Department of Oral & Maxillofacial Surgery, Dental Teaching Hospital, College of Dentistry, University of Baghdad, Bab-Almoadham, P.O.Box 1417, Baghdad, Iraq.
Department of Biomedical Applications, Institute of Laser for Postgraduate Studies, University of Baghdad, Baghdad, Iraq.
BMC Oral Health. 2020 Apr 6;20(1):96. doi: 10.1186/s12903-020-01093-8.
The posterior regions of the jaws usually represent a significant risk for implant surgery. A non-valid assessment of the available bone height may lead to either perforation of the maxillary sinus floor or encroachment of the inferior alveolar nerve and consequently to implant failure. This study aimed to evaluate the reliability of surgeon's decision in appraising the appropriate implant length, in respect to vital anatomical structures, using panoramic radiographs.
Only implants that are inserted in relation to the maxillary sinus (MS) or the mandibular canal (MC) were enrolled (first premolars [1P], second premolars [2P], first molars [1M], and second molars [2M]). All preoperative panoramic radiographs were evaluated under standard conditions. The postoperative estimation (under/over) was determined depending on the available bone height (ABH) measured from the apical end of the implant to the floor of the MS and the roof of the MC using cone beam computed tomography (CBCT). Any complication or side effect that associated with overestimated implants insertion was recorded.
The study sample included 73 patients (predominantly females) who had consecutively received 148 implants, of which 68 were inserted in the posterior maxilla and 80 in the posterior mandible. Underestimation was recorded in 93.2% of the measurements. The remaining bone height after implants insertion was < 2 mm in the majority of underestimated cases (73.9%); they were significantly (P < 0.01) more than sites with remaining bone ≥ 2 mm (26.1%). In the posterior mandible, overestimation was significantly higher than posterior maxilla. Five cases with transient paresthesia were reported in the mandibular overestimated implants.
This study specified that surgeon's choice of implants length, based on panoramic radiographs, was reliable regarding the incapability to insert implants with further length in the majority of underestimated cases, the low percent of overestimated measurements, and the minor associated complications.
下颌骨的后区通常代表着种植手术的重大风险。如果不能准确评估可用骨高度，可能会导致上颌窦底穿孔或下颌神经管侵犯，从而导致种植失败。本研究旨在评估使用全景片评估与重要解剖结构相关的合适种植体长度时，外科医生决策的可靠性。
仅纳入与上颌窦（MS）或下颌管（MC）相关的种植体（第一前磨牙[1P]、第二前磨牙[2P]、第一磨牙[1M]和第二磨牙[2M]）。所有术前全景片均在标准条件下进行评估。根据从种植体根尖到 MS 底和 MC 顶测量的可用骨高度（ABH），使用锥形束 CT（CBCT）确定术后（不足/过多）估计值。记录与高估种植体插入相关的任何并发症或副作用。
本研究样本包括 73 名（主要为女性）患者，他们连续接受了 148 个种植体，其中 68 个植入上颌后区，80 个植入下颌后区。在 93.2%的测量中记录了低估。在大多数低估病例中，种植体插入后的剩余骨高度<2mm（73.9%）；它们明显（P<0.01）多于剩余骨≥2mm的部位（26.1%）。在下颌后区，高估的发生率明显高于上颌后区。在下颌骨高估的种植体中有 5 例出现短暂性感觉异常。
本研究表明，根据全景片选择种植体长度时，在大多数低估病例中，由于无法进一步插入种植体，因此外科医生的选择是可靠的，低估的测量百分比较低，且相关并发症较小。
