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Updated: Jul 20, 2026

Measuring Maxillary Posterior Tooth Movement: A Model Assessment using Palatal and Dental Superimposition
Published on: February 23, 2024
[Clinical analysis of PLI, GI and SBI in patients with fixed orthodontic appliances]
1Department of Orthodontics, College of Stomatology, Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200011, China. danghuinew@hotmail.com
Purpose:
The aim of the present study was to carry out a detailed analysis of the data on PLI, GI, SBI in fixed orthodontic patients.
Methods:
375 middle school students aged 12 to 15 years old were selected as control group, including 196 boys and 179 girls. 331 patients with fixed orthodontic appliances aged 12 -15 years from city were used as experimental group, including 101 boys and 230 girls without mouth-breathing. Gingival index (GI), sulcus bleeding index (SBI), and plaque index (PLI) were recorded for each individual patient six months after being with orthodontic appliances. Four upper and four lower incisors were assessed, the data of the two groups were analyzed with SPSS 10.0 software package for Student's t test.
Results:
It was found that there were significant higher PLI, GI and SBI values in orthodontic treated patients (P<0.01). Although there was no significantly difference in PLI value between boys and girls (P>0.05) in the experimental group, there were statistically significant higher GI and SBI values compared boys with girls (P<0.01). There were significantly higher PLI and GI values in boys' lower incisor(P<0.01). Oral health care was difficult in patients with fixed orthodontic appliances. Boys' oral hygiene was poorer than girls'.
Conclusion:
In order to maintain periodontal health, it is very important to strengthen oral hygiene to children who receive fixed appliance, especially in boys, as well as control the level of plaque accumulation in the lower incisors.
