3D analysis of maxillomandibular morphology in hyperdivergent and hypodivergent individuals: A cross-sectional study.

INTRODUCTION: The aim of this cross-sectional study was to investigate maxillomandibular morphology in hyperdivergent and hypodivergent individuals, using 3D surface models generated by cone-beam computed tomography (CBCT). METHODS: The sample consisted of 60 CBCTs (30 males, 30 females) patients aged 12-30 years, divided into two groups comprising hyperdivergent (≥35°) and hypodivergent (≤30°) individuals, according to the mandibular plane (MP) angle. Multiplanar reconstructions were used to mark the landmarks, and 3D surface models were created to evaluate structures of the maxillomandibular complex, including condyle, ramus, symphysis and palatal height. Intergroup comparisons were performed by independent t-test. Pearson's correlation test was used (P < .05) to evaluate the correlation of the MP angle with the angles and linear measurements of other structures. RESULTS: Significant differences were found between the groups regarding condylar width, ramus height, condylar plus ramus height, mandibular length, gonial angle, palatal plane angle and palatal-mandibular angle. No differences (P > .05) were found for the condylar height, symphysis inclination angle or palatal height. Correlations (P < .05) were found between the MP angle and structures of the maxillomandibular complex. CONCLUSIONS: Hyperdivergent (MP ≥ 35°) and hypodivergent (MP ≤ 30°) individuals present different skeletal morphology regarding condylar width, ramus height, condylar plus ramus height, mandibular length, gonial angle, palatal plane angle and palatal-mandibular angle. There is a significant correlation between MP angle and morphological structures such as condyle, ramus, symphysis, palatal plane angle and palatal-mandibular angle.

Análise 3D da morfologia maxilo-mandibular em indivíduos com diferentes padrões de crescimento vertical / 3D analysis of maxillomandibular morphology in individuals with different patterns of verticalI growth

O objetivo deste estudo foi comparar a morfologia maxilo-mandibular em indivíduos com diferentes padrões de crescimento vertical, por meio de modelos de superfície 3D. Foram avaliados 60 exames de TCFC de 30 homens e de 30 mulheres, entre 12 e 30 anos, divididos em 2 grupos, hipodivergente (≤30º) e hiperdivergente (≥35º), de acordo com o plano mandibular (PM). Modelos de superfície 3D foram gerados para avaliar estruturas do complexo maxilomandibular. O Teste T foi utilizado para comparar os grupos e o teste de correlação de Pearson foi utilizado para correlacionar o PM com as demais estruturas. Foi observado, diferenças significativas na largura condilar, altura do ramo, altura do côndilo+ramo, ângulo goníaco, ângulo da inclinação palatal e ângulo palatino-mandibular, entre os grupos. Forte correlação (P <0,05) entre o ângulo do PM e estruturas do complexo maxilo-mandibular foi encontrada. Baseado nos resultados encontrados, pode-se concluir que indivíduos hipodivergentes (≤30º) e hiperdivergentes (≥35º), apresentam morfologia maxilomandibular diferentes. Variações extremas do ângulo do PM estão associadas às características morfológicas do côndilo, sínfise, ramo, ângulo goníaco, ângulo do plano palatal e ângulo palatino-mandibular. (AU)

The aim of this study was to compare maxillomandibular morphology in individuals with different types of vertical growth pattern, using 3D surface models. Were evaluated 60 CBCT exams (30 males, 30 females), between 12 and 30 years, divided into 2 groups, hypodivergent (≤30º) and hyperdivergent (35º≥), according to the mandibular plane angle (MP). 3D Models were generated to evaluate morphological structures of the maxillomandibular complex. Independent T test was used to compare gruoups. The Pearson correlation test was used (P <0.05) to evaluate the correlation of MP angle with other structures. Significant differences were found in the condylar width, ramus height, condylar plus ramus higth, 3D MP angle, gonial angle, palatal angle and mandibularpalatine angle, between groups. Strong correlation (P <0.05) between MP angle and structures of the maxillomandibular complex was found. Based on the results, it can be concluded that hyperdivergent individuals (PM≥35º) and hypodivergent (PM≤30º), present different skeletal morphology. A small or high MP angle is associated with morphological characteristics of condyle, symphysis, ramus, gonial angle, palatal plane angle and mandibular palatal angle. (AU)