Tooth Size Discrepancy among Different Malocclusion Groups in a Sudanese Sample

Abstract

Introduction: The standard model of orthodontic treatment can be divided into three different stages as stated by Proffit, namely leveling and alignment, working and finishing phases. Each of these presents different challenges. In particular the final, or “finishing” phase, constitutes the most complicated for the complexity of the various factors that need to be taken into account if an optimum result is to be achieved at the end of treatment. One of these factors, often a primary cause of difficulty, is Tooth Size Discrepancy (TSD). Problems arising from this can be alleviated if the existence of TSD forms part of the initial diagnosis and is considered when formulating a treatment plan for the individual patient.

Objectives: The present research aimed at determining the extent and prevalence in a representative orthodontic population in Sudan and to investigate the dimensions of TSD in this population that comprised a clinically significant factor. Materials and methods: The sample comprised 107 pretreatment study casts with fully erupted and complete permanent dentitions from first molar to first molar, which were selected randomly from records of the orthodontic patients. The mesiodistal diameters of the teeth were measured at contact points using a stainless steel digital caliper and Bolton analysis was carried out on them.

Results: A clinically and statistically significant anterior TSD (p=0.002) existed in comparison to Bolton’s anterior tooth ratio. Measurements of the overall and anterior TSD between malocclusion groups showed no significant differences (P=0.572, P=0.976 respectively). In terms of gender, no significant differences were observed for the overall TSD data (P=0.102). In Class II division 1 mean overall ratio was lower than Bolton’s, and Class II division 2 mean overall ratio higher than Bolton’s [overall ratio (91.3%, SD ± 2), anterior ratio (77.2, SD ± 2)].

Conclusion: Class II division 1 patients showed a tendency towards excessive maxillary tooth material and Class II division 2 patients showed a tendency towards excessive mandibular tooth material.