mandibular retrusion associated with a posteriorly displaced mandible of normal size (functional mandibular retrusion). The Class II group without PTID had mandibular retrusion due to a micrognathic mandible (anatomic mandibular retrusion). The relevance of these findings for treatment planning in Class II, Division 1 malocclusion in the mixed dentition was stressed.
Tollaro
I
I
University of Florence, Department of Orthodontics, Italy.
Baccetti
T
T
Franchi
L
L
Tanasescu
C D
CD
D000293:Adolescent; D000704:Analysis of Variance; D016022:Case-Control Studies; D002508:Cephalometry; D002648:Child; D003724:Dental Arch / Q000473:pathology*; D003769:Dental Occlusion, Traumatic / Q000150:complications; D003818:Dentition, Mixed; D005260:Female; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000145:classification / Q000209:etiology* / Q000473:pathology* / Q000628:therapy; D008334:Mandible / Q000002:abnormalities / Q000254:growth & development; D008437:Maxilla / Q000473:pathology*; D008445:Maxillofacial Development; D008844:Micrognathism / Q000150:complications; D008963:Molar; D017289:Orthodontic Appliances, Functional; D010155:Palatal Expansion Technique; D010347:Patient Care Planning; D063173:Retrognathia / Q000150:complications; D018709:Statistics, Nonparametric