Siddharth Mehta

Mandibular morphology and pharyngeal airway space: A cephalometric study

Introduction: Mandibular retrognathism is considered to be the most important risk factor for upper airway obstruction. Aim: This cross-sectional study intended to examine the relationship between craniofacial morphology and the pharyngeal airway space (PAS) in patients with mandibular retrognathism and mandibular prognathism, when compared to normal subjects. The study also analyzed the influence of mandibular morphology on pharyngeal length (PL). Materials and Methods: The PAS was assessed in 92 females (age 15-30 years) further divided into three groups - Group 1- normal mandible (76°≤ SNB ≤82°; n = 31); Group 2- mandibular retrognathism (SNB <76°; n = 31); Group 3-Mandibular prognathism (SNB >82°; n = 30). All subjects were examined by lateral cephalometry with head position standardized using an inclinometer. Craniocervical angulation, uvula length, thickness and angulation were compared among different groups. Results: The results showed no statistically significant difference in the pharyngeal airway between the three groups. Measurements of PL showed statistically significant higher values for retrognathic mandible group than normal and prognathic mandible group. Conclusion: There is no significant difference between PAS between patients with mandibular retrognathism, normal mandible and mandibular prognathism. Mandibular retrognathism patients show a significantly higher uvula angulation than patients with mandibular prognathism. Craniocervical angulation showed maximum value in retrognathic mandible group followed by normal and prognathic mandible group respectively. Mean PL for retrognathic mandible patients was significantly higher than prognathic mandible patients.

Unusual impaction of mandibular second premolar

The present case report demonstrates an unusual impaction of mandibular second premolar and a new classification for impaction of mandibular premolar based on the previous case reports.

Impacted and transposed canine

Iappreciate the efforts of Lee et al, 1 who wrote a fantastic case report on an impacted and transposed canine in the June 2017 issue. Treatment planning as well as execution in such a case is difficult. The authors were able to achieve a good occlusion at the end of treatment. They mentioned in the Discussion section that length of orthodontic treatment in such cases depends on several variables and suggested microosteoperforations to hasten tooth movement. I, however, would wish to add that the direction of pull of the canine could have been slightly modified, and the canine could have been pulled palatally as well as distally; once the overlap was overcome, the tooth could have been moved buccally. This movement could be achieved with a modified transpalatal arch appliance. Could this type of movement help to reduce the treatment time? Views are greatly appreciated. Siddharth Mehta Jaipur, India

Double-loop de-rotator

Rotation of a tooth means labial and lingual movements of a tooth around its long axis. It is most evident when viewed from an occlusal perspective. This article describes a simple and economical technique to de-rotate a severely rotated tooth.

Treatment of Class II subdivision malocclusion with congenitally missing upper lateral incisors: A case report

Orthodontic treatment for patients with unilateral or bilateral congenitally missing lateral incisor poses a challenge mainly with regard to treatment planning. The use of a diagnostic setup is one of the most important aids in the decision-making process. Two alternatives, orthodontic space closure or space opening for prosthetic replacement exist. The present case report shows use of the microimplant for unilateral upper molar distalization and space closure in a Class-II division 1 subdivision malocclusion case with bilateral congenitally missing upper lateral incisors.