Craniofacial Growth in Adolescence and its Influence on the Mandibular Incisor Crowding

Abstract

Background To analyze craniofacial growth during adolescence from the ages of 12 to 21 years and its relation to late mandibular incisor crowding. Material and Methods The study included 61 orthodontically untreated subjects (49% males). Lateral cephalograms were used to assess the jaw growth and inclination of the incisors. Little’s Irregularity Index and the anterior mandibular dental arch depth of mandibular dentition were measured. Results A reduction of the skeletal class angle (ANB) was observed in both genders, although it was significant only in males (η2=0.188; p=0.015). The growth of the mandible was more prominent compared to that of the maxilla, and it was more prominent in males than in females. The skeletal vertical dimension, however, demonstrated a significant reduction in both genders (η2=0.527-0.593, p<0.001). The mandibular incisors tended to retrocline in both genders, while the maxillary ones tended to procline in males, and slightly retrocline in females. A decrease in the mandibular dental arch depth occurred in both genders (η2=0.259; p<0.05). An increase in the irregularity of incisors for 1.8±1.7 mm on average (95% CI 1.3-2.2; η2=0.520; p<0.001) was observed in both genders. A logistic regression revealed that less sagittal growth of maxilla (increase of SNA angle ≤2°) and reduction of convexity in skeletal sagittal interjaw relationship (reduction of ANB ≥1°) were significant predictors of the occurrence of crowding (Δ Little Irregularity Index ≥1mm) yielding odds ratios of 4.9 and 4.8. Conclusions The differential growth of the maxilla and mandible is related to the occurrence of late crowding, mostly in smaller amounts in maxillary sagittal growth compared to the mandible.

The Effect of Third Molars on the Mandibular Anterior Crowding Relapse—A Systematic Review

“…Several factors have been investigated in the search for the etiology of tooth crowding relapse, which happens after the end of active orthodontic treatment. Overall, it has been suggested that crowding in the lower anterior region and third molar impaction are both the sequela of inadequate growth [61][62][63]. In cases of restricted mandibular anterior growth and inefficient remodelling, enough space may not be generated for the mandibular incisors to move forward without getting crowded [64,65].…”

Three-Dimensional Analysis of the Cranial Base Structure in Patients with Facial Asymmetry

“…The most pronounced growth is seen after the peak growth period of puberty [ 37 ]. The mandible grows particularly rapidly during this period, and this is most noticeable in cases of skeletal mandibular prognathism [ 40 ]. In particular, facial asymmetry is often associated with lateral mandibular deviation, which is an anteroposterior as well as a horizontal axial abnormality [ 1 , 7 , 8 ].…”

Increased demand for orthodontic treatments during the COVID-19 pandemic: a commentary

“…Proffit groups adult patients into the categories of younger (18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34) and older. As they achieve financial independence, adult patients seek the orthodontic treatment they wish they had growing up.…”

“…18 In adolescent patients, more crowding of their anterior teeth happens because of maxillary and mandibular differential growth, with more misalignment occurring in the mandibular incisors. 19 In later age groups, this especially becomes an issue with the relative increase of lower teeth exposure on smiling. 20 As the problem presented in such cases results from teeth moving from their location, the rational solution would be to move them back to their original positions.…”