A multilevel analysis of craniofacial growth in subjects with untreated Class III malocclusion

Abstract

Objective To analyse the craniofacial growth of a long‐term semi‐longitudinal sample of Caucasian subjects with untreated Class III malocclusion. Setting and sample population A total of 144 Caucasian subjects (of North American and Italian origin) with untreated Class III malocclusion. Materials and methods Subjects aged 2 years and 9 months up to 21 years and 7 months were selected. A multilevel model was used to calculate growth curves for ten variables for both each individual subject and for the whole sample. Results There was a statistically significant increase for total mandibular length (Co‐Gn. T2‐T1 = 8.4 mm), midfacial length (Co‐A. T2‐T1 = 3.4 mm) and lower anterior facial height (ANS‐Me. T2‐T1 = 3.8 mm). The multilevel analysis showed two points of acceleration of growth (about 3‐5 years of age and 11‐15 years of age) for seven out of ten variables. For Co‐Gn and Co‐A variables, males presented points of maximum growth delayed by 1 year in comparison with females, with a greater duration (1 year longer) and a greater total growth of about 5 mm. Active mandibular growth continued for a long time after the pubertal spurt: increases in mandibular length ended at about 17 years of age in females and at 21 years and 7 months in males. Conclusions Untreated Class III malocclusion showed a specific growth curve, especially for the mandible, whose excesses added up over time. In males, the amounts of mandibular and midfacial growth during the whole observation time were greater and lasted longer than in females.

Prognostic approach to Class III malocclusion through case‐based reasoning

“…Subjects who met criteria of maximum and minimum skeletal imbalance, calculated from the better and worse Wits appraisal for each age and gender, were considered prototypes. Cross‐sectional and longitudinal subjects were enrolled previously in estimates of craniofacial growth in subjects with Class III malocclusion 22‐24 …”

“…These subjects were left untreated because they declined treatment or because their cephalometric records were derived from historical samples taken from Growth Center Studies conducted in the United States. These subjects were derived from a database of 144 Class III patients followed longitudinally 24 . Of these, 40 subjects were discarded because the time span between T1 and T2 measurements was less than 1 year and 6 months.…”

“…Cross-sectional and longitudinal subjects were enrolled previously in estimates of craniofacial growth in subjects with Class III malocclusion. [22][23][24] To be included in the current study, both longitudinal and cross-sectional subjects had to satisfy the following criteria: Caucasian ancestry, no orthodontic/orthopaedic treatment prior to the initial cephalogram, no craniofacial syndromes, no congenitally missing or extracted teeth, diagnosis of Class III malocclusion based on accentuated mesial step relationship of the primary second molars, permanent first molar relationship of at least one-half cusp Class III, a negative Wits appraisal (<−2 mm) and ANB angle less than 0 degree.…”

“…These subjects were derived from a database of 144 Class III patients followed longitudinally. 24 Of these, 40 subjects were discarded because the time span between T1 and T2 measurements was less than 1 year and 6 months. Although the large difference in age at T1 could have led to the recommendation not to eliminate any subject from the learning set, we felt that a too short interval between T1 and T2 would not allow a reliable judgement on the actual quality of the facial development.…”

Cephalometric effects of Pushing Splints 3 compared with rapid maxillary expansion and facemask therapy in Class III malocclusion children: a randomized controlled trial

“…The early approach remains a controversial topic in both academic and clinical fields ( 6 ). The central point of this lack of consensus is the inability to predict mandibular growth that is often unfavourable ( 7 ). However, early interceptive orthodontic treatment is suggested for several remarkable functional and aesthetic reasons although aware of the uncertainty of the long-term results ( 8 ).…”