6～14 歳児 296 名のオルソパントモグラム歯科画像所見による永久歯切歯，犬歯，第一小臼歯の中歯根の傾斜の評価

Evaluation of Mesiodistal Root Angulation of Permanent Incisors, Canines, and First Pre-Molars by Orthopantomogram Dental Imaging Findings in 296 Children Aged 6-14 Years.

抄録

背景 第一小臼歯の発育前早期傾斜変化と犬歯の傾斜との関連は，犬歯の埋伏を予知する上で重要である．本研究では、インドの単一施設において、6～14歳の296名の小児を対象に、永久歯側切歯（LI）、犬歯、第一大臼歯の中歯根角度をオルソパントモグラム歯科画像により評価することを目的としている。材料および方法 参加者総数は296名で、男女同数を6-8歳、8-10歳、10-12歳、12-14歳の4つの年齢群に分けた。オルソパントモグラム（顎関節を含むすべての歯を撮影した歯科画像）で側切歯，犬歯，第一小臼歯と正中線との間の角度を測定した．萌出歯CとLI，萌出歯CとFPのなす角度を測定した．また，犬歯と側切歯，犬歯と第一小臼歯の萌出量にピアソン相関があることも確認された．結果 各年齢層の角度値には有意差があった（P≦0.05）．また，LI, C, FP間の運動は，6-12歳の男女で中程度の相関があった．本研究の結果，6-14 歳の男女において，上顎犬歯の萌出と LI，FP の萌出は同期していることが明らかとなった．

BACKGROUND Early pre-eruptive inclination changes of the first premolar (FP) and its associative changes with canine (C) inclination are important to predict canine impaction. This study aimed to evaluate the mesiodistal root angulation of permanent lateral incisors (LI), canines, and first molars by orthopantomogram dental imaging in 296 children ages 6-14 years at a single center in India. MATERIAL AND METHODS The total number of participants was 296, with equal numbers of boys and girls divided into 4 age groups: 6-8 years, 8-10 years, 10-12 years, and 12-14 years. Angles between lateral incisor, erupting canine, and first pre-premolar with midline were measured on an orthopantomogram (dental imaging which includes all the teeth with TMJ). The angle between the erupting C with LI and erupting C with FP was measured. Pearson's correlation was also evaluated between the movement of the erupting canine with lateral incisor and erupting canine with erupting first premolar. RESULTS There was a significant difference in the angular values of different age groups (P≤0.05). The movements between LI, C, and FP were moderately correlated boys and girls aged 6-12 years. CONCLUSIONS The findings from this study showed that in boys and girls aged 6-14 years, eruption of the upper canine tooth was synchronized with eruption of the LI and FP.