Developmental disturbances associated with agenesis of the permanent maxillary lateral incisor

The aim of this study was to characterise the intra and extra-oral phenotype associated with agenesis of the permanent maxillary lateral incisor. We compared three groups: (1) subjects with agenesis of one or both permanent maxillary lateral incisors (n=80); (2) first and second degree relatives of group 1 with no agenesis of the permanent maxillary lateral incisor and (3) subjects with no agenesis of the maxillary lateral incisor or family history of it (n=49). For each of the 201 subjects detailed clinical information was reviewed and panoramic radiographs were analysed. Considering only the sample with unilateral agenesis, microdontia of the contralateral permanent maxillary lateral incisor was significantly more frequent in group 1 (82.4%) than in group 2 (25%) and the control group (2%). This supports the theory that microdontia is a variable expression of the same developmental disturbance that causes tooth agenesis. The absence of third molars occurred more often in group 1 (36.2%) than in groups 2 and 3 (18.6% and 18.9% respectively), confirming that agenesis of third molars was markedly associated with the agenesis of the permanent maxillary lateral incisor. Agenesis of teeth other than third molars was not significantly different among subjects with agenesis of the permanent maxillary lateral incisor and their relatives. The frequencies of supernumerary teeth, permanent maxillary canine impaction, general health condition and minor anomalies were not significantly different between the three groups

Analysis of width/height ratio and gingival zenith in patients with bilateral agenesis of maxillary lateral incisor

OBJECTIVE: The purpose of this study was to evaluate the width/length ratio and the gingival zenith (GZ), by means of dental casts and digital caliper, in patients with missing maxillary lateral incisors after treatment. METHODS: The sample was composed of 52 subjects divided into 3 groups: BRG (n = 18), patients with bilateral agenesis treated with tooth re-contouring; BIG (n = 10) patients with agenesis treated with implants and CG (n = 24), control group. The data were analyzed using Shapiro-Wilk, Spearman correlation, Wilcoxon, Kruskal-Wallis, t test and ANOVA tests (p < 0.05). RESULTS: For the width/length ratio of the lateral incisors, BIG presented the lowest mean values (0.72 right and left), when compared with other groups. However, comparison between groups presented statistically significant differences for the right lateral incisor (BIG x CG) and for the canine (BRG x CG). GZ data evaluation showed the greatest difference for BRG (0.5 right and 0.48 left). BIG (0.95 right and 0.98 left) and CG (0.98 right and 0.8 left) presented more similar values, nevertheless, without statistical difference (p > 0.05). GZ data for the right and left sides of the smile were not considered statistically different. CONCLUSION: Although no statistical difference was found in the comparison between the groups, analysis of the descriptive values showed that group BIG showed the greatest difference in values with regard to width/length ratio. Regarding gingival zenith, BRG showed the greatest difference.<br>OBJETIVO: o propósito desse estudo foi analisar, por meio de modelos de estudo e paquímetro digital, a proporção largura/altura e o zênite gengival (ZG) em pacientes com agenesia bilateral do incisivo lateral superior após o tratamento. MÉTODOS: a amostra consistiu de 52 voluntários divididos em 3 grupos: GBR (n=18), pacientes com agenesia bilateral tratados com reanatomizações dentárias; GBI (n=10), pacientes com agenesia bilateral tratados com implantes; e GC (n=24), grupo controle. Os dados foram avaliados por meio dos testes de Shapiro-Wilk, Wilcoxon, Kruskal-Wallis, teste t, ANOVA (p<0,05) e correlação de Spearman. RESULTADOS: para a proporção largura/altura dos incisivos laterais, o GBI apresentou menores valores (0,72 direito e esquerdo), quando comparado aos demais. Porém, a comparação intergrupos revelou diferenças estatisticamente significativas para o incisivo lateral direito (GBI x GC) e para o canino (GBR x GC). A avaliação das medianas obtidas para o ZG demonstrou que o GBR foi o mais destoante (0,5 direito e 0,48 esquerdo), e que o GBI (0,95 direito e 0,98 esquerdo) e o GC (0,98 direito e 0,8 esquerdo) apresentaram valores semelhantes, sem diferença estatisticamente significativa (p>0,05). Os valores obtidos para os lados direito e esquerdo foram considerados iguais dentro de cada grupo. CONCLUSÃO: embora não tenham sido encontradas diferenças estatísticas na comparação entre os grupos, pela análise descritiva dos dados, o GBI foi o grupo que apresentou as medidas mais destoantes dos demais em relação à proporção largura/altura, sendo que, para o zênite gengival, a maior diferença observada foi no GBR