Patient Selection Criteria Zygomatic implants are indicated for several patient types, including patients who present with inadequate alveolar bone, have history of previously failed conventional dental alveo- lar implants, have undergone maxillary trauma or resection, and who present with specific congenital deformities. Inadequate alveolar bone may be caused by tooth loss. Alveolar bone will remodel and resorb after a tooth is extracted. The pattern of alveolar bone resorption in the maxilla occurs in a three-dimensional pattern with the bone changing shape in a posterior, medial, and superior aspects, compromising the shape of dental alveolar ridge, which results in a smaller maxilla.9,10 This bone pattern, known as severe dental atrophy, is defined as an alveolar ridge less than 4 mm.11 In absence of dis- ease, the mean alveolar bone height ranges from 18 to 21 mm.12 Head and neck cancers — the most common cause of resection of the maxillary or mandibular arch — are another indication for zygomatic implant therapy. Oral pathology associated with maxillary resection includes osteosarcoma, squamous cell sarcoma, ade- noid cystic carcinoma, and mixed salivary carcinoma.13,14 Unfortunately, patients who undergo maxillary resections lose dental masticatory function and facial support. Zygo- matic implants can restore masticatory function and improve facial esthetics by supporting a dental prosthesis that restores facial contour and function. Specific dental conditions associated with facial development, such as cleft palate and ectodermal dysplasia, may also need a zygomatic implant-supported dental prostheses. Patients with cleft palate who are classified as edentulous with a history of cleft palate (EHCP) usually have a severely resorbed maxillary ridge with significant scar tissue and irregular palate anatomy. A patient with EHCP may not be a candidate for dental alveolar implants (without extensive grafting) and this clinical presentation may be suitable for zygomatic implants.15 Ectodermal dysplasia is a diverse group of inherited disorders that impacts structures related to the ectodermal layer such as hair, nails, teeth, and sweat glands. With a preva- lence of one in 100,000 live births, ectodermal dysplasia may result in inadequate hard and soft tissue in the oral and maxillofacial region.16 Individuals with ectodermal dysplasia may have anodontia (absence of all teeth), hypodontia, or oligodontia. Hypodontia refers to the absence of less than six teeth and oligodontia means the absence of six or more teeth. Dental alveolar implants may not be indicated for patients with ectodermal dysplasia if the alveolar bone quantity and quality are inadequate. Zygo- matic implant placement, however, is possible without bone grafting procedures.17 A retrospective study of nine patients aged 21 to 56 with severe atrophic maxilla due to ectodermal dysplasia revealed the successful use of zygomatic implants. The treatment significantly improved the subjects’ quality of life, with no reported complications.17 Evaluation criteria used to select patients indicated for zygomatic implants consists of a medical history, radiographic series, and clinical examination. Initially, panoramic radiogra- phy is taken for the initial patient consultation to discuss zygomatic implants and demon- strate the patient’s lack of alveolar bone.5 Cone-beam computed tomography (CBCT) is required for zygomatic implants. The CBCT uses a cone X-ray beam that produces 3D images of the anatomy and potential SECTION 2 FIGURE 1. RETRACTED, SMILE, FULL FACE, AND OCCLUSAL VIEWS OF FINAL MAXILLARY ZIRCONIA PROSTHESIS. Prosthesis fabricated by Ben Brovnik, MDT FIGURE 1: FRANK TUMINELLI, DMD, FACP DORA-ANN ODDO, RDH, MA, has been an educator in the Dental Hygiene Department at New York City College of Technology (City Tech) in Brooklyn for more than 7 years, first as clinical educator and now as an assistant professor. She has also worked in clinical dental hygiene for a prosthodontic office since 2011. She is a member of the American Dental Hygienists’ Association and the Long Island Dental Hygienists’ Association. Oddo can be reached at [email protected]. MAUREEN ARCHER-FESTA, RDH, DDS, is a professor and interim dean for the School of Professional Studies at City Tech. She has also served as clinical coordinator and chair of the Dental Hygiene Department. An active volunteer, Archer-Festa serves on the National Dental Hygiene Board Examination Test Construction Committee. The authors have no commercial conflicts of interest to disclose. dimensionsofdentalhygiene.com January/February 2024 • Dimensions OF DENTAL HYGIENE 33
