Comparing Occlusal and Maxillofacial Features of Orthodontic Patients with and without Hypodontic Permanent Dentition: (A Retrospective Cross- Sectional Study)

Objective: This study compared the occlusal and maxillofacial features of a sample of Kurdish orthodontic patients with and without hypodontic permanent dentition. Methods: This retrospective cross-sectional study included two groups of patients: a hypodontia group (n=35 patients, 17 males,18 females) and a control group (without hypodontia) (n=34 patients,16 males,18 females) with all teeth other than third molars present. Pretreatment orthodontic records of all patients who visited a private orthodontic center between 2017 and 2021 were examined. Hypodontia group was subdivided into three groups and compared to the control group according to the severity, distribution, side, and location of missing teeth in jaws. Occlusal features, including overjet and overbite, were assessed using the 3shape Ortho system and all standardized lateral cephalometric radiographs were imported to FACAD Cephalometric Software to analyze craniofacial morphology. Results were compared using Mann-Whitney U, Friedman test) and Kruskal-Wallis H test at p =<0.05. Results: The results showed significant differences in dentofacial features between the two groups. Mandibles were retrognathic, chin angle, and upper facial height to lower facial height ratio decreased significantly when compared to the control group at p=0.04,0.03,0.01 respectively. Common dental characteristics were significant increase of the interincisal angle, decreases of the mandibular incisor angles, retroclination of mandibular incisor relative to the N-B line, and overjet showed a remarkable reduction in the anterior group compared to either posterior or anteroposterior group. Conclusions: Hypodontia has little impact on dentofacial structures. Generally mean values were within normal range, however, there were statistically significant differences between groups.