[The relationship between labial-lingual inclination and the thickness of the alveolar bone in the mandibular central incisors assessed with cone-beam computed tomography].
OBJECTIVE
To investigate the alveolar bone thickness of mandibular central incisors with different labial-lingual inclinations by cone-beam computed tomography (CBCT).


METHODS
CBCT and lateral cephalometric images of 60 patients were chosen. The data was respectively classified into 3 groups by L1-MP: lingual inclination group (L1-MP<85.6°); normal group (L1-MP 85.6°-99.6°), and labial inclination group(L1-MP>99.6°). Three-dimensional reconstruction was made for CBCT, and the sagittal images of the largest alveolar bone area along the tooth axis were chosen. The central incisor roots were divided into 4 sections from cementoenamel junction to root apex, then the labial and lingual alveolar bone thickness were measured and added up to get total alveolar bone thickness, and the occurrence of fenestration and dehiscence were recorded. The data was analyzed with SPSS 17.0 software package.


RESULTS
The alveolar bone thickness on lingual side and the total bone thickness were significantly different between every 2 sections of all the measured zone. The average values of bone thickness on labial side were thinner than that on lingual side in sections of middle 1/2, root apex 1/4 and root apex. The total bone and lingual bone were thinner in lingual inclination group than in labial inclination group at root apex, root apex 1/4 and middle 1/2. Labial and lingual inclination group were more likely to develop dehiscence (P<0.05).


CONCLUSIONS
Lingual and total alveolar bone of central incisors become increasingly thinner from root apex area to cementoenamel junction. The total bone and lingual bone are thinner in lingual inclination group than in labial inclination group. Labial or lingual inclined incisors have higher incidence of dehiscence.
Department of Orthodontics, School of Stomatology, China Medical University, Liaoning Institute of Dental Research. Shenyang 110002, Liaoning Province, China.E-mail:tianyulou@sina.com.
Yu-lou
YL
Tian
Zhen-jin
ZJ
Zhao
Kun
K
Han
Pin
P
Lv
Yu-ming
YM
Cao
Hong-jing
HJ
Sun
Mo
M
Yu
Yang
Y
Yue
D002508:Cephalometry; D003198:Computer Simulation; D054893:Cone-Beam Computed Tomography; D006801:Humans; D007180:Incisor; D008334:Mandible; D013529:Surgical Wound Dehiscence; D014070:Tooth; D014092:Tooth Root