title: Anatomical considerations for implant placements in first maxillary molar extracted sites in East Asian patients.
abstract: OBJECTIVE
  With the advent of cone-beam computed tomography (CBCT) for maxillofacial imaging, there has been a paradigm shift from two dimensional panoramic radiography to three dimensional imaging. This study investigated the microanatomy of the maxillary permanent first molar socket and its relationship to the floor of the maxillary sinus, especially for immediate or early implant placement.
  
  
  RESULTS
  Sixty CBCT scans of 30 Malay and 30 Chinese subjects were selected from over 300 archived images. Ninety-five percent of the subjects had sinus floor extending anterior to the first molar, while 72% had the floor dipping between the roots. Seventy-five percent of the patients had inter-radicular bone and almost 50% had intrusion of root apices into the floor of the maxillary sinus. The dimensions of the socket were as follows: the mean width was 11.42 ± 0.86 mm; the mean length was 7.70 ± 0.56 mm; the mean height on the coronal plane was 6.48 ± 3.77 mm while on the sagittal plane it was 6.85 ± 3.67 mm.
  
  
  CONCLUSIONS
  Any implant length greater than the mean height of the socket (approximately 7 mm) has a fair chance of perforation into the maxillary sinus if placed without any additional adjunct procedures. In addition, 50% of the apices opened into the maxillary sinus, thereby risking the creation of perforations or root displacements into the maxillary sinus during exodontia-mandating CBCT scanning prior to any surgical implant procedures.
authors: Department of Oral and Maxillofacial Surgery, Enche' Besar Hajjah Khalsom Hospital, Kluang, Johore, Malaysia.
authors: G K
authors: GK
authors: Ananda
authors: Department of Diagnostic and Integrated Dental Practice, Faculty of Dentistry, University of Malaya, 50603, Kuala Lumpur, Malaysia. phrabha@um.edu.my.
authors: Phrabhakaran
authors: P
authors: Nambiar
authors: School of Dentistry, International Medical University, Bukit Jalil, Malaysia.
authors: Sunil
authors: S
authors: Mutalik
authors: Department of Oro-Maxillofacial Surgical and Medical Sciences, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia.
authors: Palasuntharam
authors: P
authors: Shanmuhasuntharam
mesh_terms: D000328:Adult; D054893:Cone-Beam Computed Tomography; D003430:Cross-Sectional Studies; D015921:Dental Implants; D005202:Asia, Eastern; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008437:Maxilla / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D008443:Maxillary Sinus / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D008875:Middle Aged; D008963:Molar / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D011862:Radiography, Panoramic; D014081:Tooth Extraction; D055815:Young Adult
chemical_list: D015921:Dental Implants
keywords: CBCT; Early dental implants; East Asian patients; First maxillary molar; Maxillary sinus; Tooth loss