Does Sex, Skeletal Class and Mandibular Asymmetry Affect Tooth Length and Asymmetry in Tooth Length?

Abstract

Introduction: The aim of our cross-sectional study is to determine whether there is a link between sex, skeletal class and mandibular asymmetry in orthodontic patients, with tooth length and asymmetry in tooth length on contralateral sides of the mandible. Methods: As the source for relevant data to answer this question, 3D cone-beam tomography (CBCT) images of a total of 95 future orthodontic patients were retrospectively selected from private practice records and were analyzed. The CBCT images were part of routine orthodontic diagnosis. Patients were divided into three groups (Class I, Class III with asymmetry and Class III without asymmetry) based on skeletal variables assessed on orthodontic cephalometric images and frontal photos of the face. Three null hypotheses were developed, and a series of statistical tests was performed in order to support or reject them. Results: We have established that there exists a sexual dimorphism in some of the teeth’s lengths in our sample. Furthermore, we failed to find a link between mandibular asymmetry and asymmetry in tooth length. We have also found a link between skeletal class and tooth length differences in some of the analyzed measurements. Conclusions: Computational models used to design orthodontic appliances and to plan orthodontic treatment should be more individualized to consider a patient’s sex and skeletal class.

Sexual dimorphism in odontometric parameters using cone beam CT: a systematic review

“…Of the twenty-three studies, four were investigated in Brazil [ 2 , 3 , 19 , 20 ], four in India [ 7 , 8 , 21 , 22 ], three in Iran [ 23 , 24 , 25 ], three in Turkey [ 26 , 27 , 28 ], two in Saudi [ 4 , 5 ], one each in Poland [ 29 ], Portugal [ 30 ], Egypt [ 9 ], Ukraine [ 31 ], Italy [ 32 ], Spain [ 33 ] and Malaysia [ 6 ].…”

“…Average tooth length is greater in men than in women [ 29 ]. In both women and men, the longest teeth turned out to be canines.…”

“…Warnecki et al, 2021 found that mean tooth length is greater in men than in women [ 29 ]. In both men and women, the smallest difference in tooth length between women and men was found for the central incisors.…”

“…In both men and women, the smallest difference in tooth length between women and men was found for the central incisors. In the same study, significant differences were found in tooth length between the sexes when evaluating the literature on odontometry of premolars using CBCT [ 29 ]. Males had significantly lengthy mandibular premolars than females.…”