The relationship of anterior occlusion and skeletal variables with the frontal sinus index: An analytical cross-sectional study.

OBJECTIVE: To determine the relationship of anterior occlusion and skeletal variables with the frontal sinus index. METHODS: The retrospective, analytical, cross-sectional, study was conducted from July to November 2020 at Dr Ishratul- Ebad Khan Institute of Oral Health Sciences and Dow Dental College, Dow University of Health Sciences, Karachi, and comprised data from 2015 to 2018 related to pre-treatment lateral cephalograms for determining frontal sinus index and other cephalometric variables. The dental casts were observed for incisor classification. Patients with Class I incisors formed the comparison group, while the rest comprised 5 malocclusion groups. The frontal sinus was traced, and the sinus index was calculated. Data was analysed using STATA 15 and R 3.5.1. RESULTS: Of the 240 subjects, there were 40(16.66%) in each of the 6 groups; 155(64.6%) females and 85(35.4%) males. The mean age of the sample was 21.33±3.52 years (range: 16-29 years). The mean sinus index was higher in all malocclusion groups than the comparison group, but it was significantly higher only in Class II division 2 and anterior open bite groups (p<0.05). The only exception to the trend was Class II division 1 with and without contact in which the value was lower (p>0.05). The anterior cranial base length, sella-nasion mandibular plane angle, and upper incisor palatal plane angle significantly affected the frontal sinus index (p<0.05). CONCLUSIONS: The frontal sinus index could be considered an indicator of harmonious anterior occlusion.

Frequency and association of maxillary ectopic canine with incisor root resorption and dental agenesis.

OBJECTIVE: To assess the frequency of maxillary ectopic canine both buccally and palatally displaced with incisor root resorption and dental agenesis. METHODS: The cross-sectional study was conducted from April 8 to June 29, 2019, at the Department of Orthodontics, Dr. Ishrat Ul Ebad Khan Institute of Oral Health Sciences, and Dow Dental College, Dow University Of Health Sciences, Karachi, and comprised orthodontic patients diagnosed with maxillary ectopic canine eruption. Root resorption and agenesis were diagnosed on panoramic films. Root resorption was further confirmed by periapical radiographs. Data was analysed using SPSS 21. RESULTS: Of the 98 subjects, 86(87.8%) had buccally displaced canines of which 38(44.2%) were associated with root resorption, while 12(12.2%) patients had palatally displaced canines of which 10(83.3%) had root resorption (p=0.011). Overall, 30(30.6%) lateral incisors were resorbed, 7(7.1%) both central and lateral incisors, 5(5.1%) premolars, and 6(6.1%) both lateral incisors and premolars were resorbed. Agenesis was detected in 10 (10.2%) subjects (p=0.62). CONCLUSIONS: There was found to be no association of maxillary ectopic canines with incisor root resorption and dental agenesis.