Gingival Biotype and Tooth Shape Relationship in Maxillary Anterior Teeth

Gingival recession is prone to develop in the tooth with thin gingival biotype and triangular tooth shape. This study aimed to determine the relationship among gingival biotype, tooth shape and tooth proportion in maxillary anterior teeth.

Method:

This survey was conducted in 100 dental students at the Faculty of Dentistry, Chulalongkorn University. 400 maxillary incisors were examined by 2 calibrated examiners. Gingival biotype was assessed by transparency probing and visual assessment method. Clinical parameter such as tooth shape (TS), crown width (CW), crown length (CL) and papilla height (PH) were measured. Comparison of tooth shape and tooth proportion (TP) among gingival biotype group was analyzed by using t-test and ANOVA (SPSS v.16).

Result:

66% of subjects represented thin gingival biotype. Tooth shape can be categorized into ovoid, square and triangular tooth with the percentage of 33, 38 and 29, respectively. There was no difference of CL, CW between thick and thin gingival biotype (p>0.05). However, thick biotype had greater tooth proportion than thin bioype (p<0.05). According to the tooth shape, we found that triangular tooth had higher PH (4.26 mm.) than ovoid (3.70 mm.) and square (3.63 mm.), significantly (p<0.05). The result revealed an association between gingival biotype and tooth shape (p<0.01). Thick biotype was related to square and ovoid tooth, while thin biotype was related to triangular tooth.

Conclusion:   

This study demonstrated the relationship between gingival biotype and tooth shape. Identification of gingival biotype and tooth dimension is necessary for the esthetic risk assessment.