BackgroundThe congenital absence of one or more teeth is a dental anomaly that frequently occurs in the world’s population with a wide variability of distribution. The aim of this study is to assess the current prevalence of dental agenesis in the permanent dentition (excluding third molars) using a sample of Italian orthodontic patients.MethodsPanoramic radiographs of 4006 Caucasian children between 9 and 16 years of age (1865 males and 2141 females) performed over a 5-year period (from 2010 to 2015) were carefully examined to identify congenital missing teeth. A chi-square test was used to determine the difference in the prevalence of hypodontia between genders and between arches.ResultsThe prevalence of dental agenesis was 9% (9.1% for females and 8.7% for males). The most common congenitally missing teeth were the mandibular second premolars (20.3 and 18.1%) followed by the upper lateral incisors (17.8 and 17.7%) and the maxillary second premolars (7.4 and 6.3%). The absence of one tooth to five teeth was observed in 344 patients (8.6%), while 15 patients showed from six to nine missing teeth (0.4%). The analysis showed 363 cases of agenesis in the upper arch (0.64%) and 339 in the lower arch (0.60%). Unilateral (4.6%) and bilateral (4.4%) agenesis demonstrated a similar frequency. The most common bilateral missing teeth were the mandibular second premolars (1.9%) and the maxillary lateral incisors (1.6%).ConclusionsThe results of this study observed a higher prevalence of hypodontia compared to previous studies conducted on the Italian population. Thus, a detailed and careful radiographic examination was important in diagnosing one or more missing teeth. This could help plan the best possible treatments, both esthetically and functionally, for these patients.

A 12-year-old boy shows a restless sleep and snoring episodes declaring himself tired during the day and the school lessons. On clinical examination the patient presents a second-class profile, a retrusive jaw with a small chin and an open nasolabial angle. From the intraoral examination a tonsillar hypertrophy is denoted. The patient is sent by the ear, nose, and throat specialist (ENT) and subsequently subjected to a polysomnography (PSG). The ENT decides to subject him to a tonsillectomy and the subsequent PSG shows an improvement in the obstructive sleep apnea syndrome (OSAS) pathology with an apnea-hypopnea index (AHI) improved from 25.5 episodes/hr to 3.4 episodes/hr. Subsequently a orthodontic treatment with twin-block was start to further reduce the apnea episodes. The last PSG highlights the success of the treatment further lowering the AHI to 0.7 episodes/hr. This case report shows how a multidisciplinary approach to OSAS is fundamental also in the young patient and that the orthodontist carried out in this area a fundamental task both in diagnosis and treatment.