Predicting eruption of third molars
Bastos AC, de Oliveira JB, Mello KF, Artese F, Normando D. The ability of orthodontists and oral/maxillofacial surgeons to predict eruption of lower third molar. Prog Orthod 2016;17:21
One of the most frequent surgical procedures recommended to patients by general dentists and dental specialists is third molar (wisdom tooth) extraction. Many orthodontists and oral and maxillofacial surgeons consistently recommend prophylactic removal of the third molars to prevent crowding, although there is no scientific evidence to support or disprove this belief. The authors of this retrospective study evaluated the ability of oral and maxillofacial surgeons and orthodontists to predict third molar eruption. Twenty-eight oral and maxillofacial surgeons and 28 orthodontists were shown panoramic radiographs of 17 patients at the end of orthodontic treatment, including third molars that were intraosseous. Unknown to the participants, these patients had all experienced spontaneous full eruption of all third molars some time after their orthodontic treatment. The participants were asked to rate the prognosis of the mandibular third molars and given the options of “extraction,” “monitoring,” and “other.” Reponses of “other” were disregarded in the statistical analysis. The results showed that orthodontists indicated extraction in 37.8% of cases and oral and maxillofacial surgeons indicated extraction in 49.6% of cases. The authors concluded that both groups of specialists tended to overindicate extractions, and this suggested their inability to predict third-molar prognosis from 1 panoramic radiograph. The authors suggested that third molars should be monitored through periodic evaluations, possibly with longitudinal radiographs or 3-dimensional images. Because the study was retrospective, there was a possibility of bias. To decrease the risk of bias and improve the study design, the authors could have included panoramic radiographs of third molars that did not spontaneous erupt or were known to have caused future pathology such as caries, root resorption, or periodontal defects.
Reviewed by Ashley Phuong
Short-term effects of facemask and skeletal anchorage therapy in patients with maxillary retrognathia
Ağlarci C, Esenlik E, Findik Y. Comparison of short-term effects between face mask and skeletal anchorage therapy with intermaxillary elastics in patients with maxillary retrognathia. Eur J Orthod 2016;38:313-23
Skeletal Class III malocclusions are challenging orthodontic corrections. The unfavorable growth pattern in these patients can be seen as maxillary retrognathism, mandibular prognathism, or a combination of both. The most common pattern includes maxillary retrognathism, protrusive maxillary incisors, retrusive mandibular incisors, and a protrusive mandible. Facemask orthopedic therapy has been suggested to be effective for successfully treating growing Class III patients, since it stimulates maxillary growth and restrains or redirects mandibular growth. However, the literature has reported side effects, such as increases of the vertical dimension (forward and downward rotation of the maxilla and posterior rotation of the mandible) and dental compensations (protrusion of the maxillary incisors and retrusion of the mandibular incisors) because the facemask is tooth-borne. To overcome these undesirable effects, skeletal anchorage treatments have been proposed to apply pure bone-bone orthopedic forces between the maxilla and the mandible. Thus, the authors compared the short-term effects between these 2 treatment alternatives in 50 prepubertal patients with a midface deficiency. The results showed twice the maxillary advancement achieved in the skeletal anchorage group and more significant downward and backward rotation of the mandible in the facemask group. Mandibular incisor retrusion was observed in the facemask group, and mandibular incisor protrusion was observed in the skeletal anchorage group, possibly caused by the absence of a chincup effect. In the facemask group, positive overjet was obtained by a combination of maxillary incisor protrusion and mandibular incisor retrusion, whereas in the skeletal anchorage group, positive overjet was achieved almost exclusively by skeletal maxillomandibular movement, since the amounts of maxillary and mandibular incisor protrusion were similar. Although advantages were shown, this study has limitations: 2 surgical procedures involved and the use of 2-dimensional cephalometric images to evaluate 3-dimensional structures.
Reviewed by Cecilia Ponce-Garcia